I purchased a 2001 Jeep Cherokee 4x4 about two months ago and it’s been one issue after another. My new issues are the check engine light blinking and jeep bucking and running hard on acceleration. It will pick up speed once I come off the pedal a bit. I have changed boots and plugs, then replaced the coil pack. I was getting a Codes P0300, P0303, P0304 and also a P0455. My Dad and I did a compression test yesterday and the readings are Cyl1 175, Cyl2 180, Cyl3 75, Cyl4 75, Cyl 5 175, Cyl 6, 180, and I also put some oil in cylinders 3 and 4 and retested them, and they only increased by 10psi.

Can anyone please tell me what my next step is?

Thanks,

Lionel

 

I'd bet cracked head or blown head gasket. Usually cracks between 3 and 4. Check coolant for oil and oil for coolant and if there is any, you better hope you didn't ruin the rest of the engine with the driving you've done with it like that.

 

Thank you SatiricalHen. I will check the oil and coolant while praying I didnt make matters worse.

 

I checked the engine oil for coolant and found none. I also checked the fuel injectors with the engine started I unplugged 1 - 6. The engine made changes in all but 3 and 4. I did this about 5 times until I was sure that once unplugged injectors 3 and 4 caused no change.

Is there anything else I can test before I take her apart?

 

a leak-down test