P0012 code engine runs roughly

[dapqam]

Over recent weeks the car (2004 Corolla S) has had a loss of power upon acceleration. It set a P0012 code (related to timing). It just kept getting worse until it will not start. Replaced spark plugs. Verified that all plugs are getting spark and fuel. Battery is good. Starter turns the engine over well. Air filter is clean. I tried starting the car with the VVT solenoid unplugged. The car started but ran very loudly and roughly. I got a P0010 code since I started it with the solenoid unplugged. It seems like a timing issue. Could be the ECM, or solenoid, or timing chain stretched or out of proper position (jumped out of proper position). Please help with what I should do next. Thanks.

[mikered30]

How is your oil level and how often do you change it? Most likely it is the either the oil control valve (OCV) filter or the camshaft timing gear. Do you happen to have a modified intake at all. Just wondering, might want to clean your MAF first. I suggest cleaning the MAF followed by the OCV.

If you have skinny fingers and some patience, you do not have to remove the alternator, but it is a very tight fit to get to the OCV filter.

http://www.corolland.com/forums/inde...tenance-items/

If that doesnt work, timing gear will have to be replaced. Most likely that OCV filter will clear it up.

Maybe someone on here has access to TSB 00507 and can share it with you as it deals with this code.

[invader]

Timing gear TSB for 2005-2007 Corolla: http://www.toyotapart.com/M.I.L._ON_...T-EG005-07.pdf

[mikered30]

Well I thought that applied to your car, but your car is a year earlier, might still help though. Try cleaning the MAF (unlikely) and then the OCV filter. Let us know if it has sludge on it. If that all fails, looks like you will need a new timing gear. How many miles do you have, what oil and filter do you use, and how do you drive it?

[dapqam]

Car has 115,000 miles, I use regular recommended oil. Oil level is full. I change it every 5K miles except about a year ago when someone else took care of the car for a while and let it go 10k miles. UGH! I have cleaned the OCV filter. It was discolored but not plugged. Where is the MAF (Mass Air Flow?) Is it attached to the air filter case? How do I clean it? How do I find and replace the timing gear? Any chance that the timing chain has stretched or jumped to make it out of proper position? Should I put an aggressive cleaning agent in the oil for a while to clean things out? Again thanks for your quick responses.

[invader]

Timing gear is on the inlet camshaft, under the valve cover... Refer to camshaft2.pdf in 14-Engine Mechanical section of 2004 Corolla service manual free download. You may as well check your valve lash clearances while you're there. I did remove both camshafts to switch and replace a few lifters to adjust my valves, without removing serpentine belt and isulator mount as directed in service manual.
Replace original intake manifold black gasket for the revised orange gasket as well... MAF/IAT sensor is on intake tube between airbox and throttle body. It can be cleaned with electrical or brake cleaner spray, and the exposed IAT senor can then be wiped clean.