LS4 Performance - Impala SS Engine Trouble?
12-27-2008, 05:58 PM
I have an 06 Impala SS. The only engine related mod I have is a K&N CAI. Installed about 3 months ago.
A few days ago the car started acting up. Around 1500 rpms it feels like it is running very rough, the tach bounces around a good bit under constant pedal position. If you get above 2000 rpms it feel fine. If you stomp on the loud pedal it shifts through the gears like it should. But if you are just crusing along at low rpm it feels like crap.
I can even put it in (N) and rev the engine to 1500 rpm and you can feel it.
*EDIT Turns out this was a transmission issue ... read below
12-27-2008, 07:13 PM
No idea, perhaps a bad/clogged cat or something? Any check engine light?
12-27-2008, 09:32 PM
Make sure the filter is clean and the clamps are all secured tight around the plastic parts.....they have been known to come loose and leak....causing gaps in the powerband.
12-27-2008, 09:37 PM
oil on the maf. search on here you will find like some electrical cleaner that people recommend to clean it up.
12-27-2008, 09:40 PM
Scatchy sabotaged it.
12-28-2008, 08:18 PM
How about transmission...
On the way back from Ohio, we stopped to get gas in PA and it wouldn't go into gear anymore.
There were no check engine lights, even after it stopped working. We had narrowed the problem down to transmission after we started back. Felt like it was slipping. I thought you usually had more time when an auto started to go. This was only a few days. First noticed the problem Tuesday, didn't really drive the car until today and a few hundred miles later there was nothing.
This is why all cars should be rear drive manual transmissions.
12-28-2008, 08:21 PM
2nd gear pack fried out on you? That's the most common failure I think. Or did you get a new and exciting failure?
Welcome to the "I blew up my LS4's trans club", the other members are well, 95% of the forum.
12-28-2008, 08:34 PM
Yeah, it wouldn't go into any gear. Park worked.
So this is a common problem? I had read that GM uses this transmission in other cars and it has had previous problems. Is that true? What a piece of $#!+. 61K miles. The manual doesn't even call for service until 100K.
12-28-2008, 09:12 PM
Yeah this is fairly common. Mine rolled over and died at 28k.
As near as I can tell it is the engine heat that gets the transmission, not the power. If you look down the exhaust lines run right around the transmission and heat it up. In mine the chain had stretched, rubbing against the casing and spitting out small metal shavings into the transmission fluid. These shavings chewed up my gear packs, namely the second gear one, and that was all she wrote. I know of two other GXPs the same thing happened on. For most of the cars I think heat related deaths are what killed them in some fashion.
You can deal with this in a number of ways. Finned transmission cooling pan, a full transmission cooler, a heavier chain (say 5/16) in the transmission when you have it rebuild, heat wrap to shield the transmission from the exhaust and I'm not sure what else had been tried.
I'm not sure who will be rebuilding your trans, if its the dealer then I guess what you'll get. If you're going to a specialized trans place I'd ask them what type of cooling they will suggest. At the very least I'd be sure to get some heat shielding between the exhaust pipe and the transmission. Ideally also have them beef up the transmission as well while they're in there. A beefier transmission will also let you mod more.
As it stands at this very moment my transmission is still under warranty so I've avoided touching it. I figure if I do stuff and then it dies, the dealer will try to blame my mods and hassle me about getting it replaced. I have heat shielding over the exhaust and that is about the size of it.
Oh yeah and I think Milzy is looking into making a M6 conversion kit for W-Bodys. I'm not sure if they need a test mule or if they have a kit out for it. If you have the money you could always go that route.
12-28-2008, 09:36 PM
Thanks for the info, it's my wife's car and she game me shit about the CAI, so I am guessing that the only other mod (that's not cosmetic) would be the magnaflow exhaust. Although I doubt we will keep the car much longer after its paid off. It's given her a lot of little problems and now this.
61K miles, the 2006's only had a 36K warranty.
I guess that I could ask the dealership to use a heavier chain or heat shielding. They can only say no.
I had it towed to the dealership because I was 150miles from home and didn't know where else to take it. I asked to tow it to the GM dealer with the largest service department in the area.
It's going to cost me around $400 bucks just to get it towed back. Could probably do it for $150 if I rented a trailer and borrowed a friends truck.
There is a transmission service place near me that I would trust, especially if the dealership tries to screw me over on the repairs because my car is stuck up there.
Just to cover my ass, Is there anyway that the CAI install could have caused this problem?
12-29-2008, 08:32 AM
Ok, I have prepared myself for the worst ... full transmission and torque converter replacement.
If it does turn out to have metal shavings when they pull the pan and filter I plan to service it more frequently than the GM recommended 100K service intervals.
What exactly do I need.
Filter, gasket & Fluid?
Has anyone serviced their own trans?
Sorry if these are stupid questions, but i have not done any transmission work before.
12-29-2008, 06:16 PM
Well flushing the transmission is going to help buy you time but I'm not sure how much it will do long term. Once the chain is damaged it will keep likely keep spewing shavings. Everytime it goes over the gears the already stressed metal is likely to spit off a few more metal shavings, so flushing will buy you time, but once that chain is damaged the clock is ticking. I'd think you're better off going with some kind of cooling route myself, as opposed to plunking down money for coolant, etc every 25k miles to flush it.
I'm only at 44k miles so I've yet to go in and flush my trans, so I can't help on that. One of the higher mileage guys might have gone down that road. In general there are little generic kits you can pick up at an autoparts store and use them to flush.
PS: Make sure whoever services / rebuilds your trans flushes the system multiple times. I know one guy who got a new trans, but only a half assed flush job from the dealer, so the metal shards were still in the system. They chewed the new trans up in like 4k miles and he was back in there.
12-29-2008, 09:48 PM
they dont know if there is metal in the pan yet... were going to drop the pan and wanted to know if any special parts are required is all it sounds to me.
12-30-2008, 08:58 AM
No special tools required! Easy job, I did mine @ 30K miles, shift kit, filter and fluid. Took like 7 1/2 qts to refill, pan gasket is reusable. Should only take 45 minutes or so to drop pan and clean it, swap filters, and refill.
12-31-2008, 06:09 AM
I had to bite the bullet and get a new transmission. Comes with a warranty. The service manager told me two different numbers. He wasn't sure if it was 50k/3yrs or 100k/5yrs. Either way I was stuck getting a new one.
I will definitely be more attentive this time. If it happens again, I'd like to know its broke before getting stuck 3 hours from home. Luckily it went out near a town with a chevy dealership with a good service department.
The General and Chevy can kiss my @$$ but I have no complaints about Thomas Chevrolet - Cadillac - Subaru in Bedford, PA. Their service department was great.