2011 GT500 shuts off on the highway in 6th

[SVTrojan]

Happened again... This time I was on the freeway clutch in (I forget what gear I was in). I was in the exit lane to exit the freeway and was braking to a stop as the exit had backed up. I was pumping my brakes a bit to let the person behind me know that the traffic was at a standstill in my lane as people tend to try to fly on this exit lane without realizing traffic is stopped ahead. On about the third pump, the brake pedal was frozen and the car was shut off. Luckily I was only going about 15 mph at the time and had time to pull into the emergency lane and pull the hand brake to stop before I restarted the car. Before I entered the exit lane, I had accelerated quickly from 40 to about 60 as traffic cleared up a bit, not sure if that matters.

My car is stock except for a res delete and a/b exhaust, I changed the fuel filter about 500 miles ago. I didn't get any warning lights. I took the car in to the dealer a while ago to see if they can replicate the problem, but after driving it for a bit they couldn't replicate it. It happens so infrequently, I doubt they'll ever be able to replicate the issue... Any ideas on what it could be?

 

[ColorMatched]

Check for vacuum leaks? Loose ground somewhere? Do all of the lights flicker or go off? Does the car sound like it's starved for air/drop RPMS before it dies or does it just shut off? Is there hesitation in acceleration? What RPM does the car idle at? The key is to know what happens before the car dies in order to know what direction to start in.

My car was acting up intermittently where if I would put the clutch in coming to stops or whatever, it would drop to 800RPMs and die. It happened once every few months, then all of a sudden happened every time I started the car. Turns out I had a vacuum line on the back of my intake slowly deteriorating over time and collapsing, which would cause the car to die. The hose wore through to the point where the vacuum was thrown off and car ran like poo. I could put my finger through the hose and kill the car, thus finding my problem.

 

[SVTrojan]

It just happens so infrequently and catches me off guard, it's hard to document what happens before.

The radio didn't skip a beat, I didn't notice the headlights or any instrument lights dim. Car didn't sound different before, although I did have the clutch in so it would have been hard to hear over the sound of the freeway. It was pulling strong before it died on me though. And it started right back up no problem once I had safely pulled to the side. I know that's not much to go on, not really sure what to do going forward...

 

[SVTrojan]

That's good to know about the vacuum line, I'll check those more closely after work. Thanks again for your help!

 

[DaFreak]

Have to think it's related to the fuel filter change you mentioned. Maybe installed incorrectly or line now clogged?

 

[Phantomhalo]

Is it going into safe mode or anything? I had something similar happening to me a while back on my first tune. Basically if I was in too high of a gear such as 6th going up hill doing 45-50mph it would sense the lack of torque and go into safe mode. (At least that's what was explained to me.) After I got a few more mods and had to update my tune I never had it happen again.

 

[ShelbyGT5HUN]

Check for codes, before all the guesswork begins.

 

[SVTrojan]

Have to think it's related to the fuel filter change you mentioned. Maybe installed incorrectly or line now clogged?

I doubt that's the case, it's super easy to do, not even I could have screwed that up. Plus, this issue was happening long before I changed the filter.

Is it going into safe mode or anything? I had something similar happening to me a while back on my first tune. Basically if I was in too high of a gear such as 6th going up hill doing 45-50mph it would sense the lack of torque and go into safe mode. (At least that's what was explained to me.) After I got a few more mods and had to update my tune I never had it happen again.

The car is not going in to safe mode, it just shuts off and then starts right back up at the first turn of the key.

I never lug my engine, so I doubt it is me under-revving the engine.

Check for codes, before all the guesswork begins.

No codes, the dealer didn't find any when i first took the car in either.

 

[455HO71]

Happened again... This time I was on the freeway clutch in (I forget what gear I was in). I was in the exit lane to exit the freeway and was braking to a stop as the exit had backed up. I was pumping my brakes a bit to let the person behind me know that the traffic was at a standstill in my lane as people tend to try to fly on this exit lane without realizing traffic is stopped ahead. On about the third pump, the brake pedal was frozen and the car was shut off. Luckily I was only going about 15 mph at the time and had time to pull into the emergency lane and pull the hand brake to stop before I restarted the car. Before I entered the exit lane, I had accelerated quickly from 40 to about 60 as traffic cleared up a bit, not sure if that matters.

My car is stock except for a res delete and a/b exhaust, I changed the fuel filter about 500 miles ago. I didn't get any warning lights. I took the car in to the dealer a while ago to see if they can replicate the problem, but after driving it for a bit they couldn't replicate it. It happens so infrequently, I doubt they'll ever be able to replicate the issue... Any ideas on what it could be?

I have a fairly stock 2011. This has happened to me 3 times as well. Last time I was pulling off of the highway. I pushed clutch in after bein in 6th gear. Put it in neutral to coast and it just shut off.
15k on my car.

 

[SVTrojan]

Thanks for the reply, 455HO71

I guess it's good to know I'm not alone, sounds like the exact same thing I have experienced.

 

[RedVenom48]

If I was a betting kind of person, Id check for any chaffed wires or harnesses around the engine bay

 

[Timber Wolf]

Aren't alternators a known weak area? I know many 07 to 11 cars i believe have this go bad...

 

[LEXiiON]

I don't know if this helps, but I had a similar problem back in the day with my Audi (automatic transmission) if I exited a freeway and came to a stop it died. Started back up with the first turn of the key. Turns out it was a loose hose. Check those, especially the ones behind the blower to the lower manifold.
LEXiiON

 

[SVTrojan]

If I was a betting kind of person, Id check for any chaffed wires or harnesses around the engine bay

Just went out and checked all the wires and harnesses around the engine bay, didn't see anything that looked worn or chaffed.

Aren't alternators a known weak area? I know many 07 to 11 cars i believe have this go bad...

I know I had to replace my alternator in my 05 GT but the tell tale sign was the battery wouldn't hold a charge. No issues so far with the battery draining... although I did have to replace the batter a 7-8 months ago. How would that effect this issue though, the electronics on the car (radio, fan, etc) are still functioning when it shuts off.

I don't know if this helps, but I had a similar problem back in the day with my Audi (automatic transmission) if I exited a freeway and came to a stop it died. Started back up with the first turn of the key. Turns out it was a loose hose. Check those, especially the ones behind the blower to the lower manifold.
LEXiiON

Checked most of the hoses as well, they all look well-connected. I admit I'm no expert mechanic, but everything looked fine to me...