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Close up pics of main bearings C20XE
stevegough - 4/9/11 at 07:08 PM

OK, getting close to pulling my hair out with this problem.......

......following on from...THIS thread......

I have dropped the sump, and have taken out the no.2 main bearing cap as suggested by fellow LCBs (franky, perksy and laptopprob)...

.....I am no engineer, mechanic, etc, but to my untrained eye, the bearing doesn't look at all worn.

What would you say? - also, just a quick question.....when I refit it ( it only fits one way round) am I supposed to use new bolts? - 'cause I haven't got any!







franky - 4/9/11 at 07:18 PM

can you feel anything with your fingernail when you drag it across?

It looks ok from here although its hard to tell, you can see in the pic of mine one thats perfect against ones that are worn.

mookaloid - 4/9/11 at 07:22 PM

They look a bit less than new to me. they look scored? what does the crank look like?

Bear in mind that the bearing surface and the crank journal shouldn't actually touch - so they might be of concern to me.

you can check them using plastigauge linky which you can buy off ebay i think.

cheers

Mark

stevegough - 4/9/11 at 07:25 PM

quote:
Originally posted by franky
can you feel anything with your fingernail when you drag it across?

It looks ok from here although its hard to tell, you can see in the pic of mine one thats perfect against ones that are worn.


yes, there's a deep channel in the middle but, no, its as smooth as a boobies skin!

ashg - 4/9/11 at 07:38 PM

look like they are worn to me. stop touching them and measure them and the crank with a micrometer. any pictures of the crank?

stevegough - 4/9/11 at 07:42 PM

quote:
Originally posted by mookaloid
They look a bit less than new to me. they look scored? what does the crank look like?

Bear in mind that the bearing surface and the crank journal shouldn't actually touch - so they might be of concern to me.

you can check them using plastigauge linky which you can buy off ebay i think.

cheers

Mark


Thanks for your comments, Mark (nice avatar, btw). Did you read the reasons for the bearing cap removal, though? - I have a problem with building up initial oil pressure, I was expecting to see a vast amount of wear - similar to franky's picture?

stevegough - 4/9/11 at 07:45 PM

quote:
Originally posted by ashg
look like they are worn to me. stop touching them and measure them and the crank with a micrometer. any pictures of the crank?


Crank is dripping with oil, but I'll wipe it and photograph it - I don't have a micrometer, but the oil feed channel is just a touch over 1mm deep at either end. Pic to follow in 10 mins...

ashg - 4/9/11 at 07:56 PM

you really need to get hold of a micrometer to see if its in spec or not. machine mart sell them for under £20

stevegough - 4/9/11 at 08:00 PM

pics of crank - not easy to photograph - dark and dripping!




Wheels244 - 4/9/11 at 08:23 PM

Why not replace all the shells ?
You've got the sump off so have done all the hard work.
They don't cost that much and it's one thing you could cross off
your list of potential faults.
Crank looks ok from the photos, but I would measure it if you can
get hold of a set of micrometres.

MikeRJ - 4/9/11 at 08:33 PM

They don't look too bad to me, but some plastigauge would let you know for sure. The fact that it does eventually produce decent oil pressure tends to imply that the bottom end can't be in that bad a state.

The bypass valve can be problematic on these engines; I know you have set this up previously but have you taken it out since? It only takes a tiny bit of swarf etc. to jam the valve open, so that would be my first port of call.

If not this then an air leak on the inlet side could cause priming issues. If you are certain the pick-up pipe is ok in all respects then maybe you need to take a closer look at the pump, and especially the mounting faces and gasket.

stevegough - 5/9/11 at 07:42 AM

quote:
Originally posted by MikeRJ
They don't look too bad to me, but some plastigauge would let you know for sure. The fact that it does eventually produce decent oil pressure tends to imply that the bottom end can't be in that bad a state.

The bypass valve can be problematic on these engines; I know you have set this up previously but have you taken it out since? It only takes a tiny bit of swarf etc. to jam the valve open, so that would be my first port of call.

If not this then an air leak on the inlet side could cause priming issues. If you are certain the pick-up pipe is ok in all respects then maybe you need to take a closer look at the pump, and especially the mounting faces and gasket.


That's put my exact thoughts at this moment in a nutshell. If I replace all the shells, it means dropping the entire crank which means removing the gearbox, and hence the engine - loads of work for possibly nil gain. However, I am now even more convinced that the oil pressure fault lies within the oil pump, or, as you say - possibly even the pressure relief valve sticking again. The oil pump has to be removed first to drop the crank in any case.
There is a minisule score on one end of that shell, maybe 1/4mm wide and 1cm long, other than that and a couple of handling marks (from when it was hamfistedly fitted, possibly) it is pristine - I don't believe they are the fault.

franky - 5/9/11 at 08:56 AM

Good news then

You should be able to slide the other half of the bearing around to replace while the crank is still on(if you want to!).

Have you had the oil pump apart to check for wear in there? Or would it be worth trying a new pump and putting it back together to see?

stevegough - 5/9/11 at 09:02 AM

quote:
Originally posted by franky
Good news then

You should be able to slide the other half of the bearing around to replace while the crank is still on(if you want to!).

Have you had the oil pump apart to check for wear in there? Or would it be worth trying a new pump and putting it back together to see?


Not replacing the bearings - its a bit above my skill-base (I think that's the contemorary term!) and I don't think they're worn. Oil pump removal + strip / measure clearances is next, but It won't be until much later today.

cliftyhanger - 5/9/11 at 09:25 AM

Am I missing something here, or have you checked the big ends as well.
In my limited experience, big ends seem to wear rather faster than mains. And if they are out I would definitely replace them if they show any signs of wear.

