Experience Engines, transmissions, electrical, suspension, brakes, computer systems, radios, interior, glass and body work on late model Nissan automobiles
Expert: Von Sudderth Date: 8/7/2008 Subject: knocking noise
Question
Hello,
We are sorry, but Calvin Iwashita wasn't able to answer your question:
I have a 1997 Nissan xe pickup with four wheel drive that has 130,000 miles. Other than a clutch and an alternator this truck has run and preformed perfect. I always change the oil on a regular basis and use Mobil 1 synthetic oil. I recently started the truck one day and heard this very loud rapping noise for a few seconds and then it was quiet and ran fine. The next day about 5 miles from the house it had this chain rattling while driving.On inspection I found that the stationary trimming chain guide was missing the plastic on it. I went ahead and put all new chain, guides, oil pump, water pump and thermostat, the hole nine yards if it came off to do the chain it was replaced with new genuine Nissan parts. As far as the plastic off the chain adjuster I never found any of it in the pan (as far as I could tell as could not get pan totally off truck), the pickup, the pump, nothing. So I put it all back together and now I have this new knocking noise. I kind of sounds like a rod knock but only in the number 4 cylinder and only at 15 hundred rpm and higher at both load and no load. The knock does get louder and more rapped with higher rpm's but at idle the motor sounds and runs perfect. Now that you have the back story I have three questions. Could the plastic particles have wiped out the rod bearing on just one cylinder and nothing else? What is the easiest way to get the oil pan totally off the truck (as I am limited on tools and rolling around on the ground to do this)to make sure the deep end is also free of debris? Could this knocking noise be something else that would sound like a rod knocking.
Thanks for the help
James
Answer James,
It does sound as if the rod bearing on number 4 has spun. The only way to get the pan off is to unbolt the engine to raise it, in the vehicle. That is, support the vehicle where you can get under it. Then, use a jack under the harmonic balancer to jack it up enough to remove the pan. If you have a hoist you can lift the engine that way. Remove the rod bearing cap and inspect the bearing. You could get lucky and have caught it before there was rod damage. If there is rod damage you need to remove the piston and rod and get another one. Or, have that one resized and reinstall it. Another cause would be that it jumped timing and number four has a bent valve or a broken ring land from impact with the valve. But, I feel that it would be more than just one cylinder if that happend.
