Jason Novak

Currently on a trip right now, ran into a problem with my 98 Z28. Was fine when I left, about half way through, possibly after passing, I noticed it was at about 2800 RPM while in overdrive @ 63mph, like it was in drive. No noticeable change shifting between D/OD. Though maybe I just lost that gear, but noticed other issues when I slowed down. I used a cheap OBD2 scanner, no codes. Summary of symptoms:

* No OD, 2800rpm @ 63mph. No obvious noise when driving or manually moving between gears

* While in OD, taking foot off the gas RPMs drop straight to 800rpms, drive slowly drops like normal

* Moves very slowly from a stop, at 10-20mph have it's at 3000rpm, needs a lot of gas to get moving. Notices got better around 30mph

* Holding at about 40mph it sounds like if you keep tapping the gas to rev it

* Checked fluid, it's full but a bit dirty. I don't put many miles on it, got it with 40K around 10+ years ago, now has 75K. Haven't ever flushed it, did have an aftermarket torque converter put in no long after I got it by shop.

* No OBD2 codes

Someone mentioned maybe a vacuum line. Any help appreciated, maybe I can do something before I limp home:

*** Edit, it's possibly in limp home mode?

mrvedit

The "moves very slowly from a stop" indicates it is in limp mode (3rd gear only). A good scanner should tell you why, but it is often because the PCM detected slippage.
Unless someone corrects me, I think it is safe to drive a reasonable number of miles (up to 100?) to either get home to at least to a trans shop tomorrow. Most auto stores also have a scanner you can use for free in the parking lot.

If you need to drive more than 100 miles, perhaps someone with that experience or knowledge will chime in.

hrcslam

This, you're in limp mode. 3rd gear only and no TQ Conv lockout (why the rpms drop, off throttle, while moving). This usually indicates you lost electrical power to the trans.

Do you have a remote starter installed by chance?

Jason Novak

Thanks, made it back home. A little concerned it wasn't setting a code, but it sounds like that's no uncommon in limp mode. Can focus now on electrical issues, would be nice if it's just a fuse, bad wire, etc.

Jason Novak

To follow up, I checked the fuses and they're good, and I see 12v on the connector at the trans. Getting another connector to test the solenoids.

Now it seems to have gotten worse when I was doing a test with a new battery (parked otherwise). In Drive I can only get up to about 30-35 and then the RPMs just shoot up and the car doesn't really gain any more speed. Works better in 2nd. When this started happened I was able to drive at highway speeds in D.

Is this starting to point to something more serious?

Jason Novak

Well, got the connector and did some tests for resistance for 1-2/2-3 and torque converter solenoids, and put 12v into the 1-2/2-3 and heard them "click".

Running out of ideas and I can't really afford to do any major work if anyone has any ideas.

Someone said changing the fluid may help, it is pretty dirty for only about 30K and having a trans cooler. Doesn't seem like these symptoms would fit poor fluid, just suddenly happening? Hopefully it's not a sign of internal damage, don't notice anything physically wrong between gears, noise, etc

Here's the fluid:

mrvedit

I think it it time to take it to a trans shop and have them analyze it with their scanner and hook up a pressure gauge. For a local trans shop I always suggest a private shop and not a chain. Call a local repair shop that does not fix transmissions and ask them for a private shop recommendation.

I still think it is in limp mode, but it now looks like the 3/4 clutch is smoked too.

Jason Novak

Thanks, that does sound like the issue, and appears to be a common problem and will require a rebuild. Have to start saving my pennies and looking into upgrades, maybe rebuilding it as a 4L65e.

One last question, there's a list of common 4l60e problems that's posted many places that says it's "safe" to drive in 2nd without doing any more damage. I have my winter care I can drive as my main vehicle, but would be nice to still drive the Camaro around town since it'll be a while before I can fix it. Would people agree that's ok?

CAMSTER

iTrader: (10)

Take out your fluid pan and if you see a lot of deposits sitting there your clutches are gone, all that goo goes to the torq converter so a converter rebuild is necessary as well, when my 3/4 clutches went it was first and second quit good luck...

lmt0705

iTrader: (7)

take the filter out and crack the plastic top so you can get at the filter element, unfold it and see what you have. the filter can tell you a lot of info.