Help my Viper is making weird sounds under the car!

[supratime]

Hi,

I took my 1999 viper rt/10 out the other day and drove really fast to 60 mph. Then I noticed the motor sounds a little different then usual. When I drive at normal speeds it sounds fine, but when I floor it theres a strange popping rattling sound coming from the bottom front of the car. It only happens when I drive fast at high RPMs. Also when I turned the car off, it made a loud popping sound from underneath the car. Anyone have any idea what this might be? I going to bring it to my local dodge dealer on monday or tuesday. Anyone have any ideas please let me know. Thanks

Eric

 

[GTS Bruce]

Like in exhaust popping or motor mount shifting?

 

[supratime]

It is not from the rear exhaust. The sound is coming from under the hood or the middle of the car. It's a weird popping rattling sound that happens when you accelerate hard at high rpms. The best way I can describe the sound is if you were to take a set of dice put it in a container and shake it.. But just 100 times louder...

It does kinda sound like an exhaust pop, but it is not coming from the rear exhaust. It's more like underneath where I'm sitting or the passenger side. Sounds like something is seriously broken.

When the car is at idle, there is all kinds of popping noises. Sounds like pop corn being made in a microwave. Also when I turned the car off it made a very loud popping noise coming from underneath the hood. Anyone have any clue what the heck is wrong? Thanks in advance

Update: I noticed a very strong gas smell when the car is started. It always did have this but it has got much worst. You can smell it when you drive too.

Eric

 

[KWIK96]

Could be the EVAP canister

 

[Gerald]

Ahh, sounds like 2 marbles / dice hitting together...??


DETONATION

STop driving your car asap!!!


Gerald

 

[Ulysses]

DETONATION

STop driving your car asap!!!

I agree!!

 

[XS TORQ]

Ahh, sounds like 2 marbles / dice hitting together...??


DETONATION

STop driving your car asap!!!


Gerald

Since he has a turbo supra and a TT 300ZX, I would think he'd know what detonation sounds like... but then again, maybe not!

Supratime, I would suggest you either take the car in, or get a local Viper owner to check it out. I agree with Gerald that you probably shouldn't drive it until you make sure you are not getting detonation.

 

[Gerald]

Diagnosing the car over the internet is pretty tough :lo: . So of course it's a guess. But the statement "sounds like two dice hitting together" and the other sound could be engine run on? Do you have BAD Gas? That would be my first guess. Water in your tank?

Gerald

 

[Shelby3]

Driving a car with a very bad gas smell is not a good idea either.

 

[hemibeep]

Smelling alot of gas, possible sound of detonation...may have a cracked intake manifold. good idea to have a pressure check done at the schrader valve to see what the pressure is, then compare to specs...also check the fuel line from manifold to firewall hard line.

As for the rattling from below, may want to check the tranny rubber mount....if this is bad or loose,,,alot of strange noises

 

[MadMaxx]

Start with the basics...

Any codes?
When was the last time the plugs were changed?
What is the current fuel pressure? Check at idle and under load to make sure it changes.
Do you have cats on the car?

Sounds like unburt fuel exploding in the exhaust.

 

[supratime]

I just brought the car to Dodge and they did not say anything about detonation. Yes, I do have a 300zx and Supra turbo but never experienced detonation before. But I know it is very common with those cars. Dodge told me there is an exhaust leak and my car is running rich. The guy showed me exactly where the problem was coming from under the car. They said my headers needed to be shifted two inches to the left and needs to be welded back together correctly. They also said I need to change two 02 sensors. But is this the reason for the sound I hear?? I drove the viper tech guy around and he heard the sound himself. He did not mention anything about the engine detonating. I got no codes or check engine light. I had the spark plugs changed a few months ago. My viper has two high flow cats. The car drives fine at normal speeds. I'm going to bring my viper to Muffler Tech and see if they can fix the exhaust leak. Thank you for all your replies.

 

[Russ M]

Ok whats the deal here?

21 years old? Are you in some boy band?
2 Vipers
Vet
etc...

Anyways do you know how the exhaust got damaged? How much is the dealer asking to fix it? You may want to get some aftermarket headers if the price is too high.

 

[Schulmann]

Russ is right, if the headers are done, buy after market headers. Don't wait until your car catches fire.

Changing the oxygen sensors makes sense. That can mess the AFR and lead to knocking. Though the PCM should come up with a check light.

 

[Qualitywires.com]

I would recheck those plugs...if you haven't already. It could be knocking like gerald said. For some reason the knocking in a viper engine sounds different than what I have heard in other cars.

 

[Steamroller]

I thought the knock sensors were extremely sensitive. If the engine was detonating, wouldn't the "Check Engine" light illuminate?

 

[99 R/T 10]

I thought the knock sensors were extremely sensitive. If the engine was detonating, wouldn't the "Check Engine" light illuminate?

Knock sensors?! We don't need no stinking knock sensors! (means, that only the 05 has them )

 

[supratime]

Ok whats the deal here?

21 years old? Are you in some boy band?
2 Vipers
Vet
etc...

One viper actually. the RT/10 belongs to my brother. I'm posting this for him or actually he's posting it under my screen name. He's gonna take it to Muffler Tech and see if this fixes the problem. Thanks for your input guys!