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Discussion Starter #1
When overtaking or just generally driving like a tw*t, If I let go of the throttle at high revs (6-7K) and let the engine slow the car down, at about 3-4k a load of blue smoke can be seen Knight Rider stylee in the mirror. Think the bottom end is OK. To my knowledge the engine has never been run low on oil. Haven't got a pressure / temp guage in the 145 but the pressure light doesn't come on.

Any Ideas?

I'm hopeing;

Wrong grade of oil? - I use a semi synthetic from Uni part

Blocked breather pipe?
 

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Chris155 said:
a load of blue smoke can be seen Knight Rider stylee in the mirror.
lol - not @ fault, but at comment! :)
Have you checked the oil in the engine for creamy bits for head gasket probs? What are the overall levels like? Is it only at those revs?
 
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Discussion Starter #4
There's no mayonaise in my engine. Only Oil and silky smooth bitter.

Think its the rings. ****!!!!!!!! :mad: :rolleyes: :mad: :mad: :mad:
 

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Chris155 said:
There's no mayonaise in my engine. Only Oil and silky smooth bitter.

Think its the rings. ****!!!!!!!! :mad: :rolleyes: :mad: :mad: :mad:
Well I would do a wet/dry compression test before panicing too much .
But either valve seals/guides or rings are the most likely causes .
Not sure if could also be related to crankcase ventation problem
 

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Blue smoke = burning oil (hence blue exaust gas in 2 stroke engines)
I would look for leaks in the cylinders (i.e. worn rings)
 

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Stick new valve guide oil seasl in there first and see if it still does it - otherwise your rings are shot. A compression test will tell you.

Ralf S.
 

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I'll add my vote to the valve stem seal camp. If you get a bit of a cloud when you start from cold this tend to confirm that as well.

Also check it isn't over-filled and that all the PCV stuff is clean, clear and present!

Not that likely to be rings if you're not seeing anything when on power.


....but sound advice to check compressions.
 
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Discussion Starter #9
I would say valve stem oil seals too.
The oil gets drawn through under vacuum when you decelerate.
 

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Is it a big badda boom puff of smoke, JTD stylee - or just a ickle cloud?

Could be dodgy fuel - had this once and every time I down changed or let the engine brake, it used to release a puff, once that tank was gone and on to the next from a different fuel station it was ok.. prolly watered down fuel :eek:

But failing that.... rings or valve seals...

Does it blow a cloud when you boot it hard?
 

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You could try the compression test with and without oil down the spark plug holes to confirm whether or not it's the piston rings. Good luck :)
 
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Discussion Starter #14
Are valve stem oil seals a common problem? The engine's done 80,000 miles.

It only ever throws smoke out of the back on over-run after being run up over 6000 rpm. Never does it under acceloration.
 
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Discussion Starter #15
They do go, they are only rubber doodahs with a spring round them to hold them tight If I remember.
The vacuum created on overrun from those revs will be pulling the oil past the seals.
 
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Discussion Starter #16
Valve seals brother, if it was pistons then it would do it on accleeration too, bit harder to see then tho... change the valve seals first
 
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Discussion Starter #17
Ok,

I think we need to ask two very important questions before passing judgement..

Chris, what grade of oil do you use? If it is anything thinner than a 10W semi-synth then that'll be your problem. I would also advise against using fully-synth as the engine was not designed for this kind of oil; f-s oils did not come onto the scene until after the TS engine was designed.

Secondly, how many miles has your engine done?

If the engine is tired and you think you are not going to keep the car for too long and/or you will not be looking to rebuild the engine thus replacing all of the seals I would suggest you switch to a 15W-40 or 15W-50; that should solve the problem for another few years.

The reason why it is mostly smoking on trailing throttle is because of engine braking.. when the throttle is shut and the engine is still spinning, it is trying to pull in air and fuel thus causing quite a powerful vacuum; this may be sucking oil into the chamber from the intake valve guides (when these are open during the induction stroke) and or the piston rings. Chances are, the valve guides are gone as these tend to be more delicate than the piston rings.

Good luck,

T.
 
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