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randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Adiabatic posted:

No this guy is actually doing work to his vehicle, and has at least a semblance of understanding of what he's doing.

I haven't seen any mention of pajamas yet either.

Dude, you picked one hell of a car to learn to wrench on, but like Frank said, Mercedes support for their old stuff is top notch. You're gonna pay through the dickhole for some of those parts, but the parts exist.

As for the radiator? I'm all for OEM on 99% of parts, but when it comes to a radiator, meh. Especially when an OEM one is nearly a grand. It looks like Nissens makes an aftermarket one that's... still painful, but not AS painful, and there's plenty of eBay sellers in the UK and AU selling them.

randomidiot fucked around with this message at 05:38 on Jul 11, 2018

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randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

You might say... his old one is hella bad.

I'llshowmyselfout

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

Five minutes later, I turned the ignition to check temperature again, by which time it had crawled up to some 221 degrees (hood open, engine (and yes, fan too, off)).

Starting it up again, temperature had dropped to about 170 F, and going back down the same way was pretty much sweet sailing. I think I was stable between 180-195 F all the way home. The main fan works, the heater inside the car heats, and everything looks pretty normal from the outside. Could it be a regulator somewhere? Something I did while hammering the screws? Some hose I've forgotten to reattach, a vacuum leak, or a side effect of a new OVP?

Congrats, you've just discovered heat soak. Once you've shut off the engine, it's normal for it to heat up a little bit, as the coolant is no longer circulating. Most people will never notice unless they check the temp ~5-10 minutes after shutting off the vehicle.

Have you taken this same road (uphill) before in similar weather conditions? If so, then you might want to look at the thermostat and fan clutch. If not, it's normal for an engine to get a little warmer when going uphill - especially a big V8 in a heavy landbarge.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

No, it sounds like it probably is working as intended. There's no coolant flow with it off, so it's going to heat up a little immediately after shutdown.

If the engine wasn't putting out as much power as it should, in theory, it probably wasn't dumping as much heat into the cooling system either. Either way, you're going to be replacing the radiator soon; good time to replace the fan clutch and thermostat.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

I mean, you certainly don't WANT the engine to sit at 220-230F all day, but a trip up there now and then during heavy use is normal and expected.

So long as it's sitting below 220ish most of the time, you're generally okay (I prefer below 205 during regular driving personally, but during heat waves like we've had lately where I'm at, I've personally been seeing 210-220 once I get off the highway).

But get that radiator replaced. If it can't hold pressure, the coolant will boil a lot easier in the hottest parts of the engine (this is bad).

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

Even more glad I booked that appointment now. Looking up chain guides, they're made from plastic!? I'll never be able to understand the logic here. There are other parts like that as well, brittle little plastic things where metal would have made a lot more sense. Mine seems to have been swapped about nine years and 50k miles ago, but from the receipts I have, chain doesn't seem to have been replaced ever.

Yuuuuuuuup. This isn't just a MB thing. This is pretty much every engine with chain-driven overhead cams.

Some engines will go forever before the guides or tensioners fail. Some - see Toyota's 22R series of engines, and (not quite as bad, but close) Nissan's KA24E - have them as more of a regular maintenance item. Ignore the rattling too long, and they chew through the timing cover (which, helpfully, has coolant passages).

If you want to know of a real nightmare - one where the engineers truly should have been executed - look up Ford's 4.0 SOHC V6. See, the engine started life as a typical overhead valve (cam in block) V6, and it was a pretty reliable engine back then, and a decent performer for its day. When Ford decided to make an overhead cam version, they used essentially the same block, changed the camshaft out for a jackshaft... ran a timing chain from the crank to the cam-turned-jackshaft, then ran another chain to one of the cams. But no, that wasn't enough. You see, they cheaped out on the head design, and (mostly) flipped the other head around. Then they stuck a timing chain on the back of the engine, driven by the cam-turned-jackshaft, to run the cam on the other head.

