Chevy Colorado 5-cyl Grenaded
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Originally Posted By: bvance554
It sounds like the engine had a problem, and they found it during the smog test. Can't blame the shop for a faulty part.
Nope, they sent him out with a good smog and no discovery of anything faulty. I suspect he had still had some old gas in the truck that caused the test to initially fail, then pass after they kept the engine at max RPM with no load. Probably fatigued or cracked the stem at the base of the valve and it failed shortly thereafter. But as mentioned previously, I have no proof.
It sounds like the engine had a problem, and they found it during the smog test. Can't blame the shop for a faulty part.
Nope, they sent him out with a good smog and no discovery of anything faulty. I suspect he had still had some old gas in the truck that caused the test to initially fail, then pass after they kept the engine at max RPM with no load. Probably fatigued or cracked the stem at the base of the valve and it failed shortly thereafter. But as mentioned previously, I have no proof.
Originally Posted By: ArrestMeRedZ
Originally Posted By: bvance554
It sounds like the engine had a problem, and they found it during the smog test. Can't blame the shop for a faulty part.
Nope, they sent him out with a good smog and no discovery of anything faulty. I suspect he had still had some old gas in the truck that caused the test to initially fail, then pass after they kept the engine at max RPM with no load. Probably fatigued or cracked the stem at the base of the valve and it failed shortly thereafter. But as mentioned previously, I have no proof.
Ok. What I was saying is I highly doubt the shop broke the valve by doing a smog test. If you want to claim they did all I was saying is that the part was defective in the first place, and it was uncovered after the smog test. If you didnmt need smog testing it still would have broke at some point down the road.
Originally Posted By: bvance554
It sounds like the engine had a problem, and they found it during the smog test. Can't blame the shop for a faulty part.
Nope, they sent him out with a good smog and no discovery of anything faulty. I suspect he had still had some old gas in the truck that caused the test to initially fail, then pass after they kept the engine at max RPM with no load. Probably fatigued or cracked the stem at the base of the valve and it failed shortly thereafter. But as mentioned previously, I have no proof.
Ok. What I was saying is I highly doubt the shop broke the valve by doing a smog test. If you want to claim they did all I was saying is that the part was defective in the first place, and it was uncovered after the smog test. If you didnmt need smog testing it still would have broke at some point down the road.
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
They usually only rev them to 2500 rpm.which smog shop was it?
Chris, I'll have to check with him on which shop it was. From what he said, it wasn't 2500 RPM, but I would not bet a paycheck on it, considering the source. In fact, I didn't believe him at all until I found the shattered valve - about 60 % of the disk in three pieces, clean breaks with no distortion, discoloration or carbon noted.
I had many smog test over the last 30+ years. No smog station ever rev above 2500 RPM(may be 50-100 RPM over for a second and down to 2500 RPM). There are two tests, one is 1500 RPM and second one is 2500 RPM.
OVERKILL
$100 Site Donor 2021
Originally Posted By: ArrestMeRedZ
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
Read some of the posts in those threads I linked. That failure mode (a valve dropping and smoking a piston) is mentioned in there.
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
Read some of the posts in those threads I linked. That failure mode (a valve dropping and smoking a piston) is mentioned in there.
Don't they have to hook an inductive pickup from a plug wire to the smog computer? The all-knowing CARB might have an electronic record of this experience including a tech acting outside of the boundaries of the instructions. If you were on rollers in gear you'd be up against the redline-redline and not the 4K RPM neutral-redline.
But then they might also give test shops acting in an official capacity "governmental immunity".
Haters gonna hate. I'd be all over a rust free chassis with 22k.
But then they might also give test shops acting in an official capacity "governmental immunity".
Haters gonna hate. I'd be all over a rust free chassis with 22k.
Originally Posted By: OVERKILL
Originally Posted By: ArrestMeRedZ
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
Read some of the posts in those threads I linked. That failure mode (a valve dropping and smoking a piston) is mentioned in there.
I read they have Valve Seat issues, The one guy that posted about a dropped valve owns a V6 Terrain.
Originally Posted By: ArrestMeRedZ
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
Read some of the posts in those threads I linked. That failure mode (a valve dropping and smoking a piston) is mentioned in there.
I read they have Valve Seat issues, The one guy that posted about a dropped valve owns a V6 Terrain.
Originally Posted By: ArrestMeRedZ
It happened about three years short of the 10 year point and the parts of the engine I've seen are clean, but bad gas may have had an impact.
I'm not sure I agree with you about revving the engine. Bouncing a GM engine off the rev limiter with no load can't be beneficial. If it's a Honda, it probably doesn't matter.
