Camshaft Bearing And Oil Pressure Issues

[DiscoDwayne]

:banghead: Okay guys and gals, this is a continuation of my previous thread. My previous thread is about my 03 Disco II's (4.6L w/ 56K miles) oil pressure light coming on at idle. We've changed the oil pump with a genuine pump and with a new oil pressure switch, but the light still comes on at idle.

I will save you the details of how the truck ended up at my local Land Rover dealer (I never take vehicles to anyone to work on), but I'll skip directly to my question. (I just want to throw it out there and see what you wrench heads come back with.)

The dealership is now telling me that the truck is losing pressure because a cam shaft (not crankshaft) bearing is bad. And they diagnosed this by pulling the oil pan. So, has anyone had to replace their block due to a bad camshaft bearing, because they were losing oil pressure? And does anyone know how someone could diagnose that a camshaft bearing is bad by just pulling the oil pan? I'm not a master mechanic, but I don't see how anyone could reach the conclusion of a bad camshaft bearing w/o physically removing the camshaft.

Thoughts and opinions please!!!!

I think the stealership is working their stealership vodoo magic.:banghead:

 

[jeffro0502]

This may have been asked previously....what weight oil are you using? I've always run Castrol 20-50W in every Rover I've owned. The only oil light issue I've ever had was right after I bought a 96 D1 and the oil light would flicker at idle before I had a chance to change the oil, when I got it home I changed it with K&N filter and 20-50W flicker disappeared! My 03 now with 70K on it only gets K&N oil filter and 20-50W, hopefully I'm good.

 

[DiscoDwayne]

I use genuine land rover filter and 5W-30 per the owner's manual.

I think I'm reclaming my truck from the stealership tomorrow and getting to the bottom of this issue with my own noggin.

Please keep the opinions flowing. I'd LOVE to hear what everyone's thoughts on this topic are.

 

[ptschram]

When I worked at Land Rover Portland, I worked with a guy who had every certification for every British vehicle you could imagine. He was adamant that in all his years of wrenching on Rovers, he had NEVER seen a camshaft bearing wear out. Gary Grey's wife, however, got a bad block from Tom Wood in Indianapolis that did not have the cam bearing oil galleries drilled correctly and it ate the engine in 2500 miles,so it is not completely unheard of for there to be manufacturing problems with those late blocks.

Have you put an aneroid gauge on it to tell you what the pressure really is?

 

[ciaops07]

As I mentioned in your last thread I am have a somewhat similar issue. My light is only coming after the oil gets hot and while I am sitting. I have ran 5w 30 castrol gtx since new with kn filters. When it came on the first time I changed the oil out with 5w30 again and added a quart of lucas. it was fine for 1500 miles but the the weather got hot again and it came on after a long commute. I changed the oil out again yesterday with 15w40 I haven't had a light yet so we will see.

I would try running a heavier oil with a k&n filter and just see what happens. I've looked for replacement blocks and motors and the options seem to be rather scarce.

 

[DiscoDwayne]

Have you put an aneroid gauge on it to tell you what the pressure really is?

Getting an actual oil pressure reading is my first order of business after I get the car back from the stealership. I am not allowing them to charge me for a short block because they mircaculously have determined that a camshaft bearing is worn (by only removing the oil pan).


Plus thanks for the information from your Rover mechanic friend. I really don't think this camshaft bearing diagnoses is correct/accurate. Knowing he's only encountered bad cam bearings once, and that was from the manufacture and it took it's toll on the engine at 2500 miles firms up my theory. Of course it's all theories until I can get the truck back and start wrenching on it myself.

Thanks again!

 

[DiscoDwayne]

I would try running a heavier oil with a k&n filter and just see what happens. I've looked for replacement blocks and motors and the options seem to be rather scarce.

Thanks again CIAOPS07! I'll give that a whirl. I just don't believe that there's anything wrong with the block. I'll run my own oil pressure test once I get the thing back from the stealership and go from there.

I will still keep you posted. Hopefully, a heavier weight oil is the easy fix.

 

[kyleduncan]

I've been dealing with some engine issues for a while now, and opted for a rebuilt one. Big problems with that one, and the individual sent me a replacement block. Both of these needed new cam bearings. They were worn enough, that the cam was stuck in the grooves of the bearings. So even in my limited experience, I've seen 2 blocks with bad cam bearings. Both of those blocks are claimed to be under 50,000 miles too.

Anyway, as far as diagnosing cam bearings after just pullng the pan, it would only be from process of elimination. They may have checked all the main bearings and rod bearings with plasti-guage, and found them to be satisfactory. But with just the pan off, they would not have been able to qualify the oil pump itself.

 

[kyleduncan]

Oh yeah, and if your cam bearings are bad, that doesn't mean you need a new block. If you are so inclined you can do what i did. I stripped the engine all the way down. Took the block, main bearing caps, and cam to my local engine machine shop. For $160 I got the engine back. He cleaned it, honed the cylinders, and supplied, installed, and honed new cam bearings. Very cheap. Especially over a new block!

 

[ptschram]

They were worn enough, that the cam was stuck in the grooves of the bearings.