You wanna guess which chain guides fail first? I'll give you a hint: getting to the most failure-prone guides requires removing the engine from the vehicle. And if you ignore it long enough, it WILL jump timing and run like poo poo (best case anyway... usually they self destruct - and I can name at least one AI regular who had hers jump timing).

This isn't as bad as the timing chain setup that VAG/Audi is so fond of on their V-engines, but there's a lot more Ford 4.0 SOHCs on the road (at least in the US) vs VAG stuff.

And of course, timing chain stretch is a real issue too (even on a traditional cam-in-block, overhead valve engine), but on most engines, it's more because of wear and tear than anything else (unless you're Ferremit's brother).

randomidiot fucked around with this message at 07:27 on Jul 26, 2018

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

ionn posted:

When I took this engine apart (junkyard mid-90's KA24E, allegedly about 170000km on it), I found most of the chain guide in pieces at the bottom of the oil pan, and the chain was just under halfway through in mining it's way into the water passage. The original chain guide was plastic, the replacement one was metal with a plastic surface molded onto it.
The source of the problem is the tensioner that pushes the guide rail against the chain. It's hydraulically driven by engine oil pressure and typically works fine, but it has a spring in it to provide tension at startup before there is oil pressure. That spring breaks, causing the chain to rattle and flop about for a second or two every time you start the engine, and that rattling will break the plastic chain guide. I have no idea how long this thing was driven with a broken chain guide or how long it would have had left before water and oil had met.

Yup, I've torn into a few KA24Es now.

GM's gen 1 Ecotec family has a similar issue with the tensioner. Spring breaks in the tensioner, no more tension on a cold start. Usually the guides are fine, and GM somehow figured out that hey, this thing might need occasional service. So they put the tensioner in the timing cover. It just screws in, though you do have to pull the valve cover, get a long piece of wood, and give the firewall side timing chain guide a solid THUMP (hammer meets wood) to get the spring to release after replacement.

Oh yeah, if that engine family loses oil pressure, however brief, they're almost guaranteed to jump timing.

Too bad they also decided "hey, let's run the water pump off of the timing chain... nobody should ever need to replace it" on an engine primarily used in FWD applications. :fuckoff:

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

As for fuel, the 98 octane it absolutely demands is currently a hefty $8 per gallon. I could of course try seeing if it'll run on 95 now – I haven't tried it since swapping out injectors, spark plugs and so on – but if it doesn't like it, I'll have a 25 gallon tank of the stuff to painfully slog through. And I really can't just fill it up a little and see if it works, as that'd soon leave me stranded... seeing as the very best fuel economy I've gotten is almost 17 mpg. Worth it though. Smiles per miles, right?

Run it down to half a tank, fill it with 95. That'll give you about 96.5. See how it runs. If it runs decent, you can probably get by with 95. But I'd add only 1/4 of a tank at a time of it (beyond the initial half tank). That way you can just burn 1/4 tank at a time and start topping it off with 98 again.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Generally, bad head gaskets result in the engine consuming coolant, or the oil and coolant mixing, and generally exhaust gases entering the cooling system. I can't say I've heard of a head gasket causing an oil leak (except on Nissan timing covers :argh:), but valve cover gaskets certainly can and will (and there's about a 99% chance of them being the source of the leak).

I did have a car that had coolant seeping from between the head and block, and that WAS because of the head gasket, but it wasn't consuming coolant that I could find, just had a few drops now and then appear from between the head and block. So I just let sleeping dogs lie on that one. A head gasket job is pretty invasive and a bit beyond most DIY skill sets.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

I think you're absolutely right, it was just that mechanic's offhand comment that made me think it could help. That, and a head gasket job giving me a great opportunity to get any and all carbon deposits and fossilized matter out of all the little openings between the cylinders and everything else. What I'd REALLY like to do once I'm doing something that big is go even further, and stick a brand new crankshaft, bearings, pistons and connected items in there too. One day...

Well I mean, by the time you're doing a head gasket, the top half of the engine is off anyway. You're 1/3 of the way to a full on rebuild at that point.

