Diagnoses needed!

[PaulT]

On the way out to the campground yesterday, i overheated. I let it cool down, popped the cover and let the overflow reservoir stop boiling over the top. Added some fresh coolant, let it sit for about 30-40 minutes then tried to start it. No luck, seemed like the battery didn't have enough juice. A nice passerby offered to jump it, still no luck. Tow truck came and seemed upset about towing me 83 miles from Athol to Rowley on a friday afternoon, in rush hour (on his last day as a tow trucker)!

When we got home (took about 3 hours with rush hour and beach traffic) I gave it a go,k and it started up, but there was no oil pressure and it was rough, so i shut it down after a few seconds.

Pretty sure the water pump was my problem as the belt was soaked and the weephole was a-weepin when i lost power and pulled over.

Jumping to this morning/afternoon/evening, i replaced the water pump (the fan clutch and thermostat are only about 3 weeks old). It started right up, and spit what seems like a decent amount of water out of the tailpipe. Oil pressure at idle (according to the guage) is right below 40, but any throttle and pressure jumps up to 80. I don't know how accurate the guage is, but it usually reads dead on 40 while i'm driving.

Any jeep docs want to throw some knowledge my way?

[mopar_power]

look at you oil see if it looks milky

[ZAEDOCK]

Head gasket time. Do it soon before any liquid in the cylinders corrodes the ring packs.

[PaulT]

look at you oil see if it looks milky

not milky on the dipstick . Got an oil change a month or 2 back (less than 800 miles ago) and it looks clean on the dipstick. Tomorrow i'll drain it and see what it looks like.

Head gasket time. Do it soon before any liquid in the cylinders corrodes the ring packs.

The bucket truck at work has a blown head gasket, we do oil changes twice a month and it looks like the worlds worst milkshake, all frothy with visible layers of oil and water-ish substances. Took 9 gallons out of it friday. Pretty sure i only put 5 gallons of oil in it in May!

Thanks for the quick responses, any other ideas pop into your heads let me know!

[nostaw]

It started right up, and spit what seems like a decent amount of water out of the tailpipe.

Did you check the water to see if it is coolant?

I agree w/ Joe -- probably the head gasket let go...

JW

[ZAEDOCK]

look at you oil see if it looks milky

not milky on the dipstick . Got an oil change a month or 2 back (less than 800 miles ago) and it looks clean on the dipstick.

I'm willing to bet that the gasket compromised between cylinder 3 and 4. That's the hottest location in the engine block, especially with no coolant flow. That would also explain no coolant in the oil and excess fluid in the exhaust.

Fortunately, it is a relatively simple job that should only cost about $50 in gaskets and coolant. Don't worry about setting valvetrain clearances either - as the rockers are non-adjustable. Just tighten down to spec in place. When you pull the head, pour a little Marvel Mystery oil in the cylinders to free up any sticky rings. It will throw a little white smoke until it burns off, so expect it. 4.0L's are pretty resiliant engines. The head gasket should make it good as new.

[Carl McFly]

Tow truck came and seemed upset about towing me 83 miles from Athol to Rowley on a friday afternoon, in rush hour (on his last day as a tow trucker)!

Diagnosis, huh? OK, I'll do the best I can

Your tow truck driver was upset that he didn't call in sick on his last day, and he arrived at work regretting that decision. To late to avoid a long day, you were the recipient of his misplaced anger. He didn't see you as a victim of circumstances that were out of your control. Rather, he saw you as the source of his angst and didn't hide his ire

[PaulT]

Tow truck came and seemed upset about towing me 83 miles from Athol to Rowley on a friday afternoon, in rush hour (on his last day as a tow trucker)!

Diagnosis, huh? OK, I'll do the best I can

Your tow truck driver was upset that he didn't call in sick on his last day, and he arrived at work regretting that decision. To late to avoid a long day, you were the recipient of his misplaced anger. He didn't see you as a victim of circumstances that were out of your control. Rather, he saw you as the source of his angst and didn't hide his ire

Thats what i thought too. I figured i was doing him a favor, he could've gotten "lost" and spent his last day on the beach sipping a mai tai on company time. Some people you can't please.