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The other day a misfire code showed up so I took My Colorado to the dealership. After a day and a half of testing they determined that the #2 exhaust valve seat was worn. And needed to be replaced. So they ended up replacing to whole head with new updated valve seats. They said this is a common repair. Has anyone else had this problem?
 

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Its too hot in Texas!
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What year is your truck? I know they had a recall that delt with the head but I am not sure what the problem was
 

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US Army 19yrs and ......
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Well good for you!

I have 70K on mine 04 and no issues yet!!!!!!!!!!!!1
 

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US Army 19yrs and ......
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I know thgis issue is out there, but no issue here!
 

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US Army 19yrs and ......
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Well just so you know, bad valve seats do not cause a miss fire! Thats basic shit there. There is another issue!
 

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Lord Bearded One
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Had mine done like 9 months ago. Free repair FTW!!!

threw the code in Detriot (4 hours from home) while I was there on biz. I was changing spark plugs in the Auto Zone parking lot in Det in a freakin suit before I drove to Toledo and found a Chevy Dealership. Then drove all the way home in a broke ass truck. oh well.
 

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US Army 19yrs and ......
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If the valves don't close like they should, it will throw a misfire code.
Compression causes the valve to close either way, the seals do not throw a code.
 
Compression causes the valve to close either way, the seals do not throw a code.
Depends on how bad the problem is.

If it's bad enough, the seal will be warped to the point that the pressure leaks around half the valve = very little compression in the cylinder, a misfire from incorrect air/fuel ratio, and a CEL.

Joe, onc ethe damage rears it's head, nothing else will really get fucked up. The truck will just be way out of wack and run on 4 cylinders. it'll be out of balance, sound like a go-kart, and shake all over the place, but it won't tear anything else up unless you beat on it or do it for a LONG time. Slow and easy and you coulda driven it cross country as long as the ECU didn't shut you down, but nothing mechanical would have happened.
 

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US Army 19yrs and ......
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Depends on how bad the problem is.

If it's bad enough, the seal will be warped to the point that the pressure leaks around half the valve = very little compression in the cylinder, a misfire from incorrect air/fuel ratio, and a CEL.
Ok, fair enough. But that would have to be some woren ass seal and alot of blue smoke.
 
Ok, fair enough. But that would have to be some woren ass seal and alot of blue smoke.
Nope, no blue smoke. This is all in the intake/exhaust stream. Not the crankcase. Are you thinking worn Rings or Ringlands or maybe valve seals/guides?? The seats are what the valves sit on in the head in the combustion chamber.

here's a pic. The bronze is the valve guides, the valve seals are on the valve stem on the other end of that guide. The valve seats are the shiny area (look just inside the maroon colored circles here) where the valve head will seal up to because of valve spring pressure.

 

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US Army 19yrs and ......
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Dude, I will have to call you out here. We agree with you 99% of the time, but what happened to the L89's in the Camaros when the valve seals went bad........yup...blue smoke on start up til they were warmed up!
 
Valve SEALS is what you're talking about, not valve seats, which this thread and the 355 recall is about. Get your drunk'd ass off teh intArweb!



Ok, read above, I said the "the seal will be warped to the point that the pressure leaks around half the valve", and I meant the sealing edge of the valve seat. So I was mixing terms, but still said correct information... about valve seats. :p
 

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US Army 19yrs and ......
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Valve SEALS, not valve seats. Get your drunk'd ass off teh intArweb!
OK, your right, and I'm going for another bottle of Jack...............Time NOW!
 

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seats
[/quotation yea thats complete BS i gotta call you out it depends a bent burnt valve gets stuck compression dont push nothing ive had them crack chip an all if you get to much air its gonna fire an burn the gas but you wouldn't get your combustion it could worp an not have enough compression to create a strong combustion to slam the piston down before the next cylinder it fires stronger and makes it skip
 
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