I had a valve job done last year on it and it has a lifter noise but it got worse last week. When I start the engine it is normal but after 10 minutes or so there is a loud rapid knocking coming from the engine. I bought engine quieter and that did not help. Any ideas?
A knocking noise is not a good sign. It could vary from a mechanical failure such as a rod bearing, crank bearing, cracked piston, bent rod, cam bearings, lifters the list goes on.
If you say you start the engine and it is fine then it gets louder then the first thing to check is to see if you have the proper oil pressure. Don't go by any dash gauge or engine light; use a mechanical gauge that screws into the fitting of the oil pressure switch.
The oil pressure should be about 6 PSI at idle. The pressure should be about 35 to 75 at 3000 RPM.
DO NOT RUN ENGIN AT 3000 RPM IF OIL PRESSURE IS BELOW 6 PSI TO 0 PSI. ENGINE DAMAGE CAN RESULT.
Your local automotive professional has a trained ear to determine where the knock is coming from and can do tests to determine the cause of the problem.
So for now should I avoid freeway driving? It is time for an oil change. Could that possibly help?
Last edited by briancrotts (9/6/2011 5:07 PM)
Probably not; before the oil change have the mechanic listen to the noise and let him try to diagnosis the noise before you do anything.
Having the oil changed can determine the severity of the noise. If metal is in the oil then you are looking at a big mechanical failure and probably an expensive repair.