: Rough Idle, Clanking Noise, Jerky Tranny, CEL on



Gotham CTS-V
12-15-09, 02:20 PM
Ok, so my car has about 7500miles on it. For 4500 miles the car has been modded with the mods listed in my signature. It first started after I had a big race with a rival. The first two races my V was loosing due to heat soak. We chilled out for a bit and went the opposite way on the highway (all done in Mexico of course) and went at it again 3 times in a row. I pulled him by a few buslengths pretty easily. So the next day after my victory, I noticed the following.

-Rough Idle: the car is choppy when I am doing under 5mph or sitting at a light. It shakes and reminds me of my cammed Z06.
-Clanking Noise: There is a distinct noise coming from the engine. You can hear it in the car when sitting and while driving you can hear it clicking. I checked under the hood and had a shop inspect it too and we can't figure it out.
- Service Traction Control: this warning came on, as well as the Check Engine Light.
- Snappy Downshifts: when I am slowing down for a stop while in the normal automatic mode, the car will violently downshift from 3rd to 2nd.

Anybody have ANY clue what this is? I am having the shop put the car up on the lift and disassemble everything to find the problem but if anyone has any ideas I'm sure that could be a major help.

Thank you,

wait4me
12-15-09, 03:39 PM
hmm what engine code is thrown? The trans will go in a limp mode if the maf sensor is not reading correctly, That why the trans is possibly shifting hard. Call me when you get the codes, im here all day.

Gotham CTS-V
12-15-09, 04:47 PM
hmm what engine code is thrown? The trans will go in a limp mode if the maf sensor is not reading correctly, That why the trans is possibly shifting hard. Call me when you get the codes, im here all day.

Jesse, how do I get the codes? Can this be done through the SCT handheld that you gave me? Thanks man.

wait4me
12-15-09, 04:59 PM
Yes it can, just plug it in and follow the menu

Gotham CTS-V
12-15-09, 05:33 PM
Yes it can, just plug it in and follow the menu

Thank you very much my friend. I will call you shortly.

RapidRob
12-15-09, 11:30 PM
^^^ Well - darn it! What was the problem?:thepan:

Rob

vseries
12-15-09, 11:45 PM
:pop2: subscwibed

Razorecko
12-16-09, 01:10 AM
eeeeeeeeee - any clanking noise coming from the engine makes my heart sink

Gotham CTS-V
12-16-09, 08:42 AM
First off, thanks Jesse for staying on the phone with me while I updated the SCT and checked for codes.

Unfortunately, the code that the car was throwing was a code Jesse never heard of. He believes it is a spark plug issue and that once I change all the spark plugs (specifically #7 I believe) then the problem will go away and the car will run better than ever. I'm taking the car to the shop in 2-3 hours so I am praying that this is the issue. The shop owner thinks its a problem with something in the blower.

Nutz
12-16-09, 09:01 AM
Can't hurt to check the mass air for for oil build up from the air filter at this mileage, especially with the wot usage. Might be the rough idle.

Vrocks
12-16-09, 04:13 PM
Good luck with the car, I hope it's something minor. You'd be unlucky for a failure this early from your mods - unless something was out of whack with the ECU.

I highly doubt this applies to our car but... I've read numerous posts on FI LS engines (they started out NA). Cylinder #7 seems to be a weak area but it appears to be due to the intake manifold design (so I doubt it applies to us, since our cars had a manifold designed for FI). Boost seems to build up at the far side of the manifold, which could create a leaner condition - in this case, cylinder #7 (and 8). Like I said, I'm definitely no expert and our engines are different...

lavaman
12-19-09, 06:41 PM
Is there an update on this?

I hope it was something simple!