I've recently bought an '85 2CV, it's all good chassis-wise but there's lots of bits which need doing and parts replacing, which I'm doing now.

My dilemma is the engine and your thoughts on what to do would be appreciated.

Basically it's tapping/knocking like a 'B' on the right hand side, I know these engines being air-cooled are quite noisy but I remember them being a lot quieter than this!

So far I've checked and adjusted the valve clearances, checked compression, changed the oil and filter, checked the timing and replaced the complete ignition system.

The noise is still there and gets worse with heat. Sometimes when first started after 15 seconds it shuts up and then comes back on again quickly after wards. Oil starvation? Cam follower? Oil pressure problem?

Should I:

Investigate by having it all completely to pieces and rebuild up with new parts/recon heads.

or

Spend some money on a balanced recon 9:1 engine possibly built for racing (without the cam) as I'm after decent power (say 35bhp) with road reliability.

Any recommendations as to who can build me a proper engine would be much appreciated.

Thanks,

Robin.

Could be piston slap from a partial seizure - I seem to remember curing this by new barrels and pistons as long as heads haven't eroded......

Con-rod small end bushing?

My old 625 was as noisy as hell, finally after clouds of oil smoke, it was near impossible to start. Still had compression !!
On dismantling, the piston ring gap between top of ring and groove was about 0.03"- the other clue was excessive crank case pressure.
Make sure the engine isn't rattling against the engine mounts, bodywork, exhaust tubes etc etc. THEN
I would strip, make sure the big ends didn't have excessive play, check valves all OK in the head, then think about barrels and pistons. If you are thinking of something a bit more zippy - get a boat with a big outboard ??? Looks like you enjoy water.
BobH

Thanks for your suggestions, Yes I think I'm going to have to strip the old girl.. (Hehm)

The noise isn't 'unintentional mechanical contact' it's definitely coming from inside the engine on the right hand side, halfway between the head and the block.

9:1 compressions pistons and new barrels would probably be a good idea anyway.

I'll come back and ask if I get stuck The only thing I don't have at the mo is a method of getting the Gudgeon pin out or the bushings, I might have to buy a tool, or make one? I have threaded bar.

Here's a video, speaks louder than words..

http://www.youtube.com/watch?v=SbSoVuzDK7A

You mention using 20w/50 oil in your Youtube video, but Citroen recommend 10w/30. Might have a bearing on the issue.

Used 20w/50 from the year dot without issue in my 2CV's! You can drift the gudgeon pin out with a suitably sized socket or, as it happens, my socket wrench handle is the exact size to use as a drift......

I doubt very much whether the grade of oil used in an engine could have any effect on what's causing this noise.
Unfortunately, the only way to find what's causing it is to get the spanners out.
My bets would be either a partial seizure on that side or the piston has been incorrectly fitted, with the arrow on the piston crown facing towards the rear...

Thank you for your replies, I too have used 20W50 in 2CV's for years and years, when you rely on oil to cool your engine + give it loads of revs often you need your oil to stay in grade! It also keeps the oil pressure up and quietens them down a bit in my experience.
I'd go 15W40 in the winter but 10W30 is for modern cars IMO.

Yes it's 'spanners out' time for me.. wish me luck I'm going in