Caravan Squeals loudly Occasionally

Maintenance/Repairs
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1

Hi, Got a 2000 Dodge Caravan 3.0L with just over 100,000 miles. Just got it in June so all I know is that it was faithfully garaged kept and truly driven by a nice older lady whom doesn’t drive anymore (one owner).

Since I drive with the radio on, I am not sure when the squealing started. Am pretty sure it is belt-related, but not 100%. And it is loud enough that I’ll hear it, even with the radio on, but not necessarily at highway speeds.

Not sure if power drops while squealing but that may be a completely different issue, but in any case at times while accelerating, it seems like the power fades and then picks up - but then, I am now in the habit of backing off the accelerator as soon as I hear a squeal.

It squeals anywhere from 2-10 seconds at a time, anywhere from 2x a minute to once every 5-10 minutes. It squeals much more when driving, does not really squeal when idling.

Attempted Diagnosis
I see the method of squirting water at the ribbed side of the belt to see if it squeals more/louder or less. Since the squeal is only occasional and only for a bit if I rev the engine then squirt - the water doesn’t seem to make any difference.

So I have a few questions
What are all the pulleys on the belts? I know the small belt in the front is the A/C, with an idler. I know one pulley on the larger belt would be the crankshaft (?), then there is the alternator, an idler, the tensioner - anything else?

What’s a good approach to find what’s wrong?

HELP!

2

Good question. Alternator, power steering pump, and the stuff you’ve already mentioned… including idlers.

To find what’s squealing start with a question: when was the serpentine belt last changed? If it’s original, it’s due and changing it may just solve your problem. A worn, or a 17 year old belt, can easily exhibit exactly the symptoms you’ve described. Serpentine belts are elastomeric belts reinforced by a fabric structure. Elastomers dry out and lose their elasticity… and their frictional coefficient.

17 years is a long time for a belt. Think about it, if the average speed of the engine over its lifespan was 3,000 rpm, that means the belt has been bent rapidly back & forth 3,000 times every minute.
If the average speed of the vehicle including stop & go and highway, was 60mph, and the total mileage traveled was 100,000 miles, that’s 1,666.666 hours of operation. 3,000 back & forth bends X 1,666.666 hours = 4,999,999 (almost five million) back & forth bends.

Oh, and you also have to multiply the five million by the number of times it gets bent back & forth every time it goes around. I almost forgot that variable. Feel free to check my math, folks. I’m getting old, after all. :grin:

Add to that the aging of the elastomeric (made from rubber), and I’d suggest that the belt is a really good suspect for your squealing.

Unless you know the lady personally, don’t believe a word of this. That doesn’t mean it isn’t a good vehicle, but many car salespeople lie… regularly. Sometimes when they lie to me I mock them… sometimes I ask them questions that challenge their lies. I like to see the liars stumble.

By the way, if you have a timing belt that too is overdue. The same principles apply, except that you’ll want to consider changing the water pump at the same time if it’s driven by the timing belt… and the front cranks seal too.

3

All the 3,0 ( Mitsubishi) engines I have seen have a serpentine belt to run most of the accessories with an automatic tensioner, They have one accessory mounted forward on the engine that has a regular V belt that has to be manually adjusted. That is probably the loose belt. There is a locking bolt sideways to the idler pulley and an adjusting bolt more vertical than not. Mine needed a 13 mm deep socket.

4

Unless you know the lady personally, don’t believe a word of this.

I very much do.

5

The belt, the timing belt (I’ve heard that if the timing belt fails on this vehicle, it won’t destroy the valves, etc), I certainly recall when cars were not very reliable and certainly past the 4th year. Am amazed how long many vehicles stay on the road.

As far as what had been done and when, those are questions for another day - perhaps tomorrow.

6

You might want to also look for help on this site

http://forum.chryslerminivan.net/forumdisplay.php/30-3rd-Generation-Chrysler-Minivans-1996-2000

7

The air conditioner compressor belt is loose, you should replace it now after being loose for so long.

8

You seem to have two issues. I think the squealing is a belt and agree with commenters above. The “hesitates” part you describe would not be related to an accessory drive belt slipping. I did a little looking at CarComplaints.com (a CarTalk partner site) for the same year and model you own and other owners have reported a transmission issue that relates directly to intermittent hesitation. Maybe worth looking into. Here is what I found.

9

Your van does have a timing belt in addition to the serpentine (drive) belt. The replacement interval is 60,000 miles for the timing belt. When was it replaced last? The previous owner should have a receipt if the work was done. This is a different issue than the squeal. The timing belt won’t squeal but just plain break one of these days unless you change it in time. If the timing belt hasn’t been changed, you should get that done. Change the water pump and coolant at the same time, and then install a new serpentine belt afterwards. You have to remove the drive belt to do the timing belt anyway.

