Broken Valve Spring

[RavioliG]

Originally Posted by thomasmryan

is it possible you have an intake manifold leak?

It's possible, but to get the DI's as OP has, the manifold needs to come off, so I'm assuming the gasket was checked / resealed.

[sybrite]

They got the engine out today and found that the valve spring had gone bad. Hopefully this is the actual fix

[Element Tuning]

I wouldn't overlook the potential this is a valve rocker arm coming apart. Been there and done that unfortunately. Before a catastrophic failure the pin rocks partially out and it effects the valve lash which can result in just one cylinder misfiring.

Mine personal car did that before it catastrophically shot out the valve cover. Given all you've already done I would pull the valve cover and inspect cylinder #4 rockers!

Phil

[justatroll]

Originally Posted by sybrite

Took it next door to work and had a local guy that seems to be knowledgeable, .... Then he said the vacuum for that cylinder was very low (is compression the same?) and came to the conclusion that he thinks there is a burnt valve.
...?

Sounds like this is the guy that knows what he was talking about!

He must have pulled a vacuum on each cylinder while the valves were (supposed to be) closed and detected a leak bigger than some expected value on the cylinder in question.

That would point to a valve not closing properly or hard enough. (burnt valve is misshaped and bad spring means not pulling closed hard enough)

A leaking vacuum test could also point to a leaking DI seal, or rings, but those would leak the same under a pressure bleed-down test.

So it seems it would have been prudent to ask that original guy exactly what he meant by "leaking vacuum"

[Element Tuning]

Duh, I didn't see the post before mine. A broken single linear valve spring is really rare unless it was a rocker and the service writer had no idea what that is and told you it was a valve spring. LOL! Rocker failures have been common around here.

[sybrite]

Sounds like as soon as they get it running I might need to look to trade in. I really can't afford these expensive repairs if the potential for more internals to fail. I know it's 80k miles, but the car is only 3 years old. Kind of crazy since people talk about how long Subaru's last. I put a lot of highway miles on my cars, but I haven't really driven her that hard since I had her. Sure, every once in a while, but it just seems crappy to have these problems given that I have had all of the oil changes and services completed per the schedule with the dealership. Rarely have I ever had to use anything less than 93 in the tank, so I have taken good care of her.

[Element Tuning]

Yeah unfortunately there are just some known issues with this motor you have to deal with if you're unlucky.

[sybrite]

Originally Posted by Element Tuning

Yeah unfortunately there are just some known issues with this motor you have to deal with if you're unlucky.

Very true. It's the risk you take on getting a car in it's first model year. Still, I suppose I was fortunate to make it to 80k before anything major came up.

They are still waiting on the parts so it may be Monday or Tuesday when I figure out if this fixes it.

[GsxrMe]

Originally Posted by sybrite

Very true. It's the risk you take on getting a car in it's first model year. Still, I suppose I was fortunate to make it to 80k before anything major came up.

They are still waiting on the parts so it may be Monday or Tuesday when I figure out if this fixes it.

Start small like I don't know... maybe a burnt out sparkplug? Hm.....

[sybrite]

Alright, so I got her back today and she sounds great. They gave me the souvenirs in a box (broken valve spring). It was completely broken off a few spirals up (not sure if it was the top or bottom of the spring. But either way, I'm glad to have her back. Just unfortunately around $2800 later. I suppose, given them being the dealership, it could have been worse given all the work they did.

[GsxrMe]

Originally Posted by sybrite

Alright, so I got her back today and she sounds great. They gave me the souvenirs in a box (broken valve spring). It was completely broken off a few spirals up (not sure if it was the top or bottom of the spring. But either way, I'm glad to have her back. Just unfortunately around $2800 later. I suppose, given them being the dealership, it could have been worse given all the work they did.

Good lord! Broken valve spring? Is the head entirely factory?

Now I'm on pins and needles about this damn fa20 motor.

[sybrite]

Originally Posted by GsxrMe

Good lord! Broken valve spring? Is the head entirely factory?

Now I'm on pins and needles about this damn fa20 motor.

Yup. Everything sans the wheels and catback exhaust is fatory. It's my daily driver so I didn't really want to do anything to it. Apparently that didn't keep me from problems lol.

[sybrite]

Here is a picture of what the valve spring looked like. And the direct injector (which I guess wasn't technically bad).

[GsxrMe]

Originally Posted by sybrite

Here is a picture of what the valve spring looked like. And the direct injector (which I guess wasn't technically bad).

You sir are a lucky man. I'm so happy you didn't blow your engine and for a valve to break like that really really makes me question the quality control on these engines.