***This is not the actual vehicle that was in our shop. This is an image of a similar model. It can be found at http://www.autodetective.com/_upload/photos/dodge/grand%20caravan/2003/29051.jpg.***
We had a 2003 Dodge Caravan SE 3.5 come into the shop. The customer concern was a noise under the hood. The noise was more noticeable at idle. When the RPM's were increased the noise all but went away.
We used a stethoscope in an attempt to isolate the noise. At first we suspected the catalytic converter, but it was quiet. We then listened at the right side (rear, transverse engine) exhaust manifold. It too was quiet.
When we listened to the cross-pipe (over the transmission) and the left (front) exhaust manifold we heard the noise plainly.
We decided to remove the starter to inspect it, having had some issues in the past with starters causing noises like this one. The starter however checked out good. We took a look at the flywheel (flex plate), inspecting the teeth for any wear or issues; again, all was good.
We decided to remove the inspection plate on the bottom of the bell-housing to get a better look.
When we did this, we spotted the problem.
In the pictures below, you can see the issue. (The pictures are of the same torque converter bolt.)
The problem was the torque converter bolts (4 on this model) had become loose, allowing the torque converter movement.
On all the vehicles I have worked on, I had never seen this before. I called the customer to see if there was some repair history we had not been privy to.
Sure enough, the customer told me that within the past year a shop had the transmission out of the vehicle for a repair. Evidently, they did not tighten the converter bolts back tightly.
We applied some thread sealant to the bolts and tightened all four up. Yes, all four were loose. The one in the above picture was the worse of the four though.
We put the starter back on and everything back in place and started the engine. Everything was now nice and quiet.
