- Aug 25, 2012
- 955
I know there are like 100 of these on here but I figured mine is a little different and I love troubleshooting so here is my issue.
the description of my problem:
The past few weeks my 4.2 has been making the typical complaint of sounding like a diesel engine when at idle all the way up to about 1k RPM. The noise seems prominent on the exhaust side toward the rear, possibly at piston 5 or 6 on the exhaust valve. A week ago just for the heck of it i pulled the coil pack on piston 2 and 3 and found that piston 3 had a little oil in the well. I couldn't find any fresh leaks or traces of oil from the valve cover to the engine in that area but the plugs were replaced about 15k miles ago so it is fairly recent. Like another member on here had discovered if I take the PCV hose and plug it after it gets enough vacuum it will then stop the diesel noise. If I continue to hold the hose shut after about a minute you will hear a clacking noise that sounds like a push rod tapping onto the rocker arm. The engine runs great though despite the noise. I have 0 issues with performance, the fuel trim is perfect
Here is what I am thinking to do:
I have never ran an engine cleaner through the engine though I always use mobile 1 oil and change it at every 3k miles (yea I know its too often for our engine but I like to be overkill with protecting it). I would think that at the mileage I am at, 130k that a cleaning wouldn't be a bad idea but i am concerned about getting some gunk caught up in another part of my engine.
My plan was to take the valve cover off to replace the gasket since I had some oil in the spark plug well and suspect it to be leaking from the valve body and cover. While I was in there I was going to see how hard the lash adjusters would be to get to and maybe clean them up or otherwise re-adjust them since I doubt they were touched since the factory built the engine. I do NOT want to pull the timing chain and cam's out of the engine. I do not feel comfortable or willing to get that far into the engine. lol.
Here is what I want to test:
I want to do a compression test on all the pistons and then see how it reads as well as check the oil pressure at the filter and see if that is too low or anything.
If anyone has any suggestions on what I should try for a cleaner or if I should stay away from that please let me know. Also if anyone has insight on the valve lash adjusters on our engine I would appreciate the feedback. I looked at the service manual and can see where they are but cannot tell if these are reachable with the cams in or out. iirc another member did theirs with the cams in but I also want to clean them out and make sure they aren't stuck or anything.
the description of my problem:
The past few weeks my 4.2 has been making the typical complaint of sounding like a diesel engine when at idle all the way up to about 1k RPM. The noise seems prominent on the exhaust side toward the rear, possibly at piston 5 or 6 on the exhaust valve. A week ago just for the heck of it i pulled the coil pack on piston 2 and 3 and found that piston 3 had a little oil in the well. I couldn't find any fresh leaks or traces of oil from the valve cover to the engine in that area but the plugs were replaced about 15k miles ago so it is fairly recent. Like another member on here had discovered if I take the PCV hose and plug it after it gets enough vacuum it will then stop the diesel noise. If I continue to hold the hose shut after about a minute you will hear a clacking noise that sounds like a push rod tapping onto the rocker arm. The engine runs great though despite the noise. I have 0 issues with performance, the fuel trim is perfect
Here is what I am thinking to do:
I have never ran an engine cleaner through the engine though I always use mobile 1 oil and change it at every 3k miles (yea I know its too often for our engine but I like to be overkill with protecting it). I would think that at the mileage I am at, 130k that a cleaning wouldn't be a bad idea but i am concerned about getting some gunk caught up in another part of my engine.
My plan was to take the valve cover off to replace the gasket since I had some oil in the spark plug well and suspect it to be leaking from the valve body and cover. While I was in there I was going to see how hard the lash adjusters would be to get to and maybe clean them up or otherwise re-adjust them since I doubt they were touched since the factory built the engine. I do NOT want to pull the timing chain and cam's out of the engine. I do not feel comfortable or willing to get that far into the engine. lol.
Here is what I want to test:
I want to do a compression test on all the pistons and then see how it reads as well as check the oil pressure at the filter and see if that is too low or anything.
If anyone has any suggestions on what I should try for a cleaner or if I should stay away from that please let me know. Also if anyone has insight on the valve lash adjusters on our engine I would appreciate the feedback. I looked at the service manual and can see where they are but cannot tell if these are reachable with the cams in or out. iirc another member did theirs with the cams in but I also want to clean them out and make sure they aren't stuck or anything.