Very sick 2005
Thread Starter
Intermediate
Joined: May 2018
Posts: 34
Likes: 4
From: Woodbury MINNESOTA
Very sick 2005
My 2005 with 38,500 miles is really sick. Went out for a ride and when I stopped at a stop sign, the engine shut off. Fuel was full, oil pressure and temperature normal, and no check engine light. When I restarted it sounded and felt like it was only running on half the cylinders. The car shook, the exhaust sounded louder, and the engine would not idle. I was able to get the car to a parking lot where I called for a tow. Since this happened about an hour from home, I was able to get it to a friend’s place nearby. Once there I restarted and got the same condition now with a check engine light. I’m sure the code is for a misfire, but I have not scanned it. I didn’t inspect the engine other than to make sure the oil level was normal. All looked good on the top and bottom sides of the engine.
This is a completely stock engine and very well taken care of. Could I have lost an ignition module that controls the left or right side packs? Am I going in the right direction, or could this be something internal? Like I said, this wasn’t one or two cylinders not firing…more like four. Where would I measure power to check the module?
Oh, I was adjusting the clock when this happened, and my wife is 100% positive that’s what did it. LOL!!
Dave
This is a completely stock engine and very well taken care of. Could I have lost an ignition module that controls the left or right side packs? Am I going in the right direction, or could this be something internal? Like I said, this wasn’t one or two cylinders not firing…more like four. Where would I measure power to check the module?
Oh, I was adjusting the clock when this happened, and my wife is 100% positive that’s what did it. LOL!!
Dave
Le Mans Master
Joined: Dec 2013
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From: Charles Town WV
2024 Corvette of the Year Finalist - Modified
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you need to pull the codes first and foremost... from there you'll have a starting point. Do a visual inspection of your coil pack connectors just to confirm but yeah you need to pull the code to know where to go next.
Melting Slicks
Joined: May 2020
Posts: 2,135
Likes: 1,309
From: North Little Rock, AR
Yep you may have had a spark wire come loose. Easy enough to check.
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Thread Starter
Intermediate
Joined: May 2018
Posts: 34
Likes: 4
From: Woodbury MINNESOTA
I don't know when I'll get the codes as I'm getting ready for lots of work travel in the next few weeks. I've driven cars when they were down a cylinder and mine was way worse than that. Like I said it would not idle and power was greatly reduced.
I did read somewhere on this forum there are fuses for the left and right side coil packs. It was mentioned the ground wires could be the fault too. If I lost one side of my cylinder bank, could the engine even power the car?
I did read somewhere on this forum there are fuses for the left and right side coil packs. It was mentioned the ground wires could be the fault too. If I lost one side of my cylinder bank, could the engine even power the car?
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,621
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From: Cape Coral, Florida
I don't know when I'll get the codes as I'm getting ready for lots of work travel in the next few weeks. I've driven cars when they were down a cylinder and mine was way worse than that. Like I said it would not idle and power was greatly reduced.
I did read somewhere on this forum there are fuses for the left and right side coil packs. It was mentioned the ground wires could be the fault too. If I lost one side of my cylinder bank, could the engine even power the car?
I did read somewhere on this forum there are fuses for the left and right side coil packs. It was mentioned the ground wires could be the fault too. If I lost one side of my cylinder bank, could the engine even power the car?
Last edited by C5 Diag; Oct 27, 2023 at 06:57 PM.
Thread Starter
Intermediate
Joined: May 2018
Posts: 34
Likes: 4
From: Woodbury MINNESOTA
UPDATE UPDATE It's a broken valve spring that caused one of the valves to bend. It will be at least three weeks before the head comes off to inspect for more damage. I would like to be optimistic but I'm prepping myself for a damaged head and piston. When my mechanic pulled the valve cover off and saw the yellow springs, he knew to look for a broken one from experience. He did find the valve retainer clips and I guess that is good news as they didn't go into the cylinder. Anyway, this certinally opens up a new chapter with this car and some decisions to make with the engine. I can't believe with 38,500 miles this would happen but $%# does. If anyone has previous experience with this damage, all suggestions are very appreciated. UGH!!!!!
Last edited by Daverm; Oct 29, 2023 at 08:11 PM.
Drifting
Joined: Jul 2007
Posts: 1,294
Likes: 37
If you didn’t hear any tapping noises, I’m going to bet the piston didn’t break and just left a mark. If you swallowed the whole valve, then engine is likely toast. Good luck and report back!!
UPDATE UPDATE It's a broken valve spring that caused one of the valves to bend. It will be at least three weeks before the head comes off to inspect for more damage. I would like to be optimistic but I'm prepping myself for a damaged head and piston. When my mechanic pulled the valve cover off and saw the yellow springs, he knew to look for a broken one from experience. He did find the valve retainer clips and I guess that is good news as they didn't go into the cylinder. Anyway, this certinally opens up a new chapter with this car and some decisions to make with the engine. I can't believe with 38,500 miles this would happen but $%# does. If anyone has previous experience with this damage, all suggestions are very appreciated. UGH!!!!!
Drifting
Joined: Jul 2005
Posts: 1,634
Likes: 190
From: Austin TX
UPDATE UPDATE It's a broken valve spring that caused one of the valves to bend. It will be at least three weeks before the head comes off to inspect for more damage. I would like to be optimistic but I'm prepping myself for a damaged head and piston. When my mechanic pulled the valve cover off and saw the yellow springs, he knew to look for a broken one from experience. He did find the valve retainer clips and I guess that is good news as they didn't go into the cylinder. Anyway, this certinally opens up a new chapter with this car and some decisions to make with the engine. I can't believe with 38,500 miles this would happen but $%# does. If anyone has previous experience with this damage, all suggestions are very appreciated. UGH!!!!!
Drifting
Joined: Jul 2007
Posts: 1,294
Likes: 37
A bent valve likely didn’t severely damage the piston. Change valve, valve guide, fresh springs, valve job, and you should be on your way. I’ve had the same exact damage and that’s all it was. I did drop a valve later on after too aggressive of a cam…..that engine cracked a liner and ruined the block
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
I just saw this. I knew as soon as the OP said it was running so badly it stalled that it had to be more than a bad plug wire. I have forgotten on two occasions to plug in all 8 wires. Both times this happened it was due to an interruption. I HATE interruptions when in the garage. But neither time did the engine stall. It just ran rougher than normal, which on a cammed motor isnt as easy to notice right away, due to a rougher idle to begin with. OP, please let us know what the teardown reveals, and good luck....
Thread Starter
Intermediate
Joined: May 2018
Posts: 34
Likes: 4
From: Woodbury MINNESOTA
So here's the result of the broken valve spring. No visible cracks on the piston but I'll magnaflux it to make sure, and the push rod is bent too. The head is now in the machine shop getting all worked up.
More to come I'm sure.