I figured out what was causing my hissing sound.

[bigkane01]

Hey guys, I figured out what was causing my hissing-air-vacuum sound from my engine. It's something to do with the power steering pump. I noticed that's where the sound seemed to be coming from. Tonite I was going thru the drive thru at a local eatery and when I made a left turn around the building a really, I mean really loud hissing-air sound could be heard. When I got home I turned the wheel some more and sure enough that's it. Now here's the question, how could this cause the engine idle to go crazy? Is there some sort of vacuum connected to the pump? It really doesn't make any sense to me. I looked thru my repair manual and couldn't find anything as to how it could interfere with my engine. If anyone can solve this mystery please let me know. I really, really, really, appreciate any help. My patience with the truck is coming to an end.

[jrmcx]

Maybe youve got more than one problem. Crazy idle could be TPS or IAC. I just replaced TPS. 10 MINS. $30.

[bigkane01]

That could be, but I've replaced a lot of crap lately. It has a new IAC, TPS, MAP, plugs(autolite 3923), plug wires(mopar), distributor cap and button(mopar),speed sensor,fuel pump module, and K&N filter. I've done everything short of buying a motor. And with gas prices ready to go to $3.50/gal for regular I may be walking anyway. Thanks.

[ejazz]

I don't know the whole story behind your rough idle and hissing noise. Does it only hiss and run rough when you turn the wheel? If so, you possibly have a bad power steering pump that when you turn the steering wheel it bogs the motor enough to make it seem to run rough at idle. Could be a bearing in the pump. Try taking your serpentine belt off and play with the power steering pump pulley looking for slop in the pulley/ bearing. Also, make sure the fluid is at the correct level. It's worth a try and doesn't cost anything.

[bigkane01]

Actually I haven't heard the air in a few days, but my idle still doesn't hold steady. I've spent roughly $1500 in the last two months trying to get this idle problem taken care of. New fuel pump(dealer said it was bad),new plugs,wires,cap,button,new IAC,TPS,MAP,K&N filter. I give up. I've always been a big mopar man, but I think I'm gonna stick with the old mopars and tell the new, "Dodge, Different" corporation to stick it.

[DaBigDawgND]

If you are having uneven idle I would have the throttle control modulator checked. My truck did the same thing a couple of months ago and I took it to the shop and they replaced the modulator. It idles perfectly now.

"Mopar or no car is my motto!"

[fredjacksonsan]

Could also be a sticky valve in the power steering, that catches when you first start to turn, causing the engine to bog and hissing due to the fluid being forced through the system. You might want to try replacing the fluid. I had one car that had a muddy-looking power steering fluid and the ps would "catch" or not work properly. I took out a bunch of the ps fluid and refilled with fresh. After doing that for a bit, the fluid color cleared and it worked properly.