Low oil pressure

[williambmac]

What year is your tj

 

[TimSA]

What year is your tj

It's a 2000 model

 

[TimSA]

Good call checking the passage might be blocked. Checked everywhere else and there was little to no sludge, even on the sieve in the oil pump. Doesn't use much coolant, replaced the radiator about 1000miles ago..

No noise but does get hot!

 

[Rubicon88]

No noise but does get hot!

How hot?

And what is with doesn't use much coolant. It shouldn't use any coolant.

Where are you losing coolant at?

Any sound of rat a tat tat tat?

 

[williambmac]

your tj has the dreaded 0331 head casting. They are known for cracking and leaking small amount of coolant into the engine which in turn eats the bearings, usually resulting in low oil pressure.
You said that you loose coolant, I would remove the valve cover and inspect for a crack.

take a look at this thread, remove the valve cover and inspect for a crack. Look at the pics in post #10.

https://wranglertjforum.com/threads/no-oil-to-the-cylinder-head.41472/

 

[TimSA]

How hot?

And what is with doesn't use much coolant. It shouldn't use any coolant.

Where are you losing coolant at?

Any sound of rat a tat tat tat?

There is a few exhaust noises l, no rat a tat tat haha

Haven't needed to top up coolant in months so that's fine.

 

[TimSA]

There is a few exhaust noises l, no rat a tat tat haha

Haven't needed to top up coolant in months so that's fine.

Very hot actually! Although heat temp not ever showing hot so definitely oil related cooling

 

[Lou]

I’m confused. Is the engine overheating or not? How do you know it’s too hot? Engines get hot.

 

[Rubicon88]

Very hot actually! Although heat temp not ever showing hot so definitely oil related cooling

Huh?

The gauge isn't showing but you're very hot?

 

[TimSA]

I’m confused. Is the engine overheating or not? How do you know it’s too hot? Engines get hot.

Haha yeah but hotter than usual in a shorter time than usual. When you pop the hood you can feel it is very hot. Only drove it once to that level

 

[TimSA]

your tj has the dreaded 0331 head casting. They are known for cracking and leaking small amount of coolant into the engine which in turn eats the bearings, usually resulting in low oil pressure.
You said that you loose coolant, I would remove the valve cover and inspect for a crack.

take a look at this thread, remove the valve cover and inspect for a crack. Look at the pics in post #10.

https://wranglertjforum.com/threads/no-oil-to-the-cylinder-head.41472/

Thanks so much will investigate this!

 

[TimSA]

Definitely some coolant leaking into the engine

 

[mattmass]

Yep it will drop right down to 0 and check guages light will come on. If you rev a little or drive, as I had to it goes up a bit and light goes off but as soon as you stop or idle it will come back on.

I have the exact same situation with my 2004 LJ

 

[sublime2471]

I’m not a expert on Jeep’s 4.0 but I’ve rebuilt a few engines, if he replaces the cracked head could he roll in a set of new bearings if the crank looks alright?