Thread: PLEASE HELP! Odd water/wooshing noise when I accelerate:(

Hey all I really need your help on this one,

My 2004 Grand Prix GT was making this odd wooshing noise which sounded like pouring/churning water behind my dash. I figured it was another water problem because I have had them in the past (in my floor boards, ceiling from the sunroof...etc). After a couple weeks, I took the car in not expecting much and this mechanic tells me that is it actually a blown gasket and my heads are pushing oil into my coolant. He also said he was surprised my car was even running, when it was running completely fine with no temperature problems or anything just the weird noise. SO I have him pop the top and do new gaskets, send the heads to a machine shop, flush my coolant and replace my oil. Prior to taking my car in my engine did seem warmer than usual this one time after a 100 mile drive but after adding coolant (which was bone dry) it was fine, and my "oil level low" sign kept appearing. So after the mechanic completes the job he says its running great and I go pick it up. He installed new coils and wires (MSDs) because mine looked like they "needed to be replaced" which was odd because I had them replace not even a year ago... Anyway, I get the car home and it seems fine. When I go to park it I noticed the noise again and so I popped it in neutral and gave it a little rev and sure enough the noise was back and just as bad if not worse. Also I noticed when driving my gear change from 2nd to 3rd seemed later than it usually is. I took the car for a half hour ride while closely observing to try and notice anything but I came up with nothing except that damn noise.

Please give me your advice and I'm sorry for being so wordy but I just wanted to give as much detail as possible.

Thanks!

Does that mean my heads were probably fine and this guy ripped me off?

I have never seen a head gasket go on one of these... Upper intake(plastic crap) will melt(Via EGR tube) and dump coolant into the oil... Get those in the shop a lot. usualy the 97-2003 series 2(replaced one monday). Not sure if the the 2004+ had the same problem.

What you likely experienced was a failed set of lower intake manifold gaskets. Possibly the UIM as well, but that is less common. ALL GM 3800's from 97 to mid 05 have issues w/ the stock plastic LIM gaskets, which results in low coolant and can get coolant into the oil. HG are extremely rare. Sounds like you got took on that one, sorry.

BTW, the stock coils are the best things for these cars, so if you start getting misfire issues then I'd ditch the MSD coils and wires and go with an OEM set on both. Then just stick some good Autolite or Delco plugs (NOT PLATINUM) in it and call it a day.

A wooshing noise is an indication that the cooling system needs to be bleed properly. Assuming you are not loosing coolant.

Yeah I attempted to verify that he did the work but I dont really have the tools to check the inside. From what you guys are saying I would agree that it is my heating core. I just almost hope my gaskets blew so I didn't get ripped off.... I am going in tomorrow to investigate this guy. Thanks for your help.

Yeah but I am not too sure that the work was done... It might just say that on the receipt I guess I will find out tomorrow and let you guys know. I'm going to make that guy take the top off infront of me and show me the gaskets himself.

Originally Posted by bluegtp91

^^That.

I'd also flush out the Dexcool...honestly.

And an easy way to tell if he did the gasket's is just look...newer 3800 or not...inbetween the head and the lower intake manifold there is a small piece of plastic...the new style aluminum GM ones are a gray-ish silver color...the old crappy ones or the non-aluminum ones I have ran into...are black.

I checked the gaskets and they are still black but look new. I also went back in and he showed me my old gaskets and everything. The head gasket definitely was blown. The car runs smoother than ever now so maybe I just have a special case. I'm pretty sure he didn't rip me off.