Sanity check please - is the customer wrong, or am I? 3

[Mongrel]

As the title says. I recently quoted on a minor in-frame overhaul of a light truck engine. TM4600 used in the Ford Trader/Mazda Titan, to be precise. This included liners, pistons, rings and bearings, plus having the cylinder head overhauled and supply new VRS and sump gasket. And two new pushrods.
Story was: truck overheated due to torn lower radiator hose. Operator wasn't paying attention and had no idea till it seized. On inspection, the engine turned by hand, very stiff, had two bent pushrods and very low compression. Stripped the head and sump, found no bent valves but evidence of burnt exhaust seats. On removal of the pistons, they presented severe galling with some cracks to the ring lands, but otherwise intact. Conrod and main bearings all in good condition, no serious wear or evidence of overheat apart from piston/liner contact on the thrust faces.
Fast forward a few weeks; the head has been done, parts arrived, and I've reassembled it (head bolts pre-torqued only until I confirm it turns properly).
At this point I discover that the cam isn't moving. Strip the timing case and find the cam gear bolt and Woodruff key sheared. After replacing those - still not turning. Lifters also appeared stuck.
Stripped it back down, neither myself nor the machine shop (established 60 years and head machinist 35 years experience) can remove this thing. It runs no cam bearings and appears to have welded itself into the tunnel.
So at this point we're looking for another s/h block and cam, and here's where I would like opinions:
Is this my fault for not checking the cam rotated when tearing down the engine? With a block-mounted cam, and no damage to the bearings, I simply felt no need to!
On the other hand, the customer (a friend of a friend), contends that the quoted amount is all he should pay, of course.
While my machine shop agrees with me and so do the friends I have made in the trade, I'm starting to second-guess myself though. It's been a long time since I had a serious warranty issue and maybe I just got complacent. Maybe they're just being nice and I really did screw up... Would you guys have checked the cam given the symptoms described?

 

[SwinnyGG]

I hate to pile on... but I probably would've checked it, knowing that there were problems in the valve train.

Whether or not you have a case for not having to absorb this cost yourself...

Does your invoice or other contract state specifically what you planned to R&R initially?

If your customer has signed a purchase order or work order with a detailed list of parts and labor to be performed, he's signed up for the cost associated with only those parts and only that labor. Any additional work required to repair issues discovered during the work are additional. At least, that's how I would interpret things if I were a customer who had signed off on a detailed scope of work.

The other question you have to ask yourself..

If you have to eat the cost of a new block/cam, does that put you totally in the red for this job? If it does, is the amount you'll lose worth the word-of-mouth price you will pay by pissing off this single customer?

Only you can answer those questions, but it's what I'd be weighing if I were in your shoes.

 

[RodRico]

Yes, I would have checked the entire valve train in order to find what caused bent pushrods.

 

[TugboatEng]

If you can directly link the stuck cam to the overheat i.e. a distorted line bore due to a warped block I think the best course of action would be to offer to eat the cost of the work done so far and keep the engine yourself or get approval from the customer to continue with repairs at their cost. The distorted line bore doesn't explain the bent pushrods, though.

 

[3DDave]

If you quoted remove and replace of specific parts, then you could stick to the letter and leave your buddy's buddy with new parts in a garbage pile.

If you quoted make like new based on your assessment, and your assessment missed this big feature, then it's on you.

The former will likely affect unknown future income and the latter is more immediate but at least limited to readily identifiable costs.

It's not my money, but I'd eat the cost.

One thing that might be on the table is to build a heat box and toast the block to about 300F and see if any parts move then. Use care, insulating gloves, thorough degrease, and so forth. It doesn't take much distortion on a close fit to produce unexpectedly high loads. I'm guessing aluminum block and certainly steel camshaft? I don't know that this will result in a salvageable block, but if the cam comes out then you will be able to see how distorted it got.

 

[gruntguru]

The only time I ever experienced an engine seizure was my 850 mini. Tried to get it home with no water.

Long story short - camshaft seized in block. 850cc A-series runs cam direct in cast iron block.

je suis charlie

 

[Lou Scannon]

I think the customer should pay for any extra parts and labour needed to address the hidden issue, but only as if it had been found and done in the original job. I.e., customer should not have to pay for repeat teardown and rebuild labour, or extra gasket sets due to wastage on the original job. You could maybe eat a little on the new efforts, and reduce your markup on the additional parts, as a goodwill/business development gesture.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[gruntguru]

Of course this engine didn't seize in the first place. The camshaft seized and stripped the drive key. Inertia kept the crankshaft turning, pistons hit the two open valves and bent the corresponding pushrods.

je suis charlie

 

[Mongrel]

Thanks for the replies guys. Legally speaking, I only quoted on work performed - i.e. have head machined, supply and fit liners/pistons/bearings. Also, this guy is one of *those* customers; pissing him off doesn't factor into it as I won't be doing any further work for him. Word of mouth isn't a concern for me either as I already have more work than I can handle.
The issue I'm having is ethical, really - while this is the first time I've seen this in a little over 20 years, hindsight has me feeling I should've checked the cam anyway. My current thought is the following - owner to pay for replacement block and cam from a wrecker, I'll supply labour at no cost to finish the job. Currently I haven't been paid a cent, and have already invested extra time and money into removing the engine and workshop fees for trying to remove the seized cam. Plus the running around looking for replacement block.
For the record, it's an iron block/cam running no bearings, and Gruntguru is spot on with chain of events. I wrongly attributed the (slightly) bent rods to piston overexpansion, given that there were no bent valves or valve dents in the piston crowns.
Further information obtained from the owner today - he recalls noticing "unusual rattling" passing a road that is roughly 25 minutes from eventual point of failure, but did nothing about it. Truck was travelling at constant speed on a freeway, 100 kph.
So after that, the way I see it is: he cooked it, not me. But yes, I probably should have checked the cam on inspection. So I feel the fairest way to proceed would be the one I wrote above - he pays parts and I'll give the labour as a love job. At this point I just want to be shot of the whole mess, but I'm not the type to leave someone stuck after screwing up a diagnosis, either.

