under-hood squeak & rough idle

[Spectre]

Ok, I’m really angry right now. I just typed this up and my ISP dumped, so I’m re-typing it.I have a 95 240sx se, manual tranny w/ factory clutch, 92k miles, manufactured sept 94, all stock, recently replaced spark plugs, distributor cap, rotor, cleaned TB, and switched to Mobil 1. Lately my car has been squeaking loudly and a rough idle usually accompanies the squeak. On a rare occasion, the rough idle shows up alone. The squeak is most prevalent at idle and when under no load, like between shifts. When under load, it goes away by 2500 rpm, usually before.

I thought the squeak was my ps pump, but according to the Nissan dealership it could be one of two things. They found an oil leak from my crankshaft seal and said that my AC tensioner was worn. They recommended I only fix the oil leak, because they weren’t sure if it was my tensioner, compressor, or both and only hear rattle coming from there. The car ran great for about 30 minutes after the new seal was put in, then it reverted.

The next day, I took it to a shop I know. They found the car squeaking by putting it in reverse and slowly letting off the clutch. This did not occur in 1st. I’m confused here, why is the car doing that when being put under load by them, but does it at idle with me? They noticed by a plate covering the AC tensioner pulley want slightly bent inward, but said if it was the culprit, it should lose severity of squeak. They found that by pushing down on my engine with a crowbar, it induced squeak, more-so by making it lean towards the driver’s side. They then went all over and under the engine bay with a stethoscope and are still not completely sure. They think it is most likely worn, but not broken motor mounts allowing too much motor flex thus making something rub together that shouldn’t. They said to try spraying WD-40 on my mounts incase the rubber right there was squeaking. I sprayed a silicone spray as much as possible from above and it stopped for the majority of the next day, then came back that night after much wet weather, just as bad as usual.

I can’t afford to keep taking the car to places that are guessing and checking. Please help me out, I’m going nucking futs trying to figure this out and I can’t

[QuinGarcia]

so, if the wd-40 stopped the squeak when you sprayed it on the motor mounts, then it's the motor mounts. Once you drove in all that wet weather it washed out the wd-40 and the squeak came back. If it were movement in the motor causing something else to squeak, the wd-40 isnt gonna stop the motor from moving so that wouldnt cure the squeak. SO, your squeak has to be in the motor mounts. But, before you go and replace them, make sure that all the motor mount bolts are tight. I would also test that wd-40 theory out a bit more so you know that the wd-40 is for sure the reason why the squeak stopped. You could also try spraying the wd-40 on just one mount at a time, then test driving, to see which mount is causing the squeak.

[Spectre]

Thanks for the response Quin! If one mount is causing the squeak, I'm gonna replace all of em anyway. I might as well get some Nismo mounts, since I need them anyway. I actually used silicone spray, but it has about the same effect. If that will keep the squeak down, I'll just use that until I can afford the mounts.