Minivan Howling Noise

Ahhhhhh, the weirdness never stops...

Both my Minivans make a howling/dry bearing noise when they're cold...as in cold out...not operating temp.

I've owned one van for 10+ years, and for years, when the temps go into the 20's or lower it would howl occasionally...
Over time it got to be a regular thing...but only when it's seriously cold out.
NEVER heard it in any kind of warm weather.
Now, with this incredibly cold weather we're having around here, I've heard it the same noise in my other minivan! :confused:

Here's the situation in Van #1...

Not an engine related noise. I've shut the Van off while it was moving and howling...noise continued until the speed dropped.

You have to be moving.

At least 20 mph or faster. It will continue to around 50 mph, then it stops.

It's quite loud, and definitely sounds like a dry bearing somewhere. It has that variable pitch warbling noise like a dry bearing.

In Van #1 it is speed related. Both noise level and pitch change with speed, but it will stop around 50 mph.

Van #2 it only seems to occur at lower temps (10 and below), lower speed (10-15 mph), it isn't as loud, and seems to go away or get much quieter as speed increases over 25 mph or so.

I have wondered if the cooling fan might be the culprit...freewheeling from the airflow through the radiator...although both fans do not seem to have excessive play in them.


Feel free to throw out any ideas that might occur to you...but it's definitely not tiny little wolves in the engine compartment...I checked. :thumb:

Thanks in advance...
CG

Does the noise change when accelerating and decelerating? It sounds like the diff bearings may be the culprit

could you unplug the fan, zip tie a blade to the shroud and take it for a spin? Keep an eye on temps and keep the drive short. In rediculous weather like that I bet it would take a while to get to operating temp.

Cooling fan will do that. I have the same problem. I just oiled the fan bearings. It does com back when below -10F.

Did you ever find the source of this noise? I'm having the same issue with my 89 Caravan.

Howdy,

Yes I did.
I eventually pulled the hood and watched the cooling fans in cold weather (when I encountered the noise).
It turned out to be the cold fan bearings howling while wind coming thru the grill turned the fans.
CG

go pro need to invent an engine compartment mount - with a nice bright lamp
save us all some wondering ...