Engine Mechanical problem
2002 Nissan Altima 4 cyl Two Wheel Drive Automatic 70,000 miles
I hear loud ticking/taping noise when the engine is cold (40F) and under load. That noise is gone after it's warm. I am using full synthetic oil 5w-30.
The engine runs very smooth at 50mph without any audible noise. But the light ticking noise can be heard at idle.
Is very light raspy noise at 1500-2000 rpm caused by bad flex exhaust pipe in front of the catalytic converter?
Have you had the upper cam chain guide removed yet?
You need to have that done.
February, 26, 2009 AT 12:32 AM
What is cam chain guide? Can I see it by removing valve cover? The pre-cat is new and the flex pipe is fine. The ticking noise (like computer hard drive) occurs after 10 minutes driving at very light load (1500-1800 rpm). Higher rpm or lower rpm give no noise. No problem at neutral.
March, 2, 2009 AT 7:36 PM
Sounds are hard to diagnose over the internet.
The tone and the frequency at various RPMs may mean something to a trained ear. But trying to explain it via text is going to be hard to get across.
March, 2, 2009 AT 7:42 PM
I can say, The ticking frequency is like loud computer harddrive noise after start up. The noise is only at 1500 rpm (drive/reverse only) for any speeds and gears after fully warm up. When the engine is cold, there is almost no noise.