When cam bearings wear, they become loose, not tight.:smilelol: I suspect you had something else wrong. Also, it is unlikely that cam bearings would wear and crank bearings not wear.

 

[pjkbrit]

Cam bearing wear is unlikely to say the least...and would not necesarily result in low oil pressure anyway. As other posters have written, use 15:40W oil or even 20:50W....10:30W is too thin for these IMHO esp. in summer temps without an oil cooler, (03s and 04s). Unless there is a lot of other mechanical noise, your new oil pump and higher viscosity oil should do the trick here. Also DEFINITELY get an oil pressure guage on this motor and see what the real numbers are...10-15psi idle hot is not untypical.
Good luck.

 

[kyleduncan]

When cam bearings wear, they become loose, not tight.:smilelol: I suspect you had something else wrong. Also, it is unlikely that cam bearings would wear and crank bearings not wear.

Laugh it up man. They wear very deap grooves into the bearing. The front journal has two surfaces on it. so it therefor wears two grooves leaving a band in the center of the bearing untouched. That, my friend, is what the cam gets stuck on.

I do agree with you about the bearing wear issue though. It seems that they should all wear fairly uniformly.

 

[ptschram]

Laugh it up man. They wear very deap grooves into the bearing. The front journal has two surfaces on it. so it therefor wears two grooves leaving a band in the center of the bearing untouched. That, my friend, is what the cam gets stuck on.

This is impossible unless it has seized. The cam starts out smaller than the bearing. The bearing wears even smaller. Unless the cam or the bearing has grown in size, this cannot happen.

 

[kyleduncan]

This is impossible unless it has seized. The cam starts out smaller than the bearing. The bearing wears even smaller. Unless the cam or the bearing has grown in size, this cannot happen.

I don't think you guys are following me. the front bearing is one piece. the front bearing surface on the cam is actually 2 narrow surfaces with a space between them. When the cam bearing wears, it obviously only wears where the cam is touching it. That leaves an un-worn band around the middle of the bearing. The cam is not permanently stuck, it is just hung up on that untouched area of the bearing. Enough so that I couldn't get the cam to slide out without putting the cam gear back on and giving it a good jerk. I guess I could have used a different word than stuck. Maybe that's where the confusion lays. Regarless though. 2 blocks, both with bad cam bearings. And everyone has to admit that worn cam bearings will effect oil pressure. I still have the bearings. I'll take a picture of that front one when I can, and post it here. It probably won't be til next week though.

 

[ptschram]

Kyle:
What you have experienced is not bearing wear, but crud building up in the space between the two portions of the bearing.

Again, you fail to realize that unless something had grown in size, it could not get stuck.

When bearings wear, the ID increases. When cams wear, the OD decreases. If the bearing had worn as badly as you claim, it would have gotten looser, not tighter.

Go back and study some more and come back when you understand these principles.

 

[kyleduncan]

Kyle:
What you have experienced is not bearing wear, but crud building up in the space between the two portions of the bearing.

Again, you fail to realize that unless something had grown in size, it could not get stuck.

When bearings wear, the ID increases. When cams wear, the OD decreases. If the bearing had worn as badly as you claim, it would have gotten looser, not tighter.

Go back and study some more and come back when you understand these principles.

Just wait for the pictures. I know what you're saying. And of course it is right on. I'm not a damn moron. The problem with the cam not wanting to slide out, is not because the cam bearings were too tight on the cam. I can't imagine anybody would ever think that ID of a shell type bearing would decrease with wear. The problem was the cam getting hung up on that untouched band along the center of the ID. If I was able to perfectly line up the cam with that untouched section, it would have slid right out with adsolutly no resistance. It was simply getting hung up on a step in the bearing. Again, I'm sure it will make total sense to everyone once they see a picture. For now, I just ask that you have a little bit of faith, and trust that I am not an absolute moron. Moron maybe. But not absolute moron.

 

[mkronmal]

Its not the bearing wear, just an issue of the weight of the cam with you unable to get any leverage to keep it 100% straight on both axis. It can be tough to get it just right, especially if you are leaving the AC condenser fans in place. It is important to not pull hard to get over any snags. All you are doing is damaging the edge of the bearing.

 

[kyleduncan]

Hey look! Here it is. A wore out cam bearing. And it has a band in the middle that is smaller in diameter than the used part. Creating a lip that the cam would get hung up on. Sorry I don't have a better camera. But this shows it pretty well. And I guarantee you that this would have dropped oil pressure. I don't know how much, but it would have done it. The other block I recieved has the same thing too. That's 2 block, both with worn cam bearings.

 

[ptschram]

Kyle:
I'm not going to argue with a person who apparently has little to no knowledge of how engines work and wear. Physically and mechanically, what you are trying to argue cannot occur, but what do I know?

I have 223K miles on the engine in my Discovery and it still returns acceptable oil pressure. You can have a huge amount of wear and still maintain acceptable oil pressure. The main reason for falling oil pressure in Rover engines is oil pump wear, not bearing wear.

 

[mkronmal]

Umm, looks normal to me. There is a groove on the cam that will not provide friction to smooth the bearing in the center.