Re-Manufactured Engines

[Howard 22]

Hi, I'm a new member on here and wonder if anyone can give me some advice. I have a C200CDi, which I love however had a recent problem with the engine, which sounded like a bottom end problem. (It had covered 147,000 miles) I decided to have it re-manufactured and this has now been done. When I quizzed the company that did the work on what they had done, they were vague at first but explained that the bores were found to be within MB specification so were only honed and new pistons fitted. The crank was found to be the same and was only polished and new shells fitted. They claim this is now a 'zero mileage' engine.
They appear to be a reputable firm, specialising in MB engines however I feel that a re-bore and re-grind should have been carried out as a matter of routine.
Any thoughts anyone?

 

[DSM10000]

What did they specify in the original quote in terms of work to be carried out?

Have you a list of the actual work carried out?

 

[Howard 22]

Well contractually, I probably have them over a barrel as the process described on their website states that a re-bore and a re-grind is part of the process. I want to be reasonable however so I wondered what the general view was on what they have done.

 

[DSM10000]

If you have in writing what they proposed to do and also what they actually did then you may have cause to ask for the cost to be adjusted. How much did this cost?

They will probably say that the work they carried out gives the same or better result as a re-bore and re-ground crank.

 

[Howard 22]

Sorry DSM1000, didn't answer your other question. No list of work carried out has been issued

 

[DSM10000]

Pretty poor to not list what was done!

However, if the engine is now running well and the problems have been fixed then they could argue that they have fulfilled the contract. I would not, however, be happy without a full breakdown of the repair, parts replaced, findings etc.

 

[Howard 22]

It cost £2.2k so not cheap.

I can't see how they can claim the work done is better than a re-bore or a regrind as the bores and the crank still have 147,000 miles behind them and they haven't added any metal. The crank will if nothing else have some ovality on it.
I'm not asking the question from any financial standpoint, more in engineering terms.

 

[flango]

If the bores and crank are within spec then there is no need to regrind and rebore and this is actually the best option as long as they are honed and polished before any new parts are fitted, this way the engine still maintains it's integrity.

If you regrind and rebore you are immediately compromising the integrity and reducing the longevity of the engine compared to hone and polish.

The big question here is did they charge you for a rebore and regrind or a hone and polish as the two have dramatically different levels of labour associated with them and obviously one is a lot cheaper than the other.

 

[Howard 22]

Pretty poor to not list what was done!

However, if the engine is now running well and the problems have been fixed then they could argue that they have fulfilled the contract. I would not, however, be happy without a full breakdown of the repair, parts replaced, findings etc.

Haven't fitted it yet. I'm debating whether to return it.
Yes, I would have liked to know what I have paid for but when I asked they were pretty vague and seemed miffed that I dare to ask! I could probably press for this but I was mainly interested in the 'big' items like the re-bore and the re-grind.

 

[DSM10000]

It cost £2.2k so not cheap.

I can't see how they can claim the work done is better than a re-bore or a regrind as the bores and the crank still have 147,000 miles behind them and they haven't added any metal. The crank will if nothing else have some ovality on it.
I'm not asking the question from any financial standpoint, more in engineering terms.

A re-bore and crank re-grind will not add metal but take it away.

If they are saying that there was minimal bore wear (not unusual in MB engines) then you could argue from an engineering perspective that taking away as little metal as possible from a cylinder or crank journal is the best option.

As long as the bores are smooth and new pistons and rings are properly fitted and also as long as the crankshaft is smooth, not out of round and provides a good fit for the main bearing shells then all should be well.

I would still be annoyed at the rather poor communication from the company especially with a bill of over £2000. That price did not include removing and re-fitting????

Do you know what caused the original problem?

 

[flango]

It cost £2.2k so not cheap.

Not sure where you are and we dont have a parts list but £2.2k sounds like they are having a laugh, we used to rebuild loads of these and even with crank regrinds and rebores never got anywhere near that figure. If it were in a bad state then the easiest option is to replace it all with a remanufactured engine from Crewe engines who have been doing MB engines for about the last 40 years. If the crank and bores were good then it is the cheapest of all options

 

[Howard 22]

If the bores and crank are within spec then there is no need to regrind and rebore and this is actually the best option as long as they are honed and polished before any new parts are fitted, this way the engine still maintains it's integrity.

If you regrind and rebore you are immediately compromising the integrity and reducing the longevity of the engine compared to hone and polish.

