98JGC826

So.... replaced my head gasket about 2 months ago, and the Jeep had been running like a champ since. Torqued all bolts in order to spec. Drained, filled, drained, filled, drained and filled oil and radiator fluid... so.. yesterday it was acting funny on my way home from work.. while pressing the gas, engine didn't rev, and i was hearing a clunking coming for the front left(driver side) of the engine. Now on the way to work today, same thing, but 100 times worse... bad idle (200 rpm or so, fluctuating), clunking when pressing gas, hesitating, and backfiring out of tail pipe... only way it seemed to run okay was pedal to the floorboard... wtf is going on?! No smoke all levels are good.. don't get it.... when pressing brake, rpm's fluctuate bad.. maybe IAC dirty? Will try that first.... I work overnight as a maintenance guy (toilet plunger), so i can pull it and bring it to the shop and clean and pop her back in.. any advice is appreciated..

98JGC826

Not the IAC... still looks new... and only 2 months old..

dave1123

Is this a V8 or I6? Either one, it's possible you have a broken valve spring. You may have misadjusted one of the rockers and caused a binding which broke the spring. If the spring is broken, you'll have to pull it apart to check the valve head for being bent and for possible piston damage. Pull the valve cover first and look it over.

98JGC826

I-6... most likely gonna just call it quits on this one... broken valve spring is a cheap fix... piston.. little more.... been one problem after another with this thing since i got it... $1700 worth of parts into it in about 6 months... found a 94 zj 4x4 w/ the 5.2 and 120k miles and he is asking $1800...i have over 204k, and i got it for really cheap from a friend of my dad's who i think just drove the hell out of it and never did any maintenance on it.... might pick it up later today if all is good with it... how well are the 5.2's built? Are they as dependable as the i-6's SHOULD be?

dave1123

IDK about the 5.2. I know everybody likes the 5.9.

If you live in the "Salt Belt", check out the frame around the suspension attachment points for rust. On my 97 one of the rear lower control arms broke loose and after welding that back together, one of the fronts did the same. There was no fixing that.

pwb

Mine did backfire and would only run on high rpm. Bad plug cables.

98JGC826

Turned out to simply be an air hose... the one going from engine to the intake... had a rip in it and on the way back home from work, it ended up coming disconnected and i was hearing the air slurping... pulled into a parking lot, wrapped it with electrical tape and she.is once again running like a champ...

98JGC826

Muahahaha.... in FL here... only salt here is the beach... lol

dave1123

That's just as bad if it was surf driven. A lot of the old CJs used for beach patrol are no longer with us because of this practice.

Glad you found a cheap fix. Sounds are hard to diagnose on a keyboard. When you said "clunking", I was imagining mechanical noise. Sorry to frighten you!

98JGC826

Put a new hose on pulled out of my driveway and it was running fine for about 5 blocks .... super confused.. the backfiring tells me it is running super rich, but the clunking up front i dont understand. Sounds like it is coming from somewhere near the power steering... but it sounds like a clunk clunk clunk clunk and then finally a backfire and it will accelerate...

98JGC826

Hard to describe, but doesnt sound like a rod knock or a clunk like that... like a loud click i guess you can put it, but not a fast click... and every click I feel on the gas pedal..

98JGC826

Going in the morning to get it scanned... if no codes come up, i am gonna go have the cylinders compression tested... if the compression is bad, i am gonna part it out as it has a 6 month old transmission in it and go buy a 4x4..

98JGC826

Dropped it off at my neighbor's shop. He said he will get to it first thing in the morning.. will post for anyone who looks for answers in the future since I couldn't find any resolutions online.. alot of the same problem, but no one saying what fixed it.. hopefully not a major problem, so i can get her fixed and then start looking for a 4x4...

BlueArmadillo

I had a similar issue on my 95 i6, I put in a new o2 sensor, coolant temperature sensor, plugs, wires, rotor, button and cap, fuel filter, and then a fuel pump. All of these things helped bit by bit, but definitely check the fuel pump, or just the pressure for that matter. Also I had a similar knocking and it was my exhaust pipe smacking my crossmember, but new motor mounts and a transmission mount fixed that.

98JGC826

Plenty of pressure in the fuel line... first thing I checked... i dont know... I will find out tomorrow what is it I hope... that's why they get paid the big bucks... but definitely not dumping more than another $3-400 into it... already have over $2k into it... just not worth it... it's a 2wd for christ sake!