Intermittent warm Knock, frame creak

[dhcomp]

Ok, with the dmax down, the 91 is back on deck.

Hasn't been driven a ton this summer. Has developed a warm knock/stumble, and a weird creaking.

The knock. Runs pretty good until warmed up, and then still runs good for another 10-15 min.

Then under moderate throttle, it has a bad hesitation/knock. Pulled a knock sensor code, replaced knock sensor, no improvement. Although, not a delco sensor. Amazon was late, so i put in an off brand. Delco going in next week.
What could it be? Feels like the computer is cutting spark, but maybe something in the ign system? Plugs/wires/cap/rotor are low mileage.


Creaking. Frame creaks/pops when steering, and close to lock. Everything is lubed, replaced steering box, adjusted preload, everything. Frame isn't cracked, have ORD brace on, steering box is tight. Have been under the truck when someone turns the wheel, and can't pinpoint it. Do the frame crossmember rivets loosen up and creak over time? Its a disturbing noise that needs to get fixed.


Thoughts? I'm really good at throwing parts at problems, but on this one, i'd like to trouble shoot at least a little.

 

[Blazooki]

Tie rod end on the drag link going bad or gears inside the steering box out of adjustment / wearing out? The sound can carry thru the box and bounces off the frame making it sound like it's somewhere else...I've never seen enough factory rivits on any bracket go bad to the point that it loosens the bracket. You can tell a loose rivits pretty easy too. Most of time you can grind those things till they're almost nothing left and they still won't let the bracket go.

 

[Kain]

have someone turn the wheel and get under there and see if you can find it

 

[jeff in co]

That creaking is driving me nuts, too! I've been looking and looking for months. I'm thinking it's some rivet that is worn that I can't really pinpoint.

I've redone all my steering joints, steering box and also drilled out the rivets and installed brand new front spring perches. Frame has weld-in repair.....still can't find it.

 

[dyeager535]

Ok, with the dmax down, the 91 is back on deck.

How old is the fuel? I've seen problems at about 6 months old. Going to depend on a lot of variables, but it's an easy thing that you have to throw money at anyway.

Seems a bit weird that it's after it warms up for awhile, but if fuel is suspect, try it.

 

[rpcraft]

Check the cross member rivets (and the middle of the cross member for cracks. Also, check the frame mounting points on your rear shackles. I guess one last spot you can check is the bolts and bolt holes on the steering box. I'd suggest if you have it parked with a spare person nearby and have it to where it's popping I'd have them jump in and turn the steering wheel while you look underneath for whatever might be making the noise. If you can't find it that way try jacking it up and putting the frame on some jack stands to see if loading or unloading the suspension might help expose something that is hidden when everything is at ride height.

 

[dhcomp]

replaced coil. Hoping that fixes stumbling, as I'm driving it a couple hundred miles this weekend. We shall see, didn't have time for a test drive.

 

[dhcomp]

Coil didn't do it.

Now that I looked it over in the daylight, I bet it will run better with the 8th plug wire hooked up.....

 

[Kain]

Might help a little bit.....

 

[dremu]

I bet it will run better with the 8th plug wire hooked up.....

I keep thinking I should print up Occam's Razor and hang it on the wall. My version is "If it don't work, assume the simplest thing is broken."

-- A