Exhaust valve failure #2 cylinder 2011 with EGR delete.

lmorris · May 18, 2016

Customer had Reductant repairs to do and opted for the delete package instead. Shop that did it said they put in a "Tow 90 hp" custom tune with emissions deleted. Ran for 3 days before the thing can to a stop. #2 glow plug tip broken, pulled the head and both exhaust valves are broken, one intake valve is broken and it's push rod is bent, also made a mess of the piston, bore and the head. Identical to the left bank valve failures we have seen. Seeing as I have never seen this failure on the right bank on a tuned truck I am leaning towards blaming the tuner. On the other hand there are a lot of trucks with the same set-up running around these parts that are problem free. I am stumped on a cause. Any suggestions?

jimmy57 · May 18, 2016

Would love to know the exhaust temps that tune created.

Does your autotopsy lead you to believe the intake was consequential damage from failed exhausts? Exh valves imbedded in pistons or witness marks from that? Sounds like that is the deal.

lmorris · May 18, 2016

The intake was definitely a result of the exhaust valve failure. may have been temperature related but I have another scenario to add to the mystery. Was on the phone with the customer discussing tuner options and he told me he did all the work for the delete himself. Was in the process of getting the lifting bracket set-up when I found a center punch and half a drill bit down in the valley. Then it hit me, the block off plate on the exhaust manifold had one factory bolt and one "other" bolt. He was obviously in there drilling out the broken bolt, I wonder if he dropped something into the manifold and it made it's way to the valve. It is the next port in line after the EGR tube. :facepalm: :surprise: :ohnoes:

Matt Saunoras · May 18, 2016

No other exhaust valves are cracked?

Keith Browning · May 19, 2016

I would not say this valve breaking phenomenon is just a left head thing. The first two of these engine failures with valve related issues were most certainly the right cylinder head. One was a F450 tow truck the other a F350 pick up. Both 2011 models. But I am going to admit that I haven't seen a valve related failure now for a couple of years. Knock on wood!!! Are you guys seeing valve failures on left heads only?

The timing of the failure to the delete is interesting though.

RyanG · May 19, 2016

Are there any indents anywhere that are shaped like the head of a bolt?

Matt Saunoras · May 19, 2016

Honestly I've only seen 4 valve failures and they are spaced so far apart time wise I can't remember which cylinders they occurred on.

I mentioned this before but a few years ago I did a shortblock on an 11 F-450 for main bearing failure. Upon removal and inspection of the heads I found that at least half of the exhaust valves in each head were cracked. In addition to the shortblock I installed 16 new exhaust valves. Even though they hadn't failed yet I was sure they would eventually. I saved 2 of these valves and I can take a pic if anyone wants to see

lmorris · May 19, 2016

No other exhaust valves are cracked?

The only damaged glow plug was #2, I didn't remove the left head though and didn't disassemble the right one. Customer only wanted to pay to determine what could have been the cause. He is purchasing another tuner, one that we have had very good success with. If it was something that fell in the exhaust manifold, well it definitely shouldn't happen again.

Are there any indents anywhere that are shaped like the head of a bolt?

Nothing that looked like a bolt head, but it may not have been a bolt, maybe some other debris. Only speculation at this point. Given others have seen this failure on the right bank makes me think it was on its way out and the tune may have pushed it over the edge.

Keith Browning · May 19, 2016

Usually a bolt will leave marks from the threads in the piston. Cant miss it. But in cases like these failures there is usually so much damage it is difficult to tell exactly what happened.

PowerSToKed · May 19, 2016

Don't think delete has anything to do with it. Just pulled right head off 2011 6.7 that has all 8 exhaust valves cracked and didn't even pull head for that reason.