Transmission shudder

[motzmaniac]

Hello,

For the past several months, my 96 3100 has been having trouble shifting. It usually happens when I have to pull out into traffic going even slightly uphill. I press the gas and it usually goes fine at first but when it tries to shift to 2nd or 3rd the car will start to shudder or shake and it will just kinda of hang there. The RPMs will stay (at 3000 for example) until I let off the gas completely and then slowly hit it again. So its not revving the engine. I put some lucas trans fix in there about 6 weeks ago. It seemed to help (not sure if it did) but now the problem has come back even worse.  Its more often now and sometimes I have to let off 2 or 3 times to get it to go. I'd say 80% of the time the car shifts perfectly, but I need to be able to go when I pull out into traffic. The car has 172K on it so its probably something internal that would require a rebuild. I can really afford that...or a new car at this point, so can anyone think of things to check that are more easily fixable? I heard something about vaccuum lines, but I'm not sure what they do. Not sure if its related but the other day I had the AC on and all the sudden the HVAC completely shut off. I turned the knob and didnt hear any vaccuum hiss or anything. None of the settings (AC, vent heater) would do anything. Then all the sudden it started working again. Then on Friday the SES light came on when I was driving home. I'm getting it scanned at the shop tomorrow, but if it just comes back as the stupid EGR flow then Id like to know where to start. Sorry for the long post. Thanks,

Brian

[quad4gtz]

I am pretty sure there is no vaccuum modulator on that auto. Is the fluid level up? Is it dirty or show signs of debris? When was the transmission last serviced? Was there a lot of clutch material in the pan?  Scanning for codes could definetly help you here if the problem is valve body related.  If it throws and EGR code again like you say... maybe it should be addressed.

[Cliff8928]

The 4T60-E does have a vacuum modulator.

[motzmaniac]

The code indicated a "dead" miss in cylinder 6. It took the mechanic some time, but he found that the intake gasket (what a surprise) is leaking and sucking oil vapors from the lifters and causing the mixture in the cylinder to become rich and misfire. He said that could cause the transmission to shift poorly. I'm not really sure what to do. I spent the money to rebuild the car last year after it was totaled, now i'm not sure that at 173,000 miles  if its worth the $700 to fix the engine. But I hate to waste all that time and money we spent last year and get rid of the car. The rest of the car is beautiful. Plus im getting married in Sept. and our bills are gonna be sky high without a new car payment. What do you guys think?