The big question here is did they charge you for a rebore and regrind or a hone and polish as the two have dramatically different levels of labour associated with them and obviously one is a lot cheaper than the other.

That actually coincides with what they are saying, that the engine is stronger without the re-bore and re-grind. Why do you think it would compromise the integrity? These are fairly standard procedures for an engine surely?
The question of cost is next on my agenda as yes, in theory, they have charged for this to be carried out as the price was inclusive. That would be my next tack if I don't return it.

 

[DSM10000]

Re-bore and re-grinding crankshafts are hardly standard procedures with modern engines.

As Ian (flango) has said, removing metal from critical parts will leave you with an engine that does not have the original design integrity although if done correctly will still leave you with an engine fit for purpose.

 

[Howard 22]

A re-bore and crank re-grind will not add metal but take it away.

If they are saying that there was minimal bore wear (not unusual in MB engines) then you could argue from an engineering perspective that taking away as little metal as possible from a cylinder or crank journal is the best option.

As long as the bores are smooth and new pistons and rings are properly fitted and also as long as the crankshaft is smooth, not out of round and provides a good fit for the main bearing shells then all should be well.

I would still be annoyed at the rather poor communication from the company especially with a bill of over £2000. That price did not include removing and re-fitting????

Do you know what caused the original problem?

Yes, I realise that these processes remove metal, what I was trying (badly) to communicate was that honing and polishing doesn't restore anything to its original size. It actually takes away metal on a miniscule basis so the components still have 147,000 miles of wear behind them.
No the price was for the engine only. I have an ex MB mechanic doing the fitting.
They seem to operate on the basis that the engine goes through a standard process and they know what they are doing. Like you, I would have preferred a list of the work done and maybe I can insist on this.

 

[DSM10000]

I am sorry if I am misunderstanding you but how can the engine components be restored to their original size? You do not add metal to a cylinder bore (unless you have wet liners and replace it) and you would not generally add metal to the crankshaft. You remove damaged areas, clean, polish, hone as required and fit oversize pistons, rings and bearing shells so that everything matches.

 

[jotter22]

you seem put out by the fact that you have not had a re-bore and re-grind i would have thought to have been told your engine did not require this would be more greatly accepted your dilemma as i see it is now you would expect some cash reimbursement as the end result was far more cost effective than the original planned works!

Tony.

 

[Howard 22]

Not sure where you are and we dont have a parts list but £2.2k sounds like they are having a laugh, we used to rebuild loads of these and even with crank regrinds and rebores never got anywhere near that figure. If it were in a bad state then the easiest option is to replace it all with a remanufactured engine from Crewe engines who have been doing MB engines for about the last 40 years. If the crank and bores were good then it is the cheapest of all options

Sorry but I had to smile at that one. The £2.2k included vat and the work was done by.......Crewe Engines!!!! You have probably answered my original question with that last endorsement!!

 

[Howard 22]

you seem put out by the fact that you have not had a re-bore and re-grind i would have thought to have been told your engine did not require this would be more greatly accepted your dilemma as i see it is now you would expect some cash reimbursement as the end result was far more cost effective than the original planned works!

Tony.

No, it was never about the money. All I want out of this is the best result. As I said in my second post I want to be reasonable. Given the mileage and what was said on their website I expected them to re-bore and re-grind as a matter of course. I was more concerned at leaving worn parts more or less as they were.

 

[Howard 22]

I am sorry if I am misunderstanding you but how can the engine components be restored to their original size? You do not add metal to a cylinder bore (unless you have wet liners and replace it) and you would not generally add metal to the crankshaft. You remove damaged areas, clean, polish, hone as required and fit oversize pistons, rings and bearing shells so that everything matches.

You have taken what I said a little too literally. I wasn't trying to say they could add metal, just a figure of speech really.

 

[flango]

Sorry but I had to smile at that one. The £2.2k included vat and the work was done by.......Crewe Engines!!!! You have probably answered my original question with that last endorsement!!

Ah, have Crewe engines re manufactured your own engine or have they took your engine to remanufacture and supplied you with another engine? Have you checked the engine numbers?

If its done by Crewe you dont have a worry we dealt with them for years and never once had any complaints about the work, not sure who you are talking to but we used to get a blow by blow account of exactly what had been done to an engine they are by far one of the most competent engine rebuilders out there