H3 Help!!!!!Have a Question

[J-Hews24]

I have a 2007 H3 with 96,000 miles on it I have noticed a kinda loud knocking noise when I Start the engine in the mornings before work. There is no check engine light, all the fluids are fine no leaks what so ever. It drives like nothing is wrong. If I drive it a mile down the road the noise stops and I never hear it again until the next cold start. I have a pretty long trip coming up next week and the noise just has me a little worried. Has anyone ever had something like this happen if so any help or advice would be appreciated.

 

[amrg]

I have a 2007 H3 with 96,000 miles on it I have noticed a kinda loud knocking noise when I Start the engine in the mornings before work. There is no check engine light, all the fluids are fine no leaks what so ever. It drives like nothing is wrong. If I drive it a mile down the road the noise stops and I never hear it again until the next cold start. I have a pretty long trip coming up next week and the noise just has me a little worried. Has anyone ever had something like this happen if so any help or advice would be appreciated.

Could be lifter noise, pretty common to hear when engine is cold.
Any idle issues? Esp when you come to a stop? Check your oil levels anyway.

 

[J-Hews24]

no problems at all when at idle. after I drive about a mile it idles very smooth. Heck even with the tapping or knocking noise It idles fine just has the noise. I checked to oil its fine!!

 

[Dennis]

I hate to sound negative, but I've been around cars and engines for over 50 years..and the sound you described sounds like it could be a rod or bearing knock..due to little or no oil pressure at start up when cold..as the engine heats, metal expands a little tightening up the tolerances in the bearings...what type and weight of engine oil do you use and how old is it?

But in summary; sounds like engine wear has begun to show it's ugly head maybe.

 

[scoreh3]

I had something like that a couple years ago , same thing only at start up . I did a motor flush and oil oil change , I've never heard it again . It could be a lot of of thing , but a flush and oil chain is a very cheap way to start trouble shooting it .

 

[4speedfunk]

GM motors (all of em) are prone to piston slap at cold start-up. Its basically caused from the cold piston "rocking" back & forth slightly inside the bore. Once the piston heats up and expands...it fits tighter and the noise stops. I've heard brand new motors (both factory and modified) do it. I've also heard 200,000 mile motors do it. Obviously, this situation is not great for the skirts or rings but, its not the end of the world either. The general attitude toward piston slap is "let it be"...its not worth a tear-down. The bigger question is: Is that really what the noise is? Frankly, it could be many things. You should consult a pro engine guy, and see what he thinks. If it is crank bearings, wrist-pins, or some other important component...then all bets are off. If it is indeed piston slap...just turn up the stereo until it warms up.

I agree on the oil treatment. My 240,000 mile 5.7 (99 Burban) had some annoying lifter-clatter at start-up. Obviously, it was all gummed-up with varnish and I was planning a tear-down and new lifters. Figuring I had little to lose...I tried some stuff called "Rislone". I approached it with a "this is total bull****" attitude. But, I gotta say...it worked. The motor is whisper quiet and runs great. Saved me a ton of labor and about $500 in new valvetrain parts.

 

[J-Hews24]

Thank you all for the imput I am going to do a motor flush first thing in the morning ans see if that helps. I will update then. Thanks again for all the imput guys!!!

 

[derian06]

I have the same sound, it's the lifters. It went away when It got warmer. Atleast I hope its the lifters and not some of these other things.

 

[4speedfunk]

The Rislone works best if you do an all day highway trip. I drive around for a week with no results. Then I drove up to northern Michigan (900 miles) and that seemed to activate the stuff.

 

[J-Hews24]

Update time!!! I did a motor flush and drained the oil checked my pan there was no metal or shavings in the pan so that is good. Put mobile one in it new K&N oil filter. The knocking/tapping noise was still there but quieted down a lot I put Rislone it it and drove about 20 miles. Now the sound is gone!!!!! I think it worked now to see how long it last.. I also replaced my air filter just because.

 

[digglesworth]

How long do you keep the stuff in your engine? a full oil change cycle?

 

[J-Hews24]

It says it can stay in there throughout until the next oil change.