11 replies to this topic

[ChrisL]

My Engine is smoking but only under heavy acceleration

Starting from cold there is no blue smoke and driving gently its fine, If i give it some it smokes and uses a lot of oil.

I did a 100 mile trip running at 60 - 70mph and used from max level to below the min.

Is this the oil rings?

[998dave]

probably, especially if it's smoking, almost certainly rings, have you checked your crankcase filters are clear and plumbed in properly?

D

[alexcrosse]

usually rings on acceleration

and stems on overrun

[Its a mini thing]

mine use to smoke bad when i started it from cold, so we stripped the head, replaced the valve stem seals which were all split and leaking, cleaned all the head off, new gaskets etc and now it does what yours does, when i look in the relfection of my other car and i rev the engine hard theres a stream of blue smoke that comes out the exhaust

[miRon]

welcome to the club,lol
are you sure nobodys slapped an old turbo on the back?
it sounds like the rings
as dave said check your breathers.....

[pantera2075]

Not necessarily just the rings, this sounds like piston slap - your bores may have gone a bit oval - I reckons you will see a lot of wear if you pop the head off.

[ChrisL]

The breathers from the timing cover and clutch housing have the little filters on and the carb part blanked off.

What would be the cause of piston slap?

I am taking the engine out again after the normanby hall show to sort a few oil leaks. I will take the head off then and have a look.

[dribble]

I've got the same problem, except I think its only smokes on engine braking. The heads been replaced with a big valve, stem seals done and new head gasket fitted. everything else looked ok, so i was told, but Its still smoking. It has to be the rings thinks my mechanic. So Im now looking at loads a money to get it sorted.

Good luck with getting it sorted ChrisL, I know how frustrating it can be.
I just wish i did mechanics at school now, so i could sort this out myself.

[ChrisL]

Its really frustrating, the car has 90BHP on the rolling road so no problems there. Its embarasing when I give it some and the person behind can't see where he's going!!!

[pantera2075]

That's a weird one. If it's still pushing 90 horses, but smoking like that, it's likely a couple of things:

Bores are glazed and need a light hone.
Piston compression rings are ok, but oil control rings are shot/poorly fitted.

It could be valve guides too, but less likely

[ChrisL]

It certainly is strange, especially sinse its only when the engine is above 3k revs and under load.

The oil rings seemed very loose fitting when assembling the engine but i dont know what they should be like, they were not a nice fit in the pistons like the compression rings.

[ChrisL]

Hopefully the problem will be sorted!!

Stripped the pistonns out and took everything to the machining shop, his first comment was I have the wrong oil rings fitted.
The old ones were in 3 parts wereas the new ones seem to be one piece with a spring inside.

Fingers Crossed......