But why? Your existing crank and pistons are most likely fine (barring some carbon buildup on the pistons), unless it's been run low on oil. Bearings are certainly wear items, so are rings... but so long as good oil is kept in the engine and it sees at least somewhat regular oil changes, they generally last the life of the vehicle. Unless it's blowing blue smoke or white steam once warmed up on a warm day (coolant making its way into the combustion chambers), there's no reason to tear that far into it.

Get a compression tester, find a way to measure real oil pressure (if this behemoth doesn't have an actual gauge already), and get a vacuum gauge. Those will tell you everything you need to know about the internal health of your engine without tearing it apart. The oil pressure will give you a general idea about the health of the bearings and oil pump. A compression test will tell you what you need to know about the condition of the rings. A vacuum gauge will tell you a bit more about how well everything's working (hint: you don't want to see the gauge moving at all at idle, and vacuum should decrease smoothly as the throttle opens). If you really want to go all out, a leakdown test will tell you about the valves and rings. All of this combined, even if a shop does it, will be a lot faster (and likely much cheaper) than doing a full engine rebuild.

I get that you want to refresh this thing and make it as good as new. I've been there. Don't do it. Yeah, it's a Mercedes, it's one of the most expensive Mercedes models (at least compared to what we get in the US), it's probably the easiest Mercedes to work on of that era.... but it's a 26 year old Mercedes, and one with a shitload of PO fuckery and neglect. That's gonna be a hell of an expensive and time consuming rabbit hole to go down, and it's a hole I've fallen in way too many times. The PO didn't take good care of it, your best bet is to fix whatever it needs to stay legal on the road (and reliable), and just drive it. Enjoy it. Take it off road a bit. Get it dirty. Go camping. Do whatever it takes to make it trustworthy on trips, but don't make it a garage or show queen. Just use it the way it's meant to be used, stay up to date on maintenance, and use quality parts (preferably OEM) when you need to fix it.

randomidiot fucked around with this message at 08:43 on Apr 26, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Sorry man, I worded that a bit harshly - but you understood what I was getting at.

It's a very unique vehicle - a Benz G wagon that's actually been used for what it was built for, with a first year V8, first year AMG, and currently an owner that gives a poo poo about it.

The parts you're talking about aren't easily done with the heads off. You need to tear the bottom end apart. If you're at that point, just yank the engine, tear it apart, and rebuild the whole thing at once. Don't do it bit by bit; you'll spend a lot more money, it'll take a lot longer, and you'll lose all of your hair from the stress. Cranks don't normally need much more than a polish during a rebuild, unless a bearing spun. Pistons may need replacement during a rebuild, or just a bit of cleaning up - it depends if the cylinder bores need to be "bored out" (enlarged due to wear). Rings and bearings are generally replaced during a rebuild (unless you run the sloppymechanics youtube channel) (don't follow their advice for anything you want to last, only for stuff that you want to make insane power with for a few days), but the ones you use depends on if the crank gets polished or resurfaced, and if the bores get enlarged slightly or not.

We've all been at the "I don't know anything about this thing, but I want to learn about it" stage. The smartest people, IMO, are somewhat stuck in that stage for their entire lives, for everything they run across.

The oil pressure gauge sounds like it's at least somewhat reflecting reality (most "real" ones are still heavily dampened; it sounds like yours is, but at least it actually moves a bit!). If it's showing 2 bar at idle, and 3 bar at speed while warm, that engine has a very healthy bottom end and oil pump. I've had cars that showed less than 0.3 bar at idle, and below 2 bar at 5000 RPM (that particular car told a lot of knock knock jokes, and the real oil pressure gauge I put in had a severe case of tourette's at idle, and looked like an alcoholic going through DTs at cruising speed).

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

Yep, this is pretty much me! I still get, very occasionally, some nasty valve slapping noises for a few seconds right after firing it up, which someone mentioned might be lack of oil pressure, I seem to recall. But the needle points in healthy directions all the time; maybe checking it out with a proper measuring tool at some point is a good idea anyway.

