kataklyzm

i have a mystery knock i've been trying to diagnose for a while now, it happens when the engine is cold/cooled down, and it only makes the noise when in gear/holding the brake. i can push it into neutral, and the noise stops immediately, put it back to drive while holding the brake, it comes back.

it almost sounds like rod knock, but the engine runs fine. no metal/glitter in the oil. i thought it might be a timing belt tensioner bearing or something of the sort (no idea why it would be that tbh) so i changed out the timing belt, water pump, tensioners/idlers, and tranny mount, but the noise is still there

weird thing is, it is very faint when you're outside and the hood is open. you have to strain yourself to hear it, but if you're inside the car, it is quite audible.

dealer told me there are two engine mounts that need replacing (i knew about one for a while) but would mounts be able to cause it? it is a pretty consistent *knock-knock-knock* that goes with rpm, until you pass 2k, then it disappears, or, again, when you throw it into neutral.


its been driving me nuts and i dont want to just throw parts at it. dealer checked the timing side of things and found nothing


i dont know if it would matter, but the transmission was replaced by acura a couple years ago, and the subframe was replaced the year before that...

everything works and runs 100% fine. its just that damn noise that is driving me insane

Vlad_Type_S

iTrader: (3)

Yes, it could be an engine mount causing the noise.

If they need to be replaced anyway, I wouldn't consider that throwing parts at it.

Can you say with confidence that it's not valve train noise? That's usually described as a tick, not a knock.

I would start with the engine mounts as it is definitely possible for those to make a knocking noise.

kataklyzm

i did the long screwdriver to the ear trick to listen in on the valve covers and injector area. pretty much all over the top of the engine (and the PS pump)

its not long enough to reach the mounts though (thats what she said)

i just wasn't sure if the mounts could be causing it, but i kinda thought that it might have SOMEthing to do with it, since once the trans is in park or N, it goes away. stepping on the gas, it goes away too, (i would have thought it'd get worse, unless its putting pressure on whatever is rattling)

i feel better now that you mention there is a possibility of it being the mounts, as it is a $500+ fix (at the dealer anyway).

is the mount something that can be done at home? (for sure i know its the barrel shaped one in front by the radiator, the one with the vacuum line attached to it and im 80% sure the other one is the one on the timing belt side of the engine) i replaced the subframe myself, but i had a shop with a lift at the time...