2000 4.0L high rpm and loud upon start up

Hello everyone

This is my first online forum so please bare with me.

I have a 2000 JEEP Grand Cherokee 4.0L. I bought the car from a nurse who obviously had a very busy lifestyle and couldn’t properly care for the car anymore.

When I bought the car it would turn over just fine but had a very very faint engine tick to it. It had low oil pressure light (0-10 psi) whenever stopped at a light after the car was on the road for over 15-20 mins.

I didn’t notice any difference in performance while this was happening and made a poor choice to ignore it for approximately 2 years with 10-W30 royal purple oil changes every 3,000 miles.

One day when I was leaving work the car just couldn’t go on any longer. I got about a 1 mile from my job, noticing that the low oil pressure light was activated upon start up now and sounded pretty rough. I drove up this steep hill and the truck just lacked power. I was pushing the gas was close to the floor and it just clunked out so I pulled over. I was working over time at the job and was late for an oil change that week. I went to the store filled it with 2 quarts of oil from the station. I had it towed and parked it at my parents house for 3 and a half years.

I developed an interest in cars recently and started using this truck as a project car. With the little knowledge I acquired from reading and watching YouTube, I immediately blamed the head gasket for the issues so I ripped apart the engine bay finding a massive amount of sludge in the valve train and taking off the cylinder head (out of sequence smh... ) to replace the head gasket with a new one from 1Aauto. The sludge made me question the oil pump and the oil pan so I removed both (a massive pool of sludge at the bottom of the pan) and replaced the oil pump with a new one from 1Aauto.

I put everything back together with all new gaskets (oil pan, head, valve cover gasket, intake manifold gasket, exhaust manifold gasket) and in proper torque spec and sequence. I did not do any machining to the head or block because the car never overheated and this was just a project anyways. I also cleaned the head using 4 or 5 cans of brake cleaner and cleaned all the sludge from the lifters and the valley (cam seemed nice and smooth).

With everything put back together and fluids topped off. I charged the battery and attempted to start the car. It wasn’t pretty. The engine seemed as if it was redlining a start up and it was loud as hell!! (the missing exhaust flange bolt probably didn’t help the cause)

Scared half to death, I turned it off but noticed it had a check engine light on. I can’t remember the code (Sorry about that) but I know it was some sort of transmission sensor.


I would love to use this truck as a budget beater for my lawn care service until I can replace the engine someday. If you guys give me a clue I would really appreciate it.

 

Welcome @TJGC ....you’ve done a lot. Scan for the CEL code at local Advance auto/Autozone

 

You have a vacuum leak on the intake.