A/C compressor noise - TSB 24-27-93

[dan brooks]

Does anyone have more info on TSB 24-27-93? The only info I have just says: "A growling noise may be heard with the engine running" and that the repair involves a revised compressor valve plate assembly. I'm getting a noise from the front of my engine that seems to be worse in gear, at idle, and with the A/C on. It almost feels like the exhaust is hitting the frame somewhere, but I've looked everything over from front to back and it's fine, along with the motor mounts.



Just wondering if this might be the culprit... ...

 

[BushWakr - RIP]

Hi Dan,



Can you add any more info on this? Have you tried taking a 3' piece of garden hose and putting one end to your ear then hunting for the sound? (watch out for moving parts, I nearly got slapped silly when I first tried this)

You may be able to localize the sound then go from there.



Bob.

 

[dan brooks]

I tried that without success... . between the fan noise and just the engine itself, it was kinda hard to hear anything else from under the hood. I just bought the truck so haven't had much time to really track it down - was just wondering if anyone had the "full" TSB and if it gave anything more.

 

[farmall]

My neighbor has a 92 D250 and his is making a terrible noise also. We have tracked it down to the pulley assembly. The bearing is going bad and screechs, growls, knocks, you name it. It is a one piece assembly and go figure it is a dealer only item. So we are going to take it apart, press the bearing off and go to a bearing parts house and try to match it up. You might check that, our dealer said it is a common problem. Oh, by the way it is real fun to get off if someone before you rounded all the bolts off. Bill

 

[BushWakr - RIP]

farmall, you're not referring the screech at shutdown are you? If so this is normal/common... . just wondering.



bob.

 

[dan brooks]

farmall - I don't know if I should hope the idler is the problem or not... sounds like a PITA, but probably not as bad as a compressor problem. One good thing is that mine has probably never had anything done to it, so rounded bolts shouldn't be a problem.



\To be honest, I'm not sure what it is. I've been trying to pay a little more attention to the noise, and it occurs with or without the A/C on. At idle and in drive/reverse, it sounds and feels like the exhaust is against the frame or body, but I can't find any place where there is contact. In park/neutral everything seems fine. I'm hoping that maybe this is just "normal" for the CTD at idle.

 

[AMikonis]

Mine was making sort of a clanking sound with the A/C on, and it turned out to be the belt tensioner. Once I figured it out you could see it moving with the engine running and A/C on. The spring must have gotten weak. New unit was around $80 about 3 years ago. Easy job (if someone hasn't rounded the bolts off already!)

 

[farmall]

BushWakr I am not referring to when you shut down the motor. It is very noticeable when the mototr runs and gets worse as the bearing warms up. We have isolated it after searching for a good while. Thanks for all the info about my pump. Bill

 

[dan brooks]

AMikonis - How much was your tensioner moving? I do have some movement in mine at idle, but not a lot. Mine isn't clanking, but sounds/feels like the exhaust against the frame. It's driving me nuts, and I've gone over the whole engine with the garden hose stethescope and still can't pin it down. It is coming from the front of the engine somewhere, but that's as close as I can narrow it down.



I guess if all else fails I can remove the belt and start it very briefly to see if that eliminates it... . unless there is something about the diesel that will prevent trying that.



Thanks again, everyone.

 

[AMikonis]

It was pretty obvious what was going on once I saw it, so maybe it's not your problem. It was moving an inch or two, and hitting its stop (I guess. ) I could watch it swing and hear the noise as I saw it hit.



Running it for a minute without the belt shouldn't hurt anything, and it will help you locate or elimate the problem somewhere in the accessory belt drive. Turn all the pulleys by hand when the belt is off (engine, too!) to see if you hear a bad bearing in the water pump, alternator, etc...



Andy

 

[dan brooks]

Andy - Thanks again for the reply. I got a little better light under the hood and started looking a little closer, and I'm 99% convinced that the tensioner is the culprit. It moves in time with the noise, and I used a tire iron to carefully put a little tension on it. That seemed to take care of a lot of the noise, but as tight as things are in there I wasn't able to do much.



Did you get your new unit from the dealer or were you able to find an aftermarket source? I can order the pulley itself, but not the entire unit, at least at the "chain" stores that were open today.



I haven't looked that closely at how it comes off - any tricks or is it just a bolt or two and swap the part (I hope... . after installing an adjustable track bar on the rear of my Jeep yesterday I've used up all my patience for the month). I'm pretty sure there has never been any work done to this thing (only 47k miles), so the bolts shouldn't be rounded off.....

 

[AMikonis]

I bought a Cummins part from a truck parts place. Didn't look for it anywhere else.



The R&R was simple. I think it was only one bolt. Been a while ago, though...

 

[dan brooks]

Great, I'll call around today and see what I can find. Thanks for all the help, and I'll let you know if it takes care of the problem.

 

[csnider]

Dan,

I replaced my tensioner for the same reason... I had a dayco tensioner in there, not sure if it was original. I got another Dayco from the local Pep Boys for $89. . The Local Dodge Dealer wanted $174 . I didn't ask if theirs was a Dayco . . It cured my vibration problem when the a/c was on at idle. I went ahead and replaced the belt too... Tight fit for sure... ... ..... Hope this helps... ... ... ... Chuck

 

[dan brooks]

Andy - You're right, just one bolt. I was getting pretty worried because I couldn't find a wrench to fit it - 1/2 and 13mm were too small, 9/16 and 14mm too big. I finally realized that there was so much **** paint on the bolt that the wrench wouldn't fit.



Once I got the tensioner off I compared it with the one I bought..... and it's the wrong friggin' one. I don't know what this one fits, but it sure as heck ain't a '92 Cummins. To top it all off, the new belt I bought is about two feet too long. I hate incompetent parts guys.



Hopefully I can find some place that has the right one in stock in the morning. Otherwise the Dodge will be parked for a while and I'll be stuck driving the Jeep..... topless, in the rain.



csnyder - You wouldn't by some chance remember the part number for your tensioner, would you? The one I bought is a Dayco (#89215), but it ain't even close... .



Did I mention I hate incompetent parts guys???

 

[csnider]

Dan ,

the Dayco part # is 305219 or 219 for short... . Sometimes you got to make sure the parts guy isn't giving you parts for a 360 (5. 9Litre) V8 gasser!! I can't read the # on the tensioner in my truck but that's the # on the box and instructions that has a clear picture of it... It is the same as the one I took out except the first one takes a 3/8" drive ratchet to release the tension and the new one takes a 1/2" drive... . Hope you have better luck with the parts guy. I always watch the screen when they pull up a part # if I can... Good luck to ya... ... ... ... Chuck

 

[dan brooks]

Thanks for the quick reply. I just finished checking Dayco's website and, sure enough, the idiot gave me the tensioner and belt for a 5. 9 V-8. I specifically told him it was the Cummins. Friggin' incompetent... ..... well, you know.



Guess I'll head over there tomorrow and raise a little **** and see if they have the right one in stock. With my luck it will be a special order item. Mr. Murphy has really been having his way with me lately... ...

 

[dan brooks]

Well, everything is swapped and - so far, anyway - seems to have taken care of the noise. Just drove it a few miles to the gas station (got 19. 8 MPG on the last tank, mostly around town), so we'll see how it does on the way to work tonight. Keeping my fingers crossed.....



Thanks again for all the great info and quick replies.