But I'm definitely putting it back together a little better each time I do something

If you're not driving it at least every few days, I'm gonna call this normal. Oil has to get circulating, and if it's been sitting several days, it has very little anywhere except the oil pan. The crank and rod bearings will usually get oil first, the top end last. I forget if you've mentioned what kind of oil you're running, but synthetic claims to cling a lot better when sitting awhile. If you're not already running synthetic, it may help a bit.

The exception would be if the timing chain were rattling, in which case you'd want to be looking at timing chain guides and tensioners (oh gently caress I just caused another chapter of scope creep, didn't I?). But that's a bit different sound vs some valve noise at startup.

And the attitude you have - putting it back together a little better each time - is the best attitude for any DIY work (not just cars).

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

... I should have added a "* Excluding Subarus and old ACVW / AC Porsche stuff" disclaimer, but it's a Mercedes thread, so... :downsgun:

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Was the engine fully warm?

That definitely sounds like the fan, but fan clutches also tend to drag when the engine is cold. They take a little bit to warm up and let the fan spin freely.

When it was running hot, did you hear that same whine when you revved it? If not, your fan clutch may be done.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

When the engine is warm (but not super hot), yeah, you should be able to turn the fan by hand. It won't spin easily like an electric fan, but you should get a rotation or two out of it if you give it a good shove when the engine is warm (but not super hot, and not heat soaked from being parked for a little bit immediately after getting off the highway).

When it's cold, it'll have a lot of drag for the first few minutes (so you'll hear it a bit). When it's super hot, it should be pretty much locked to the water pump and absolutely screaming. Kinda like what it's doing now. :v:

Since it's sounding like a really expensive hair dryer it all the time, yeah, your fan clutch is done. But that wouldn't cause the engine to run hot. I think I remember you mentioning it needed a radiator anyway, right, from the old one being cracked? It's possible the new radiator will help out quite a bit if it's clogged. Thermostat wouldn't hurt either, it may not be opening fully.

Getting the fan clutch replaced should help your fuel usage significantly too.

randomidiot fucked around with this message at 06:06 on May 14, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Maybe something like the 55 mph marker in orange on a lot of US speedometers in the 80s? It was meant to be a "hey, this is the highway speed limit nationwide, and big brother figured out this is the most efficient speed to drive at" thing. Except 55 isn't the most efficient speed to drive at, at least today.

Yeah, just because the hoses get hot doesn't mean it's opening fully. They're not usually bimetal - instead they normally have a wax pellet inside them that forces it open at a specific temp. Sometimes the springs break and leave it sitting in one position, sometimes something gets jammed in the spring and keeps it from opening fully, sometimes the wax pellet breaks free and no longer opens it at all. If you can get it out easily, toss it in a pot of boiling water - it should fully open pretty quickly (pretty much all of them are fully open before 100C). Don't use a nice pot for this, use a beat up one that you can clean easily (or don't care much about).

There's probably a sensor on the housing for your dash temp gauge; it's a common place to put them. There's often another sensor for the engine computer's coolant temp sensor, normally plumbed into a head (one of the hottest parts of the cooling system). Don't know if yours has a separate sensor for the ECU or not, though.

Fan clutches are normally pretty cheap (unless you're GM and toss a bunch of electronics in them!). The hard part about replacing them is not spinning the water pump while trying to break the fan clutch bolts loose :v: (protip: make sure the belt is tightened properly before you try.. and even then you may need a way to try to keep the water pump from spinning)

randomidiot fucked around with this message at 08:21 on May 14, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

chrisgt posted:

This is actually all completely incorrect for a mercedes, assuming the fan clutch is anything like the one on my 84 300TD and the other mercedes I've worked on.

They do use a bi-metalic strip in the fan clutch. When it heats up, it bends inward and pushes on a pin in the end of the clutch to divert the flow of fluid through the vanes causing it to lock up.

Excellent info, and I'd be very happy to be wrong in this case.