OK, I would highly recommend draining the fuel tank before starting your new engine! Also have the Injectors Flowed/Tested, Flush the fuel lines etc. I had a customer let his 6.0L Chevy sit for a few years....When he went to crank it up....An Injector stuck open, Flooded the Cylinder, Hydro-Locked the engine & Bent a Connecting Rod. The other 7 Injectors were stuck closed....Go figure? The fuel we have had for the past 15 years goes bad FAST.
As far as the rev limiter, They are set very conservative for what a Bottom end/Valvetrain can handle. If them "Free Revving" the engine could really cause this....I would be a lot busier than I am now. Engines are one of the most bullet proof parts of an automobile as long as they don't get hot or ran out of oil.
A Honda being stouter than a GM engine, Really? You seem to have a level head on your shoulders?
It happened about three years short of the 10 year point and the parts of the engine I've seen are clean, but bad gas may have had an impact.
I'm not sure I agree with you about revving the engine. Bouncing a GM engine off the rev limiter with no load can't be beneficial. If it's a Honda, it probably doesn't matter.
OK, I would highly recommend draining the fuel tank before starting your new engine! Also have the Injectors Flowed/Tested, Flush the fuel lines etc. I had a customer let his 6.0L Chevy sit for a few years....When he went to crank it up....An Injector stuck open, Flooded the Cylinder, Hydro-Locked the engine & Bent a Connecting Rod. The other 7 Injectors were stuck closed....Go figure? The fuel we have had for the past 15 years goes bad FAST.
As far as the rev limiter, They are set very conservative for what a Bottom end/Valvetrain can handle. If them "Free Revving" the engine could really cause this....I would be a lot busier than I am now. Engines are one of the most bullet proof parts of an automobile as long as they don't get hot or ran out of oil.
A Honda being stouter than a GM engine, Really? You seem to have a level head on your shoulders?
I've had many vehicles smogged here in Kalifornia. The last time I went to a shop that had the waiting room next door to where they did the smog test. I could hear a very loud whine - and asked the guy at the desk (who I later found out owned the shop). He said my engine would only be turning around 2,000 - 2,500 RPM, that the whine I was hearing was from the dynamometer spinning.
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Originally Posted By: clinebarger
OK, I would highly recommend draining the fuel tank before starting your new engine! Also have the Injectors Flowed/Tested, Flush the fuel lines etc. I had a customer let his 6.0L Chevy sit for a few years....When he went to crank it up....An Injector stuck open, Flooded the Cylinder, Hydro-Locked the engine & Bent a Connecting Rod. The other 7 Injectors were stuck closed....Go figure? The fuel we have had for the past 15 years goes bad FAST.
As far as the rev limiter, They are set very conservative for what a Bottom end/Valvetrain can handle. If them "Free Revving" the engine could really cause this....I would be a lot busier than I am now. Engines are one of the most bullet proof parts of an automobile as long as they don't get hot or ran out of oil.
A Honda being stouter than a GM engine, Really? You seem to have a level head on your shoulders?
I plan on following that advice on draining the tank, flushing the lines and checking the injectors. As to Honda engines being stouter, I meant they can spin a lot higher, but in this case, yeah, I think they are. With GMs, I've had great luck with the LS, 5.7 Vortex and other V8 small blocks. Not so much with the smaller engines. I would much prefer almost any Honda engine to this 5-cyl or any of the 60 degree V-6s. Personal experience and opinion only.
I'll check out the valve seat once I have the truck back together and have time to pull the head. If that's the problem, I'll ditch the suspicion about the smog shop.
OK, I would highly recommend draining the fuel tank before starting your new engine! Also have the Injectors Flowed/Tested, Flush the fuel lines etc. I had a customer let his 6.0L Chevy sit for a few years....When he went to crank it up....An Injector stuck open, Flooded the Cylinder, Hydro-Locked the engine & Bent a Connecting Rod. The other 7 Injectors were stuck closed....Go figure? The fuel we have had for the past 15 years goes bad FAST.
As far as the rev limiter, They are set very conservative for what a Bottom end/Valvetrain can handle. If them "Free Revving" the engine could really cause this....I would be a lot busier than I am now. Engines are one of the most bullet proof parts of an automobile as long as they don't get hot or ran out of oil.
A Honda being stouter than a GM engine, Really? You seem to have a level head on your shoulders?
I plan on following that advice on draining the tank, flushing the lines and checking the injectors. As to Honda engines being stouter, I meant they can spin a lot higher, but in this case, yeah, I think they are. With GMs, I've had great luck with the LS, 5.7 Vortex and other V8 small blocks. Not so much with the smaller engines. I would much prefer almost any Honda engine to this 5-cyl or any of the 60 degree V-6s. Personal experience and opinion only.
