Advice from diesel expert needed please.

[woolybanana]

Can anyone please tell me how one tests the crankshaft,, crankshaft bearings and block in a diesel engine after the cam belt and shaft have blown and the pistons have been hit by the valves.

[Mme poivre]

Hi Wooly

Rich Says give hime some more inforamations and he might be able to advise you :-)

[AnOther]

Oops[:(]

Without a total strip down there is no way to conclusively determine what damage might have been done but as a basic check if the crank turns and the pistons reach the same levels in the bores that could be taken as a reasonable indication that all is OK. Significant damage to the block would normally be self evident. It's fairly unusual to lose a block or the bottom end in a cam belt valve crash.

How badly are the pistons damaged, if it is relatively minor, and you wouldn't even consider reassembling an engine with seriously damaged pistons, that of itself is a good indication that the damage has been lmited to pistons and head. A photo of the pistons might be useful.

What is the car ?

No difference between a diesel engine or petrol in this regard BTW [;-)]

[woolybanana]

Hello Mrs Pepper, well, as you know, CC engine seized and the thing has been expertized. They say that the block could have been saved, I made them change the engine for a standard replacement one.

The cam belt went and the cam shaft was shattered and the pistons stamped if not broken. It occurs to me that before one can say if the crankshaft has not been damaged and the crankshaft bearings, and the piston casings, there has to be some sort of test carried out to see if they are good or not. Which they do not seem to have done, and are now saying I could have salvaged the block.

So, I just was trying to find out if there is a test for the crankshaft and bearings and block which should have been done and which I think they did not do.

Confused? Me too, but I am trying to get me money back off the insurance people who are, as you know I expect, not born of man or woman, but of stone! 

You ok Mrs Pepper?

[woolybanana]

Sorry Ernie, crossed messages.

I just don't know how deep the damage was but am worried they wanted to do a quick fix rather than a proper job, as cost is the only thing they seem interested in.

[Théière]

[quote user="AnOther"]Oops[:(]


No difference between a diesel engine or petrol in this regard BTW [;-)]

[/quote]

Diesel cranks and blocks have to cope with much more load due to the compression 22-1 compared to 7-1  for petrol, so are much stronger. That doesn't mean the the shell bearings haven't been compressed under the extreme load applied when it went bang. Removal and replacement of bearings together with putting the crank and rods on a test bed is the only way to be sure.

[Quillan]

As Ernie says you need to strip the engine because the only way to tell is to physically examine the shells in the bearings as well as the crankshaft which could require some for of NDT (none destructive testing) like dye or ultrasonic. To be honest if it were me I would have prefered to have a recon fitted as it's normally a complete rebuild and you should get a warranty.

[woolybanana]

That, Q, is what I have, but getting the insurance people to admit the necessity of it on paper is another matter. Still about a grand outstanding on my side before the opposition expert makes his play!

[Chancer]

No_one will know without stripping the remainder of the engine but (and its a conditional but) they are probably right that the block and crank could have been saved and re_used.

I do think that you did the right thing in specifying a new motro though as they could easily have cocked something else up or missed something important.

When a cam belt lets go its usual for the valves to make contact with the pistons and bend, the valve guides and seats in the cylinder head may also get damaged which could entail replacement of the head, the camshaft usually survives intact although it appears that yours didnt.

You are the left with the short block to inspect, if the pistons have only been lightly kissed by the valves then  probably  no other damage has been done, if the engine has inclined valves this is often the case.

If there is significant piston damage then they must be removed to see if the upper ring grooves are distorted requiring replacement.

Now we get on to what is left of the engine and is the bargaining point, the rods, crank and block.

One or more rods could be bent but only if there were massive piston damage, the bottom ends of diesel engines are massively strong. beznt rods can be straigtened but no-one does these days except for exotica.

If rods are bent then it normal practice to replace the bearings as well but they are unlikely to have been damaged.

There is very little chance that the crank or bock will have been damaged, this would only have happened if the engine had thrown a rod which is clearly not the case.

