My 89 maxima recently started a knock or a rattle that is coming from the timing belt side. At first I thought it could be a pulley, but all the outside pulleys are good. The knock isn't consistant but I can feel it when I put my hand on the lower timing belt cover. I removed the timing cover and everything seems fine. I'm wondering if it's a main bearing or a rod? Just wondering if there is something else I should check before pulling the motor. Any advice is much appreciated. The car only has 135,000 miles and was well taken care of. I feel like the motor itself would still be fine, but again any advice will help right now. Thank you

 

Hard to evaluate without a sound clip, but VG's tend to have a little top end noise at times. If you can hear a slight knock at idle sometimes, but goes away as soon as you give it a little gas, I definitely wouldn't pull the engine over it. Keep oil in it, change it in conservative intervals, replace the timing belt when required, and it will most likely hit 300k before something major goes wrong.

 

I've had a water Pump give me constant knock rattle noise. Something else you could look into

 

I'm going to check the water pump before I go any further. The timing belt seems a little loose as well

 

could be a bit of piston slap, mine had it

if it spun a bearing, you would know. when my engine went it spun a bearing and it was a loud deep knock