RPMS running high in OD...tranny problem???

[Mike93]

I've noticed this the last few days while taking the 15 mile highway drive to work. In OD (93 ATX) at 70mph or so the rpms are in the 2600-2900 range. Then after about 8 miles or so it finally drops down to 2100 (ballpark). Best way I can describe it is that it is slipping for a while, then it engages. Is this a torque convertor issue??? Tranny issue??? Computer???

Car has 135k on it and the trans has been replaced at around 80k from the previous owner. All history before 100k when I bought it is more or less unknown...but the owner said the tranny had been replaced. Anyway, at about 115k I began to notice a problem with the tranny shifting when at WOT. Since then I have been pretty easy on the car knowing that the 93 ATX's were weak. Now, if I give it WOT it will still hesitate on the 1-2 and 2-3 shift. At around 120k I decided to try out Lucas Oil tranny additive. Was told this may help shifting. The bottle itself was about 1 quart worth and directions stated to add to existing fluid with out draining anything...does this overfill the tranny???

Where do I look to try to get this figured out??? I don't have the money to get a $3k trans. What other options are there for remedying (sp?) these trannys??? Any rebuild kits out there??? I know my car could benefit from the D4UI, LPM, and a shift kit, but this is all out of my budget right now.

Any thoughts on how serious of an issue I may be looking at here or in the near future???

Thanks, Mike

 

[SHOZ123]

The TC is not locking up until the fluid warms up to a certain temp.

 

[SHO#7]

Sounds like the TC is waiting to lock until the TFT ( transmission fluid temp sensor ) tells it too. Just like Paul said.

 

[Mike93]

So are we talking bad sensor somehwere or is it in the torque convertor??? Please excuse my lack of knowledge in regards to the ATX on these cars...never really had to deal with an issue on this car that I was undereducated on.

 

[HopefulSHO]

What are your average daily tempatures there? It sounds to me like your tranny is doing just fine. It has to heat up a bit (remember there's 12 quarts of fluid to heat, plus a cheezy cooler in front of the radiator) before the converter will be locked up.

 

[Mr Anonymous]

So are we talking bad sensor somehwere or is it in the torque convertor??? Please excuse my lack of knowledge in regards to the ATX on these cars...never really had to deal with an issue on this car that I was undereducated on.

Nope, we're talking about the perfectly normal operation of your PCM and TCC (tq converter clutch) now that the temperatures have gotten colder!

As to the shift hesitation at WOT, that may just be a PCM issue. A D4U1 may (and I stress may) help alleviate that. You are probably also due for a tranny flush and filter change.

 

[Mike93]

Temps have been in the 40's lately. The times that this has been happening hasn't been very cold. Tonight on the way home the torque convertor never locked...rpms were 2500@70mph, a few hundred higher than normal. Thing I notice the most is that I can apply more throttle and rpms will rise a few hundred and speed will slowwwwwllly increase. When locked the car will move. This has never happened in the 35k miles that I've driven this car (in MN winters)...which leads me to believe that something isn't cool.

Then an hour later I went out to run an errand and everything worked fine. Is there any sensors or anything to help lock the convertor??? How about sensors for shifting??? My car shifts like crap...not sure where the problem is here.

Tranny flush may not a bad idea. Any suggestion to a better fluid to use?

Also, any time I give it some gas I throw a check engine light. Has only happened 3 times, all were on onramps accelerating in third gear. Light gets thrown a few seconds after getting off the gas. I am long overdue for plugs and wires, and I know the plug seals are shot and filled with oil. So, not sure if the light thrown has anything to do with this???

Thanks, Mike

 

[Axianator]

I am long overdue for plugs and wires, and I know the plug seals are shot and filled with oil. So, not sure if the light thrown has anything to do with this???

I believe you answered at least part of your question right there ...

Out of curiosity, have you pulled your codes yet? If so, what did you find?

As for your converter issues and crappy shifting, I would be highly suspect of the VSS. Does your cruise still work?

 

[Mike93]

Plugs, wires, and seals are coming up as soon as all the holiday craze calms down.

Haven't had a chance to pull codes. Cruise still works.

 

[AutoSHO]

I think you should definately check codes. I wouldn't be surprised if you found a MAF code in there (possibly a 157). It helps the transmission calculate load, and also would cause a CEL when you let off after hard accelerations.

As for the intermittant OD lockup - I cleaned the electrical plug on my transmission where all the wiring runs in, and the problem did not return in th 10k or so I had the car before it got rear ended.

 

[Slo-Sho]

That damned TOT (trans. oil temp.) sender likes to wreak havoc on my mpg. Thermistors usually default to the cold side of it's temp range when they go bad. I've always wondered if I could splice in a resistor to trick the EEC into thinking the trans is hot.

 

[shoteen95]

i've noticed a similar issue lately in my ATX SHO.

i'm not an idiot, and can easily tell if the TC is locked up or not. On a 40 min drive back from my gf's house, about 10 min before i got home i noticed that the TC had not locked up. Usually you can feel that surge of acceleration with a locked up TC and the RPM's wont change much, but just feathering the clutch spun the motor up an unusual amount.

Turned off the OD, then back on again, and the TC locked right up. I've never known it to act this way when warmed up...

Also, what is the reasoning for safeguarding the trans/tc from locking up the tc before the fluid is warm.. *maybe an idiotic question*

 

[N3FOL]

ATX Torque Converter

So are we talking bad sensor somehwere or is it in the torque convertor??? Please excuse my lack of knowledge in regards to the ATX on these cars...never really had to deal with an issue on this car that I was undereducated on.

Mike,

The guys here are right about the symptom that you have on your car. I do have the exact symptom on my 1995 ATX, which has 138K miles on its original tranny. The temperature here in PA. has been averaging around 40 to 50 daytime temps.. But next week, temperature is expected to stay in the high 30's. So...take it easy for about ten miles on your throttle and wait for that fluid to warm up...then you can punch it.

 

[Axianator]

I've always wondered if I could splice in a resistor to trick the EEC into thinking the trans is hot.

You could, however I wouldn't recommend it.

Also, what is the reasoning for safeguarding the trans/tc from locking up the tc before the fluid is warm.. *maybe an idiotic question*

The long of the short is:

Unlocked converter = higher RPMs = more heat generated = warmer fluid = better viscosity

And remember - there are no idiotic questions, only idiotic answers (did I just incriminate myself?).

 

[Mike93]

Well, it sounds like it could be a few differnt things based on what's been said. First thing will be to check the codes...should be able to do this tomorrow. Then I'll take it from there. Thanks for the replies, Mike