I will be tackling the head replacement in the coming weeks and have a few questions I couldn't quite find answers to in my search. I bought this vehicle with the cracked head (fail) and am unsure how many miles the issue has been occurring for.


Issue and Contemplation: Engine has 89k I don't think this has been going on for a very long time because inside the valve cover doesn't seem to be too gunked up nor any on the dipstick. After a fair amount of research some folks say to just do cam bearings because they are likely shot. This seems to be correlated to oil pressure and my oil pressure appears to be OK exception being the start pressure build being a little laggy
Most point to the oil filter for this issue which is a "Carquest R85085" The oil (and coolant) has about 3k on it now. I'm really not in any position to do these bearings and am not planning on doing them.

I also don't appear to have any ticking or knocking. Just a bit of a rough idle (code P1294 - Idle Speed Performance) Clearwater guy on the phone recommended maybe replacing the lifters (cue new lifters/old cam debate) and replacing the water pump.

Brass Tax: I am thinking of foregoing the lifter replacement and avoiding bearings altogether. Unless y'all think it's OK to put some cheapo lifters in there talking like $5 a pop. Thoughts? I've also been told to make sure the block is clean and flat. How do I do measure the flatness? Ordering a water pump to throw in while it's off. New Head Bolts, New Exhaust Bolts, New Fel-Pro Gasket Kit HS9076PT4.

My current situation is that I cannot replace this head for at least 2-3 weeks. In that time I will probably run the engine for about 150 miles. Should I change the oil before the head change?

 

Pressure looks fine to me. Where is it while driving?

 

If it's warm weather, I think that that oil pressure at start is fine. Spec is min. 13psi at hot idle - 75psi. I'd worry if the pressure was not right while driving and at hot idle.

If you have coolant in your oil and have no other options but to drive, I'd change the oil now and again after doing the head replacement... well, I just wouldn't drive it, but if you have zero choice then keeping the oil as coolant free as possible is your goal.

 

I'd check the IAC for the idle, per the standard diagnostic recommendation. There's no reason to assume that everything is internal engine related just because you have a cracked head. If the IAC and TB are clean, then start considering other possibilities.

 

Yep, I have the IAC on my "most wanted" list pre-crack diagnosis. It will get it's 15 mins of fame I just wanted to include the idle in case it set off any red flags with more experienced minds. Much obliged

 

Thanks Pat, I guess I was referring to the guage not jumping to 40 but lagging and then slowly creeping up. If that's is normal tho then I feel a lot better =]

 

fb97 (prefer to be called something else?) - It runs about 35-50 while driving

*I should probably start using the quote reply for these short replies

 

35-50 seems right. The needle should be between the 20 and 60 mark - 20 side while idling, 60 side under load, the same in every Jeep I've driven (one was my DD for 14yrs/300k). As you mentioned re: the start-up, the oil filter may be involved if others have similar experiences. My 95 really likes the WIX filter which I could only find at a local independent parts store but is sold at Napa as a "Napa Gold".

 

Agreed. Pressure is fine, but I don't like that lag.

I really think you need to lose that shortie filter. The ONLY reason to use one is if your filter sticks out at a right angle to the block. If you have the right-angle adapter that runs the filter alongside the block, use the longer filter. WIX 51515, or better yet, if you can handle the price, the Wix 51459. Don't go cheap on oil filters!


WIX makes them for NAPA, also for Bosch. I get them on sale at NAPA or I buy them by the case on Amazon. My family vehicle uses the same filter, so I go through them a bit.

 

Thanks for that info, I will grab an adapter when I do the head swap.

 

Here's another good place to buy the Wix/Napa Gold filters in quantity, and cheaper than Amazon:


https://www.fleetfilter.com/filter/51515.html

 

Ah! There they are!

I had found that years ago and forgot to bookmark it. Thanks, Tbone!

 

Napa sometimes as often as twice a year runs their Gold filter sale. You can buy them at below cost. Last time they did this I stocked up and paid $3.90 each for the 1085's. Not sure what the 1515's would run.