My '93 CDV with 70k miles has a loud groan that I'm not quite sure what it's coming from. I thought it was the PS pump, since my '94 Deville had made a similar sound before I changed it's PS pump. But I changed the PS pump on the '93, and the groan remains! I'm not sure if it's the water pump or the A/C compressor. Does the water pump make a groan when it's going bad? Any suggestions, before I go changing parts needlessly?
Automobile(s): 1995 FWB 100,*** miles CURRENT. 1991 Seville 175,000 SOLD
Re: 4.9 groaning
You might want to remove the serp. belt, turn accessories by hand and carefully listen to the noise (if any ) they make. That's not an easy task if they make noise only at higher RPM though. I have had some groan for two years (not in park) and the pitch changes with rather RPM than speed. Still cannot locate the source.
That's good to know! I tried what HUF suggested earlier with spinning the accessories by hand, but that's hard to do when parts like the PS pump and water pump don't move very fast by hand.
My next plan was to try using the 62" serpentine belt that bypasses the A/C compressor, to confirm that it is the water pump and not the A/C compressor. But I am kinda thinking that it is the water pump that is making all the noise! It is quite noisy too, it's a loud growling, grinding noise. Sound familiar?
I've got a 92 DeVille that I think makes the same noise that you're describing. It doesn't seem to affect the performance at all though. I came up with the same theories (a/c compressor, water pump etc). I even thought that it may be the tranny at first, but thank God I think I'm wrong about that one. At times I smell a slight burnt rubber smell under the hood, which really makes me think that it's one of the network of pullys that the 4.9 has.
I'm interested in hearing what you come up with, and also am interested in any other ideas about this. the noise on mine seems to dissipate at higher speeds/RPMs, but it may just be that I can't hear it as well then because of other noise.
My 91 Fleetwood had the same thing, turned out to be the A/C compressor. At first I thought it was my water pump as well. I removed the access plate from the passenger side wheel well and took of the belt. When I turned the A\C pulley by hand not only could I hear it, but I could also feel the roughness.
Automobile(s): 1992 Town Car Cartier & 2014 Accord LX MTX
Re: 4.9 groaning
My '92 deVille made a groaning/whining sound like that last winter...I had a hell of a time trying to find what it was, but it turns out it was a bad bearing in the Alternator...a $40 rebuild fixed that!
My '93 Eldorado w/ the 4.9L developed a groan about 3 weeks ago. 2 weeks ago, I took the serpentine belt off and rotated all pullies by hand, however, none of them were obviously bad. This weekend, I took off the belt again and found the water pump had an obvious grind. After its replacement, the groan has disappeared.
By the way, a reman water pump @ AutoZone was only about $27 and took about 3 hours to replace. Careful when torquing the bolts/nuts as you can see in my post from a few hours ago.