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I have a Dodge van 1992 B350 with the 360 V8… Has A/C. I have a noisy belt problem that has been there a long time. Only squeals when you hit the gas hard while in park or when the tranny down shifts to second going up a hill which raises the rpms. At idle everything is fine. I figured it was a bad belt since none seemed loose. I had to replace the water pump so I did that and replaced all the belts and hoses. Two belts for the A/C and one for the alternator, power steering and air pump. I tightened them all and then went back a month later and tightened them again pretty tight. The problem is still there. I had an old wax bar and tried that and it changed nothing. My thoughts are that this is not a belt problem but something else. The alternator is fine, the A/C compressor either on of off doesn’t matter. The steering pump does not make a sound when going full right or left. The only thing left might be the Air Pump. Have you ever heard of those going bad or failing at high speed? Not sure how one could test that.
Just had a flash of wisdom. I can loosen the belt and actually remove it from the air pump and that way remove that one item from the chance it is causing the squeal. I can not do it with the alternator as those two belts also run the A/C and water pump. I could try the steering pump but that seems to not be a problem from my testing. Just curious if Air Pumps have issues like this.
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You might want to check the idler pulley and see if the bearing is bad. Also, do you have a belt tensioner? If so when you hit the gas it could cause the tensioner to be pulled in which in turn would create slack on the belt and cause a squealing noise and the tensioner might need to be replaced.
Check out this video from ETCG.
[video width=550 height=309 type=youtube]ZSTZdTAB_As[/video]
If you have multiple belts you can take one off at a time to see what the problem is.
[video width=550 height=309 type=youtube]0UY35PUdv2c&list[/video]
This does not have an idler pulley….it is an old V8 360 that is old school with v belts and no tensioner or idler.
Belt tension all good?
One thing to double check is any pulleys that appear to have a “mirror” like finish on them. That’s known as heat glaze. Oddly enough it’s the same type nonsense that causes brake squeal on disc brakes. Heat actually polishes the metal like glass.
Long story short? (I know, to late) If you have a glazed over pulley–then each time you downshift or hit the gas—the engine RPM changes rapidly. And anything belt driven that can have any drag on it? (alternator, ac, etc…) Inertia kicks in. Objects at rest tend to stay at rest..and all that stuff. Sounds like the belts are slipping a bit on the glaze.
Just an idea. If you have any pulleys that have a hard mirror finish? Looks like glass? You can knock it down with a wire wheel on a drill motor, or using sand paper to roughen up the contact area. (Do I have to tell you—DO THIS WITH THE ENGINE OFF!) banana: Just covering our fanny
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It sounds like you’ve covered most of the bases, but it might not be the belts. You might also want to check the harmonic balancer. Sometimes the rubber that works as the damper goes bad and allows the crank pulley to slip. If this happens it can produce a noise very similar to a belt noise. More info on finding noises here.
http://www.ericthecarguy.com/faq/diagnosing-noises-in-your-car
Keep us posted.
When you say the crank pulley to slip do you mean it slips in reference to the crank shaft? Is there a way to repair that? Is it part of how the pulley mounts to the crank? I do not have the manual but I thought it was mounted with 4 bolts directly to the crank. I will try to find a parts pic for that area. I have used a wooden dowel held against my ear to find noises but with this noise at such a high rpm it could be difficult. It is so loud and terrible sounding.
I guess i need more info on how this rubber damper works. I have an engineering background so be technical.UPDATE: I went and looked up the part…I was thinking it was the pulley itself but as you know it is the heavy, wide piece that is closest to the timing chain cover and has the grooves used for timing. Apparently there is a rubber sleeve that goes between the heavy outer weight and the inner piece that fits over the crankshaft with a key. If it is slipping it might have to continue since getting to it might be a pain. I replace the water pump and all that is involved but getting to this will require removing the radiator to do it right.
if I leave it alone will it damage anything? is there any jerry rigged fix that might work in the mean time?
The damper IS the front pulley. If you look closely at it you may see a thin rubber area inside it. In fact, I believe there’s a pic of one in the article link I gave you.
Bottom of the page here.
http://www.ericthecarguy.com/faq/diagnosing-noises-in-your-car?start=3
I see that but this engine does not have that. The harmonic balancer is first from the front of the engine and then a another pulley that contains two v-belts and then another pulley in front of that for another v-belt. This motor is before they went with a single belt system…old school v-belts all over the place…5 all total. Still maybe the problem but will find out if using a conditioner works or if removing single belts finds the problem. It still could be the balancer but sort of not thinking it is since when I reach up and grab it nothing is loose. But then again at high rpm it might be slipping on the rubber ring….that could be scary.
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