BUT bearing wear usually means oil pressure drops when hot, and better when cold. I am a bit perplexed with this.
Did the problems start with teh new pressure valve was fitted, or did it make any difference?

stevegough - 6/9/11 at 09:12 AM

quote:
Originally posted by cliftyhanger
Am I missing something here, or have you checked the big ends as well.
In my limited experience, big ends seem to wear rather faster than mains. And if they are out I would definitely replace them if they show any signs of wear.

BUT bearing wear usually means oil pressure drops when hot, and better when cold. I am a bit perplexed with this.
Did the problems start with teh new pressure valve was fitted, or did it make any difference?


No, I'm not planning to investigate the big ends, I'm doing the oil pump first, I've now got it out and I'm cleaning it thoroughly before opening it - I'm hoping to find something obvious in there. I will also strip out and clean that pressure relief - valve port again.

The nil - oil pressure on start up may have started soon after fitting the valve, I honestly can't remember, but I DO remember that the oil pressure was zero constantly before I fitted it (although I wasn't running and driving it then) - as soon as I replaced it with SBDs one, the oil pressure was instantly there. - The current fault may well be down to that little blighter sticking again, even though it is supposed to be non-stick.

Watch this space.

coyoteboy - 7/9/11 at 06:35 PM

Looks a little scored to me, any I've pulled that were not dead were pretty shiny still. Barring the slight scoring I'd say they looked fairly healthy.

Checkout : http://www.engineparts.com/publications/CL77-3-402.pdf for help diagnosing plain bearings.

stevegough - 7/9/11 at 07:19 PM

quote:
Originally posted by coyoteboy
Looks a little scored to me, any I've pulled that were not dead were pretty shiny still. Barring the slight scoring I'd say they looked fairly healthy.

Checkout : http://www.engineparts.com/publications/CL77-3-402.pdf for help diagnosing plain bearings.


That's an extremely useful link, coyoteboy. Saved for future reference.




However, to bring the thread up to date I stripped the oil pump and it was quite well worn - the alloy casing where the gears revolve was badly abraded and scored, there were also a couple of unspecified shards of metal embedded in these surfaces. In addition, as a couple of you have said, the pressure relief valve was also stuck open with a few crumbs of metal - just goes to show that SBDs nylon valve can stick, too!
I could have made a reasonable oil pump out of the two I had, but I decided to get a new pump. (QED) - fitted it today, and when I've got a new adaptor for the oil press sender (I sheared the one I had this afternoon - no idea how, I had only just put the spanner to it - virtually no force at all!) I hopefully should finish it tomorrow. Oh! yes, one more thing - I've fitted a magnetic sump plug to scavenge any more little shards...eBay - The UK's Online Marketplace


By the way, thanks for all the advice and help along the way, everybody.
Regards, Steve

[Edited on 7/9/11 by stevegough]

NS Dev - 12/9/11 at 07:24 AM

was typing a big follow up and just lost it, so to summarise:

Mains on an XE, to all intents and purposes NEVER go wrong

Big ends, change every 90K (will go much longer but usually tired at this mileage)

Relief valves, NEVER, EVER WASTE money on a nylon one, they are utterly useless

Once a relief valve starts to stick, change the whole pump, they are never right once they've done it once (no, I don't know why! )

stevegough - 13/9/11 at 02:12 PM

quote:
Originally posted by NS Dev
was typing a big follow up and just lost it, so to summarise:

Mains on an XE, to all intents and purposes NEVER go wrong

Big ends, change every 90K (will go much longer but usually tired at this mileage)

Relief valves, NEVER, EVER WASTE money on a nylon one, they are utterly useless

Once a relief valve starts to stick, change the whole pump, they are never right once they've done it once (no, I don't know why! )



OK, thanks for your reply and pm, Nathaniel - you are a bit late, as I have already wasted my money on the SBD nylon one. I also cleaned it up and refitted it to the new oil pump, even though it was a bit scored. I will now remove it and replace it with the new metal one which came with the oil pump before I start driving the car again.

perksy - 16/9/11 at 08:02 PM

Problem with the SBD nylon valve is any crud/dirt seems to embed itself into the nylon

Polishing up the standard XE valve seems to work ok but as you've got scoring in the pump body it needed replacing anyway

As said before the only way you'll know if you have a crank/bearing issue is to micrometer it first and then plastigauge the assembly

Big ends on the XE suffer more abuse than the mains which usually last quite well

I've seen worse bearing face/s than those in your photo and pulled some Big ends out of a zetec a couple of months ago that were in a terrible state, but the oil pressure was fine, it was just knocking itself to death


One thing i'd deffinatly do is make sure the inside of the sump is very clean before refitting it otherwise you'll be back to square one

stevegough - 16/9/11 at 08:52 PM

Thanks, perksy - that all makes sense there were bits embedded in the nylon, removing the valve took quite a bit of force, and I had to push it out from inside - there's no way I could have pulled it out, it was stuck really fast - this caused even more scoring of the relief valve bore. Anyway - I have replaced the pump, and now fitted the proper metal valve back in which came with the pump - and the engine is running a treat - even hot it is only dropping to about 50 psi. (showing nearly 90 cold!).

Now moving on to planning winter mods - mostly repainting the wishbones which I probably should have got the same quality powder coating done on as I did on the chassis!

perksy - 16/9/11 at 09:30 PM

Good news

Now you can get back out and enjoy it

stevegough - 17/9/11 at 08:04 AM

quote:
Originally posted by perksy
Good news

Now you can get back out and enjoy it


Certainly can....went for a quick thrash on thursday round the lanes near here, trouble is, some guy in a great fat CL 63 AMG was holding me up......AND he was trying not to - don't you just love these cars on the twisty bits?