compression test results..advice?

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tomgt106

Member +
hi guys..

did compression test this morning as car has been smoking abit on idle and already changed the turbo so just trying to narrow down my problems really!

got the engine to operating temperature..

and got the following results..

1:190
2:192
3:190
4:190

now from what i have read they are a little high but would this point to anything in particular..

i have white smoke on long idle and then puff of whitish-blue smoke when i pull away..

idle sometimes is abit rough when the smoke appears..

any ideas?

or are the results ok and its not engine related problem?

tom.
 
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AdamB

Member +
It seems ok to me, I've always thought the higher the compression ratio, the less lazy the engine is and it will have less lag. Turbo engines from
my experiance are suppose to burn a bit of oil. But if it's bad'ish it could be the valve stem seals, seeing as yove already changed the turbo. I would check that the Pcv valve is also working properly :)
 
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turboloon

Member +
i would say there a tad high for a turbo engine,but i ain't no engineer/mechanic...iirc it should be in the region of 170-180 ish..but you have good pressure across all 4 cylinders..
 
dac69er

dac69er

Super Moderator
has the head and block been skimmed quite a bit in the past?
could be excessive buildup of carbon in the combustion chamber or ontop of the pistons?
 
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tomgt106

Member +
I thught that..how would i get rid of the carbon..wouls i need to run an additive to clear it?

Would carbon build up cause smoke?
 
dac69er

dac69er

Super Moderator
unlikely. but if you have excessive carbon buildup, chances are its overfuelling.

you can try the decoking cleaners to see if it will shift it. one cheap trick is to pour a small amount of diesel down each of the bores. this is meant to soften up the carbon. i heard it mentioned in an mx5 forum i was a member off. i tried it and noticed no difference, but it didnt hurt anything.

obviously the best way to do it is to remove the head, but thats alot of hassle.
 
corofin12345

corofin12345

Member +
head is defo skimmed id say.. if you look into the engine bay and down underneath dizzy where the head meets the block you should be able to see 4e stamped on the block.. if its faint or not there at all it was decked and skimmed.. first thing id check is the timing
 
weeJohn

weeJohn

Lifer
Valve stem oil seals.

Remove the exhaust mani and see if there is traces of oil on the exhaust ports from the valve guides.
 
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