Loud banging under car when hard rain...
 

2013 5.0 6-speed Manual
All stock except for cat back
9,200 miles

This morning was the 2nd really hard rain I have driven in where there was standing water on the road. I get this really loud banging noise after having to drive through a few of the water puddles. It is very hard to pin point because these cars are very loud inside when raining hard.

It seems to do it when I accelerate and it almost feels like the car is not accelerating as it should when it happens. Also, when I pulled into my parking spot this morning (hard left with clutch pushed in) it did it.

It only does this when it is raining hard enough for water to collect on the roadways. Therefore it is very hard to reproduce it.

Anybody got any ideas?

How weird. That's going to be difficult to guess without actually hearing it unfortunately.

Advance trac may be kicking in. Its hard to tell without actually hearing the noise. If its still raining on the way home turn advance trac off and see if you can reproduce it. Ive noticed it will make kinda of a clunking sound when it kicks in sometimes.

Mmm maybe ... which would make sense if you hit a puddle that is enough to cause some slight hydroplaning.

It has only happened twice now. Althought the first time it did it , it lasted for the last 2 miles home. I honestly thought my exhaust had dropped down and was dragging across the road. Got home looked under the car and everything was fine. Went in changed and took it for a test drive and couldn't make it do it.

:word:

Agreeded. As traction control kicks in on my car it makes a noise and bogs hard. Not so sure about the "loud" bang noise.

This has no bog with it like you get with the traction control. The banging sounds like it is coming from transmission forward and on the right side. (But again very hard to pinpoint). Sounds/feels like a monkey hitting the underside of car with hammer.

The first time it happened 3 things ran through my mind:

1)exhaust came loose and was dragging ( obviously it wasn't when I checked)
2)Extreme exhaust leak ( I checked all exhaust clamps when on lift and all were tight)
3) really really really bad clutch chatter ( doesn't make sense when turning left into parking spot when clutch is pushed in and on the brakes though).

If its making the noise for that long its not advace trac. Its weird it only does it randomly in the rain. If it was consistent when it gets wet that would atleast make it alittle easier to pinpoint.

That would explain why I've never heard it because I don't drive my car in the rain. lol.

That would be my guess

I tell you what, I'll ask some of the other techs in the shop and shop foreman if they've ever come across a customer complaint like this, and will check TSBs and SSMs on the car and will get back to you.

Traction control w/o a doubt.

The onyl reason I doubt that is because it last for a while and it feels nothing at all like the traction control system. Traction control jerks you and cuts power. This sounds like non stop hammering. It reminds me of when I broke a u-joint at the drag strip in my other car and the driveshaft was slapping the floor.

Also why would traction control come on when coasting into a parking spot using no throttle at all?

Thanks.... this is the hardest issue to describe and the fact that I can not reproduce it keeps me from taking it somewhere.

Anytime the Ecu detects slip it cuts power. I remember the old V6 mustang ssounded like there was an elephant under the car.

Oh you are definitely a true Vette owner at heart. lol

I'll take that as a compliment. lol

Wouldn't the traction control light come on? Also, I know what it feels like when it cuts power...and this is not it. It is almost like its revs but doesn't get to wheels...like clutch slippage.

Go try to do a dounut with advancetrac ON and see if its the same noise. I agree its weird that it did it for so long that one time but maybe you just did something to freak out the system that time.

I spin all the time in my truck when its wet and will kick on the traction control light but its pretty rare.

I'll give it a try.

Does advanctrac act diferent when sliding/turning and losing traction than it does when just spinning the rear tires in a straight line (normal traction control).

Yes, I can spin straight at times like its not doing anything. Advance trac flat out stops things when it kicks in. I tired to do a dounut on a wet road with just traction control off once and it flat out wouldn't do it. Just kept clunking and fighting to go straight.

Daily drove my C5 for 5 years. Seen rain, hail, ice etc. Not to detract from the thread. Hope all goes well for the OP.

how so? i drove my vette on mickey thompsons in the rain, snow and ice...and it made a little more power than most of the 5.0s here.. never had an issue.

Pretty sure he was just joking.

-Alex

Alright man, I've asked around at my dealer, no guys here in the ship have ever come across such a concern. Let me know when you come to your conclusion.

The car is not lowered at all? No suspension mods?

Good thinking. But he mentioned all stock other than a cat back exhaust.. unless he forgot.

I had a similar noise before my LCAs that was caused from the stock ones not being at the proper angle. it would happen over large bumps but other than that I have no idea what it could be.

No bumps are involved. I am leaning towards the advancetrac after reading these responses. I will try to narrow it down more when I get a chance.

Hasn't rained in awhile. Any updates Joey?

-Alex

Nope...can't make it do it when not raining. I have not tried the donuts in a parking lot yet though.

Yeah I was wondering what you figured out. That's a bumper man. Keep us updated, and be careful when doing the donuts.