On my way to work this morning my H3 serpentine belt squeaked for about a mile or so. I didn’t think to much about it as it’s been extremely wet and humid here. Soon after there was a lot of loud snapping noise under the hood, almost like a very bad short on a coil, the higher rpm the more consistent. I pulled over and at idle rpm opened the hood and couldn’t see or hear anything, belt looked good, no frays or loose strings etc. when I shut the hood the “snapping” started for a second then went away. The noise does not sound mechanical at all however it’s happening under the hood so I can be hearing a little distortion. I originally thought it could be a coil but as bad as it was I’d assume I’d get a check engine light. No lights, no over temp, just loud snapping for about 20 miles. I’m a new member and did search the forum but I didn’t see any exact issues. Any ideas would be appreciated.

 

Belt tensioner is very loose? Belt is skipping?
When did you changed belt/tensioners/pulleys?
Power steering full with fluid?
AC on/off ?

Not much of idea though how it can be related with closed hood.

 

Hey Thanks for the reply, I don’t think it’s any thing to do with the hood open or closed except the fact when shutting the hood it caused some extra vibration Allowing me to hear it again. It makes no noticeable noise at idle, Tensioner is tight, pulley on tensioner also seems ok but will verify it when I get home. I checked it out on my break a while ago so I had some day light unlike this morning at 5am on the side of the road. I started it up and heard no extra noise that I did this morning. As far as the history of the belt, tensioner etc I do not know. We purchased this last week. (It made an 11hour trip from where we purchased it with no issues) Since buying it I’ve only replaced the oil+filter, air filter, both headlights added 2 additional key fobs and installed a 3rd row seat. This is our first h3 (06 with 152k)

 

The my truck makes ___________ sound are very difficult to respond to on line with real help, since none of us can hear it.

Is the Vin# withing the range of those made with the heads that have the defective valve seats?

Does the sound increase with RPM? Exhaust leaks can make funny sounds, and I5 H3s are known to have the exhaust manifolds crack.

Have you checked the radiator fluid making sure it is nothing but clean Dex-Cool?

 

I can agree with that statement, wish there was a way to load audio. The vin# is after the head issue was supposed to have been corrected for this year. Yes the coolant “looks” clean and is dex, but no guarantees on age etc.. I just left work and drove home and It didn’t make any noise at all.. I will be digging into it here shortly and post an update

 

Watch the magic happen:



Just upload to YT then paste video url on your next reply:

 

Hummerz = genius .. so my “non mechanical noise” was In fact all mechanical.. a water pump!! Maybe it was just to early for me to pay attention. Lucky for me Napa had one in stock. After removing the belt and turning everything the water pump pulley had a slight catch every so often, I’m assuming under a load and high rpm that “Catch” was much louder. So my apologies for misleading in my original post. Even out of the car it spins freely with just a very slight Catch every so often. The Napa pump is actually stamped “Gates” so I’m ok with that for now. Pump, belt and new fluid I’m out slightly over $100.. one thing I’m curious about is the water pump bolts only recommend 10nm? Either way I appreciate all the replies. Definitely not like working on my X5 but it’s growing on me.

 

My pump is still oe, however, I did replace the belt, tensioner, and idler many years ago.
I prefer to diagnose with a::>> mechanics stethoscope
Run engine, don't touch any moving parts, and listen for the abnormal noise..

 

I have an old sears mechanic scope somewhere buried in my shop, maybe it’s time to dig it out. I Did notice a smog pump in your video.. I’m assuming that’s not an option on an 06 or maybe someone did a good job of removing mine? Lol. So far we love our H3. It’s never really been a car on my list but after having it about a week it fits us pretty good.

 

What are you referring to? Post a picture. Also interested to see a picture of your 3rd row seat.