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-   -   Bad valve guides or piston rings? (http://www.toyota-supra.info/forums/mkiii-supra/18919-bad-valve-guides-or-piston-rings.html)

free_couch 04-05-2011 06:30 AM

Bad valve guides or piston rings?
 
I have a 86.5 supra with a 7mgte and I pulled the head yesterday when a leak down test forced coolant out of the radiator on every cylinder. I found the head to be poorly surfaced, looks like it was done with a hand sander or grinder, and it is also warped. This explains the coolant problem but I also found that the valves in cylinders 3, 5 and 6 have heavy oil/carbon deposits. I also noticed that the spark plugs from these cylinders were covered in oil as well. I know my engine had been burning a little oil on startup, it used to burn a lot of oil on startup but i replaced the valve stem seals last summer. I'm hoping that the oily valves are caused by bad valve guides but someone on another forum thinks it looks so bad that it must be the piston rings. Any thoughts? I had good cylinder compression: cylinders 1-6: 170,170,182,175,180,180. (note the higher compression on the cylinders that have heavy oil/carbon deposits)
Here are some pictures:
http://www.flickr.com/photos/61419666@N06/

Green7mgte 04-06-2011 03:48 AM

Quote:

Originally Posted by free_couch (Post 94097)
the valves in cylinders 3, 5 and 6 have heavy oil/carbon deposits. I also noticed that the spark plugs from these cylinders were covered in oil as well. I know my engine had been burning a little oil on startup, good cylinder compression: cylinders 1-6: 170,170,182,175,180,180. (note the higher compression on the cylinders that have heavy oil/carbon deposits)

tsrm says you can expect a varation of up to 14psi between cylinders. (please correct me if im wrong)
valve guides usually present themselves with smoke on startup / deceleration
Hows your #3 valve cover gasket.
Its hard for me to give you a definite answer, I really never fiddled with my valves first hand.
with your car at idle can you see bubbles oozing out around your spark plugs?


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