Engine Problem - I Fear the Worse - YOUR THOUGHTS?
06-01-2018, 01:10 PM
#21
Safety Car
Thread Starter
The stumble is likely from the bad knock sensor.
If the knock sensor is detected bad by the PCM it will not advance timing during acceleration and this causes a stumble like you show here.
The knock sensor may not be bad itself. There could be a short to ground (more likely a melted wire touching the block somewhere).
I wont speculate on the coolant and steam issue until the knock sensor issue is resolved.
It could be caused by elevated engine temps caused by an incorrect timing solution for long periods of time. (Being driven by the faulty knock sensor).
Fix the knock sensor issue and you may find all is well.
If the knock sensor is detected bad by the PCM it will not advance timing during acceleration and this causes a stumble like you show here.
The knock sensor may not be bad itself. There could be a short to ground (more likely a melted wire touching the block somewhere).
I wont speculate on the coolant and steam issue until the knock sensor issue is resolved.
It could be caused by elevated engine temps caused by an incorrect timing solution for long periods of time. (Being driven by the faulty knock sensor).
Fix the knock sensor issue and you may find all is well.
FWIW, I value your input. I've always found your knowledge and willingness to help resolve issues to be EXCELLENT. Many people try to "help" by guessing and throwing their guesses out there. You on the other hand offer educated observations. I just don't think your hypothesis is correct this time. Too many other symptoms occurring for it to just be a bad sensor. However, it sure as hell wouldn't be the first time I was wrong.
Last edited by rikhek; 06-01-2018 at 01:11 PM.
06-01-2018, 01:14 PM
#22
Safety Car
Thread Starter
However, when at elevated track temp as shown in videos significant steam/smoke out the exhaust. Same as depicted in video coming from engine compartment.
I'm curious about your "hope it's covered under warranty" comment. Why would you have any doubt about warranty coverage? Car is 1.5 years old with 17k miles.
Rick
Last edited by rikhek; 06-01-2018 at 01:19 PM.
06-01-2018, 01:40 PM
#23
Reply appreciated but I'm willing to bet LARGE as stated in initial post the sensor is a symptom of the problem, not the problem. I believe water in a combustion chamber is causing the engine to knock and the sensor is picking up the knock as it's supposed to.
FWIW, I value your input. I've always found your knowledge and willingness to help resolve issues to be EXCELLENT. Many people try to "help" by guessing and throwing their guesses out there. You on the other hand offer educated observations. I just don't think your hypothesis is correct this time. Too many other symptoms occurring for it to just be a bad sensor. However, it sure as hell wouldn't be the first time I was wrong.
FWIW, I value your input. I've always found your knowledge and willingness to help resolve issues to be EXCELLENT. Many people try to "help" by guessing and throwing their guesses out there. You on the other hand offer educated observations. I just don't think your hypothesis is correct this time. Too many other symptoms occurring for it to just be a bad sensor. However, it sure as hell wouldn't be the first time I was wrong.
You and the others are probably correct here.
After re-reading your post if you actually are seeing that much water the knock sensor output high could be the result.
However the knock sensor code you presented is a code for a bad circuit. Not excessive knock. Could the sensor circuit be shorting out due to the water? Could be... not sure. But the code is for a shorted or faulty circuit not for excessive knock. Additionally if the knock were actually real it would certainly be detected by both knock sensors not just the one and consequently you would have a code for both sensors.
This leads me to believe the sensor or the wiring to that 1 sensor are faulty.
The water issue like you and others have stated may be another totally unrelated issue.
Let us know what you find we are all curious.
The last sentence here caught my attention as well.
https://autoservicecosts.com/obd2-codes/p0328/
Last edited by dar02081961; 06-01-2018 at 01:58 PM.
