Quick version 2008 V8 Runner. Losing Power 2 months ago, battery was old, it was cold, figured battery was going. Voltage meter showed alternator was not working correctly. Took to mechanic, found the cam seal was leaking into the alternator, thus causing sporadic charging. Replaced both cam seals, valve cover gaskets, while it was opened up had them replace water pump, and timing kit. Guy working on it ended up getting sick with covid, someone else picked up the work, and when they were removing it from the shop they had an issue with the Valves getting bent #3 and 4. Valves sent out, complete valve job? Adjust Lash/R/R Cams, Rocker Assembly. The shop they sent it to took forever, and finally had another shop get it done.

Talking to them, they said if its on them, they'd take care of it. Good people, but they're saying that it was something wrong with the lifters so the damage was due to that and not to a timing belt. Meanwhile it sounds like a diesel. Is running fine otherwise.

IS there any other way Valves get bent that could be a cause of Lifters or power loss? Good shop for me in the past, seems to be one thing after another, just getting the feeling that valves don't bend unless something gets put together wrong. Thoughts or tips appreciated.

"It was something wrong with the lifters" is not a valid mechanical diagnosis, it's just technically illiterate gibberish. If the shop wants to evade responsibility for destroying your engine, then they should explain what went wrong without you having to search the internet for an excuse they can use.

It sounds to me like they installed the new timing set incorrectly… If it was not dieseling before you took it in, and now the valves are bent and it is dieseling… There's only one way it could've gotten that way.

/SNIP

To be honest, this is all I'd need to know.

I'd want the whole engine inspected...heads, cylinders, pistons, block etc...then fixed, and I'd want documentation (including pictures) along with a warranty.

Random thoughts: I know strange things happen, but the alternator is down low on the passenger's side and the cam on bank 2 is up high.

How much oil were you losing through the bad seal? I suppose it's possible that oil could have dripped down and contaminated the alternator, but there is a lot of real estate to cover...not to mention I feel like the timing belt itself would have been oily.

Prior to it going in for the alternator, I didn't notice any oil spots or anything in the driveway to lead me to think it was leaking. But truthfully hadn't checked the oil level in probably a month. Belt was due mileage and years wise. Good advice on documentation.

It sounds like the mechanics didn't do the timing belt properly and screwed up the head causing damage to the lifters. I'd be threatening the BBB to them TBH. Or take it to a civil lawyer to ask what your rights are in this case.

I will tell you exactly what happened:

Upon reassembly, the mechanic accidentally swapped the Left cam wheel for the Right cam wheel. This caused the timing to be way off for most cylinders and exactly opposite for cylinder 3. When the mechanic attempted to start the engine, obviously it did not fire, but made a clanking sound. Upon reinspection, the mechanic noticed that the cam wheels were swapped because the computer stated that there was a "crank/cam relational timing error" code in the ECU. The mechanic then put the cam wheels on the correct sides of the engine, started the engine and noted excessive noise in some of the valve train. After checking compression, it was noted that cyl 3 had low compression -- this just happens to be the cylinder in which the piston contacted the valves, but it did not happen on any other cylinders because the timing belt kept all other valves from contacting any other pistons.

Next, the shop looked up the price of simply getting new heads and swapping them out real quick and noticed that the price of new heads is so high that they would not make any money on the job and then informed you that "the head has problems" and needs to go to a machine shop for repair.

I may have had direct personal experience with this exact thing and will never take my truck to a "shop" ever again... its either me or the dealer doing the work.

There's no doubt in my mind that the shop screwed up with the timing belt. Got it out of time some how. It's a tough pill to swallow for a shop but it's there's to eat. I believe in coincidence to a certain extent but this one is too unlikely. I'd give them the opportunity to correct it but if they acted like they weren't going to I'd contact the magistrate or whomever handles small claims in your area. No way this happened on its own.

"They" the first, second or third shop did something wrong.

Just an FYI, your engine doesn't have lifers, they either don't know what they are talking about (not good) or just deceiving you to try and get you to go away and not blame them, it's an overhead cam engine, meaning the cams are in direct contact with the valves and have no lifters, even if these engines had lifters the lifer would have to get longer to cause damage to the valve by causing the valve to travel further than it would under any normal condition and hit a piston which can't happen, there is no scenario that can cause a lifer to get longer, in engines that have lifers, there are 2 different types of lifers, solid lifers and hydraulic lifers, a solid lifer are just that a solid piece of steel and can't get longer, a hydraulic lifter has a solid steel but hollow body but has a small piston inside of it and when the engine starts that small piston has oil pressure pushing it up inside the lifter's body to cushion the force of opening the of the valve resulting in a smoother running engine and less wear on the other parts involved in opening the valves, vintage engines and racing engines use solid lifers, any modern engine that has lifters would use hydraulic lifers, but most if not all modern engines now use overhead cams.

I was waiting for this to come up since the first post.

Engine doesn't have lifters... @Seymore Butts pointed out it's just illiterate jibberish spouted out. (lol'd at screen name, thank you.)

Lifters are a domestic thing... I don't think any Toyota engine has had lifters since the early 80's.

Duffdog's explanation is likely the case, speculation as it may be. Don't take the truck back to that shop if you can help it... they'll screw new things up while trying to fix the problems already there. The 1UZ is a fairly complicated engine, I'd only trust shops/techs that have plenty of experience with them.

Perhaps a new long block from Toyota and send them the bill?

The following doesn't excuse the fact that the shop wrecked your engine....it's more of an informational thing.

The 2UZ-FE doesn't have a lifter in the sense that most are familiar with...ie like in a domestic V8. The adjusting shim sits on it.

While I haven't rebuilt a head off a 4.7, I have rebuilt a couple 1MZ-FEs that have the same basic design.

This pic is of the V6 since it shows better than the V8 one I have. I'll post the V8 one below

Toyota part number 1375150031

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It's #13 in this diagram.

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While that diagram calls that a lifter, it's not what a true lifter is, it's a cup that sits on top of the valve and doesn't lift anything, the cam lobe pushes the cup down and thus pushes the valve down which opens the valve, a true lifter sits on the cam lobe and get lifted up which pushes a pushrod up into a rocker arm which pivots and pushes down on the valve and opens the valve.

I agree 100%. I hope I didn't come across as argumentative....I tried not to.

My goal was to give him some information so when he pursues this, he doesn't have a bunch more "tech-speak" thrown at him.

L-I-F-T-E-R

Sorry ;-)