Is there a (simple) way to check piston ring broken?
Is there a (simple) way to check piston ring broken?
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a1115604

Original Poster:

3 posts

195 months

Wednesday 27th January 2010
quotequote all
My car is an Astra MK4. It burns oil when engine hot and press accelerator. People said different reasons: piston wear, broken, stem seal,....

Any advice would be greatly apreciated.


Boosted LS1

21,200 posts

284 months

Wednesday 27th January 2010
quotequote all
A compression test would be a good place to start. Also, can oil be seen from the tailpile on throttle lift off etc. What colour is any smoke?

a1115604

Original Poster:

3 posts

195 months

Wednesday 27th January 2010
quotequote all
Thanks for reply.

Can compress test tell us ring broken?

Boosted LS1

21,200 posts

284 months

Wednesday 27th January 2010
quotequote all
It will tell you if a certain cylinder has a fault. Then you can do further checks to establish if it's a broken ring, duff valve or stem seal, head gasket etc. Also do a pressure check on the coolant if you can. Check the oil in the sump for water.

Pumaracing

2,089 posts

231 months

Thursday 28th January 2010
quotequote all
Compression tests are covered in detail on my website.

http://www.pumaracing.co.uk/comp.htm

A leakdown test would be a better way of pinpointing where any problem lies but the engine would need to be stripped to positively confirm something like a broken ring. It's actually much more likely to be general wear and tear. Rings don't tend to break for no good reason.

Smoke being produced at all times or under acceleration is likely to be piston, ring and bore wear.

Smoke primarily at first start up or briefly when you reapply the throttle after having lifted off is usually worn stem seals or guide wear. The oil gets sucked through the guides into the cylinder when you lift off the throttle and burns out as smoke when you reapply it.

Blocked or misrouted engine breathers may also lead to oil being forced into the inlet manifold and burned so this would be a good thing to check first. Anything else is going to need a stripdown to fix and probably not worth the cost.

CNHSS1

942 posts

241 months

Thursday 28th January 2010
quotequote all
apologies for off topic, but your site mentions you are writing a book Puma, is it out? where can i buy?
cheers CNH

EDIT: just been reading more of your site, and have switched regularly from learning to laughing and back again, very useful info and wittily written, good work!
my only worry is im convined im a mix of customers 3 & 2 i guess laugh (erring on the 3 hopefully...)

Edited by CNHSS1 on Thursday 28th January 15:54