Hey all
I have a 1996 5-speed, 3.9L with 129,000 on it. Lately my engine has been running worse and worse. When starting cold it seems to take a few more cranks than usual to start. The idle is pretty bad no matter what temp. I have replaced all normal stuff cap, rotor, plug wires, plugs, coil, TPS, IAC, pulled and cleaned my throttle body, and replaced all vacuum lines. Still when idling the engine shakes every few seconds and it sounds like a very slight 'wump' coming from the exhaust when the engine shakes. I have looked down in the intake and I see some fluid mainly concentrated on the pass side. I have heard this could be a plenum gasket leak. Might this be the troubles of my rough idle? When I rev the engine in nuetral, it sounds normal, but when I am in gear and accelerate, there is this sound that sounds like fuel injector noise, but much louder..kinda of a tsk tsk sounds the moves with the RPM's. I have not replaced the timing chain, and it does rattle only when the engine starts to shake. Replacing the chain is my last ditch action due to costs, and don't most chains last longer than 129,000 mi? Should I just bite the bullet and replace the chain, or do you think it would be the gasket leak causing this. I would hate to replace the chain and still have this problem
Thanks

 

If you see anything in the intake then it needs to come off . And a standard is alot harder on a chain than an automatic .Using the engine as a brake pulls the chain in one direction than yanks it in the other.

 

Hey I Think you might have something wrong with the valves system. Like a lifter or a valve itself. Or abering lose on your crankshaftor any intrnals.You might alsohave a leak in the plenum gasket because of the oil that you seebut that should mostly cause a burning oil smell or smoke. It could affect the idile by it losing vacum, you also would know by a pinging sound that will be because of the vacum loss.The cain does last a while but they do strech and itcan happen at 75000 or higher.The best thing is take it to a shop. most will do a free test drive and they can tell you what they think.

 

could be a number of things. It sounds like its a stuck lifter though. That sucks casue it means you need a rebuild. It could be the timing chain however. at the next oil change substitute one quart of oil for one quart of Lucas Oil Additive. It may help smooth out the lifter noise. You also may try replacing the coolant temp sensor. a ten dollar part that may help the cold starts

 

I don't think my idle was rough when my gasket blew. Low power, big knocking, and horrible gas mileage.