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230 miles now and still running strong.. however I’ve noticed it’s a bit smokey until it reaches full op temp (normal for new rebuilds I hear), but it still smokes a little when at temp, while I’m driving It seems to go away but if I hit like a red light and then go on green for instance, it smokes for a little bit again. Granted it is cold and I live in a sorta humid area, but is this bad or am I just paranoid? It’s just white smoke and feels a bit moist to the touch, coolant levels seem good though although I haven’t checked it in a couple days
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Are you talking about smoke coming from the engine, or in the exhaust?
My '93 525i "steams" a little until that massive (relative to the engine size) exhaust system heats up. Can take 5-10 mins of driving, and much longer at idle only. It's not coming from the engine, but when I first got the car I was worried that it had a head gasket leak too!
'98 740iL E38 201k, TCG at 190k, 5HP24 at 195k
'97 540i/6 E39 Dinan blower & stage 1 suspension 114k
'93 525i E34 "Golf Ball" (hail damaged) 334k
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From the exhaust.. I must admit I’m missing a couple header studs and my mid-pipe seals are f-worded but there’s no exhaust leak so I decided to be lazy about replacing (picking up the new seals tomorrow though)
shade tree mechanic
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Exhaust Smoke | Color (Black ,White, Blue) and its Causes https://learnmech.com/exhaust-smoke-...20Blue%20smoke
The most common cause of white smoke is when the car has just been started. The white smoke is just steam from condensation that clears as the car warms up.
My E32 750 with the big exhaust is in winter like a smog machine and it takes many, many miles till the exhaust is hot and it stops, no coolant and no oil problem, same as every winter since 30 years
Shogun tricks and tips for the E32 series are HERE!
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Worn exhaust valve guidesOriginally Posted by Wandrnge34
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
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Why the guides? I have the same exact issue as OP, but I am concerned about something as well - my oil appears a little bit diluted and smells a bit like petrol. Can oil contamination appear from a potential valve guide problem or piston rings is the only potential culprit?
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Even with brand new seals?
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Fresh rebuild as well? I’ve read a few other threads and it sounds like you could be running a bit rich, it will wash down the cylinder walls and end up in the crankcase.. that or worst case your rings could be worn/not quite seated. Generally bad valve guides/seals will result in just burning a bunch of oil as it leaks into the combustion chamber. If it’s older/has a lot of miles I would look towards the rings or valve seals, they could be not expanding enough until it’s warm
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Why new seals? was this already a problem?
Fresh seals can mask worn guides to a degree.
Oil expelled into the exhaust stream at idle while standing then burns off as exhaust stream temps increase with further revs. Oil is burning in the exhaust, not the cylinders.
Spark plug examination will be useful. If no oil burning indicated by spark plugs then smoke is likely from oil entering the exhaust stream through the guides.
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
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When it starts to smoke, pull over and check with flashlight and an telescopic extension mirror. You can smell if it is oil, and trace around where the smoke is, and see if the head cover gaskets are leaking oil on to the exhaust. Also check crank timing sensors as originals were metal housing and new replacement are usually plastic housing and deteriorates over time and not sit flush causing oil leak that splashes oil back when you drive. Also check oil cap, they fail over time and leak and cause oil to splash back onto exhaust.
Last edited by E34 Lives; 01-11-2022 at 09:17 PM.
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It has new seals cause I rebuilt the engine lol, that being said, quick update: at about 825 miles and smoke has gone down to normal amounts but still will sometimes come out of the tailpipe if I sit and idle too long.. if I drive for at least a good 10/15 mins smoke goes away completely. Im just going to chalk it up to humidity and being cold, when the temp is above 40 it doesn’t smoke at all. I replaced the exhaust pipe seals as well, the old ones were pretty gnarly, maybe it’ll help it breathe a little and more quickly dispel any moisture that gets trapped. I guess the new rings were just seating and I was trippin’ about it
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If you installed new rings, have you floored the throttle yet? Without cylinder pressure, the rings might not be able to wear in, and you'll continue to have blow-by and smoke.
You can definitely check for fuel in the oil with a sniff or (more reliably) a Blackstone analysis.
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I mean I don’t FLOOR it but I do punch the throttle when I can, bring it up to 3500 rpm sometimes 4 for a few seconds and then let off, as I get higher in the break-in mileage I do drive it a little bit harder though only once it reaches/gets close to op temp.
Once I get to my 1500 mile oil change I’ll make sure to give the oil a good sniff and see how it smells, oil burning has gone down considerably though
Last edited by Wandrnge34; 01-14-2022 at 09:10 PM.
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