Strange oil contamination

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alanworland
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Strange oil contamination

Post by alanworland »

Went for my first run of the year today, started first time and I thought went really well(for a sidevalve!) Did about 30 miles with the idea of changing the oil upon arriving home.
Dropped the oil and allowed it to drain while took filter off. The engine has always made 'sludge' so just before I was about to replace drain plug I put my finger into the sump and was most surprised to feel what was like grit! Not loads but wasn't expecting any!
Not magnetic but feels almost like sand?
Next job is to jack up and remove sump for a better look and washout.
Don't understand what it could be I always change oil very frequently and it's probably not done 2k since I replaced crank shells (big ends and mains)
Hoping to reuse the sump gasket perhaps with the addition of some sealant? Any recommendations? I would normally use Blue Hylomar.


Alan
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philthehill
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Re: Strange oil contamination

Post by philthehill »

If it feels like sand it most likely is.
It could be some casting sand which has been released from the block. Why now - I do not know.

If you have the air cleaner fitted at all times external sand would not get into the engine.

You are right to remove the sump examine and clean the inside.

If you lightly grease the gaskets you can fit, remove and refit without using sealer quite a few times without problems.

Greasing the gasket keeps it supple and stops it sticking to the sealing faces.

I never use sealant only grease.

Phil

alanworland
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Re: Strange oil contamination

Post by alanworland »

Most odd? I rebuilt the engine about 80k ago and as I said have had the sump off fairly recently and I can remember the insides being painted in what looks like a thick red lead primer and because of that the insides are quite smooth, unless it's the paint breaking down and coming off?
As you are probably aware the crankcase on the sidevalve is a very straightforward affair with no real nooks and crannies that could retain such debris.
All will be revealed.

Alan
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paul 300358
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Re: Strange oil contamination

Post by paul 300358 »

It may be worth looking at the centre main bearing when you have the sump off as it has been known for the white metal to flake off.
alanworland
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Re: Strange oil contamination

Post by alanworland »

Paul it's interesting you say that, as when I removed the old 80k shells they were showing signs of breaking up and I decided I was changing them just in time.
The originals weren't noisy or causing low oil pressure just that I thought they had served their time (the sidevalve works hard for reasonable progress!) and I found no debris at that time.

Alan
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alanworland
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Re: Strange oil contamination

Post by alanworland »

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Removed sump tonight and there was far less contamination than I had feared with none in the oil pickup recess.
Photo is of centre main journal which looks fine considering its done 80+k with endfloat measuring just over 0.003
Investigating the debris it is strange, if rubbed between fingers the 'grit' breaks down into a sludge?
Don't know what it was or where it came from - could it have settled out of the oil over the winter?
Lost sump gasket as it stuck to sump and block so will try and source some cork gasket material tomorrow.
At least things were better than I imagined I was fearing scored crank and shells, contaminated oilways the lot!

Alan
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oliver90owner
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Re: Strange oil contamination

Post by oliver90owner »

Are you using a detergent or non-detergent oil? If the latter, I’m not unduly surprised.
Bowie69
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Re: Strange oil contamination

Post by Bowie69 »

Is it magnetic?
alanworland
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Re: Strange oil contamination

Post by alanworland »

Not magnetic and as I said if 'massaged' between your fingers it breaks down into a sludge?
It's Halfords Classic 20-50.
Years ago I had a Castrol GTX which had a sediment in the bottom of the 5l container, looked like cloudy dirt.
Contacted Castrol who assured me it was fine and it was an additive which had settled out, didn't look very reassuring though!

Alan
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Bowie69
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Re: Strange oil contamination

Post by Bowie69 »

I'm not overly familiar with the sidevalve, even my '54 splittie traveller has a 1098 in it, but are there any bit of thin steel that could rust?

That would not be magnetic, and after a first run of the year could well dislodge small particles which would of course collect in the sump.

Crank looks good! :)

Peter.
GavinL
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Re: Strange oil contamination

Post by GavinL »

I came across similar 'grit' recently when replacing the head on a 96k. K series engine. This engine has through bolts about 400mm long which clamp the engine together and screw into a plate below the crankshaft. Every time I screwed the bolts in and out whilst measuring for stretch of the bolts, the threads came out with this granular black material on them, which I assume is burnt oil which has collected around the bolts / clamping plate.

I considered flushing the engine to remove this sludge, but the collective wisdom is that in a high mileage engine this can do more harm than good, moving the sludge from where it is doing no harm to somewhere where it could do harm such as oil ways.
RobThomas
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Re: Strange oil contamination

Post by RobThomas »

Could it have been corrosion of the Alloy castings round the timing cover after a long lay-up with condensation? Cork side cover gasket dried out and flaking?
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paul 300358
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Re: Strange oil contamination

Post by paul 300358 »

I would be tempted to change the filter, fill with new oil and the run it for a couple of hundred miles then change the oil and filter again.
alanworland
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Re: Strange oil contamination

Post by alanworland »

I agree that it is most odd, never found anything like it before. It never does short journeys so the engine always gets properly up to temp (it even has a pre heater so doesn't start from 'cold' anyway)
Last ran probably late October, been out of use a lot longer in the past and always kept in an attached garage.
New sump gasket on the way so once fitted I will give it a quick oil change after a few miles just in case without using a flush as I have heard similar stories about debris being dislodged that was doing no harm. Insides are black but no build up anywhere.
Might even stop the sump leaking with the new gaskets!

Alan

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RobThomas
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Re: Strange oil contamination

Post by RobThomas »

Alan. Are you using a screw-on filter?
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alanworland
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Re: Strange oil contamination

Post by alanworland »

Rob, no still have the original paper filter in the cannister.

Alan
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RobThomas
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Re: Strange oil contamination

Post by RobThomas »

You can save quite a bit of trouble and some cash if you get the conversion. Easier to find filters, too.
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alanworland
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Re: Strange oil contamination

Post by alanworland »

I had forgotten what a performance replacing the sump was! In particular the rear cork seal.
I moaned about the seal not being cut to length/fit the rear bearing, glad it wasn't because the 'ear' needed on one side was twice as big as the other side!.
Anyway held it all in position with grease and bolted up the sump onto it all. Ran it up to temperature today and all seemed well, as in no leaks so far!
Will get a few miles in shortly and see how well I did it!
It always has leaked a bit but a bit less would be great!

Alan
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paul 300358
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Re: Strange oil contamination

Post by paul 300358 »

Alan, after a couple of runs, get back under and see if any of the bolts require nipping up. I have found that the cork compresses a bit. It may be just me but it costs nowt.

Paul
alanworland
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Re: Strange oil contamination

Post by alanworland »

I had it running yesterday and all seemed good so today I nipped up all fixings after getting hot and they seemed ok.
Today did about 40 miles of varied travel so got good and hot and when I returned home I slipped my drip catcher under and it only got one drip from the jiggle pin!
Front of crank seems oil tight (for now!) and I rate one drip from the rear as good - I have quite low standards when it comes to Morris's oil retention!
I will see if the gaskets have settled before next run.

Alan
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