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View Full Version : Drivetrain Issues...need Opinions


AConvertedChevy
09-21-2011, 11:33 AM
Lately my 03 (94k miles) has been jumpy. It feels like something is slipping out or disengaging with throttle input. It happens mostly under 3/4 to WOT. It feels like its in the back of the car where the problems are.

It happens in the middle of the gear. It happens mostly at 3600 and up in first, above 3k in 2nd, and barely at all in 3rd and 4th/overdrive. Its a popping kind of sound and I can feel the power not being applied to the wheels, making lugging sounds and jerks as opposed to normal smoothness. It almost sounds like I'm hitting a rev limiter of some kind and powering through it.

Its not a banging so much as a few slipping thud kind of sounds. Here are my thoughts on what the problem could be...

Injectors maybe needing to be replaced?
Torque converter having problems?
Axles chewed up or something like that? ( had to replace one axle last winter) not same sound or feel though.
Differential problems?
Transmission problems?
Zack Tune clashing with new full 2.5 stainless w/ headers?
Some electrical malfunction?

Thanks in advance for anything you guys come up with.
I HAVE TO GET THIS FIXED BEFORE MARAUDERVILLE! :banana2:
Paul T. Casey
09-21-2011, 11:38 AM
With the new headers, a tune would be very beneficial, however, I don't think that's your problem. Sounds like a tranny/torque converter issue to me. Get a hold of Zach (your tuner) and maybe he can upgrade the engine tune for the headers, and you can go from there.
ctrlraven
09-21-2011, 11:44 AM
So it just started doing this? What was the last mod you did and how soon after that mod did it start?
AConvertedChevy
09-21-2011, 12:15 PM
It started maybe a month or so ago. It was a little apparent before the 2.5 tailpipes but i think its worse now because i can hear the motor sounds better now.
It didn't start in any reasonable time after any mods, just randomly. thats why I'm so confused
LANDY
09-21-2011, 01:00 PM
Dattalog the car and check for the converter slipping.
Do you still have the factory COP's?
AConvertedChevy
09-21-2011, 05:22 PM
Dattalog the car and check for the converter slipping.
Do you still have the factory COP's?

Yep, only engine/drivetrain mods are Kooks Longtubes, Kooks catted X-Pipe, 2.5" Over-axle/tailpipes, Zach flash tune, JLT and aftermarket wheels/tires.
I put new spark plugs in last summer at 70k miles. Coils are factory, so are injectors.
ctrlraven
09-21-2011, 05:57 PM
You should really get a dyno tune if you have headers and full exhaust done cause your AFR could be way off especially if it happens when you got 3/4 throttle or WOT.
Blackened300a
09-21-2011, 06:10 PM
I installed headers and never changed anything in my tune and never had any issues like described. Did you hook up the EGR or eliminate it with the header install? When was the last time you changed the fuel filter? Cleaned the MAF recently? Also do you hear anything rattling that may be a blown out cat thats causing a blockage in the exhaust?
tbone
09-21-2011, 08:39 PM
Check the TPS. (Throttle Position Sensor)

http://www.buzzle.com/articles/symptoms-of-a-bad-throttle-position-sensor.html
AConvertedChevy
09-22-2011, 08:15 AM
Check the TPS. (Throttle Position Sensor)

http://www.buzzle.com/articles/symptoms-of-a-bad-throttle-position-sensor.html

I did notice coasting downhill that the idle was going up and down by 500-700rpms or so.
That doesnt happen all the time though.
I have no check engine light, but ill take the xcal out today.
Those tps symptoms are pretty accurate. Ill look into this.

Car has all new fluids and filters, ill clean out maf today as well. Im just praying its not mechanical and an expensive time consuming, I wanna be able to race at marauderville.
AConvertedChevy
09-22-2011, 08:20 AM
do you hear anything rattling that may be a blown out cat thats causing a blockage in the exhaust.

I don't think that's what im hearing, but ill look under for damages or signs of cat issues.
ctrlraven
09-22-2011, 08:20 AM
Pick up some CRC QD Electronic Cleaner, give you MAF, IAC and TPS a good spray cleaning.
Dragcity
09-22-2011, 09:24 AM
Could be tune tissue with odd size tires and shift rpm overlap
AConvertedChevy
09-24-2011, 10:10 PM
No DTCs. Took the tune off and I can feel it more. I need to clean some stuff out then look at other possibilities.
AConvertedChevy
09-27-2011, 06:01 AM
Check Engine light came on today after driving with the tune off for a few days.
Came back with a P0153 and a P1000. I guess the car is just really leaned out. Im going to take a look at various sensors around the car.
ctrlraven
09-27-2011, 06:05 AM
Get with Dave (ImpalaSlayer) and get his tuner's info. Get your car dyno tuned. Without doing so you're not getting the full benefit of the headers and full exhaust.

Of if anything talk to the tuner and get his thoughts on things.
AConvertedChevy
09-27-2011, 07:31 AM
Get with Dave (ImpalaSlayer) and get his tuner's info. Get your car dyno tuned. Without doing so you're not getting the full benefit of the headers and full exhaust.

Of if anything talk to the tuner and get his thoughts on things.

Yea im making an appointment asap. Should solve the problem.