The Chrysler Minivan Fan Club Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
Howdy everyone... first post here; enjoying the information on this great site.

I recently picked up a used '07 Caravan SXT. It was examined by a mechanic before the purchase and is overall in very good shape (a lease return with about 81400 kiolmetres on it).

I recently became aware of a problem which, as you'll see in a moment, was not possible to detect when I was evaluating the van.

Any time the engine is completely cold when I start it up, there is a brief grinding or rattling sound as the engine revs up and down during the start. Once it's running, I no longer hear it while the car is at rest, even if I press on the gas pedal.

When I drive off, I hear the sound intermittently for about 2 more minutes, and then it's gone. No matter how I drive (fast, slow, completely at rest, whatever) the sound is no longer heard, even if I kill then engine and restart it. It will return, however, if the engine is allowed to cool down completely and is restarted cold.

The sound is quite brief, about 1/4 or 1/2 second long, and comes from the driver's side in front, as best as I can tell from within the car. When driving, the rattles are highly intermittent and don't appear to coincide exactly with gear changes in the transmission, though I am more likely to hear them when the engine RPM is higher. The volume of this sound is always loudest during engine start; it's quieter when I'm driving.

What puzzles me is that the sound is heard both when the car is at rest (i.e. during a cold start) and when driving. It seems that something is being jerked loose during a cold start, and then it settles down after a minute or two and behaves itself.

Any suggestions as to what this might be? I will, of course, take the car to my mechanic, but since the sound is only heard briefly during a specific set of circumstances, I'm concerned the mechanic might not be able to hear it unless he leaves my car sitting around all day to cool off.

Help would be much appreciated.
BM
 

·
Registered
Joined
·
377 Posts
A common problem that might cause this is the power steering reservoir. Next time you start it when cold, turn the wheel back and forth a bit and see if it changes pitch. There is a filter screen in the bottom that plugs over time and restricts the flow of fluid, more noticable when cold because the fluid is thicker. Several here have changed the reservoir, others have had success simply by siphoning out the fluid from the reservoir and refilling with fresh fluid.
 

·
1000 Post Club Member
Joined
·
2,509 Posts
Of course, you don't know how it was maintained by the lease guy, but it could just be normal. When my 05 sits for a day or so, it will clickity or clatter for about the length of time you are talking about until the oil gets to the head area and then it stops. If that is all it is doing, there is likely no problem. I added a 1/2 qt. of HyperLube from OReilly's each change for improved cold weather starting lubrication. You may find something equally good. You could have a sticking lifter (I know that isn't what they are called) and a run through or addition of a high detergent oil for one change may help or addition of a little Risolene, but it sounds like just a normal thing. Make sure you are using the right viscosity oil for your climate.
 

·
Banned
Joined
·
547 Posts
it helps to have a helper, to isolate where the noise is coming from.
Before starting the car, raise the hood and have someone start the car. (or use the remote starter).
Listen for where the sound is coming from, and that will help determine whether it is engine related or something else.
You can have the helper turn the steering wheel to see if it is the steering pump.
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #5 ·
Thanks very much for the replies to date.

The sound is definitely more of a grinding or buzzing sound, not a rattle, now that I've listened to it more closely.

I tried moving the steering wheel left and right a couple of times just after starting the engine, but that doesn't trigger the sound.

There are YouTube videos about the power steering filter issue which say it can lead to a grinding sound during engine start, so maybe that's the problem. I'll report back after I see the mechanic next week.
 

·
3rd gen > all others
Joined
·
3,465 Posts
If you're mechanically inclined, you can rule out the power steering and other belt driven accessories by first removing the serpentine belt from the crankshaft pulley, then cold starting the engine. You wouldn't need to run the engine more than 10 or 20 seconds to determine if the noise is gone, and that short of time won't ruin the engine. Then re-install the belt and try it again. If it makes noise after putting the belt back on, then you know it's belt drive/accessory related.
 

·
Registered
Joined
·
1,927 Posts
Could be the starter solenoid sticking briefly or the exhaust shield.
 

·
MOPAR Parts & Service Pro
Joined
·
3,052 Posts
Make sure it has a good quality MOPAR (or other good quality) oil filter on it. Also make sure it has 5w/20 oil in it.
 
1 - 8 of 8 Posts
Top