Cylinder pressure issues???

Bought a used 2017 Toyota Tacoma, first day I got it home check engine cane on. Took it back to the dealership and has been there ever since Nov. 18th, the code it threw was for injector failure/low cylinder pressure. Ultimately the dealership is gonna take responsibility for the repairs and is ordering new heads and injectors. Showed me the old heads and the specific cylinder had a burnt valve, under further inspection it was loose and didn’t seat correctly allowing lose of pressure. Has anybody run across this problem? Once heads and injectors are replaced should that fix the issue or is there another source for the issue? Any ideas? Thanks in advance

 

Which valve intake side or exhaust? Unusual in the 3.5 engine leads me to believe it started with cooling issues. Anyway with new heads should be good to go.

 

Cylinder 3 intake valve...valve wouldn’t seat properly due to it being so loose. Cooling issue? Like maybe cylinder wasn’t cooling down properly or what?

 

if you havent noticed, if this happened to half of 3rd gen owners on this site
they would refuse fixing the truck and demand the dealership provide them with a new truck and accessories of their choice for the pain and suffering of having a defect on their truck.

 

A burnt valve can be from all kinds of things. Including defective parts from new.

I'd be less concerned about the root cause and grateful that the dealership is handling it for you.

But for the sake of curiosity........

Mileage on vehicle?

Previous owner leave any signs of mods or wheeling?

 

Not a common issue. I hope the dealer gets it fixed up for you, that really sucks.

 

Ok I’m sure it’s not very common issue as Toyota does make a great product hence such a large following. I’m merely asking because moving forward I’d like to know what to expect and also if I need to try and sale it ASAP and try again or what... dealership has already made the first month payment, they put me in a loaner vehicle, so I’ve not been too terribly inconvenienced by this but still I want the truck I’m paying for. Also mileage was just over 78,000 no signs of wheeling or mods other than a possible camper shell at one point in time, had one very slight unnoticeable chip just under cap on tailgate. Bottom of step bars have no slide marks or hard impact areas.

 

@OVTune , how does the ECU know cylinder pressure? My interest is piqued and has me curious!

 

I have probably read 20K+ posts on the 3rd gen. This is the first time on this issue. Just enjoy it.

 

Based on the power the coil used to fire the spark plug. It require a different amount of energy based on the on pressure. Can't recall the specifics but that's the general idea at least on a Ford. I assume Toyota is similar.

 

Interesting. Kinda like a relative compression check.

 

A valve can get into a non-sealing state for several reasons which may include but not limited to:
Carbon buildup
Physical valve damage
Sticking at the valve guide
Broken, damaged or weak valve spring

The valves by themselves can’t handle the extreme heat from the combustion process that’s why they are tucked up in the head against the seat to transfer heat.
A weak valve spring sounds like the culprit couldn’t keep the valve tight against the seat to transfer heat...pieces start to burn off around the edge of the valve which leads to a loss of cylinder pressure.

 

2nd time for me. There's another guy that blew his motor on here. Don't have a link srry.

 

I've never seen anyone burn a valve before. U remember the circumstances?

 

1. Well this is not the one, but found one. You replied in this thread too.

https://www.tacomaworld.com/threads/blown-head-gasket.606153/

2. This guy added too much oil blew the motor.

https://www.tacomaworld.com/threads/after-40k-mile-engine-misfire.638704/

3. Same engine not a tacoma. Blown.

https://www.tacomaworld.com/threads/2gr-fks-engine-failure.643500/

4. Another one.

https://www.tacomaworld.com/threads/2018-tacoma-major-engine-work-after-1-year.632469/

5. @Skydvrr this is the one. Valve issue motor blown.

https://www.tacomaworld.com/threads/engine-failure-at-35k.605928/

 

Not a valve issue tho. You're talking just general engine issues.

 

Damn he hydrolocked it haha

 

I'm talking catastrophic engine failure. I'm adding more links as I find them.

 

Fair enough. Keep sending em. They're fun reads haha.

 

Don't forget homeboy w the afe intake haha.