The fallacy in your first premise is that coolant is heavier than oil. More dense. Therefore, pressure would rise because pressure is resistance to flow.

 

exactly what he said

 

True. Glycol & Oil = higher viscosity

 

Glycol + Oil = Ruined engine

 

My engine does have a strange tick that I haven't been able to put my finger on but it is not loud. Been running that way for thousands of miles though.

I think I am going to go with a cylinder head from clearwater and swap it in. Hopefully any bearing or other internal damage will take a while to manifest. This is really the only option I can afford as well. Somewhere down the road if and when I ever have some money I can rebuild or maybe pull one from a junkyard and do everything I want to it while still having my DD.

Unless anybody wants to buy a 2001 XJ with a cracked cylinder head haha.

 

Hmmm...I was thinking (I see now improperly) that while oil weighed less than water it was less likely to be spatially condensed under pressure and that is why oils is used in hydraulic lines like brakes and jacks. I see where that would make it more dense and would then sink in water, not float.

sorry

 

Oh, there are PLENTY of those available!

 

In addition, a fluid is non-compressible.

The oil is used in hydraulic lines because it doesn't promote rust, and its freezing point is below that of water.

 

Go ahead and get the junkyard engine if you can't totally rebuild yours now. The internal damage has already manifested itself in your low oil pressure.

It might be easier to do a complete engine swap than to replace the head. You have to buy the fluids anyway.

 

Pulling the whole engine would be difficult for me though as I don't own an engine crane. I am also afraid of getting a junkyard engine with no warranty and who knows what kind of problems. My oil pressure is right at about 10-13 at hot idle so I'm hoping that things will last at least another few thousand miles. I still plan to get my oil tested and if those results return some insanely high levels for iron then I'll have a better idea of how soon it should be addressed.

I have faith in the Cherokee to take a beating and keep running. She ran over 4,000 miles this summer with no complaints and I'm fairly sure this problem existed then (I know, that could also be looked at as a bad thing).

 

Man, the paint on that valve cover is nicer than the paint on anything I own. lol

 

If that is the only option your budget allows go for it. If it makes you feel any better mine had only 4psi and I made the decision to keep driving until it started knocking. That was almost 40k miles ago and I am still driving with 4psi and no noise,so it is now a quest to see how far it will go.

 

4 PSI at idle or 4 PSI at highway speeds?

 

4psi @ 650, 20psi @ highway speeds. Slight tick at hot idle but has not increased in intensity in the past 2 years. Burns no oil,runs great,18mpg. Salvage 2000 in a 2004 GC, motor mileage unknown.

 

I have a much Better way to Secure a Coil Rail on a pre 0331 head(With out bosses). I just did this to the 1992 7120 head im putting on my 2000 block. I Will get pics on here soon. Basically, you Drill and then Tap threads directly into the head where the bolts would usually go. If you were to Drill too far, its alright(though no need to drill more than 1/2")because whats behind are the head bolts. You can use a Longer bolt or cut coulplers