Carry on Reverend.

 

Yeah, that's fine. However, get the facts straight before you give someone false hope.

FYI, my lawnmower engine remark was correct in the context of your post. Some small engines like them do rely on splash lubrication. But not car engines.

I think it is wrong, and bad, advice to tell someone they can drive around for a while with no oil pressure.

 

So it does make sense to take the head to get checked out at a shop?

 

No, that was already talked about earlier in this thread.

You need to first determine WHY you have no oil pressure. You said that you replaced the pump before this happened. If you want to remove something, remove the distributor as you were directed to earlier and spin up the oil pump with a drill. Turn the Jeep to "on" and have someone watch the oil pressure gauge. See if it indicates pressure or not.

I'm not real familiar with the exact arrangement of a 4.0, but I have worked on plenty of 200 and 289/302 CID Ford engines. If they do what yours did, the first thing to suspect would be to make sure the oil pump drive shaft did not snap in two. In fact, this actually happened to my mother on a '71 Mark III Lincoln 460 about 1978. The oil pump could have locked up first and then the shaft broke, I don't know. In any case, she drove it with no oil pressure and burned it up.

Back to your Jeep, you are going to have to pull the pan sooner or later and find out what happened down there. You could have mis-assembled something when you put it back together the first time. In fact, I'm wondering why you replaced the pump in the first place. They normally last the life of the engine, and then some.

My firm advice at this point is to leave the top end intact. That's not where your primary problem is.

 

It wouldn't hurt anything, but could turn out to be some wasted time and money. Or it might even turn out to have problems after all that you might not have known about. Kinda a 50/50 shot....If peace of mind is what you'd prefer, then by all means, take it in.

I agree with Firestorm though, it's not where your primary issue is. Find out why it lost pressure, THEN think about what else it possibly could've affected. I know even just running the engine with no pressure is a no-no, let alone driving three miles....For the time being, I'd just hope the residual oil in the head lubed the cam long enough to prevent serious damage and take care of the main problem.

 

Rog. I'll keep you helpful gentleman posted.

 

TwoXJs means well, but oil does not stay in the head.

In any case, camshaft bearings are pressure lubed, as was correctly stated earlier. Remember, oil does not only lubricate, it is equally important that it carry heat away from moving parts that tend to have very close tolerances.

 

I've changed rod bearing inserts before on engines, only because I could reach them, they are supper cheap, and often the first thing to fail.
These linlks explain how to use Plastigauge, for those following that might not be familiar with it.
You could check your clearance on a couple rods, take that from there. > http://en.wikipedia.org/wiki/Plastigauge
http://www.plastigaugeusa.com/how.html

 

Zero oil pressure all of a sudden points to something other than rod bearings at this time for the OP.

 

Oh....Well, thanks for that clarification! I didn't realize it flowed back down....Which now that I think about, makes sense since the oil is filled through the valve cover.

 

I think DFlintstone meant that they would be the first thing to fail after running it with zero pressure. I'm confused about all this talk about the cylinder head. Shouldn't inspecting your oil pump and bearings be your first priority?

 

I figured it went without saying that you need oil pressure.

 

YES and everyone needs to stop jumping to conclusions and saying his engine is toast. He suddenly lost ALL oil pressure....that is what the focus should be on. If the cause is a bad pump/drive he needs to address that first. 2 to 3 miles ain't nothing. I seen a dirt track racer go 9 laps and win after busting his oil pan and losing pressure!

 

Uh huh. And how many feet in a lap? On that track?

His engine was slag when he crossed that line. Race engines are built loose anyway to allow for thermal expansion at high RPMS and WOT. They expect to have to rebuild them all the time, sometimes after each race or two.

BTW, everyone is not jumping to conclusions about a ruined engine. But there is no residual oil stored up in the crank or bearings that would keep him from harm, as you seem to claim and believe in earlier posts.

I have already said a couple of times earlier that he needs to do some more investigating to see what really has happened.

 

An interesting read http://blog.oregonlive.com/complaint...enrys_you.html