.... maybe. It sounds like the AMG style one the dealer is quoting him is the type you're talking about, and the non-AMG style is probably a viscous type. Just basing that on the prices quoted, anyway. I hope for OP's sake that it's not the bi-metallic style, but it seems like he has a 1 year unicorn.

Any idea if the bolt holes would line up between the two types? It sounds like the cheaper one is a lot easier to find, and would probably would okay so long as he's not going full throttle up mountains. I was going by the loud whirring at all RPMs as my basis for assuming it was a failed viscous clutch (but the symptoms sound like a failed fan clutch no matter what type it has).

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Thought of this thread when I parked next to this at the grocery store:



Appropriately enough, someone in a tracksuit walked up to it and got in after I got out of my car.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

Widened wheel arches, 18 inch rims with just a thin sheet of rubber wrapped around them – and that lovely red magic marker styling on the V8 emblem. The perfect tracksuit-bro automobile. I still love it though. What's up with the indicator light bolted onto the side just below the molding, by the way? Up front there? Some kind of DMV requirement?

Yeah. Instead of the side marker actually being on the side, it's often on the corner like that for USDM vehicles. Various makes do it differently. Except this one has had the lenses swapped; they're supposed to either be amber, or have amber bulbs.

A good example is my old Integra.... here's the USDM light setup:



Inner lamp is the fog light, middle is headlight (glass), outer is two bulbs (both light up as a parking light, one white, one behind the amber lens). They also had the automatic strangulation devices (loving motorized seat belts :fuckoff:).

The rest of the world got this:



A one piece composite housing (fog, headlamp, corner lamp all in one, and the fog lights up yellow instead of white), with a single bulb for the corner lamp, and a separate side marker on the fender. The bumper light is a little different on that second, but that's because it's a 92-93 vs the 90-91 in the first pic.

I converted mine to the JDM/NZDM composite housing (literal night and day difference in how well they lit up the road, the USDM ones were like having candles in front of the car), stuck an amber bulb in the corner lamp, and never had any hassle aside from finding the unicorn H4H headlamp bulbs (nothing sold in the US ever had them, though you can modify an H4 bulb to fit).

randomidiot fucked around with this message at 06:08 on May 23, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

mmmmm, no there wasn't. It has 2 supplemental electric fans that are meant to only kick on with the AC, but will also kick on when the engine is above 95C; he was talking about running just those (once he gets the second one working again).

Those fans alone wouldn't be enough to do much more than just tool around town, but add a big (or two medium) puller fans on the other side and it just may be enough. The problem you'd run into at that point is if the alternator can keep up.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Oh holy crap, I was just assuming <100 amp output going by the age.

Teenage me would have done terrible sexual favors for an alternator like that in the 90s.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

I wouldn't leave it in there overnight (really, no more than an hour or so, after flushing with water first), but it won't hurt metal or rubber that's currently in good shape. It may unclog any leaks that are currently clogged up (and from your cooling system issues, I'm betting that radiator is clogged to hell, but no idea if it has any leaks that are clogged). You already have that new radiator on hand, right?

If your current water pump or heater core are held together with dreams of iron oxide, you're just going to accelerate how soon they need to be replaced.

e: VVV EXACTLY. Sucks that so many parts are hard to find, but I'd rather they fail when I'm at home instead of a $300 tow and a day or month of inconvenience away. The radiator (which he planned on replacing already; it already runs hot under load anyway, so it's suspect) and heater core are the most likely things to have issues with a flush, but ANY flush, or even fresh coolant, or hell, just draining it and putting plain water in it, will clear out a lot of clogged leaks. The water pump is pretty unlikely to be corroded to hell unless the PO ran plain water for a decent amount of time.

randomidiot fucked around with this message at 10:59 on Jun 10, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Yeah, even my pedestrian 4 cylinder has a block drain on it. I can only get about half of the cooling system emptied using just the radiator petcock or by pulling the lower radiator hose.

You're gonna need to account for the water in the block when you fill it with your coolant mixture, otherwise you may get a nasty surprise when winter rolls around.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

Now I suppose it could be that I botched the thermostat install, and that something is wiggling around inside the thermostat housing.

