Oil Pump Failure On A 4.6 Again !

[MUSKYMAN]

I have heard of MANY folks doing so and it alleviated oil-flow related noise problems.

I think the clamping force is generated by the screws, not the dowels.

yes for sure the clamping force is from the bolts, but what I am talking about is locating it.

Once again I am just guessing here I havent seen it or tried it but my gut says they would leak at some point. Maybe if you forwent the gasket and used right stuff?

hydraulic forces are crazy things and there is no doubt that cold oil will be exerting some crazy side forces on that front cover.

 

[MontrealRR90]

Here, also I'm out of VIN range...

Im talking with a changed oil pump ? have you changed yours ?

 

[SSped]

It all depends on the problem inside the motor causing oil pressure loss. the front cover problem is not a clamping force problem but alignment of the pump on the crank shaft. if the pump came apart you might get away temporarily with a new one. (you would have no oil pressure even off idle though) most of the time the crank or cam bearings are the problem and need to be replaced. this still does not negate the fact that the motor is not machined properly but can buy you time.

I put a new cover on mine and it still has no oil pressure at idle. The old pump was intact when i took it off and inspected it.

The end result is that it needs a motor.

I have seen them fail at 7000 miles on the 1st oil change.

 

[MontrealRR90]

It all depends on the problem inside the motor causing oil pressure loss. the front cover problem is not a clamping force problem but alignment of the pump on the crank shaft. if the pump came apart you might get away temporarily with a new one. (you would have no oil pressure even off idle though) most of the time the crank or cam bearings are the problem and need to be replaced. this still does not negate the fact that the motor is not machined properly but can buy you time.

I put a new cover on mine and it still has no oil pressure at idle. The old pump was intact when i took it off and inspected it.

The end result is that it needs a motor.

I have seen them fail at 7000 miles on the 1st oil change.

interesting info. I will probably go with a 4.6 from a RR instead of trying a new cover then. Do you work for a dealer ?

 

[SSped]

Yah, I am at a dealer. Been here for almost 9 years.

I have a 2004 that came in today with no oil pressure so this is not just a 2003 problem. The engine i am swapping out of my own truck lasted 100,000 miles and the pump is in tact. that tells me that this is not just a pump alignment issue. I am going to rebuild the engine I am taking out and put good quality bearings in it. That way I will have another engine ready to go for next time.

I think a used Rover engine is the way to go. they hold up really well.

 

[pdxrovermech]

last one i did with oil pressure problems actually turned out to have a the outer gear broke in half. Wasnt noisy and didnt cause any damage. Probably not your situation, but I had never seen that before, so i just thought i'd post it.

 

[roverMc]

So is there engines still running and after hoe many miles tks

Mine's in the VIN range with 140K on it. Fingers still crossed!

 

[Big Papa]

Im talking with a changed oil pump ? have you changed yours ?

No I haven't...

 

[lforgue8]

most of the time the crank or cam bearings are the problem and need to be replaced.

as far as oil pump failures of 03's the problem IS the pump and alignment...not bearings they are only secondary failures from metal bits int the oil.

musky i kind of agree with you but have never thought of it though that cold oil would create some big hyd forces for sure.

 

[gardrover]

http://www.discoweb.org/forums/showthread.php?t=55265

this thread should be more accessible

 

[turbodave]

I was wondering if anyone would remember that post!

 

[Blaewen Draca]

I replaced just the oil pump gears in my front cover back in August. Put about 5k miles on it since then. I don't have an oil pressure gauge, but my oil pressure warning light has not come on since I replaced my pressure sending unit. When I found my broken gears, they were broken but hadn't actually separated, so my engine was fine.

 

[RVRSRVC]

What was the specific problem in machining? Was it that the dowel holes were drilled at an angle or the cover holes and the block holes aren't quite aligned? Or something else?
And I've seen several failures out of VIN range.

 

[jymmiejamz]

Mine's in the VIN range with 140K on it. Fingers still crossed!

Did you buy your truck new? If not, it was probably already replaced once under warranty

 

[ptschram]

What was the specific problem in machining? Was it that the dowel holes were drilled at an angle or the cover holes and the block holes aren't quite aligned? Or something else?
And I've seen several failures out of VIN range.

Tooling wear resulting in wander of holes.

The one I dealt with had tremendous oil pressure once it started, at start-up, it made a horrible noise, but as soon as it got going, it was fine and was driveable.

I could not believe the damage that was done to the crankshaft, it's so bad that it can't be ground for use, even with the smaller journal bearings and might not have enough meat to turn it to accept Honda bearings on SBC-style rods.

The cam that was put in 700 miles earlier is running fine in another truck.

I have pulled several front covers and been shocked to find no dowels whatsoever!

 

[MontrealRR90]

Did you buy your truck new? If not, it was probably already replaced once under warranty

Did they eventually replace them with corrected engines at least ? or its like the abs modulator replaced with the same problem

 

[ptschram]

Did they eventually replace them with corrected engines at least ? or its like the abs modulator replaced with the same problem

There were claims that when the machinery was sold, some of it bore tags indicating the machinery had come out of GM's R&D lab and had dates of late 1950. Much of the tooling was also that old. When the problem was identified, supposedly, Rover made some tooling changes to regain control over the process and later engines were supposed to not be plagued by the same problems.

It's all supposition though as few know the truth and they aren't talking.

 

[jymmiejamz]

Did they eventually replace them with corrected engines at least ? or its like the abs modulator replaced with the same problem

Well just based on the fact that the majority, I know not all, of the failures were in a specific VIN range I'd say that they did correct the problem at the manufacturing level.

 

[Ppaulred96]

I am running a old 4.6 block that had blow an oil pump. When my 4.0 #5 liner went I used a 4.6 block that had a blown oil pump. I removed the dowel pins. I converted the block to a GEMs button for the crank Sensor. I re-used the 4.6 crank and rods from that block (new bearings) - I used my old 4.0 pistons and put them on the 4.6 rods, also installed a new 4.6 cam & lifters (lower budget HP rebuilt). I think I have just about 30,000 miles on the rebuild. No leaks or issues at least until I make this post and the gods get even with me for my past good fortune. I used Hi Temp GM orange gasket seal on the front cover - - everything was super clean and GM orange is good stuff IMO - - several friends argued the value of the right stuff - - but I used GM orange. Thus far I have No leaks and it still runs strong. I've been in the rev limitor several times and I think the motor is fully tested by this point. I think it is important to line everything up carefully if you do remove the pins. In my case I felt if I did not remove the pins I would trash the oil pump. I can say I've done it (removed the aglinment pins for the front cover) and it has worked out and held up for a couple of years.

 

[ptschram]

I re-used the 4.6 crank and rods from that block (new bearings) - I used my old 4.0 pistons and put them on the 4.6 rods,

WHY?