Strange clunk on shutdown

[Uno Mas]

Hello from N. IL. I've been member on another site for 11 years and this is the one I come to for technical info. I've been a dmax owner for 12 years and have done everything from head gaskets (on my brother-n-laws '05) to injectors. But I'm nowhere near the expert most of you guys are. I'm not really into the hotrod stuff but enjoy the hell out of learning about anything diesel and wrenching on them.

I thought it's time to join because I've got an issue that is puzzling and I can't nail it down. When I shut off the engine a hear a clunk noise that sounds like it's coming form the front of the engine. I've checked the exhaust, the fan shroud, the idlers are less than two years old, motor mounts look good, no issues with the AC compressor.

I tried to post this video to you tube but for some reason I'm having trouble with it. So I posted it to instagram. Thanks!


https://instagram.com/asamccp/

 

[OregonDMAX]

I had a somewhat similar noise, it wasy exhaust hitting the crossmember from motor twist when shut down. With it being 5" though that is why it hits.

 

[whitetrash21]

I had a somewhat similar noise, it wasy exhaust hitting the crossmember from motor twist when shut down. With it being 5" though that is why it hits.

My old truck had a 5" and it would occasionally bang the cross member.... sounded similar to that. Just for shits and giggles, chek your motor mounts though.

 

[Awenta]

Hard to say. Have someone shut it off and listen

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[Uno Mas]

Okay, had someone with a flashlight crawl under it as I shut it off a dozen times and nothing obvious. One thing I did notice, I cold started the truck and moved about 50' in my driveway and shut it down and no clunk.

The next thing I'm going to try is to warm up the truck and remove the serp belt and see what happens.

 

[Uno Mas]

One other thing, I recently changed the oil and there was no change in the clunk.

 

[1ATony]

Thanks for joining, it's great to have you here

Tony :hello:

 

[Uno Mas]

I got a chance to pull the serp belt and start the engine. No clunk. I did this 5-6 times and no clunk. All the pulleys feel tight and smooth when spun by hand. So I reinstalled the serp belt and wouldn't you know it, no clunk. I had the wife start and shut off the truck 6 or so times while I looked around underneath and nothing.

So far, as I find it hard to believe, the serp belt is the cause. Maybe in stead of a squeal it sounds like a clunk?? Unless someone can confirm with a similar experience, I guess I'll keep an eye on it.

 

[Awenta]

Check the motor mounts?

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[Uno Mas]

Yes. Didn't see anything obvious.