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Hello all!
So recently my car has been shooting out some decently thick white smoke upon start up. The smoke doesn't smell sweet like coolant, it has a burnt oil or gas smell to it. The car isn't overheating, and the idle will jump up to about 1,100 rpm randomly before dropping back down to normal. The smoke only happens on a cold startup, and after the car is warm, the problem doesn't repeat. I think recently I might've added a little too much oil, but I just did an oil change today and experienced the same problem.
Occasionally the car will bog down to about 500 rpm, when it usually idles at about 600. I do have an unconfirmed code for a rich mixture (P0172 I believe) and a confirmed code for a lean mixture (P0174).
If anyone has any ideas as to what it could be that'd be great, I usually love to work on this car (just finished a 5 speed manual swap) but a head gasket seems like a daunting job so I'm really hoping it's not that. Thank you all for your knowledge and time!
-Kohler
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Could be the valve seals getting tired. Symptoms of a compromised head gasket are overheating, coolant loss and sometimes misfire codes. I wouldn't worry about the head gasket. They don't just fail, overheating is required.
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Well no misfire codes, or overheating, but the expansion tank is empty, I did a coolant flush back in October of last year I believe. Haven't topped it up since then. The car did also overheat for a short period of time back in January, when my belts snapped without me knowing. As soon as I saw the temp gauge (which was already in the red but only had been for maybe 5 seconds) I turned the car off and turned on the heat on full blast, then found my belts lol. I don't think the car was hot long enough to warp the head or cause problems. Like I said that happened back in January and I've experienced no problems until now.Originally Posted by nonturbodan
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That's not good. You would have much less to worry about if it had never overheated. Sometimes it only takes once, sometimes they are alright. Overheating without coolant loss is generally less severe so if it didn't blow a hose or the expansion tank it is a good sign.
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The expansion tank had failed previously before that, (pretty sure it was the original, so it lasted about 140,000 ish miles) that's why we did the coolant flush when I got a new tank. However when it overheated the only thing that was destroyed were the belts, no hoses or tanks took any damage. This problem only recently occurred, nothing was out of place after that slight overheat event.
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Last edited by Kohler00; 06-28-2020 at 12:05 PM.
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Have you refilled the expansion tank to the proper level and bled the cooling system?
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White smoke, smells like oil on startup is valve seals. A head gasket would cause problems when warm.
How much oil do you go through?
If it isn’t excessive, just live with it.
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Alright guys, I'm pretty sure I understand what happened, wannabemer is right. I accidentally overfilled my oil one morning while I was in a rush to get to school. I believe the overfill caused some oil to blow out some of the valve seals. After the car is off for some time it's allowing oil to drip past the seals and burn off on startup. That explains why it's only on start up. Lesson learned, take your time, might go about replacing those, might not, depends on how much oil it consumes. I appreciate all the info guys!
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The overfill didn't blow anything out. They are simply a little worn. What is the mileage?
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I think it's sitting at 156,XXX right now, didn't have any problems before the overfill that I know of.
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Overfilling can cause oil to be blown through the crank ventilation system into the intake. Probably pools a little bit on the back of the intake valves after shutdown and burns off on startup. That could do it.
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Interesting, is there a line or something I could pull on the pcv system to check to see if there's an excess amount of oil?
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Not really. Is the dipstick showing it is still overfilled?
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No, oil level is fine now after the oil change.
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Little update, after some more research I suspect the CCV is bad. I didn't know that these components were pattern failures, but I believe I am sucking oil up through my dipstick due to the diaphragm inside the CCV being bad. When I remove the oil cap while the car is running I can feel and hear air rushing in due to high vacuum. Now I gotta figure out if I want to buy a new CCV or install a catch can and PCV in it's place. Any thoughts?
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Time to do the M56 valve cover conversion!
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Well, another update. Just bought a disa rebuild kit, lower intake boot, a whole new CCV and the corresponding CCV lines, and some new vacuum lines, as well as a intake manifold gasket. Planned on pulling everything this weekend and taking care of all the old rubber lines that way I wouldn't have to worry about a vacuum leak for some time. Unfortunately on my way home from school today I noticed my engine was chugging, I limped it the rest of the way home and ran the codes. P0302 (cylinder 2 misfire). Great. I looked at some live data, car seems to be running an 18:1 A/F ratio, with both STFTs sitting at around 27% and long term bank 1 sitting at 10%, LTB2 was at 0% if I remember correctly (this was earlier today). There's a hissing coming from the engine bay, near the disa, maybe underneath it, I can't tell exactly but it's loud. Sounds and looks like a major vacuum leak. If only it could've just lasted until this weekend.
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Ccv cured my white smoke problem. Was only at start up.
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Bringing this thread back to life. Pulled the intake manifold, rebuilt the disa, replaced the CCV, and lower intake boot, new dipstick o-rings, new icv grommet, and intake manifold gaskets. The CCV was definitely bad, and that was causing my vacuum leak, turns out that diaphragm burst and allowed full vacuum to the crank case, sucking oil up through the dipstick. Here's a photo of the diaphragm. She's running good as new now, which feels nice! Thank you all for your help, it's greatly appreciated.
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