Ok, I have a 1997 XJ with the 4.0 6cyl.
The jeep has 264,000 miles on it.

In the last month it has been acting up, here are the symptoms:

1.)Bad misfires on all 6 cylinders. Its worst on cylinder 1,2,and 3
2.)The misfire is very bad at cold start and seems to go away except for the misfire on cyl 2 once car gets to normal operating temperature.
3.)During warm up the car at low rpms gets VERY jerky but at higher rpms will not jerk but has a significant loss of power. Can only get to about 45-50mph
4.)When cold, only on occasion the car will POUR white smoke out of the exhaust, but only do it for about 4 or 5 mins of driving them it clears up.
5.)Throwing codes now for P0300 Multiper Cyl Misfire and P0301-P0306 for misfire on each specific cyl.
6.) Oil pressure spends alot of time at 7psi but them randomly will jump to 50psi when on gas and then down to 25psi off the gas, and when at idle will go back to 7psi.
7.)Coolant in reservoir tank is low, and it looks like chocolate mile and you can tell there is an oil film. When I add coolant to the tank, thats when the white smoke forms most when cold started after sitting for a while.
8.)The motor has NEVER overheated at all.
9.)Makes a whistling sound at idle but when I get on the gas it goes away. The whistling does not happen every time I drive it though.
10.)Car does not use up oil. It stays the same level on the dip stick.

Now before the misfiring got really bad there were no misfire code and all I got was P0204 and P0206 for fuel injector circuits. The coolant was still the same color.

So far this is what I have done to try to resolve any issues:

1.)Ignition coil
2.)Cap and Rotor
3.)Spark plug wire
4.)6 new fuel injectors
5.)New coolant temp sensor
6.)Valve cover gasket(gasket was shot and leaking oil)
7.)New cat. convertor
8.)New O2 sensors
9.)Throttle body gasket (tried to fix whistling)
10.) 3 cans of Mopar Combustion Chamber Cleaner
11.)New oil pressure sender sensor
12.)Used a node to check all the wiring for the fuel injectors and all is ok
13.)Checked spark plugs and all are fine. No carbon build up or fouled plugs and all gaps are in spec.


Only thing I can think of at this time is head gasket, cracked head, burnt valves, or maybe a piston ring or scortched cyl wall.

Anyone have any advise. Im not sure where to go next. Anything like this happen to anyone else before.

I do all the work myself so if you suggest it I can do it.

Thanks for your help in advance.

 

sounds like a blown head gasket tyhey can be blown but not blow the typical white smoke or have oil in coolant

 

yea u got a blown head in there sounds like! i wouldn't drive it anymore to prevent further damage. compression is almost lost.......

 

Yup sounds like a head gasket. Easy to do with a hayns manual and not to $ and with those miles a good idea anyway. Even if running good.