I'll check out the valve seat once I have the truck back together and have time to pull the head. If that's the problem, I'll ditch the suspicion about the smog shop.
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Thanks to all with suggestions and support. Once this is done, I'll effectively have a new small truck.
Originally Posted By: clinebarger
They can rev it all day long, That would not happen to a healthy engine, The PCM has a rev limiter, You speak as if a 10 year old car with 22K is a good thing....It is probably what was wrong in the first place....Sticky valves.
Even my old "low speed" inline 6 had no problem spending a few minutes straight at the red line this winter while doing some snow wheeling!
Heck, a few minutes at 5500RPM and it stopped knocking for a few weeks!
The power steering pump's thoughts on the matter are a bit different. It's a bit more vocal these days
They can rev it all day long, That would not happen to a healthy engine, The PCM has a rev limiter, You speak as if a 10 year old car with 22K is a good thing....It is probably what was wrong in the first place....Sticky valves.
Even my old "low speed" inline 6 had no problem spending a few minutes straight at the red line this winter while doing some snow wheeling!
Heck, a few minutes at 5500RPM and it stopped knocking for a few weeks!
The power steering pump's thoughts on the matter are a bit different. It's a bit more vocal these days
I agree that a smog test should never involve really high revs...sounds like some goon work to me!
That said, the GM I-5 is not known as a high-end 'revver' of an engine...agree with the OP's comment that a Honda would have survived this.
That said, the GM I-5 is not known as a high-end 'revver' of an engine...agree with the OP's comment that a Honda would have survived this.
OVERKILL
$100 Site Donor 2021
Originally Posted By: clinebarger
Originally Posted By: OVERKILL
Originally Posted By: ArrestMeRedZ
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
Read some of the posts in those threads I linked. That failure mode (a valve dropping and smoking a piston) is mentioned in there.
I read they have Valve Seat issues, The one guy that posted about a dropped valve owns a V6 Terrain.
Correct, he did, good catch, I just went back and read it.
The other guy, whose i5 died just lost all compression in the one cylinder.
That said, depending on how the seats fail, if they come out, like on the Ford Focus SOHC i4, there is a possibility of them bending/dropping a valve when they go, leading to the type of failure noted in the OP.
Originally Posted By: OVERKILL
Originally Posted By: ArrestMeRedZ
That is possible, it's just I've never seen it before, and the timing of events is too much of a coincidence for me.
I got an incredible price on the crate motor, so I'm not going to be out on the deal.
Read some of the posts in those threads I linked. That failure mode (a valve dropping and smoking a piston) is mentioned in there.
I read they have Valve Seat issues, The one guy that posted about a dropped valve owns a V6 Terrain.
Correct, he did, good catch, I just went back and read it.
The other guy, whose i5 died just lost all compression in the one cylinder.
That said, depending on how the seats fail, if they come out, like on the Ford Focus SOHC i4, there is a possibility of them bending/dropping a valve when they go, leading to the type of failure noted in the OP.
I once visited a long-time machinist friend of mine as he was tearing down a 460 he'd built recently. The customer had dropped the motor into the service truck it had come out of which had been parked for a few years. There was a lot of gas in the dual tanks and gas is expensive so... That was a big mistake. There was all kinds of goo smeared on the pistons, cylinder walls, valve stems, etc from the bad fuel. It was bad enough that the engine stopped.
I once revived a '64 Plymouth Valiant that had been sitting a long time. The previous owner had been running the car once in a while. Well, he gummed up the valve stems so bad there were several bent pushrods.
What may have happened to your boy's truck is an intake valve stuck open and met the piston.
Drain that gas tank for sure.
I once revived a '64 Plymouth Valiant that had been sitting a long time. The previous owner had been running the car once in a while. Well, he gummed up the valve stems so bad there were several bent pushrods.
What may have happened to your boy's truck is an intake valve stuck open and met the piston.
Drain that gas tank for sure.
It might take me a while to get to it, but when I get a chance I'll tear the head apart and see if I can tell what went wrong. I'll post up here when I find out something.
Again, to all thanks for the information. I would have never thought of stuck valves or a valve seat being possible culprits. From other research, I see the engine is an interference design with tight valve to piston clearances, so any delays in closing could be catastrophic.
Again, to all thanks for the information. I would have never thought of stuck valves or a valve seat being possible culprits. From other research, I see the engine is an interference design with tight valve to piston clearances, so any delays in closing could be catastrophic.
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