94XjSport94

My endorsement. Congrats dude!

My 4.slow only has 208k on it.

I just rebuilt the top half, rod bearings, rings, and all the seals at 207k though. I had a lot of oil burning and a blow by issue. I changed from using the Wix 51515 filter to another wix filter in Salad's thread that supposedly had the same flow and bypass ratings, but as soon as I did the oil and filter change the next morning I drove to go wheeling and when I got there there was a pretty big cloud of blue smoke behind me all day. Wasn't like that before and it didnt go away by changing filters back to a 51515 afterwards. Now I am at about 500 miles after the rebuild and am due for another oil change. I'll be going back to my mobil1 10w-30 synthetic.

fritzthekatt

With your top half rebuild did you gain back any power you felt you lost? How's your oil pressure holding up?

dukie564

go 5w-30. No reason to make the engine work harder then it needs to when it's cold.

nowhres

I wants 0w-30

sycoglitch

:P but people say to use 15-40 to build pressure BwahahHh,

I kid, i kid lol

94XjSport94

Oh yeah. I could tell a difference in power. Granted my Jeep was a slug beforehand on 4.56's and 35's, but now it is slightly less of a slug. Runs great and based on the oil pressure gauge on the dash is holds pretty high, like a little under 40 then up to about 60 or so when he RPM's go up. My gauge has always been a little funky like that though, it hasn't ever gone as low as I have seen others run at so I don't know how accurate it is nor have I ever checked it for validity. Still chasing a high idle in park and neutral though.

I am not sure what to put back in it yet as far as keep running conventional or go ahead and go back to synthetic. It has 5w-30 in it now. I might keep running that for a while. Even when it is cold here it doesn't get cold. During the coldest time of winter we might see single digits a few times a year. I know you didn't mean weather cold lol. I always worry about the cooling system when it gets cold and busting my block.

fritzthekatt

Yep mines a slug but instead of burning oil I can't keep pressure and I eat coolant. Do you have a parts list you could send over?

94XjSport94

I could make one. I think a lot of my restored power came from the new rings. Mine were worn pretty well but the cylinder walls were still in great shape. I rented a compression tester back in March and my compression was **** poor. I can't remember the numbers, but it was terrible and a wet compression test yielded that the rings were in bad shape. I haven't done a test yet but I could tell a big difference turning the crank when it was on the stand.

My valves and seats were pitted so I sent it to a local machine shop and they cleaned the head, did a nice valve job, replaced all the springs, valves, and seals. I bought the parts before hand but I didn't like how the seats looked and I wanted it clean so it was easier for them to do it that for me to take another day on it. They also said it was slightly warped and they milled it down so I got my moneys worth out of the $200 something I spent there.

They also removed a broken manifold bolt in the bottom rear of the head and put a helicoil in. That temperature sensor in the back of the head on the early model ones is a PITA to get to without sitting on the damn engine once it is in the Jeep. I broke the stock one removing the engine, I got a bad one from O reilly, I broke the replacement one they gave me, then I said F it and got an aftermarket gauge with an aftermarket sender without the plastic clip at the top.

With synthetic oil the last 40k I had 0 sludge and the oil pump screen looked mint.

nowhres

Speaking of mileage, caught this earlier on red XJ, 123456.7 miles

my89xj

That's awesome

I've been running 15-40 Rotella and a mopar filter in the zj since I've gotten it when I opened it up for the head gasket it was extremely clean and healthy in there.

And I will say, after having my head milled the zj runs amazing. I'm pretty sure the head gasket had been leaking for a very long time.

dukie564

receptionist just said a 3' x 1' x 1" thick box just came that weighs 40lbs. I'm going to guess that my bumper kit has arrived, and that dirtbound is really good at packaging stuff lol

NewKindOfClown

Mileage?

Uhh...I'm shopping for a third 4.0L

94XjSport94

Have you ever thought about taking care of a vehicle?

Lol. Fix that ****.

NewKindOfClown

Have you ever heard of previous owners and preexisting problems?

94XjSport94

No. What does that mean?