Novak Conversions Jeep Wrangler TJ radiator

New owner of 2000 TJ 4.0: What would be a good course of action with this engine?

QHolmes

New Member
Original poster
Joined
Jan 13, 2025
Messages
1
Location
Ontario Canada
Hello, I have been going through lots of posts here.. We just inherited a 2000 TJ from my late father in law. I unfortunately do not know the full history of the vehicle. He was going to give it to my son when he turned 16 and then he passed away a year ago.

My son just started driving it a few weeks ago. Loves it.. I think it has about 140km on it. The Jeep body is in good shape. not really any rust except on the front fenders that my father in law had replaced with new a few years ago.. not sure what happened there.

So far it seems that we have low oil pressure as the light comes on a lot (he had a piece of tape over the light) hehe.. and it uses coolant. So we had it safetied and they did an oil flush, new oil pump and new pressure sensor... still does he same thing for the oil pressure. It does not seem to make a lot of noise when the pressure is sitting at 0.. so that is strange. We are in Canada and its winter so the pressure is up when the engine is cold and then as it warms up it drops.

Next i remembered something about coolant and the Jeep and my father in law had a bunch of coolant bottles. So i got to watching the coolant levels. and they go down for sure. I am trying to understand just how fast it is going down. Its winter so no over heating issues. I do not see any leaks.

I assume the coolant is a head gasket or head.. I will work out what head it has. probably original.

The oil pressure... bearings maybe? not sure.

So my question is what would be a good course of action with this engine? I tinker with stuff and do all my own renovations etc. but not really into vehicles. Do i ask around about someone rebuilding it for me? What kind of rebuild would cover these symptoms?

Thanks for any help people are willing to give.
 
I'd get a mechanical gauge and check oil pressure and verify it's consistent with the dash gauge. The oil pressure sensor that typically functions is a Mopar. Most folks that use part store brands have issues.

Then I'd do a combustion gas test. Sounds like that one's pretty much a given that you've got coolant in the oil.

Next up I'd drop the oil pan, take off the girdle and pull a main bearing cap and take a look at the bearing condition and note the numbers down. Good to look up if it's a factory size or if the cranks been messed with.

If the bearings look fine then I'd do as @Zorba suggested and check the casting on the head, possibly replace the head but I'd probably slap a Felpro head gasket kit in. They're pretty quick and easy to do. You'll spend more time getting the exhaust apart.

Might want to do a compression and leak down test.

All this will tell you if it's worth spending time on this engine, getting it rebuilt completely or what you do next.

-Mac
 
Novak Conversions Jeep Wrangler TJ radiator