You made the right decision for your pice of mind to specify a new engine, at that time a visual examination of the block together with rtotating the crank by hand would have been enough to have been 99% certain whether what remained was serviceable or otherwise.

Good luck with the negotiations Wooly.

Editted. If they, or your wallet had convinced you to keep the existing block and bottom end any damage would probably (that word again) be visible when replacing the pistons and if left would probably be evident when the engine was started, I doubt that the insurers would consider ultrasound or other non destructive testing of the components, this normally being reserved for highly sterssed racing engines or light aircraft.

Let me put it to you another way, if I were repairing my own camping car engine and was reasonably happy that the piston damage was minimal then I woud rebuild the engine re-using the block and crank, I would inspect the bearings and only replace them if they were worn, I really dont believe that they woud be damaged but the rods not.

If i were in your shoes and some garage was doing the repairs for the insurers I too would insist on a new short or even full engine and bite the bullet regarding the cost (although you should battle with them) there is just too much risk of someone getting something wrong for me to have peace of mind.

I dread to think what the final cost to the insurers is going to be with all this faffing about and experts here there and everywhere for a relatively banal cam belt letting go.

[AnOther]

I'm confused Wooly, repaired or replaced why are your insurance paying out for a siezed engine in the first place ?

[woolybanana]

Thank you guys for all the advice.

If fact, the cam belt went because it was cut by a bit of protective cowling which had been badly refitted by the servicing garage and which had then shattered and flown off, with all the subsequent damage. It took the experts a moment or two to find the cause but they have done so.

My 'assurance juridique' have taken it on and are satisfied we are right to pursue a claim. The debate is whether I should have made the garage put in a replacement engine or not

The sum my assurer wants to ask the other side for is just a bit short of the total cost of a replacement engine so I shouldn't come out of it too badly provided they accept the figure, but I think there will be a bit of negotiating yet.

[powerdesal]

[quote user="Chancer"]

 

Let me put it to you another way, if I were repairing my own camping car engine and was reasonably happy that the piston damage was minimal then I woud rebuild the engine re-using the block and crank, I would inspect the bearings and only replace them if they were worn, I really dont believe that they woud be damaged but the rods not.

[/quote]

Having rebuilt a number of engines over the years I would ALWAYS replace the big end bearing shells, irrespective of how worn they may or may not have appeared. Similarly rings are automatically changed, as is the clutch and release bearing. Its false economy IMHO to not change them given the hassle of subsequent early failure (if it occurs - which it does according to Sods law)

[woolybanana]

Yes, PD, I am sure you are right but these are insurance companies and they are mean faztherless people who only want the job done cheap.

[nomoss]

woolybanana

In your situation I would simply not have accepted the garage's just replacing the top end of the engine without my being absolutely sure the bottom end was undamaged, especially as the pistons hit the valves hard enough to break the camshaft(s)

That would mean a complete tear-down. inspection, possible replacement of parts, and reassembly, something that few garages want (or are equipped) to do these days. Most, if not all, are far more likely to fit an exchange unit. These, normally being being rebuilt by specialists with all the parts and equipment to hand, usually work out cheaper than the labour, parts and hassle of garages doing complete engine rebuilds theselves, plus they don't have to carry a warranty for the engine.

The insurance company could argue that, by your now having a rebuilt engine, you have better than before (depending on the mileage of the car), and could try to apply a charge for that. However, the residual value of the old engine is taken into account in the price for an exchange unit.

 

[woolybanana]

Yes, nomoss, that is the kind of detail we are now into. The exchange unit is very good so far

[nomoss]

There could be a problem in that (as you said) you made the garage replace the engine. This should normally have been agreed by the insurers if they were already involved. Then you would probably have had some more expertise involved before any agreement was reached [:)]

If not, it's all very well for the expert to now say the block could have been saved - did he strip it down to substantiate his statement? maybe you should insist the insurance pay for that - but you can argue that you were strongly advised that the crankshaft, bearings and rods were very likely damaged. Did the garage recommend stripping and rebuilding the engine at the time?

