Jeep Strokers

Here is what I am working with...

2000 XJ, had a cracked head.
Built a 1994 4.0L motor into a 4.6L
New everything except for block, head and valves. Bored .030 over, assembled per XJ Factory service manual, all clearances checked perfectly on bearings with plastigauge.

I finished my engine install today and cranked it up. It started right up and ran great, sounded great, etc... I have a manual Oil pressure gauge on it so I can monitor the pressure and make sure its all up to snuff. It was running around 6-8 psi and I was getting some rocker chatter from under the cover. I revved it up a little and the pressure came up a bit, but went right back down to the 6-8 range at idle. More chatter. I ran it for about a minute or so and decided it wasn't oiling properly and shut it down.

I checked for leaks, stewed around, drank a beer, etc... came back and started it up again. This time 0 psi. I shut it down immediately.

When the engine was still on the stand I ran the oil pump with my cordless drill and I got 15 psi or so. I figured it would be low because that drill does not have a lot of power. I pulled the Camshaft positioning sensor out and just ran the oil pump again but with a bigger drill. I was getting approx 25 psi.

I am now totally confused because of the erratic behavior. I wondered if my gauge was malfunctioning but that would not explain the rocker chatter. I looked inside of the rocker cover, doesnt look any different in there than when I assembled it, its just plain not oiling. For some reason the lifters and pushrods are not pumping up.

My immediate conclusion is that my oil pump is not pumping the volume that it should be. I have to believe that if a bearing was installed incorrectly or that an oil passage was blocked that my pressure would be higher than normal.

All oil galley plugs were installed and sealed.

Let me know what you guys think. I don't want to tear back into this thing without a good plan.

Check here first: http://www.jeepstrokers.com/forum/viewt ... =34&t=2671

i keep thinking on this issue and I think it has to be sucking air somewhere. After reading that write-up, I would bet good money on the oil pickup and the oil pump combo. I did notice some of the things that were listed on that writeup, the pickup was an SOB to install as well. Looks like I am pulling off the pan and investigating further. Theres nothing quite like doing all this stuff from underneath instead of on the stand! I have the pickup out of my 2000 engine, I will compare that one to my current one, but will most likely just end up buying a new one. I have a hard time believing that there isn't an O-ring or something in there to help it seal. Anyway, it does run so thats a big hurdle. I just need to get it so it won't turn into a knocking, solid paperweight in the process.

I would look at the bearings, or at least a couple rods and mains, to make sure you didn't hurt any bearings. Look up at the cam bearings to make sure they didn't start to wear and push out.

It could a big internal leak. When you are running the pump with the drill, the crank is stationary and some of the oils holes and oil passages aren't lined up, so you are getting some pressure. When the engine is running, oil passages are lining up with oil holes and you are loosing pressure.

Check the pickup tube to oil pan clearance. Maybe when running the oil pump with a drill, the oil pump isn't running fast enough to starve the pump. But when the engine is running, the oil pump is spinning much faster and can't pull enough oil.

Oh.. and don't forget to check the galley plug behind the cam gear.

SilverXJ wrote:Check here first: http://www.jeepstrokers.com/forum/viewt ... =34&t=2671

Good call. I was just thinking the same thing.

Had the same thing happen when I got my motor back from the shop and they´d put the timing cover on without installing the galley plug- by the way, starting it and running it with the galley plug out for even 30 seconds absolutely destroyed my cam bearings- I had to tear out the whole motor and start again. Hopefully you didn´t suffer the same fate, but have a look at the bearings while you have the pan off to make sure you don´t see bearing material oozing out...

That would really tick me off....

Well, I removed the oil pan this evening. What a treat that is while in the vehicle. I got all the bolts out in like 5 minutes and actually said, "this won't be bad at all". Then two hours later I finally got the pan off. For some reason they could not move the front axle like 1/4" further forward in order to drop the pan easier. What a PIA. I ended up disconnecting lower control arms, steering stabilizer, etc... I am wondering if I can use a ratchet strap to pull the whole front axle forward a little bit in order to make it a bit easier to install.

Anyway, I found something pretty interesting. I pulled the oil pump and the pickup tube was not seated all of the way into the pump. It was sticking out about 1/8" to 3/16". The little ring on the tube that is supposed to be seated right up against the pump was sticking out a little bit. I wonder if that could have led to my pump sucking air and it not sealing properly. Anyway, I will be doing a detailed comparison between the new pump and the original pump. Hopefully I find something definitive.

I wasnt going to be able to sleep after reading that previous post. I had to go out and check the cam bearings. It all looks good. No metal material oozing out form any of the bearings. All my end plays were in tolerance. I think I am alright. I am hoping its just the oil pump thats messing with the pressure.

DoubleOXJ wrote:I wasnt going to be able to sleep after reading that previous post. I had to go out and check the cam bearings. It all looks good. No metal material oozing out form any of the bearings. All my end plays were in tolerance. I think I am alright. I am hoping its just the oil pump thats messing with the pressure.

That´s good news-

Now, make sure you hook up the mech. gauge and prime the pump with a drill before you try starting it again, verify that you are building 65+ psi- Prime for a min, rotate crankshaft 90 degrees with a 3/4" socket and breaker bar, prime for a min, rotate crankshaft 90 degrees, and so on and so forth, verify pressure holds and if you want, you may even pull the valve cover to verify lifters are pumping up. Then button her up and start her up, and break in the cam.

MYSTERY SOLVED:

I pulled the pan last night. Warranteed my pump today just in case. Took the original pump that came off the 94 block and re-installed it into my Stroker. I held a jug of oil up to the pickup and had my wife run the drill. Oil came pouring out of the timin cover. I have a missing gallery plug. Either it fell out, which is highly unlikely. Or I never installed it, which is far more likely. Anyway. I have the front of the engine all torn down and will install the plug and re-assemble tomorrow. I'm just glad I caught it before it wreaked total havoc on my new engine. Thanks for all the help guys! That's why I come here!!

DoubleOXJ wrote:MYSTERY SOLVED:

I pulled the pan last night. Warranteed my pump today just in case. Took the original pump that came off the 94 block and re-installed it into my Stroker. I held a jug of oil up to the pickup and had my wife run the drill. Oil came pouring out of the timin cover. I have a missing gallery plug. Either it fell out, which is highly unlikely. Or I never installed it, which is far more likely. Anyway. I have the front of the engine all torn down and will install the plug and re-assemble tomorrow. I'm just glad I caught it before it wreaked total havoc on my new engine. Thanks for all the help guys! That's why I come here!!

Exactly how I diagnosed my missing galley plug- good job. Glad to hear the cam bearings were spared.

How frustrating, and this was assembled at a shop?

The block was machined, cooked, etc... at a shop. I did the assembly. I guess it was ultimately my responsibility to check that it was in. Not real sure how I missed it. The thing that has me stumped is that the gallery and freeze plug kit I received only had 3 threaded pipe plugs in it. There are 4 required for this engine. One on the front, one on the back, two on the side. I also have 2 extra press in freeze plugs with this kit that I couldnt find a place for them. THey are about 3/4" diameter. I am guessing they are for a different vintage block. Anyway, I picked up a new gallery plug and now am in the reassembly phase.

I am glad that my cam bearings were spared as well!