Shrapnel in the sump, likely source?

[PeteStupps]

Hello all, long time no post. Hope everyone is making better use of the sunshine than me!

Did an overdue oil change on my trusty 1300fwd yesterday, and discovered some small battered lumps of non-ferrous metal in the old oil. Also lots of red coloured detritus in the oil filter, possibly paint, and general grimy sludge.

One piece of metal in oil filter, so not much of it apparently went through the pump.

What would be the most likely source? I'm guessing it's a bit of piston, which has scraped around inside the block and brought some general debris with it.

Oil pressure is good, engine is a bit noisy though. Haven't done a compression test but might do if it's worth it. 

Cheers - pics below

[RedRooster]

No idea about Fwd, does it share the same oil as the gearbox ie mini? 

Not much non metallic, I'd be dropping the sump to check bearings. 

RR

[Nick Jones]

Oh…. Suboptimal.

Given that these things don’t share their oil with the gearbox….. that seems most likely to be a bit of piston. Small crank 1300 pistons are occasionally a little fragile, though the problem ones I’ve come across have cracked through the upper ring grooves causing the crown to detach. Both examples actually ran like this albeit not very well, and with some odd noises. One gentleman drove 200 ish miles home like this and then replaced the piston in his driveway with a used one from his spare engine.  It was fine 
 

Not sure if it’s a thing on the 1300 but some of the 1200s had 4 rings, with an extra one in the skirt. Pretty sure I’ve read that they can fail in interesting ways…..

Probably check your breakdown recovery is up to date and keep driving it…..

[PeteStupps]

7 hours ago, Nick Jones said:

Probably check your breakdown recovery is up to date and keep driving it…..

Ha! This sounds like I should take the engine out and investigate. Don't really want to get stranded for 6 hours on summer holiday duties. It has been making some odd noises, but I thought was clutch related.

@RedRooster as Nick says the engine and gearbox don't share oil so it's most likely piston. Oil pressure is still very good so bearings can't be falling apart, I don't reckon. Unfortunately you can't drop the sump on these, you have to lift the block off the transmission casing to see inside.

@Nick Jones I did re-ring it when the engine went in a few years back, it's just the normal 3 rings.

Thanks for the input gents, i'll dust off the engine crane and see what's what. Have got some used standard pistons from the Spitfire rebuild so might be able to do a cheap fix...

[Nick Jones]

Good luck - May the Force be with you!

[Escadrille Ecosse]

2 hours ago, Nick Jones said:

Good luck - May the Force be with you!

Oh dear. This^^^^

[PeteStupps]

My my, how time flies. I ignored this problem, drove the car another 3000 miles and then belatedly changed the oil again a few weeks ago. More little flecks of aluminium were recovered along with a sense of deja vu. Irresponsible behaviour, really. Must do something about it after xmas...

I think the non-shiny bit of debris is glue from the oil filter, which I cut open to inspect. 1/4 UNF nut shown  for scale (not found in the sump, thankfully)

 

[JohnD]

A trivial amount, compared with the previous, so one hopes no more harm done?

[PeteStupps]

I like your attitude John! Adapting the old adage about oil leaks, I will start to worry when no shrapnel falls out of the engine, as that would suggest there's no piston left.

[John I]

2 hours ago, PeteStupps said:

I like your attitude John! Adapting the old adage about oil leaks, I will start to worry when no shrapnel falls out of the engine, as that would suggest there's no piston left.

Why worry at that point hopefully you’ll still have 3 other pistons to play with.

[Escadrille Ecosse]

2 hours ago, PeteStupps said:

I like your attitude John! Adapting the old adage about oil leaks, I will start to worry when no shrapnel falls out of the engine, as that would suggest there's no piston left.

[JohnD]

Irony, irony, they've all not got his irony!

[Escadrille Ecosse]

7 minutes ago, JohnD said:

Irony, irony, they've all not got his irony!

I get it OK John, my comment was also ironic 

[Nick Jones]

Few laps of CC at your usual full-attack mode?  In the interests of science obviously…… What could possibly go wrong? Maybe the engine will provide you with an additional inspection port 

No other symptoms? No starting on 3 cylinders, no smoke, no heavy breathing?  You say it’s a bit noisy - what kind of noise?

[Escadrille Ecosse]

13 minutes ago, Nick Jones said:

No other symptoms? No starting on 3 cylinders, no smoke, no heavy breathing?  You say it’s a bit noisy - what kind of noise?

 

 

[PeteStupps]

On 12/12/2025 at 5:36 PM, Nick Jones said:

Few laps of CC at your usual full-attack mode?  In the interests of science obviously

😆

No other symptoms of malaise Nick, apart from a periodic tick-tick-tick when cold, which I thought might be little end or piston slap, but not sure. There was a more alarming rattle, which happily turned out to be a loose dynamo bracket.

Oil pressure is still good and I don't think consumption has increased.

Obviously need to get into the engine and have a proper look, when I can summon the time and energy

[Nick Jones]

Endoscope through the sump plug to look at the bottom of the pistons? *

Is this the same engine/replacement for the engine that dropped a valve and ate a piston. If so, is there any possibility these are remnants of that incident?

* Disclaimer: I have never tried this so no idea if it’s even possible…. But I’m looking forward to the video……

[thebrookster]

4 hours ago, Nick Jones said:

* Disclaimer: I have never tried this so no idea if it’s even possible…. But I’m looking forward to the video……

If you have one of those endoscopes that have an inbuilt light it could work, with some patience.

However, and I can't stress this enough, you need to leave a good while for any stray oil to descend first. Otherwise any drops of oil absolutely will drop directly onto the lens and blur it, just after you spent 5 minutes getting the damn thing in the correct spot to see something useful.................

[Escadrille Ecosse]

1 hour ago, thebrookster said:

However, and I can't stress this enough, you need to leave a good while for any stray oil to descend first. Otherwise any drops of oil absolutely will drop directly onto the lens and blur it, just after you spent 5 minutes getting the damn thing in the correct spot to see something useful.................

As ever the innate hostility of inanimate objects....

[Nick Jones]

8 minutes ago, Escadrille Ecosse said:

As ever the innate hostility of inanimate objects....

True dat….