blown motor?
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Heel & Toe
Joined: Nov 2024
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blown motor?
I have a 2000 C5 base 6mt, and after doing an oil change and going for a drive, I noticed my car was misfiring and smoking pretty bad. After inspection, I noticed a lot of white smoke, followed by the header of the cylinder misfiring being quite colder than the other cylinders. The car has had a slight ticking noise since my headers were installed december of 2024. if anyone has advice on my next step or ideas of what may have happened please let me know, thank you.
P.S - I am totally open to opening the motor, but definitely not optimal.
P.S - I am totally open to opening the motor, but definitely not optimal.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
I have a 2000 C5 base 6mt, and after doing an oil change and going for a drive, I noticed my car was misfiring and smoking pretty bad. After inspection, I noticed a lot of white smoke, followed by the header of the cylinder misfiring being quite colder than the other cylinders. The car has had a slight ticking noise since my headers were installed december of 2024. if anyone has advice on my next step or ideas of what may have happened please let me know, thank you.
P.S - I am totally open to opening the motor, but definitely not optimal.
P.S - I am totally open to opening the motor, but definitely not optimal.
What exactly did you do when changing the oil. While it could be a coincidence.......it would be helpful to know what you did.
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From: Cape Coral, Florida
White smoke can also be raw unburned fuel if not a blown head gasket...your ticking noise may be an exhaust leak...seek out an auto diagnostic shop and not a repair shop or dealership...you will just waste your time and money !!
Thread Starter
Heel & Toe
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Code was a PO300, so not consistent enough to pull the PO30X.
Oil was drained into the pan, oil filter removed, new filter replaced, new oil filled.
I ran the car for about 20 mins after the oil was filled, and everything seemed fine. I also checked my catch can and didn't see much oil, but emptied and cleaned while I was there.
I went for a 20 minute drive, and when I parked I noticed the car shaking and knew it was a misfire etc..
Oil was drained into the pan, oil filter removed, new filter replaced, new oil filled.
I ran the car for about 20 mins after the oil was filled, and everything seemed fine. I also checked my catch can and didn't see much oil, but emptied and cleaned while I was there.
I went for a 20 minute drive, and when I parked I noticed the car shaking and knew it was a misfire etc..
Thread Starter
Heel & Toe
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thanks for the info, still need to check plugs and do a leakdown test/compression test.
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From: Cape Coral, Florida
Other than plugs and wires you won’t be able to diagnose this without some advanced diagnostic equipment…you’ll only be guessing !!…just do a “clear flood crank”…hold the gas pedal to the floor while attempting to start the car…if it sounds like the file below you have some compression problems !!...BTW, a compression test only tells you the ability of the cylinder to "seal"...there can be other issues so it is not a 100% test.
Thread Starter
Heel & Toe
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Other than plugs and wires you won’t be able to diagnose this without some advanced diagnostic equipment…you’ll only be guessing !!…just do a “clear flood crank”…hold the gas pedal to the floor while attempting to start the car…if it sounds like the file below you have some compression problems !!...BTW, a compression test only tells you the ability of the cylinder to "seal"...there can be other issues so it is not a 100% test.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
I would start simple with a mechanics stethoscope to try to isolate ticking, and see if it correlates with the cold cylinder/header. You may have something as simple as a broken valve spring.
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From: Cape Coral, Florida
You need a diagnostician and not a “mechanic”…these guys only replace parts as 99% do…you can look for something like a burned valve with a borescope and you can pull the valve covers to look for valve train movement or a broken valve spring…if your mechanic doesn’t use a labscope he will fail at finding your issue…my next door neighbor had a single cylinder misfire last week and with my labscope I was able to diagnose it in about 5 minutes….let us know what your mechanic finds and how many parts he changes… good luck !!
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Heel & Toe
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it seems like this may be the case, but would that cause smoke and a misfire? thanks
Thread Starter
Heel & Toe
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You need a diagnostician and not a “mechanic”…these guys only replace parts as 99% do…you can look for something like a burned valve with a borescope and you can pull the valve covers to look for valve train movement or a broken valve spring…if your mechanic doesn’t use a labscope he will fail at finding your issue…my next door neighbor had a single cylinder misfire last week and with my labscope I was able to diagnose it in about 5 minutes….let us know what your mechanic finds and how many parts he changes… good luck !!
Pro
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From: Northern Utah
If it really is white and not blue, you likely have a blown head gasket near where that cold header is. If it's actually blue smoke you could have a whole slew of other problems.
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From: Dyer, IN
Oh? Never seen white smoke generated from unburned fuel?
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From: Cape Coral, Florida
Thread Starter
Heel & Toe
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Instructor
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From: Cape Coral, Florida
Well you can put a borescope into the combustion chamber and see if you see coolant in there after sitting for a while or check for the injector control circuit being grounded at all times…do you smell fuel at the tailpipe ??…what do you mean you can “feel” an increase in exhaust pressure ??
Tech Contributor
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From: Dyer, IN