Exhaust smoke when cold...Help
Discussion
Hi all
I recently bought a BMW 328, whenever I start the car from cold I get a blueish smoke from the exhaust, however sometimes it is more white in colour. It only smokes for about 30 seconds but quite a lot comes out and it doesnt do it after a warm start.
Does anybody have any ideas what this could be?
Thanks
I recently bought a BMW 328, whenever I start the car from cold I get a blueish smoke from the exhaust, however sometimes it is more white in colour. It only smokes for about 30 seconds but quite a lot comes out and it doesnt do it after a warm start.
Does anybody have any ideas what this could be?
Thanks
A good test would be to find a longish hill that you can cruise down on overrun (meaning in 4th / 5th - depending on speed, with foot off throttle) - then when the road evens out, just plant the throttle briefly - if you see a lot of blue smoke that'll be valve stem oil seals for sure. It's usually best to get somebody to follow you for this.
Other thing to try, is when the engine is warm, leave it idling for 2 -3 minutes, then 'blip' the throttle - if you see lots of blue smoke that's another indication that valve stem oil seals are tired.
You don't need to be going fast either - so it's quite safe...
I would be really surprised if your car has tired seals at that mileage though.. Perhaps the grade of oil you're running is too thin? That could cause a similar problem.
Other thing to try, is when the engine is warm, leave it idling for 2 -3 minutes, then 'blip' the throttle - if you see lots of blue smoke that's another indication that valve stem oil seals are tired.
You don't need to be going fast either - so it's quite safe...
I would be really surprised if your car has tired seals at that mileage though.. Perhaps the grade of oil you're running is too thin? That could cause a similar problem.
TonyRPH said:
A good test would be to find a longish hill that you can cruise down on overrun (meaning in 4th / 5th - depending on speed, with foot off throttle) - then when the road evens out, just plant the throttle briefly - if you see a lot of blue smoke that'll be valve stem oil seals for sure. It's usually best to get somebody to follow you for this.
Other thing to try, is when the engine is warm, leave it idling for 2 -3 minutes, then 'blip' the throttle - if you see lots of blue smoke that's another indication that valve stem oil seals are tired.
You don't need to be going fast either - so it's quite safe...
I would be really surprised if your car has tired seals at that mileage though.. Perhaps the grade of oil you're running is too thin? That could cause a similar problem.
Ive just tried the overrun method and I did get the blue smoke from the exhaust, so it is looking like valve stem seals.Other thing to try, is when the engine is warm, leave it idling for 2 -3 minutes, then 'blip' the throttle - if you see lots of blue smoke that's another indication that valve stem oil seals are tired.
You don't need to be going fast either - so it's quite safe...
I would be really surprised if your car has tired seals at that mileage though.. Perhaps the grade of oil you're running is too thin? That could cause a similar problem.
Thanks again people.
98 328 burning oil?
can you find the build date, or put in the last 7 digits of the chassis number into http://www.realoem.com/bmw/select.do and see when the build date was.
can you find the build date, or put in the last 7 digits of the chassis number into http://www.realoem.com/bmw/select.do and see when the build date was.
Yea, M52 engines had a bore lining that would wear away prematurely, and BMW did quite a big engine swap program when the problem turned up. At first they weren't quite sure, so replaced the block, then after a while, it sunk it that the lining material, Nikasil wasn't up to the job. The next phase of block swap were to steel lined blocks(the M52s had alloy blocks and the older 325s etc had iron blocks)
The same issue hit the 4.0 V8s too, and eventually a new lining material called Alusil was introduced for the next generation engines.
Now there are quite a few people who will say it was down to northern high sulphur petrol which has all been phased out, so nikasil bore wear doesn't happen anymore, but i still hear of plenty of smoky cars dying from it.
Another less frightening possibility is blocked crank case breather plumbing which does still happen, but leaky valve stem seals are rare on BMWs
It was mid March when BMW introduced the alusil block on the e36 production line.
The same issue hit the 4.0 V8s too, and eventually a new lining material called Alusil was introduced for the next generation engines.
Now there are quite a few people who will say it was down to northern high sulphur petrol which has all been phased out, so nikasil bore wear doesn't happen anymore, but i still hear of plenty of smoky cars dying from it.
Another less frightening possibility is blocked crank case breather plumbing which does still happen, but leaky valve stem seals are rare on BMWs
It was mid March when BMW introduced the alusil block on the e36 production line.
Forgive me if this is a stupid question, if it was engine bore wear would it be smokey all of the time rather than just on startup?
Ive just checked the build date for the engine and it is Feb 1998, does this mean that it will be most likely Nikasil?
Ive just checked the build date for the engine and it is Feb 1998, does this mean that it will be most likely Nikasil?
Edited by pringle1988 on Thursday 22 April 11:21
it will mean it originally came with a nikasil lined engine but it could have been changed from there on.
the pattern of smoke is pretty similar to valve stems, and the way to differentiate is by a compression test, looking for low compression, and then repeated with a drop of oil added to each cyl and seeing if the numbers get higher
the pattern of smoke is pretty similar to valve stems, and the way to differentiate is by a compression test, looking for low compression, and then repeated with a drop of oil added to each cyl and seeing if the numbers get higher
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