Started violently shaking at 70mph. Cyl#5 broken valve spring

Lol, op - tell the dealer to shove a 2jz in there

 

I just don't see how it can pass quality control and then fail completely so soon.

The cynical nature in people will point out that quality control sucks, but in reality this is a mature product and a mature industry.

I can't comprehend how it got to be zero compression.

 

Well the 3.5 is relatively new. Not as proven as the 4.0. Op could have been getting on it on the road, hit a couple of bumps and boom. Dead.

 

Vavle retainer falure? Due to improper seating, it was a friday and engine assemblers were like lets get out now?

 

Have seen valve troubles before on the TW, #1 cylinder. Low miles. Could have something to do with simulated atkinson timing method. But could be broken valve spring, retainer problem, etc.

 

I'm sure they'll really get into it. This is the kind of issue that can cause huge $$$$ recalls.

 

I don't have the wealth of experience that some have when it comes to the causes of engine failure, but I was looking at two potential reasons for the failure.

1. no compression due to loose mechanical connection.

2. No compression due to very large gap between piston and sleeve.

I suppose you can come up with a long list of causes for each of those two failures, but did I miss a third scenario?

I thought about hard driving, but unless it was driven beyond redline for an extended period, or if there were not underlying preexisting damage, I don't see how with of these two causes could be attributed to the severity of engine load.

 

I just can't get over what the hell is toyota doing. They can build stout motors if they wanted to
it's like they are too afraid to go out of the box. My old 09 cts-v was pushing 650rwhp to the wheels on a new cam, pushrods, and heads with a couple extra psi. It had zero issues when i got rid of it at 100k

 

That's why I mentioned bumps in the road, Trac control can kick in and really throw fuel off for that split second under heavy acceleration

 

That's my point. In this case it is a little more than a spec being out of whack and throwing a code on a sensitive engine. "No compression" is pretty major.

 

This thread is almost as scary as me sitting in the Starbucks parking lot next to the dentist waiting for my gf while soccer moms carelessly park their Tahoe’s 6 inches from my truck at highway speeds and all the kids fling there doors open like they’re pulling up to a fuckin chucky cheese. Good read though.

 

That's why I always break my new cars in hard and change the oil at like 300 miles. If it's gonna break due to a qc better it do it early on. Especially coming from hp cars last thing you need to do is build hp ontop of a weak foundation

 

It's been around since 2004. It was upgraded to include Atkinson cycle in 2015. But the same basic architecture is still there.

 

With Tacoma's the theory is similar because we add weight, body armor, winches etc. Stresses the motor no different than hp increase

 

Than the atkinson cycle could be the weak link like you mentioned

 

If op is still around may I ask what dealership you purchased from. I am from mass and have used quite a few dealers would be interested to see how they deal with this situation.

 

I believe it was noted to be corroded valve seats?

 

Gawd I hate the CTS rear carrier bushing. Makes me glad me nor anyone in my immediate family drive a GM product

 

Pucker factor 10, for sure. I'd have to get up and move the truck further out in the lot.

 

If that's the case then what are they using for the seals ? Recycled Tacoma frames ?