06-01-2018, 02:42 PM
#24
Pro
Based on what I saw on the video and read in the posts I think you have an issue with a head bolt. These are TTY bolts and if there is a failure of one of them they can lift, not resulting in a blown head gasket (right away) but coolant bypass. The knock from the water bypassing lead to pulling timing and loss of power. The videos where the car is stopped but the engine is running is worst case for this, heads and block are cooling, less clamping force on head gasket. Under normal driving you will probably be fine as everything stays sealed.
Have them do a oil analysis, betcha find coolant there.
Hate to see this happen to you. It probably happened when you were running down that Mustang a while back.
Just kidding about the Mustang.
Have them do a oil analysis, betcha find coolant there.
Hate to see this happen to you. It probably happened when you were running down that Mustang a while back.
Just kidding about the Mustang.
06-02-2018, 03:01 PM
#25
Safety Car
Thread Starter
Dealer called and said preliminary tests indicate head gasket. Pull head to confirm is next step. Very happy to hear from them as their schedule was such that they weren't supposed to even look at it till Monday.
Rick
Rick
06-02-2018, 04:14 PM
#26
Imagine that, TTY bolts ftw 
Maybe you could slip the tech a couple bucks when you bring those arp head bolt to him. The money isn’t to put them in, it’s to say he didn’t
John
Maybe you could slip the tech a couple bucks when you bring those arp head bolt to him. The money isn’t to put them in, it’s to say he didn’t
John
Last edited by JHEBERT; 06-02-2018 at 04:14 PM.
06-06-2018, 07:49 AM
#27
Pro
Rick,
Any updates?
Thanks, Chris
Any updates?
Thanks, Chris
06-06-2018, 08:33 AM
#28
Melting Slicks
Member Since: Feb 2009
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2020 Corvette of the Year Finalist (track prepared)
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You are obviously on the right track with head gasket diagnosis but I also noticed some really low idle oil pressure. I know the general rule of thumb is 10 per 1k rpm but that was 18 or so at idle and not super hot. What weight oil is in that engine? Maybe I've never paid that close attention to mine but I don't think it gets that low. Then again, I'm usually running 15w/50 100% of the time.
Last edited by fleming23; 06-06-2018 at 08:34 AM.
06-08-2018, 11:03 PM
#30
Safety Car
Thread Starter
Service adviser called me today and stated techs were having to replace entire head on Bank 1. Also replacing knock sensor.
Service adviser didn't know what failed, or failure mode on the head. She was just reading from the work order/log. I'll ask the tech when I see him. If I was forced to take an educated guess I'd say it cracked as there was steam being released into the engine compartment and out the exhaust.
A bit frustrated that they've listed the wait on parts at 4 days.
Service adviser didn't know what failed, or failure mode on the head. She was just reading from the work order/log. I'll ask the tech when I see him. If I was forced to take an educated guess I'd say it cracked as there was steam being released into the engine compartment and out the exhaust.
A bit frustrated that they've listed the wait on parts at 4 days.
Last edited by rikhek; 06-08-2018 at 11:04 PM.
06-09-2018, 01:42 PM
#31
Le Mans Master
06-11-2018, 09:42 AM
#34
Safety Car
Thread Starter
For clarification, I take your opinion on mechanical issues to be if a machine breaks you get rid of the machine even though the manufacturer stands by it and fixes it. Just illogical.
Curious what you'd do if one of the A/C units goes out on your house. Your logic dictates you'd sell the house.
Christ, it's a lousy stinkin' car/machine. I use my car as it was intended by utilizing the performance offered on track and elsewhere. I'm surprised something hasn't given out prior to this incident. Cars/machines break on a somewhat regular basis, more so when they are actually used as intended.
I'm really lucky from the stand point that I'm getting an assortment of new metal pieces to replace "old" pieces that have been subjected to 17k miles of upper design parameter usage (i.e., no car shows or cruise-ins). I was hoping I'd get "lucky" and have the entire engine needing replacement, however, I'm never lucky.
Some people's kids.....
Last edited by rikhek; 06-11-2018 at 09:54 AM.