10

The cause of belt/pulley/idler squeal clues can often be discovered by doing a few experiments , like turning the AC on and off, turning the headlights to bright on and off, turning the steering wheel all the way to the steering stop and back to the other one, and listening for any changes to the sound. Another idea, as the engine idles in the driveway pop the hood and use a length of old garden hose as a stethoscope, see if you can hear it that way, and narrow down the area it is coming from. You can ask a helper to change the controls like above while you listen.

11

I appreciate all the suggestions and comments, will try to respond to each one.

But first: Regarding gas mileage My first full tank yielded about 19.5 MPG, the 2nd about 22.5, then 21.2, 20.3, 19.6, 17.9, then 17.5. If I start the engine and walk around the back, the exhaust smells rich of fuel. Tires are well inflated, about 38 PSI cold. Had wheels aligned between 2nd & 3rd tankfulls.

Back to the squealing.

I am not very certain about the hesitation. So, assume for now that it is a figment of my imagination, as I tend to lay off the gas a bit or turn the AC off when I hear the squeal.

the_same_mountainbik
In addition to my previous reply, I contacted the prior owner and no info was maintained about any services.

jtsanders
If I have read Caravan comments, the timing belt will not cause other damage if it actually breaks. Is there some way to look at it and gauge its wear? I will certainly consider doing the water pump at the same time - as well as those seal(s).

Is the water pump driven by the timing belt in this Caravan?

oldtimer_11 & Nevada_545
The A/C is on a separate belt. It was replaced in mid-June; so it isn’t old at all. But the squeal didn’t start until mid- to late July, maybe even early August. Perhaps it has stretched a little bit and is now broken in. I can try tightening it a bit and see if that eliminates the squeal.

Waterbuff
Looks like a good sub-forum but neither search on “squeal” or “gas mileage” brought up any hits.

gorehamj
WOW - a lot of unhappy customers with tranny issues.

GeorgeSanJose
AC does not seem to make it better or worse, HOWEVER, when it starts squealing, if I let up on the gas or turn the AC off or both, the squeal subsides and stops - til the next time it starts.

It will start squealing without the AC on and the frequency and length of squealing does not seem any different if I am running with the AC on or not.

Steering does not seem to have any effect whatsoever. Nor do lights on/off/bright.

The stethoscope idea sounds great, no pun intended!

OK - so I was not able to get under the hood today. And probably not for a few more days.

12

Maybe try posting your situation there. Others there may have encountered or fixed it.

13

It sounds like it is some component on the AC belt loop. One idea that’s cheap and easy to do, might work , just replace that belt. If it doesn’t work, worse case you’ll have a spare belt.

14

Yes, the timing belt drives the water pump. The timing belt has to be removed to change the water pump. While the belt is off, you might as well replace the pump. When you replace the pump, you have to drain the coolant. Might as well replace that, too.

While it is not an interference engine, there is no telling when it will fail. You might be in front of a huge 18-wheeler that is tailgating on a steep down grade when it breaks. It might break in your driveway, but what do you think the chances are of that?

IMG_0059

15

If you are using defrost mode it will run the a/c, that would explain the intermittent squealing with the a/c off. My experience with the V-belts on this engine is that they always stretch after install and need to be re-.tightened

16

ALL

I’m going to try replacing the serpentine belt 1st, for $15, it’s a chance. Also, Gates offers a free tool that checks for wear. Go to http://bit.ly/2wrklqe and click on the link to request a 2-pack, for free.

Will post results as they come in - the wear gauge, the new belt (Poly-V quiet belt from either Continental or Goodyear).

oldtimer_11
I’m not running in defrost mode, but thank you for that tip. I like that choosing the blower on the windshield (defrost mode) automatically runs the AC and I believe chooses fresh air.

jtsanders
Thank you for the pic. very helpful!

19

I replaced the serpentine belt (unknown age) and re-tightened the A/C belt. The squeal is gone.

Thanks, all!

20

Congratulations on a job well done.
Happy motoring. :grinning:

21

The squeal is back. :slightly_frowning_face: It squeals once in a while and only when A/C is on.

I wonder if either the water pump or the A/C is such a load that the belt slips.

As I recall, there is an auto-tensioner on this belt, so I really cannot adjust the tension… right?

Seeking WOTL. Help, please!

22

The waterpump shouldn’t be an issue unless the bearings are shot. Look fr coolant leakage at the shaft.

If the compressor is driven by the serpentine belt, try replacing the tensioner.