1991 Dodge Caravan, 3.0 L V6.

Last night we noticed a whine coming from the passenger side of the engine. It seems it is coming from around the belt/power steering area. I'm thinking it might be PS pump but want to make sure the diagnosis is right.

Additionally, maybe related, maybe not, is the fact that after we turn off the engine, I hear a bit of a high pitched vacuum sound, almost like a whistle, for just a second after shutdown.

Any ideas are welcomed. Thanks!

 

You can use an empty garden hose with someone at the other end to localize engine noises.
For sure, check the PS fluid level. Using the proper fluid is important.

 

There is a vent hose under the aircleaner, that just falls off for no apparent reason, and can cause oscillations in the air cleaner housing. This noise is easily mistaken for P/S noise, and will change with engine speed. It will also explain the suction noise when you shut the engine down.

Along the same lines, make sure the intake tube is tight to the throttle body, and all the vacuum hoses are in place and secure.

P/s Noise will generally change when moving the steering wheel, and slightly , when accelerating. If the fluid is full, and you can verify moving the wheel changes the noise, that narrows things down to pump or rack and pinion unit.

 

I'd do a couple things to try and isolate it as best I could........First I'd go on and off with the A/C as it's belt runs independent of the rest of the engine. Listen for any change in the volume or tone of the noise. Then torque the power steering one side to the other. Again listening for change in sound.......A long screwdriver like the ones we used to adjust headlights (many moons ago) also serves as a good "stethoscope".......Once you know which belt is generating the noise.....remove it and feel for roughness in everything that belt turns....

 

If you fuss with the P/S anyway, I think the pressure of this hot fluid is usually around 4000 PSI, so wear face protection (petroleum products in the lungs can cause pneumonia).

 

Fluid level is fine, and I see no hose on the bottom of the air cleaner unit, just a hole (for drainage I'm guessing?).

 

If that's a serpentine belt setup [have to check] could be a tensioner or idler pulley bearing going.

Be sure to post back when you find the source.

 

Okay guys, before I could do anymore diagnostics, this problem seemed to take a worse turn.

The van, having the infamous Mitsubishi 3.0 L V6, burns oil. We get blue smoke mostly when accerlerating after sitting for a while, and smoke on idle. However, driving today, the van started whining more and more and the smoke suddenly seemed to become outreagous - we were just PUFFING it out. Now I'm thinking the whine is related to this sudden increase in smoke that just started... any ideas? The whine SEEMS to be coming from the passenger side of the engine. Also, the whine also does get worse/is most pronounced when accelerating from a stop.

Much thanks everyone. Summer has just begun and we need a vehicle to get around.

 

Most of Automotive power steering fluid the pressure is not that high at all more like 500 to 1500 PSI depending on what it set up.

 

Valve guides were usually the reason for the smoking. Maybe that whine is coming from your timing belt, and it finally skipped a few teeth & worsened your valve problem. Maybe a couple of reconditioned heads are in order, or have yours done at a reputable automotive machine shop. Either way, it's not going to be cheap. I guess the current mileage of your engine and budget, will determine whether to get it done, or buy a known good used 3.0L, or new rebuild.

 

The engine has 260000 kms so it is more than worn and tired. Since it isn't the greatest shape, it doesn't matter a lot of money but we'll see.

I checked around some more, and when i acccelerate while just sitting, and the engine tone comes back down, it starts to shake and wants to die on me.

Any other things I can check myself to rule out other things before I have to spend a lot elsewhere?

 

Update:

Driving today, the smoke was nominal, nothing like last night's episode. The sound is still there. Our engine has always had a whiny tone to it, and it sounds like that sound except multiplied.

It's also worth noting that prior to the severe smoking, we were stuck in traffic idling (Canada Day festivities) and our rad. fan turned on (temp gauge was in the middle at normal temp though).

Any further information is appreciated.

 

Any more ideas? Smoking is still back to normal but the whine has remained.

 

Suppose I recorded the sound it was making so everyone could hear? Perhaps a trained ear could identify it right away. I'm not sure if using the hose or screwdriver trick would work too well because it can't be heard very well at idle (acceleration is the worst).

 

After shutdown, the only place there would be any residual vacuum (if the sound is a vacuum leak) would be the brake booster, but that's not going to be on the passenger side. The fact that it's on that side would tend to point toward an accessory (ac, ps, alt), belt/belt pulley, or something internal, i.e. timing belt. I'm afraid you may need a local trained ear on this one.

 

I'll see what I can do. In terms of getting a local mechanic to take a look, I doubt the vehicle is even worth it at this point.

The vacuum sound at shutdown - I am unaware which area it is coming from. All I know is it is from the engine area. Regarding the whine, it seems more pronounced on the passenger side, and fairly less on the driver's side.

Thanks!

 

Thought I'd repost here since I never did find the problem to my whine until yesterday, so I believe.

Saw a nice little green suprise under the van yesterday. Rolled it back and ran it for a while and shut it off, low and behold got an antifreeze drip drop from the belt/water pump area (aka passenger side). I later read in my Haynes manual that failing water pumps make a "howling sound". Well, my whine could be described as that and it does worsen on acceleration!

 

I have a 2006 Dodge Caravan SXT. About 8 months ago it started a whining sound. It was just very light and I didn't have the money to pay a huge mechanic bill. We added a little power steering fluid as it was a bit low. I started my research and found out about the Power Steering resevior. We replaced it and guess what?? No more noise at all! I am so relieved I found all the information here. I have 75,000 miles on my van and we take a lot of trips in it. I've kept up with all the maintenance so I was a bit worried as to what it could be. Thansk again.

 

Hi everybody,

We have a 97' grand caravan 3.3L with 260k on it and for the last year or so has been making strange noises. When it first started making the noises I took it into dealer to get new serpentine belt and belt tensioner (told wife this had to be problem, 100k+ on these since replaced).... no real change but not really any problems other than noisy, so rather than spending more $ decided to roll-on... so last week, (about 10 months later) wife is comming home from airport and it overheated. Come to find out the water pump has been problem all along! $70.00 for pump, thermostat and 2 gallons of coolant really made this thing sound like new again! I thought it was the belt tensioner when all this started and then was leaning towards the alternator.... never would have guessed this!

Hope this helps someone!