Garage bent my valves during a cambelt change - advice please

If the pistons are alloy, which I suspect they would be, and if they've hit anything enough to bend a valve then the piston tops will likely have valve and debris imprints on them. I would suspect that anything below the pistons would be OK. The head itself could also be damaged I guess. Sounds like they want to install new valves and guides (to the head) and if the shop does it properly this requires grinding new valve seats. I guess you could argue that that reduces the life of the seats but it wouldn't get you very far.

The head should be re-installed with new bolts etc but I'd be seriously worried about letting a garage that can make that kind of mistake do anything else on my car. I guess you've given your approval for them to fix it. You should have asked for guarantees etc back then. Ask them to throw in an oil change etc etc but again, how'd you know they do it?

If it runs ok when/if you get it back then just get rid of it ASAP, let someone else have the (possible) grief.

I have never, ever seen a rebuilt engine that has been done to the quality of an original factory built engine, no matter what the make, no matter who does it. It may run acceptably, but it is never the same, and modern engines are much more critical than old. On most (all?) French engines the cylinder liners are removable, problem is that they seal with a rubber ring at the bottom of the liner, when removing the head it is ever so easy to disturb that ring and internal leaks start to occur. The slightest variation in combustion chamber size, valve seat width etc. etc. will all make a difference. Most garages will not even have the right glue available to reassemble it, they will probably use pattern gaskets and parts, etc. etc.

Mrcheerful

IANAL

It might be worth checking in uk.legal as well, and I wonder if you pay by credit card you get additional protection from them for ongoing problems (consumer credit act section 75 makes the card issuer jointly liable for purchases)

Well my old Fiat engine worked much better after I rebuilt it & I can't remember an A series that wasn't reassembled better than it came from the factory.

Depends on the engine. Older ones use selective assembly for things like pistons. Crank throws often weren't exactly 180 degrees to one another - (four cylinder). Combustion chambers were simple castings and not matched in volume. Etc, etc. A good machine shop would sort most of these when reboring and regrinding. The balance could also be improved over the factory standard. And a skilled mechanic or DIYer make at least as good a job as the factory at re-assembly. Of course this probably isn't true anymore with decent engines but I'll bet it still applies to some.

Yes. The last engine I did a full re-con on was a B-Series 1800, and that ran like a sewing machine afterwards - far better than it ever had before.

I hope you don't mind, but I'd like to vent a little spleen here. No, not specifically at you, just about 0.004% spleen for everyone who wants to fling a car with a problem onto someone else - that way, everyone who deserves it gets some.

Let's say you have a Fnord Monvavoo which has an irritating rattle on startup that lasts about 15 minutes and then goes away. You post on a newsgroup and the advice coming back is that the 4th exhaust valve has become un-noduled and a repair is £215+vat and fitting (a total of £415) is needed. If this valve becomes totally nodule-less, it will promptly grow teeth and gnaw a hole through the engine meaning a complete new engine is required. At this point, you decide you don't want to pay the £415 and would rather flog the car and get a replacement. You put an ad in a newspaper and someone rings saying they want to look at the car at 2pm. You take the car for a run at 1:45 to get rid of the rattle. The punter buys the car and drives off...

You go to a garage with the money and test-drive (subsequently buying) another Fnord Monvavoo which you notice is already up to temperature(bah! coincidence!). It's not long after you find the 4th exhaust valve has grown teeth and eaten through the engine. Someone else has sold a dodgy car to a garage, covering the evidence and they've sold it to you doing the same. Wouldn't that piss you off?

It would be nice to find people who are willing to point out problems with cars before they're sold - so far I've bought cars from decent people who have said (sometimes with prompting) what is wrong with a car and it makes me more liable to buy it knowing what I have to fix. There have been plenty of cars I've looked at and then told the owner to go poke it because they tried to cover up problems just to shift them and the expense onto some poor sap The least anyone could do when selling a car because of a fault is let the buyer know. If that scares you because of a potential non-seller, then fix the fault or sell to someone who appreciates honesty. Don't be a bastard and sell a lemon to someone who wants a peach.

I think that's quite fair of you to ask. I would. A main dealer did something similar to my car and put it right the same day. Not a word said until I went to get the keys and the manager explained there had been a problem. I was quite annoyed but the car has been fine and that was three years ago.

Thank you for the replies and please keep them coming. I want to get the problem fixed since the car has been very reliable to date. I would not pass it on to someone without explaining any faults with it. That's just not right. Cheers.

Well, do let us know the outcome.

French engines the

Hmm, what glue should they use to put the valves in and the head back on? Are you *really* saying that removing the head can disturb the cylinders liners? I'm not syaign that it can't but seems very very odd, but then again it is a Renault.

If the job is done properly then I can see no problem but the word "properly" is key here.

The factory glue is incredible stuff, but when you put a tube in front of the average mechanix and say that's 30 pounds please, most of them say I'll use some cheapo silicone, especially when they are paying (because of a messed up job) Genuine gaskets are three times the price of cheapo ones, but for a good reason: they are much higher quality.

And yes, any wet liner engine can have the sleeves dislodged by a careless head removal, I have even seen one removed with the head!!!

Peugeot make special tools to unstick the head without disturbing the liners, and a special set of tools to lock the liners down while the head is off, no garage will have these, most won't even have heard of them.

If the job is done properly throughout then there would be no problem, but reality says it won't be done right.

Mrcheerful

Demand to see the engine when they've taken the head off before they do any more work. Check the piston crowns for gouging. The head they'll have to do properly or it won't run but it's feasible to just file the bits off the piston crown and it'll run OK but it's not a proper repair.

Personally I think I'd be asking for a recon engine as it is possible to bend con rods, little ends and shag big end bearings too.

Pretty rare though.

I have encountered two superb reconditioned engines:

1) A Herald engine, for my sister's car, done by John Kipping (now Canley Classics). Absolutely superb.

2) A VW 1600 air-cooled engine, for my camper van, from Vege. Cost about twice what everyone else charged, but excellent.

Ian

I must admit I was thinking of more modern stuff, you know, post WW2

Then just how often have you seen a reconditioned modern engine? Most outlive the rest of the car - apart from things breaking, which isn't the same as wearing out.

I am talking about (in general) any modernish engine, which has been taken apart (most often for head gasket or valve problems [often/usually caused by lack of or poor maintenance]) Nowadays there seems to be no other reasons to take any engine apart.

The engines I have seen rebuilt after the sort of problems which nowadays cripple an engine, have not been rebuilt to any sort of adequate standard compared to a factory built engine.

Mrcheerful

That's probably because they've been done by the average garage 'mechanic' who simply isn't used to or skilled in this sort of work. Those who'd attempt a full engine re-build are usually better.