Hey guys, I got a problem that I'm hoping you can help me with. The car is a 1994 GMC S15 Jimmy with the 4.3 Vortec engine and auto transmission. OK so the car makes this awful noise (sometimes its even louder) only under certain conditions, it'll be easier to list them:

*The engine is cold
*Transmission is in Reverse
*Wheel is turned all the way in either direction (like in the video)
*Brake is depressed

Sometimes the car will continue making the sound a bit softer when I shift into Drive but it'll stop when I straighten out the wheel or let go of the brakes. And once the engine has been running for a few minutes, it won't make that noise at all. My dad thinks that the power steering pump is low on fluid. It's kind of embarrassing backing out of a parking spot after the car's been sitting for a few hours because it can get pretty damn loud and people turn and stare lol. What can it be?
Youtube Link:
http://www.youtube.com/watch?v=hrKnNk7MWuQ

 

Well, have you checked the fluid level in the power steering pump reservoir? Couldn't tell anything from the video.

 

Oh silly me I forgot to mention that haha. The level seems fine, it's kinda hard to tell. The wet mark seems to be within operating range. Although I noticed that it smells pretty bad, kinda as if its burnt. I'm not sure what power steering fluid is supposed to smell like but it smells a bit worse than the auto transmission fluid (I heard that they're very similar with the only difference being the red dye in the A/T fluid). It's also appears brown on the paper towel, isn't it supposed to be clear?

 

Your fan is hitting the shrowd is where the noise is coming from its usually caused from worn motor mounts u can look at it take your hand and turn the fan and u should be able to see where its hitting at mine did the same thing also check your fan to make sure theres no play or to make sure its not loose

 

Ditto on that one. I think your motor mounts are shot too, and the fans slapping the shroud around it. It only happens sometimes cause it will only happen when there is a load on the engine. If it happened all the time I would suspect the fan hub is done. Easy test is shake the fna with the engine off, it it wiggles, then the fan hub needs replacing. When you put it in reverse it prolly slaps it some when the engine shakes, or when you really step on it.... Right?

Have someone hold the brake and rev the gas while you look at the motor mounts, there will be one on each side and you will see plenty of movement. You will prolly also be able to see the edges of the fan shround are chewed up a little, and the tips of the fan are shiney....

Let us know what you find out.

 

Yeah the fan shroud turned out to be the problem. I noticed a shiny spot on the bottom of the shroud about 3 inches long. Although I don't need to really hit the gas for that to happen, it'll happen during idle too. I went into detail some more on the comments in that video. I guess I'll just grind away the shroud where it's hitting so it'll stop.

 

I cut a big chunk of shroud away because of the same problem months ago but the noise has come back. Instead of wasting your time with the fan I would replace the mounts.

 

Yeah the mounts are cheap, and unless you have headers on they are not too hard to change. Put a block of wood up against the oil pan for when you got jacking under there to get the bolts out.

 

Jack against the oil pan? Even with a piece of wood in between that doesn't sound pleasant. Ugh this is gonna be such a PITA. What's the worst-case scenario with bad motor mounts?

 

The mounts prevent twisting and rocking of the engine while accelerating or under load. With them broken you risk over stressing parts.