my 79 528i runs well, idles smooth, stars every time and pulls strong but it lets out a puff of blueish grey smoke when i shift after reving to higher rpm under acceleration. if i go easy and shift before 4500, no puff. if i wind it out to 5500-6000 then i get the puff. also, there's zero smoke while at full throttle, only when i let off.
are my rings going? or could this be valve guides or seals.
i'm pretty new to e12s but not to older german cars.
let me know what you think. thanks!
smokin'
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- Posts: 106
- Joined: Fri Jan 09, 2009 12:39 am
- Location: half moon bay CA
smokin'
the early nineties called. they want their awesome back
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seals/guides
off-throttle smoke, esp. cases like coming down a long hill, usually mean valve seals.
KenB
1980 528i
1991 535i 5-speed
1980 MBenz 300TD (gas conversion project)
KenB
1980 528i
1991 535i 5-speed
1980 MBenz 300TD (gas conversion project)
How's your oil consumption? Even with high miles rings aren't normally a problem, but valve guide seals are. If you're using oil, my money is on the seals.
Mike W.
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
Another vote for valve seals...perhaps valve guides.
Another way to check.... first startup of the day, have someone else start the car while you watch the pipe. Oil will have drooled down the guides overnight and be pooled on the valve heads, ready for that first start of the day.
The good news... other than plug fouling over time, you're out a bit of oil keeping it topped up, but not affecting performance since valve seals/guides are unrelated to cylinder compression.
The good news... other than plug fouling over time, you're out a bit of oil keeping it topped up, but not affecting performance since valve seals/guides are unrelated to cylinder compression.
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- Posts: 106
- Joined: Fri Jan 09, 2009 12:39 am
- Location: half moon bay CA
thanks for the replies guys. like i said, the car makes power and pulls strong, so i don't think it's down on compression. it does burn oil at the rate of about a qt every 1000 miles, no too bad. i guess i just have a head rebuild in my future as i find a smoky car to be a bit embarrassing. although it can help deter tailgaters.
the early nineties called. they want their awesome back
OO==00==OO
OO==00==OO
Re: Another vote for valve seals...perhaps valve guides.
An almost sure sign of worn guide seals.larsobg wrote: first startup of the day
Sherman
TexFest LSB&F V
95 525iT (Her DD)
92 ///M5 (????)
91 ///M5 (T donor)
88 ///M5 (Das Beast)
86 535i (Snob)
79 528i (1st 5er)
TexFest LSB&F V
95 525iT (Her DD)
92 ///M5 (????)
91 ///M5 (T donor)
88 ///M5 (Das Beast)
86 535i (Snob)
79 528i (1st 5er)