clunk
NAXJA Forum User
- Location
- West Kootenays, BC (canada)
I have been experiencing some loud ticking for the past 3000k+, which I originally suspected to be a sticking lifter. After doing some reading, I'm not sure if the problem lies in the lifter, or if it is in fact something else. I can't seem to isolate the noise to a specific cylinder, which has led me to start looking elsewhere. I suspect the timing chain could be the culprit, as it was *marginal* when I checked at the time of a rear main seal job. The front main seal weeps a bit, but probably only 1-2oz of oil per change, nothing major. 1990 4.0l with a c-hair over 100k on it.
Heres the symptoms:
-intermittent rattling/ticking/clicking noise, it is NOT a knock-type noise. This can be really loud sometimes, and pretty quiet other times. Seems to be intermittent, but I noticed it can be more frequent when the engine is hot. The sound will usually only last a few seconds---tick tick...tick tick tick tick.. then it'll be quiet for a while. If I remove the crankcase cap, it seems to be in harmony with the rockers moving up and down.
-I have ZERO oil blowby, the air filter is as clean as the day I put it in over 5000km ago. The old air filter that I replaced (which I suspect was many, many years old) had around a teaspoon of oil on the filter after a long life. This kind of leads me to believe that I don't have a lifter problem, as Ive gathered that a bad lifter will cause excessive blow-by.
-Pulled all the plugs, and they look brand new, no fouling or other damage when comparing against the chart at the back of my Haynes manual.
-Engine runs well, burns around 1/2qt of 10w30 per oil change. Oil pressure is well within factory specs.
-When I did the rear main seal job, I checked the main bearings for wear and obvious damage and they were all in great shape. Had a mechanic friend look at the bearing caps and he couldn't believe how good of shape they were in for a 17 year old truck.
-cleaned quite a bit of sludge out of the oil pan, and have run MMO through the last oil change to flush anything else. Sifted through the sludge I cleaned out for signs of metal with none found. Changed oil at 3000 miles, again checking for any metal indicating serious engine wear--none found. Added a qt of risolene concentrated oil treatment to the last oil change, which definately seems to have quieted down the top end, but the ticking persists.
What is this ticking noise?!? It's driving me crazy! Would a worn timing chain cause this type of intermittent ticking?
Heres the symptoms:
-intermittent rattling/ticking/clicking noise, it is NOT a knock-type noise. This can be really loud sometimes, and pretty quiet other times. Seems to be intermittent, but I noticed it can be more frequent when the engine is hot. The sound will usually only last a few seconds---tick tick...tick tick tick tick.. then it'll be quiet for a while. If I remove the crankcase cap, it seems to be in harmony with the rockers moving up and down.
-I have ZERO oil blowby, the air filter is as clean as the day I put it in over 5000km ago. The old air filter that I replaced (which I suspect was many, many years old) had around a teaspoon of oil on the filter after a long life. This kind of leads me to believe that I don't have a lifter problem, as Ive gathered that a bad lifter will cause excessive blow-by.
-Pulled all the plugs, and they look brand new, no fouling or other damage when comparing against the chart at the back of my Haynes manual.
-Engine runs well, burns around 1/2qt of 10w30 per oil change. Oil pressure is well within factory specs.
-When I did the rear main seal job, I checked the main bearings for wear and obvious damage and they were all in great shape. Had a mechanic friend look at the bearing caps and he couldn't believe how good of shape they were in for a 17 year old truck.
-cleaned quite a bit of sludge out of the oil pan, and have run MMO through the last oil change to flush anything else. Sifted through the sludge I cleaned out for signs of metal with none found. Changed oil at 3000 miles, again checking for any metal indicating serious engine wear--none found. Added a qt of risolene concentrated oil treatment to the last oil change, which definately seems to have quieted down the top end, but the ticking persists.
What is this ticking noise?!? It's driving me crazy! Would a worn timing chain cause this type of intermittent ticking?
