[bdavies11]

So I've been having intermittent issues with starting when the engine is hot. Been to the dealer several times, they can never reproduce the issue. Frustrating but understandable because even for me, it's very intermittent. They've tested the battery, starter, cables, heatshields, among other things and everything checks out OK. They wind up giving it back to me and several days/weeks later guess what, it wont start after the engine is hot and i get stranded somehwere until it cools down. One thing I do know is that it has NEVER had an issue starting when cold.

Anytime that it has happened I've tried jumping it from a battery pack, jumping it from another car, even tried grounding the block to the chassis and nothing helps until the car has cooled off. This last time it happened, I waited about 30 minutes, then it started and I drove straight to the dealer. Finally, they were able to pull a code that pointed to the crankshaft position sensor. They ordered a new one to be put on my car to hopefully resolve the issue once and for all. Today, I get a call from the dealer and they said, since my car has been in 3 times in the last 3 months for this issue, they put a call into GM for additional assistance and GM told them NOT to replace the crankshaft sensor because the code that was tripped was due to high voltage from trying to jump the car with a good battery.

I'm not a mechanic but know how to do a little research. So I did a little research on a 'bad' crankshaft position sensor and literally one of the first symptoms usually experienced from a sensor going bad is the refusal of an engine to start when hot, but will start again once cooled off. Exactly 100% to the T what I've been experiencing, yet GM wont let the dealer change the sensor on my car claiming that the code for the sensor was tripped due to high voltage from trying to jump the car with a good battery. WTF? I'm hearing now they are trying to get an engineer from GM to come out and work on my car but who knows how long that will be and I've already been without my car for a time totaling nearly three weeks from 3 different trips to the dealer. Anyone ever come across something like this?

[Smudo]

Hi Dave,

could be a lot of things, Sorry for you and good luck.
Fingercross

[bdavies11]

Sounds like not many have experienced this...

Just an update: Two weeks without my car and GM thinks it boils down to a bad ground. They are going to install a new negative cable and hopefully will have it back tomorrow. We will see.

[Calvear0]

Could be a bad starter. I had the same issue which took them 2 weeks to figure out.

[SoCal Smith]

My car never had an issue starting.

But, it did have an issue with crank sensor and grounding! They did the wiring harness cover and it fixed my issue.

Took them a very long to figure it out and I had started the lemon law process. Now I am shopping for a new car :(

[bdavies11]

Originally Posted by SoCal Smith

My car never had an issue starting.

But, it did have an issue with crank sensor and grounding! They did the wiring harness cover and it fixed my issue.

Took them a very long to figure it out and I had started the lemon law process. Now I am shopping for a new car :(

If it wasn't an issue with starting, what issue did you have?

[Jamesg89]

Have them check endplay on the crank if its an M6 especially. My 2016 was doing the same thing for months before they figured it out. Had to replace the motor due to thrust bearing failure.

[tmmk11roberts]

I've had the same issue intermittently on my 2016 2SS. I have understood it to be heat soak because of the close proximity of the starter to the exhaust manifold. I bought a DEI heat wrap to install on my starter. Hopefully that works.