 

[romke]

i think when you note bent pushrods a thorough investigation of the valve actuation system would have been called for. there must be a reason why specific pushrods were bent and others seemed ok. a check would have made clear a seized camshaft.

from a commercial point of view things might be different. depending on local law your obligations might vary and also depending on the type of offer you made obligations may be such that "it's your fault". most offers are made at the basis of "for as far as we can assess the damage and the work to be done" and have some possibility to add extra charges for work that needs to be done that was not immediately evident.

whatever the case, the repair should include a working valve actuation mechanism and the cost for that imho should be borne by the customer (who actually destroyed the engine). whether you can apply that straight logic will depend on the local situation and the customer. sometimes it is wiser to choose a solution that may not necessarily be correct but is good for securing future business.

 

[RodRico]

I think it's fair to charge the customer the amount it would have cost them had you properly diagnosed the problem in the first place. In other words, they should pay for the block and cam, but none of the rework resulting from the faulty diagnosis. Just my opinion.

 

[3DDave]

I'm reminded of when a motor I had started backfiring; to the point that I ended up disconnecting the plug wires to that cylinder to move the vehicle. I took it to a place that does engine rebuilding and they informed me that the valves needed some work and a few other things. I asked how long they might take and I think it was a week or so. About 3 weeks in I asked how things were going and, not getting a good answer, made a trip to find out.

The top of the engine was still in pieces in various boxes. I don't recall clearly but I expect the valves and valve surfaces were done so it was unclear what the delay was. They had even repainted the head/intake manifold the correct color. I noticed the rocker arms on a rocker tube had not been cleaned; it looked just like it was in the motor and took it out to look at it. I moved the rocker arms a bit until I came upon one that did not turn. So I asked the guy if this was any sort of a problem (no kidding, right?) and he became a bit frustrated with the owner who had done the tear down. He took some time to work that arm loose and chucked the tube in a lathe to clean the baked-on oil off of it with some emery cloth. Probably that arm had a close fit, the path clogged a bit, lowering oil flow and voila. There wasn't any damage. I guess either the engine was a clearance engine or the force supplied by the piston was enough to move it without damage to it or the valve.

The big holdup on their end was that there was a plug missing in the intake manifold/head casting; they had taken it out for some reason, no doubt for cleaning purposes, only to realize that Ford had a better idea. Instead of sticking to the standard sized freeze plugs, this was on a 1/32 too big/too small increment. Make a half-million engines and you can order whatever you want for the factory. I guess the engine rebuilders were hoping the freeze plug fairy would eventually come to their rescue. As a solution to that I suggested an expanding rubber plug, which worked fine for many years until the gasoline vapors caused it to fail and get spit out. Which is why I had kept a spare in the glove box. I think the second one got an aluminum foil wrap to cut down the fuel exposure.

Not that this story has much to do with the OP. It's just weird how engine repair can progress more like Plinko than one would expect.

 

[CWB1]

Not to be impolite, but stateside we'd call you Bubba for trying a hillbilly rebuild. Some shops will still do so for close friends and family with the customer's approval/warning that it may cost a lot more to fix after, but even that is rather rare as you get into these questionable situations where even close relatives may sue if you inadvertently cause more damage by an improper repair.

Stateside we would say that you attempted a major in-frame (minor being top end only) on an engine that by OE and common sense should've been pulled, torn down, and had every component to be reused cleaned, inspected, and rebuilt. In-frames and other partial rebuilds are based on the premise that you find only normal wear in the long-block, not damage (galling, bent pushrods) or major potential damage (overheated engine). Personally I'd recommend rebuilding it properly, seeing if you can get the customer to compromise a bit on price, and quit the hillbilly shortcuts on others' vehicles.

 

[TugboatEng]

If you can't find a block you can cut the cam into pieces and hammer it out, line bore the block, and sleeve the cam journals with bronze bushings.

 

[Mongrel]

Appreciate the continued input, everyone. So far we haven't had any luck with heat and a 60-ton press; might try cutting the cam as suggested since another block appears impossible to source locally. These little trucks don't seem to have sold well here!
TBH, I really should have checked the cam. It just didn't occur to me. Stupid? Sure. I usually live by "do it once, do it right" and it's served me well. This time... eh, I don't know what happened. Certainly not a mistake I'll be making twice! It really had me questioning myself... which isn't a bad thing, from time to time.
At the end of the day, I'll gift the labour and he will pay the parts. It certainly wouldn't be ethical to ask for extra labour after a misdiagnosis, but it's also not right for him to ask me to pay for damage he caused. So, that's the arrangement we've come to.
And chalk up a lesson in always checking everything! Heh.

 

[3DDave]

Seems like the most equitable outcome.

 

[PackardV8]

FWIW, we had a similar jugfuck come along. We loosened the cam by sending the engine block through the bake oven. Overnight at 600 degrees will burn out the carbon and free galled parts.

Good luck.

jack vines

 

[itsmoked]

The arrangement you've come up with is probably the very best for the situation. Kudos on that.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[enginesrus]

Study this sort of thing on the various car forums. You will see they (the customer) loose all the time when it comes to the way some dealers and auto warranties work. Personally I would not have mentioned doing an inframe on a known over temp engine.
It should have been a total out of vehicle overhaul, you would for sure have discovered a cam that is stuck then.
Oh if this was some big dealer shop, they would pack up the parts and send the guy and his stuff on the way, and still bill him for all the work. He should be happy with what you are doing.