Newly rebuilt top end, no oil to lifters: what would you do?

Just got back from the mechanic, he says oil pump is giving plenty of pressure, though he wishes it were a little higher at the oil sending unit (put a gauge on it to test). He suspects bearings around the camshaft are worn, which he says can cause loss of pressure higher in the engine. I don't know much about the oil pressure dependencies of a 2.5l engine, can anyone confirm is that sounds reasonable?
 
Yes, but... that's taking the engine out. I'd start with rolling in new rod and crank bearings, replacing the oil pump and I'd replace the timing belt and pulleys...new crank pulley... shouldn't be too expensive...and easy enough to do on your back under the Jeep.

-Mac
 
Is there a good write-up of this process?

I've seen good videos of the process from DeXJs and Junkyard Digs.

It's fairly simple to do...pull the pan and girdle, loosen up the bearing caps...pull some out, look for stamped numbers and get the right sizes and the correct range of plastigauge.

-Mac
 
Just got back from the mechanic, he says oil pump is giving plenty of pressure, though he wishes it were a little higher at the oil sending unit (put a gauge on it to test). He suspects bearings around the camshaft are worn, which he says can cause loss of pressure higher in the engine. I don't know much about the oil pressure dependencies of a 2.5l engine, can anyone confirm is that sounds reasonable?

Does oil come out of the pushrod holes when the oil pump is primed? The valve cover and distributor need to be removed for this.

The shops premises about worn bearings is possible. If you had coolant in your oil from the blown head gasket it would attack your bearings
 
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Just got back from the mechanic, he says oil pump is giving plenty of pressure, though he wishes it were a little higher at the oil sending unit (put a gauge on it to test). He suspects bearings around the camshaft are worn, which he says can cause loss of pressure higher in the engine. I don't know much about the oil pressure dependencies of a 2.5l engine, can anyone confirm is that sounds reasonable?

Worn bearings reduce oil pressure. Rods, mains, cam bearings would all effect oil pressure similarly if badly worn. Sounds like bs that cam bearing wear would affect top end pressure more than other bearings.

I have to say it seems you are probably dumping money into a trashed engine. And your "mechanic" is just helping you throw money at it.
 
An even more important consideration is this. If your bearings are so trashed that no oil is getting to your valve train, expect the following:

Trashed cam and lifters.
Possibly galled valves/guides
Grooved crank/rod journals
Other damage from oil starvation

At this point, I don't think I would be paying your shop more money to try and salvage this engine. And you'll never know if most of the damage occurred before the work you had done or because of it.
 
Does oil come out of the pushrod holes when the oil pump is primed? The valve cover and distributor need to be removed for this.

The shops premises about worn bearings is possible. If you had coolant in your oil from the blown head gasket it would attack your bearings

There was coolant in the oil from the blown head gasket, and the jeep sat for probably 6 months before it went to the shop, so this seems plausible.

I should know more next week, but now the decision appears to be approaching whether I rebuild this engine, or get a reman from Titan Engines (I live about an hour away from them so can avoid shipping costs) and just drop in a remanufactured engine.

It seems like a very doable job dropping in a replacement engine, especially since my setup doesn't have an AC, radiator already changed to electric fan radiator, already familiar with removing all manifolds, brackets, pumps and everything besides distributor and oil pump. I've got access to an engine crane. Biggest unknown for me is I've never separated a transmission (mine has the AX5).
 
Transmission is easy.

I'd pull the transfer case. Disconnect the front fenders and let them drape/dangle to the sides...way to much stuff to disconnect...remove the front grill...lot easier to pull an engine and transmission without the grill/radiator in the way.

And it's a lot easier lining up the splines on the transmission with the engine out of the Jeep.

-Mac
 
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Transmission is easy.

I'd pull the transfer case. Disconnect the front fenders and let them drape/dangle to the sides...way to much stuff to disconnect...remove the front grill...lot easier to pull an engine and transmission without the grill/radiator in the way.

And it's a lot easier lining up the splines on the transmission with the engine out of the Jeep.

-Mac

Are you saying pull both engine and transmission and hook them up together outside of the jeep, then reinstall both?
 
Transmission is easy.

I'd pull the transfer case. Disconnect the front fenders and let them drape/dangle to the sides...way to much stuff to disconnect...remove the front grill...lot easier to pull an engine and transmission without the grill/radiator in the way.

And it's a lot easier lining up the splines on the transmission with the engine out of the Jeep.

-Mac

That is a lot of unnecessary work. Especially with a 4 cylinder.

Remove radiator so it doesn't get damaged sure,but I easily swapped the larger 6 leaving sheet metal and trans in place.

-Rotate the tcase output if needed to get the transmission input shaft splines to line up.

-wiggle things into place,never use the bellhousing bolts to get the motor and trans to pull together.
 
I agree with @Rickyd that it's more work...I've just had and seen a lot of folks struggling with getting an engine and manual transmission lined up in a vehicle.

You can always give it a shot and fall back to the harder method!

-Mac
 
Welp, got the call from the mechanic this afternoon and it was great news! They ended up pulling the pan, verifying the oil pump and pressure, checked the cam bearings and they are within spec albeit old. They ended up pulling the head back off and replacing the lifters and now she sounds like a sewing machine!

I provided the lifters and he warrantied them with his supplier anyway, I only paid a couple hours of labor, couldn’t be happier especially since now I know the cam bearings are in decent shape.

I just got done driving it back to the house and it drives better than it has since I’ve owned it. I’ll follow up with a video of it tomorrow so you can hear the difference. Cheers!