I have had my Bu for 4 years now and had been running great till 6 months ago and parked it. Engine and trans are very clean, well maintained by dealer, had new revised intake gasket set install due to Tech Bulletin, and $2k work done on fuel injection and trans flush, and new MAF sensor along with tune up.

Problem is still there..... When first driven all is great and no Check Engine Light ever, within a few minutes the trans hesitates and winds up the shift from 2 to 3, then I let off the gas and it shifts it, and then 4th is great. Downshifting is fine, no issues at all. Car has great acceleration and no problems otherwise. Spedo and tach work, no jumping, no running issues whatsoever with engine.

Possible Issues:
1) Torque Converter
2) Bad shifting band/clutch
3) Vane Sensor

I have a spare tranny with torque converter that is my last option, open to other suggestions or anyone have this issue and fixed it?

Please email me as I get email directly to my phone. Thanks

 

Welcome to the forum. The transaxle on yours is electronically controlled by the PCM. Has anyone hung a scan tool and monitored it while in action? Without that, you can't really come close to a correct diagnosis.

 

Thanks, I have been looking at every possibility with forum searches and google with really no luck.

The dealer diagnosed it as the MAF sensor, but I have had it changed already. I took it to AAMCO and they kept it for a day and test drove and diagnosed it as an internal trans issue. But of course they would as they want $2500 to pull it, rebuild it, and reinstall. Most tranny shops will fully rebuild the trans for $1400 as the 4T40E is said to be the expensive one like the 4T45E brother model.

Because there is no Check Light and it doesnt affect anyother gear, it is said to be internal.

These cars require alot of work to pull motor/trans, must drop the subframe. So ill have a shop locally swap my trans/tc out and see. I will post up when that happens.

I have been through alot with these Malibu's knowing that 98-03 parts are swappable and some arent

 

Drives fine for the first couple minutes when cold? I don't think anything hydraulics can be that sensitive to temperature. It sounds like a delayed shift rather than a slippage, i.e., a transmission control issue. The shift points are determined from the calculated engine load, throttle position, MAF, and MAP, etc. You may want to find someone who's willing to hang a scan tool and figure out what's out of whack. It'd be a shame to go through a swap or rebuild for no reason.