[Chancer]

[quote user="powerdesal"][quote user="Chancer"] [/quote]

Having rebuilt a number of engines over the years I would ALWAYS replace the big end bearing shells, irrespective of how worn they may or may not have appeared. Similarly rings are automatically changed, as is the clutch and release bearing. Its false economy IMHO to not change them given the hassle of subsequent early failure (if it occurs - which it does according to Sods law)

[/quote]

Until about 10 years ago I would have wholeheartedly agreed with you P, and if it were an old engine or even a low mileage older generation engine I would change all that you say as a matter of precaution, what changed the way I look at things was doing literally hundreds of rebuilds on race engines either preventative, where actually its better for the rebuilder to change all these bits to charge the customer, or after things letting go such as valve trains; with the less scrupulous rebuilders especially when the well heeled customers have their engine refreshed every season the parts just do a merry go round between different customers engines.

Modern engine are built to such close tolerances, modern oils and filtration so good, oil pumps so well made that changing perfectly good and bedded in bearings and rings has no real beneficial effect and can have the opposite, to the doubtfull nature of a lot of parts in the OEM supply chain makes changing anything a risk

The above naturally does not apply if any of these parts show signs of wear, oil contamination or the oil pump shows signs of having passed debris or abrasives.

Wooly it looks like after all the paperasse has been shuffled you wont be too fa out of pocket and have a new engine, I am quite impressed with the tenacity of your insurers considering how this started out with the CC garage, was it them that had done the service? Is it something that you paid for or they claimed had been done before resale?

[woolybanana]

There were three experts in the end, and it did take three months to find the cause. But I dont think any one of them actually had it stripped down to check the crankshaft and bearings etc.

Once they had found the cause I had it put back on the road as I wasnt bloody waiting any longer. I'd still be waiting now if I had waited for them to agree finally.

[Quillan]

The thing is Wooly that you have an exchange engine. Now I don't know how it works in France but in the UK your old engine goes back to the company that the exchange engine came from and they will strip it down, rebuild it and then send it out too somebody else in the same boat (or camping car [;-)]). Theoretically they (the insurers) could ask the company to say what was actually wrong with the engine but with most companies that do this sort of thing will regrind the crankshaft, replace all bearing and shells, pistons and rings etc because they give a guarantee and its not worth the hassle just to fix the broken bits because to them if the engine blows up 6 months after installation its going to be a load of grief (and expence) to them.

[Mme poivre]

HI Wooly

Sorry for the lack of reply Mr Poivre is on the road but as the owwers of two cars whose cam belt snapped last summer he ususally would have some sound advice. One going after only 5000 miles on new cam belt :-( but all sorted both cars running well now.

10 days and counting lol see you in August if not before.

[mint]

What, Mme P and Wooly having an assignation in August?

To keep up with the latest happenings, it's clear that you have to read all the threads very carefully indeed.

There're subliminal and other messages all buried in these here posts......

Where are the conspiracy theorists when you need them?

[woolybanana]

Mad Poivre assembles all the conspiracy theorists plus a few mudbloods and locals at her place in August and I take the CC so I can get rat-posteriored and loud and late and be a real bore. Then sleep it off in the church car park afterwards. This year she is doing buffet egg and bacon breakfast the next morning. Strong girl is Mad Poivre.[6]

[Quillan]

[quote user="woolybanana"]Mad Poivre assembles all the conspiracy theorists plus a few mudbloods and locals at her place in August and I take the CC so I can get rat-posteriored and loud and late and be a real bore. Then sleep it off in the church car park afterwards. This year she is doing buffet egg and bacon breakfast the next morning. Strong girl is Mad Poivre.[6][/quote]

I wonder if they are both ........ no, no, I won't go there I might get 'bitten' by a 'dog'. [;-)]

[Mme poivre]

Ha Ha Mr poivre might just have somthing to say to that mr Quillan

And Wooly you know your wish is my command ha ha any particular type of bacon preferred?  Any way last year it was nearly breakfast time anyway lol