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06-11-2018, 09:44 AM
#35
Rikhek, at least YOU have a solid grasp on reality
Carry on and enjoy the machine
Carry on and enjoy the machine
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06-13-2018, 09:15 PM
#36
Race Director
Your opinion is comical at best.
For clarification, I take your opinion on mechanical issues to be if a machine breaks you get rid of the machine even though the manufacturer stands by it and fixes it. Just illogical.
Curious what you'd do if one of the A/C units goes out on your house. Your logic dictates you'd sell the house.
Christ, it's a lousy stinkin' car/machine. I use my car as it was intended by utilizing the performance offered on track and elsewhere. I'm surprised something hasn't given out prior to this incident. Cars/machines break on a somewhat regular basis, more so when they are actually used as intended.
I'm really lucky from the stand point that I'm getting an assortment of new metal pieces to replace "old" pieces that have been subjected to 17k miles of upper design parameter usage (i.e., no car shows or cruise-ins). I was hoping I'd get "lucky" and have the entire engine needing replacement, however, I'm never lucky.
Some people's kids.....
For clarification, I take your opinion on mechanical issues to be if a machine breaks you get rid of the machine even though the manufacturer stands by it and fixes it. Just illogical.
Curious what you'd do if one of the A/C units goes out on your house. Your logic dictates you'd sell the house.
Christ, it's a lousy stinkin' car/machine. I use my car as it was intended by utilizing the performance offered on track and elsewhere. I'm surprised something hasn't given out prior to this incident. Cars/machines break on a somewhat regular basis, more so when they are actually used as intended.
I'm really lucky from the stand point that I'm getting an assortment of new metal pieces to replace "old" pieces that have been subjected to 17k miles of upper design parameter usage (i.e., no car shows or cruise-ins). I was hoping I'd get "lucky" and have the entire engine needing replacement, however, I'm never lucky.
Some people's kids.....
Well, maybe I should have explained my thinking more clearly. My bad for not doing so...
My view is that because you are using the car as intended, and given that the engine is being partially re-built and not replaced,
could the same failure occur again, and sooner ? Do you want to deal with that if so ? I for one would not, hence my comment.
Maybe you have plenty of warranty remaining and are willing to accept the risk.
You don't have to agree with me, but we all don't have to think alike.
Last edited by Gary '09 C6; 06-13-2018 at 09:40 PM. Reason: sp & format
06-14-2018, 07:31 AM
#37
Tech Contributor
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"Ask Tadge" Producer
More data is needed. And I'll bet a pay check that after said data is learned, it won't be that big a deal. Replace the head. Go.
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06-14-2018, 12:37 PM
#38
Exactly right jvp, for all we know it’s a casting flaw in the one head. No worries
John
John
06-14-2018, 01:10 PM
#39
Melting Slicks
Service adviser called me today and stated techs were having to replace entire head on Bank 1. Also replacing knock sensor.
Service adviser didn't know what failed, or failure mode on the head. She was just reading from the work order/log. I'll ask the tech when I see him. If I was forced to take an educated guess I'd say it cracked as there was steam being released into the engine compartment and out the exhaust.
A bit frustrated that they've listed the wait on parts at 4 days.
Service adviser didn't know what failed, or failure mode on the head. She was just reading from the work order/log. I'll ask the tech when I see him. If I was forced to take an educated guess I'd say it cracked as there was steam being released into the engine compartment and out the exhaust.
A bit frustrated that they've listed the wait on parts at 4 days.
06-14-2018, 01:14 PM
#40
Le Mans Master
Member Since: Oct 2005
Location: Metro Detroit Michigan
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Hey Rick - was talking with Tony Avedisian of Tony's Corvette Shop in Gaithersburg, MD on Saturday and he indicated he has had to replace heads on several Z06's because the valve guides were elongated!!! He showed me one of the heads and there was so much play between the valve shaft and the guide it was unbelievable! He indicated there have been around THIRTY engine failures plus other problems like you indicate and GM is aware...........