Les Henson Posted October 2, 2005 Share Posted October 2, 2005 After sorting all the electrics out on the 'Free S3', I managed to get the engine running the other day and it smoked like a smokey thing, ran as if on three cylinders at low revs, and was difficult to start. After checking everything I could think of I resigned myself to taking the head off, which I did this morning. Not a prettys sight! The head is damaged as well, but not beyond use maybe. The exhaust valve for No1 cylinder is chipped, so It'll have to be replaced. After cleaning and a bit of digging, I found these bits of metal embedded in the piston crown. They look like bits of piston ring to me. Not that there's anything else that it could really be. I wonder why the ring broke up, the other cylinders are fine. Perhaps a carp repair job in the past - the valves are definitely not the originals. Anyway, the pistons are not all the same, And marks on them are as follows:- No1 piston = BLON494401 B (?????) obscured by damage. No2 piston = AE350386 + 0.762CTF No3 piston = BLON494401 B 030T AE MVX No4 piston = 0.30 NO3 101 Has anyone any idea if these are standard pistons or not? The different marking make it difficult to figure. I think I can assume that No's 1 and 3 are the same size. Dunno about the rest. It seems there was a bit of a bodge sometime in the past. Les. Quote Link to comment Share on other sites More sharing options...
steve_a Posted October 2, 2005 Share Posted October 2, 2005 Nasty, I had my S3 apart for a similar reason and found 2 pistons with broken rings, one had done the same thing as yours, but not so serious - the head was fine. Looks like it might be expensive, one or more cylinders has been rebored is my guess from the numbers, mine were marked with RTCxxxx A or B the +1 and new markings make me thinks that's the case. it's pointless just putting a new piston in and hoping, you will probably have to take it to a good garage who can check the sizes accurately and advise, the head will need to be skimmed to be safe with the dents and as you said new valve. The cylinder with the knackered piston might need a rebore or at least a hone since the ring will have made it's way up there, then you are best taking the other pistons out and checking them and putting new rings on since you are in there and so on and so on It's really clean - did you do that or was it that way when you opened it up? even after loads of cleaning mine was still dirty looking Might be worth considering sourcing another engine all considered. I can get some pictures of my piston marking this week if it would help. Steve Quote Link to comment Share on other sites More sharing options...
Les Henson Posted October 2, 2005 Author Share Posted October 2, 2005 Well the pistons out and the top ring is the culprit. Still none the wiser as to how it happened. The bore is pretty good still, although there's some slight scoring, but it might polish out. I'm not going to chuck money at it that's for sure, I can re-build another for less possibly. Small and big-ends are ok, and the other pistons/bores are ok too. I'll identify the damaged piston size if possible and replace it. That'll do for now and as long as it's ok, I'll worry about major work in the future. I went round to see the previous owner this afternoon and he says that a local (to Swindon) 4x4 garage replaced all the valves and did other engine work, so it looks like someone did a rubbish job. He also said that it did seem to smoke quite a lot when he got it back, but was told it's the engine 'settling in' - yeah - right! Two more pics anyway:- 'Exit hole' where the broken ring worked it's way up the side of the piston. The amount of ring that got out - around a third of it! Les. Quote Link to comment Share on other sites More sharing options...
Ant Posted October 2, 2005 Share Posted October 2, 2005 Hi Les I recently aquired a 2.25 Ltr series petrol engine which I'm doing a 'slow' rebuild on i.e. I've taken it apart to see how it works and will be slowly putting it back together. You're welcome to it if you want it as a replacement for your diesel lump. Apparently it was a 'runner' before I got it, but I know little of its history. I've only just taken the head off and it looks alright. There's a fair amount of carbon build up and the valves look asthough they need replacing. 3 of the piston tops look fine, but one has a small chunk out of it so will need replacing. You're welcome to come and have a look if you want. I'm in Swindon also (you recently did the timing belt on my 200tdi!). Cheers, Ant. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted October 3, 2005 Author Share Posted October 3, 2005 Thanks very much for the offer Ant. The engine appears to be the original, so I'd like to stick with it if I can. I'm having enough problems with putting an engine in catflap, without having to start on another motor. When did I do your Timing belt and what truck have you got? Les. Quote Link to comment Share on other sites More sharing options...
Ant Posted October 3, 2005 Share Posted October 3, 2005 No problem Les. The offer stands if you change your mind or find another use for it. I'd just rather it didn't finish up in a skip if there's life left in it. Mine's the green defender 90. You did the belt about a month ago. I thought I had a problem with it losing coolant but it's been fine. Quote Link to comment Share on other sites More sharing options...
02GF74 Posted October 3, 2005 Share Posted October 3, 2005 my suggestions for what its worth. You should replace both valves in case a bit of piston ring got past and then the valves close on it - the chips in the side may be the result of that. Check the push rods/rockers on that cylinder as well. Maybe worh checking inlet and exhaust manifolds in case there are some chunks left that could fall back into the engine when reassembled. The head should be fine. I wouldn't try to grind or polish out the dents too much as it will change the volume; it may be possible to use a punch to flatten out any protrusions made by the piston rings - this will keep the same amount of metal in the head but don't go crazy with the hammer. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted October 3, 2005 Share Posted October 3, 2005 Broken piston ring damage, takes me back to my Lambretta days ! Mo Quote Link to comment Share on other sites More sharing options...
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