Nope, that's just plain worn out. You just didn't notice it until the new thermostat. :sigh:

Better that you noticed it now rather than on the side of the road.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

If you haven't checked the ATF yet, let it idle awhile, then put it into each gear for a minute or so, through each gear position. Then do the same the way back up to park. Then check it with it still running (you can do so immediately after putting it in park). Since you have questionable cooling at the moment, keep an eye on the temp gauge; the trans does take a bit longer to warm up vs the engine (you may try firing up the heater on high to keep the engine cool[er]).

randomidiot fucked around with this message at 16:45 on Jul 7, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Think of the heater as a smaller radiator. Because that's exactly what it is, except you're using the heat from the engine to warm the cabin. It's still removing heat from the engine, it's plumbed in just like a radiator, it just doesn't dump out as much heat as the radiator can.

It's a good trick to help cool off a toasty engine a bit quicker, assuming the cooling system is full and the water pump is circulating coolant. At one point, owner's manuals suggested doing this if your engine was getting hot. And yeah, try to get those electric fans working too.

And (automatic) transmissions are absolutely alien black magic, and nothing you can say will convince me otherwise. :colbert:

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Fuel pump would be my next guess?

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Yeah if they're meant to kick on with the AC, they'll only do so when the compressor is actually engaged and working. No idea why they're not kicking on once the engine passes 110c (that's the same setpoint, or very close to it, that GM uses if the AC isn't on, I believe).

90f is adorable though. :allears: I guess if you're not used to it, it feels like "oh god I'm gonna die". Here, it's a relatively nice day for outdoor stuff, so long as the humidity is below 60%. But driving without ac does get pretty annoying at that temp. Especially in a dark vehicle. STAY HYDRATED and keep your water out of the sun!

randomidiot fucked around with this message at 17:26 on Jul 29, 2019

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Pursesnatcher posted:

Weather chat: July is always the hottest month of the year, but that's with an average temperature of 62°F – with highs and lows being ten degrees off from that. To make matters worse, I grew up further north, where you can shave another ten degrees off all of those figures. This heat is just pure torture; I much prefer a nice, chilly 10-15 degrees to this madness.

I'm insanely jealous of your summer temps, but you can keep that 10-15 degrees.

I spend a bit of time every (work) day in a -20F freezer. That's loving torture for me, even bundled up like I'm going to the arctic circle. I made the mistake of wearing shorts to work yesterday too (wasn't supposed to be working in the freezer yesterday) - my berries still haven't come out of hiding.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

When the RPMs get that low, the alternator stops charging. Normal running voltage of a car is 13.8 to 14.5 volts. A fully charged battery is 12.9 volts - and it won't be fully charged immediately after starting the car. That voltage difference is why the lights are dimming.

That's a really weird issue. I'd love to blame the fuel pump, but I'm out of my element on this.

randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

Wait.

It has a ~700-800 RPM idle while stone cold? That seems really low for anything that's not drive by wire.

Which one of you knows what the cold idle circuit is like with whatever version of Jetronic this has?

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randomidiot
May 12, 2006

by Fluffdaddy

(and can't post for 11 years!)

FWIW my DBW car doesn't idle above 1k unless it's below freezing out - at which point it gets slightly above 1k (maybe 1100). That's an 06 GM. When the engine coolant temp sensor got unplugged, it would idle at ~1250 and the PCM was reporting arctic temps (far below 0F).

GF's 05 Toyota, which is also a 4 cylinder DBW, idles at ~2k when cold, up to 2500 in winter, but drops quickly to ~750 (over a couple of minutes). :iiam:

But I've never seen a non-DBW car idle below 2k when cold. And agreed that the dips are something hiccuping in the fuel injection, but that could also be caused by the PCM not expecting it to be idling so low with a cold engine... maybe? I know most traditional setups used a FITV, but I know Bosch is its own special breed.

randomidiot fucked around with this message at 04:59 on Aug 29, 2019

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