Here's one for ya, what kills an intake valve?
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Joined: Sep 2013
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From: Glendale, WI
Here's one for ya, what kills an intake valve?
Hello again folks 
Just got my head back from the machine shop. Surprisingly, 4/5 cylinders on this 20 year old, 270k mile hunk of aluminum had absolutely no leaks at all. The last one (actually #1), had a small leak. It was also the cylinder into which coolant was leaking due to a blown headgasket.
Right before I left I happened to ask the machinist for the valve which was replaced, and was surprised to see that it was an intake and not an exhaust. I've looked around the interwebs, but can't seem to find an answer as to what might have caused that valve to go bad. Looking at it, there is a small section (about a 60 degree arc) that has what looks to be extremely faint crack-like distortions in the metal. Faint enough that I can't get a picture with my phone camera. However, they don't seem to extend onto the sealing surface. Anyways, any idea what might have done this valve in, and if those little distortions are any kind of indicator?
Looking forward to some insight!
Just got my head back from the machine shop. Surprisingly, 4/5 cylinders on this 20 year old, 270k mile hunk of aluminum had absolutely no leaks at all. The last one (actually #1), had a small leak. It was also the cylinder into which coolant was leaking due to a blown headgasket.
Right before I left I happened to ask the machinist for the valve which was replaced, and was surprised to see that it was an intake and not an exhaust. I've looked around the interwebs, but can't seem to find an answer as to what might have caused that valve to go bad. Looking at it, there is a small section (about a 60 degree arc) that has what looks to be extremely faint crack-like distortions in the metal. Faint enough that I can't get a picture with my phone camera. However, they don't seem to extend onto the sealing surface. Anyways, any idea what might have done this valve in, and if those little distortions are any kind of indicator?
Looking forward to some insight!
Last edited by awfulwaffle; Oct 28, 2013 at 11:00 PM.
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Just a guess....
Aren't the exhaust valves sodium filled or something? Maybe one cylinder was getting hot (leaking injector or something?), and the exhaust valves were able to withstand the heat but the intake valves weren't
Aren't the exhaust valves sodium filled or something? Maybe one cylinder was getting hot (leaking injector or something?), and the exhaust valves were able to withstand the heat but the intake valves weren't
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Timing that is off enough to hit valves would hit more than one valve.
Bad gas would affect all cylinders.
If you had coolant leaking in that cylinder, the combustion process was likely affected in one way or another. If that causes crap to build up on the valve, it can damage it.
Bad gas would affect all cylinders.
If you had coolant leaking in that cylinder, the combustion process was likely affected in one way or another. If that causes crap to build up on the valve, it can damage it.
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Joined: Jul 2008
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From: Pac NW
Timing that is off enough to hit valves would hit more than one valve.
Bad gas would affect all cylinders.
If you had coolant leaking in that cylinder, the combustion process was likely affected in one way or another. If that causes crap to build up on the valve, it can damage it.
Bad gas would affect all cylinders.
If you had coolant leaking in that cylinder, the combustion process was likely affected in one way or another. If that causes crap to build up on the valve, it can damage it.
Besides after that many miles, you really need to analyze it? Was the coolant leak on the intake side per chance?
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