Engine Mechanical problem
2001 Toyota Corolla 4 cyl Front Wheel Drive Automatic 76000 miles
I have a 2001 corolla that I have only owned 2 months so I can't speak of it's history. It uses oil, quite a bit in fact. One trip of 150 highway miles burned 1 quart. A couple weeks later, a 500 mile trip burned 1 quart. During that last trip, the check engine light came on. No oil appears on the driveway and it doesn't appear to burn oil when we just go around town with it (though we might not drive hard enough to notice it).
Toyota dealer says it is the piston rings, but his diagnosis was not really based on many facts. He said it smokes, but I don't see that. He said he pulled the valve cover and everything looked ok so the only way out is for the oil to get past the rings. He want's $4k for an engine replacement.
I took it to somebody else and he said nothing is wrong with the car (I haven't gone back to him with the check engine light on). He said some oil burn is ok and suggested heavier oil (even though Toyota calls for 5w-30). I started topping the engine off with heavier oil just to see what would happen and that was during the 500 mile trip when the check engine light came on. May or may not be related to me using 10w-40.
I took it to yet another guy who I trust more and he did a compression test. The 4 cylinders are 138, 138, 150, 155. He said that is a problem and he looked up some stuff on the computer and said the corolla specs are 217 max and 145 min. He also checked the PCV valve which he pronounced ok by taking it off and shaking it. It rattled so he said it's ok. This guy also read the check engine problem - it's P0420. This means it's either the catalytic converter or O2 sensors. He's guessing the catalytic converter because I am sending oil down the tailpipe and the catalytic converter has burned itself up trying to burn that oil.
Looking for some help, some suggestions. How do the compression numbers sound?
Monday, October 9th, 2017 AT 10:11 AM