Issues

[umdmaz]

Let me first say im new to the forum and new (pretty much) to off roading. This forum seemed like the best one online and im sure theres a ton on here i can learn and maybe some ppl around me to hit the trails with. Anyway i have a 91 4.0 YJ with about 5.5 inches of lift and 35's on it and have ran into some problems. When i bought it i was told (from a friend, who knows if its true) it had a recently rebuilt jasper motor in it with about 10K miles. Ran great sounded great and so on. I was offroading at my friends place and attempted for about 20 minutes a 40 or so ft tall 45 degree hill and since then ive been getting a knocking sound from the engine. The oil at the time wasn't low but but a little above the "safe" line. I've checked and refilled my oil to the top (synthetic if it makes a difference) and it doesnt help. The noise is coming from the front cylinder or cylinders so i can only assume i starved them of oil and messed something up. I compared the front spark plug with the last spark plug to see if the front has any signs of damage and both look almost as good as when i put them in a month or two ago. I'm fearing i might have bent a rod, grinded up my camshaft, or maybe done something to one of the valves. Any help or thought as to what i can look for or what this might be would save me alot of sleep so anythings appreciated. Anyway thanks for the help and good job from what ive seen of the forum so far it really has alot of good stuff on it.
~Maz

[George]

Welcome to the board! You are correct, there is alot of good information in here. Sorry I can't help you on this, but I am sure some here can.

[sabastian]

does the sound get louder with increase in RPM's? were you over heating at all? is the sound loud like a ding ding ding or a tick tick tick? kinda sounds like you may have bent a rod considering you were getting on it for a while. normal oil level or not.

[mrbeerbaitnammo]

another possibility is its the valves tapping, because of wear of just to thin of a weight of oil

[umdmaz]

Thx for the replies guys. The sound stays about the same as you lay on the gas, its most noticeable at idle because the other noise of the engine is relatively low, at three grand or so you really cant even hear it. As for overheating i couldn't tell you because the gauge is broken sadly from the last owner. As for sound its not so much a tick tick tick like a valve its more of a bom bom bom like something bigger is smacking or loose. As of now the oil level is at the top, then it was a little lower but not at the add line yet.