CLUNK now no start
Thread Starter
Team Owner
Joined: Mar 2012
Posts: 27,118
Likes: 135
From: Montgomery, Alabama
2017 C6 of Year Finalist
CLUNK now no start
I think I broke something in the Vette when I went to the store yesterday. Heard a clunk while going about 55. It did not effect power. When I stopped the rpms fluxuated between 400 and 700 before I shut it down. When trying to restart it, the rpm fluxuated wildly and it barely started before it died. The fuse box and relays were extremely hot when I tried swapping relays. After they cooled off some and after the third relay swap it finally started and was able to drive it home with no problem. Turned it off when I got home and when I tried to start it it again did the same rpm fluxuation and dying thing. Decided to wait until this morning to see if I could get it to start.
Had a similar problem the end of last year and I followed the recommended removing and swapping the fuel pump relay with a different one. That worked intermittently so followed the suggested cleaning of the fuse box posts. No difference so I replaced the entire fuse box. Problem was solved with no problems for four months until yesterday.
When trying to start it this morning it turns over but will not try to fire. Nothing works to get it started.. All other functions work fine and battery is fully charged on a tender.
Had a similar problem the end of last year and I followed the recommended removing and swapping the fuel pump relay with a different one. That worked intermittently so followed the suggested cleaning of the fuse box posts. No difference so I replaced the entire fuse box. Problem was solved with no problems for four months until yesterday.
When trying to start it this morning it turns over but will not try to fire. Nothing works to get it started.. All other functions work fine and battery is fully charged on a tender.
Thread Starter
Team Owner
Joined: Mar 2012
Posts: 27,118
Likes: 135
From: Montgomery, Alabama
2017 C6 of Year Finalist
Thread Starter
Team Owner
Joined: Mar 2012
Posts: 27,118
Likes: 135
From: Montgomery, Alabama
2017 C6 of Year Finalist
Checked for codes using an actron Auto Scanner Plus and these are the results:
I/M Monitors Since DTCs Cleared
Malfunction Indicator Light Status
ABS
Hydraulic Brakes
No ABS
Misfire Monitor....OK
Fuel System Monitor....OK
Comp Component....OK
Cat Monitor....Inc
Htd Cat....n/a
Evap Sys Mon....Inc
Sec Air Sys....n/a
A/C Refrig Mon....n/a
Oxygen Sens Mon...Inc
Oxygen Sens Htr….Inc
EGR/VVT Sys Mon....n/a
OBD11/EOBD....No Codes
Engine....No codes
Trans...Link Error
DTCs (codes)….None found
I/M Monitors Since DTCs Cleared
Malfunction Indicator Light Status
ABS
Hydraulic Brakes
No ABS
Misfire Monitor....OK
Fuel System Monitor....OK
Comp Component....OK
Cat Monitor....Inc
Htd Cat....n/a
Evap Sys Mon....Inc
Sec Air Sys....n/a
A/C Refrig Mon....n/a
Oxygen Sens Mon...Inc
Oxygen Sens Htr….Inc
EGR/VVT Sys Mon....n/a
OBD11/EOBD....No Codes
Engine....No codes
Trans...Link Error
DTCs (codes)….None found
Thread Starter
Team Owner
Joined: Mar 2012
Posts: 27,118
Likes: 135
From: Montgomery, Alabama
2017 C6 of Year Finalist
The Vette has been sitting in the carport under a cover since about this time yesterday. Went to get the owners manual and decided to see if it would start. Hit start and it fired up and immediately died. Tried again and it again turned over but would not start.
Thread Starter
Team Owner
Joined: Mar 2012
Posts: 27,118
Likes: 135
From: Montgomery, Alabama
2017 C6 of Year Finalist
Went out to see if the Vette would start after sitting since the 3rd. It fired right up but immediately died as it did on the 3rd. Tried again and it was back to the crank but no start. Totally confused.
Le Mans Master
Joined: Oct 2000
Posts: 6,504
Likes: 717
From: Sausalito CA
Um...driving at 55 steady throttle, then a clunk.
Now starts but does not idle and dies?
Also no clunk heard during these re-start attempts?
No stored codes.
Clunk implies metal to metal failure to me anyway.
Pully assemblies would seem likely, but assuming these are all okay.
Fusebox & relay previous issues could be a lead, yet again "clunk" sound.
My only other suggestion is to remove your valve covers and inspect the valve train.
If possible maybe do a compression check.
I recall reading about a cam/timing sensor failure on previous posts.
"I got noth'in".
Good luck.
Now starts but does not idle and dies?
Also no clunk heard during these re-start attempts?
No stored codes.
Clunk implies metal to metal failure to me anyway.
Pully assemblies would seem likely, but assuming these are all okay.
Fusebox & relay previous issues could be a lead, yet again "clunk" sound.
My only other suggestion is to remove your valve covers and inspect the valve train.
If possible maybe do a compression check.
I recall reading about a cam/timing sensor failure on previous posts.
"I got noth'in".
Good luck.
Last edited by Kenny94945; May 7, 2019 at 08:03 PM.
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Thread Starter
Team Owner
Joined: Mar 2012
Posts: 27,118
Likes: 135
From: Montgomery, Alabama
2017 C6 of Year Finalist
Um...driving at 55 steady throttle, then a clunk.
Now starts but does not idle and dies?
Also no clunk heard during these re-start attempts?
No stored codes.
Clunk implies metal to metal failure to me anyway.
Pully assemblies would seem likely, but assuming these are all okay.
Fusebox & relay previous issues could be a lead, yet again "clunk" sound.
My only other suggestion is to remove your valve covers and inspect the valve train.
If possible maybe do a compression check.
I recall reading about a cam/timing sensor failure on previous posts.
"I got noth'in".
Good luck.
Now starts but does not idle and dies?
Also no clunk heard during these re-start attempts?
No stored codes.
Clunk implies metal to metal failure to me anyway.
Pully assemblies would seem likely, but assuming these are all okay.
Fusebox & relay previous issues could be a lead, yet again "clunk" sound.
My only other suggestion is to remove your valve covers and inspect the valve train.
If possible maybe do a compression check.
I recall reading about a cam/timing sensor failure on previous posts.
"I got noth'in".
Good luck.
What has me really confused is that it will start but immediately die on the first attempt to start it after sitting for a couple days. Then it goes to cranking but no start.
Drifting
Joined: Jul 2005
Posts: 1,634
Likes: 190
From: Austin TX
Um...driving at 55 steady throttle, then a clunk.
Now starts but does not idle and dies?
Also no clunk heard during these re-start attempts?
No stored codes.
Clunk implies metal to metal failure to me anyway.
Pully assemblies would seem likely, but assuming these are all okay.
Fusebox & relay previous issues could be a lead, yet again "clunk" sound.
My only other suggestion is to remove your valve covers and inspect the valve train.
If possible maybe do a compression check.
I recall reading about a cam/timing sensor failure on previous posts.
"I got noth'in".
Good luck.
Now starts but does not idle and dies?
Also no clunk heard during these re-start attempts?
No stored codes.
Clunk implies metal to metal failure to me anyway.
Pully assemblies would seem likely, but assuming these are all okay.
Fusebox & relay previous issues could be a lead, yet again "clunk" sound.
My only other suggestion is to remove your valve covers and inspect the valve train.
If possible maybe do a compression check.
I recall reading about a cam/timing sensor failure on previous posts.
"I got noth'in".
Good luck.