Idle knock

[KGS]

I used the search feature and only found one post that was close to what I am experiencing.

When the engine is warm(operating temp.) I have a loud knock at idle, in gear. Don't notice it in neutral or park and goes away as soon as brake is released and start rolling forward.

The noise sounds like it is coming from the right side of the engine.

Thnx

[More Power]

Might want to include more info... Like model year, mileage, previous service history, power adders, how it's driven, etc.

From your description, it sounds like a fuel knock. An injector balance test can help locate a faulty injector. You can do this test with either a Predator programmer or a Tech II scan tool. A Tech II can also be used to disable each injector - one by one - to help locate a problem like this.

Let us know what develops.....

Jim

[KGS]

'02, 73k miles, Edge Juice/v1.5, never had and injector problem and run level 3 for daily driving and level 2 for all towing.

The knock did start after returning from a trip to East Cape Baja Mexico, towing a 20' boat and loaded with 4 guys and enough gear for a week. I haven't burned a full tank of fuel since returning and have added Power Service fuel additive.

I am just making sure I have a good idea what the problem is before I take it into the dealer for the work. Our dealer around here is pretty clueless most of the time.

Thanks

[imsweetdaddy]

My 02 does the same thing, on right hand side up high. It's not very loud but I noticed it one day while under the hood. Kind of a ping/knock, not a clanging/knock(like wristpin). I don't know what mine is either... More Power, will have mine tested... and will reply when I have fixed it. I absolutely think you are right.... there isn't anything else it could be, is it? Thanks More Power!

[KGS]

Well I took it to our clueless dealer today and got the typical "we couldn't get it to duplicate your symptoms" routine. This isn't the first time for this famous quote by them either.

So I took the truck for a run down the freeway, approx 10 miles round trip and got the truck to make the knocking/hammmering noise and took it right back about 10 mins after leaving the shop. I had the head mechanic listen to it and the noise seems more noticable in the cab than outside. He has no idea what it could be seeing how the injectors checked out "fine" on their scanner. He mentioned something about the ultra low sulfer diesel and how this could be from that, maybe???? I don't know.

This is starting to bug me big time!!!! Any other ideas????

Thanks

[More Power]

Ask the mech to go for a ride with you. When it's making the knock, have him disable each injector one at a time using the Tech II, to see if one of them behaves out of the ordinary.

Jim

[KGS]

Thanks Jim

I was kinda thinkin' that after reading some of the other posts. I need to try and get back there this week.

What(if any) are the effects of running the engine like this for an extended period of time???

[DmaxMaverick]

Some early models had a problem with cracking the downpipe mounting tab. You can check it by looking through the passenger side wheel well (pull back the liner and use a flashlight). The tab bolts to the exhaust manifold. If cracked, it can knock pretty loud, and sound like a fuel knock under the right conditions. I had mine welded by the dealer once at about 12K miles, and welded it myself again about 30K ago. No biggie, but can make an annoying noise.

Later models have a clamp type mounting tab, and I haven't heard of any of those cracking. They are obvious, as there is a 3/4" clamp around the downpipe.

[KGS]

Thanks DM

I will check that this afternoon. The sound seems like it is coming from that side of the engine.

I took a quick peek at lunch and the bracket is cracked all the way, I will weld it up and hopefully that takes care of it.

[KGS]

Tab is welded and the bolts are tight.

Still have a knock, so off to the dealers tomorrow to take the mechanic for a ride.