After putting in some new spark plugs (ACDelco Rapidfire'*) and a new wire set (Duralast) my hesitation under load is gone (I was getting a Cylinder 6 misfire). BUT, Now I'm getting a hesitation mainly when the tranny does the 3-4 shift. If I'm on an on-ramp to the highway and I drop the pedal to the floor, I get a sloppy downshift and silky smooth acceleration until I let my foot off the gas. As soon as I back off, the tranny shifts to 4th, and I get quite a hesitation. When the hesitation occurs, my speedo might fluctuate 2 or 3 mph...

If I'm light on the gas, the shift isn't nearly as noticeable. It also helps to shift into 3rd while accelerating through 48-54MPH, and then drop it into OD... In that case, the hesitation won't occur.

It also happens if I'm traveling up an incline at about 40 or so and step on the throttle. When it down shifts, I get a few hesitations before it finally positively engages into gear.

I've been reading other tranny posts, but most have been getting the P1811 code... I've been checking my codes, and I haven't been getting anything. I'm not sure if that rules out PCS failure in the tranny.

This happens when the car is hot. Any ideas? This is the 4T64e tranny in a 1998 Olds Regency.

What'* your fluid like? Smell burned? Any metal flakes suspended in the fluid? When was the last time you dropped the pain, changed the filter and put in new fluid?

While reading this my first thought was your fluid, then I thought perhaps a sticking shift accumulator. But when you mentioned the speed it shifts, 48-54, that got me thinking it'* your TCC solenoid switch. Take a look at this write up. https://www.gmforum.com/t284972/

I was thinking the TCC also Dan. Then I re-read it and thought at a minimum the fluid needed to be ruled out. It sounded like a pressure issue that you can get when you have a clogged up filter. Checking the TCC is less invasive with a pan drop, filter change and fluid refill.

I just purchased the car a week ago. The fluid doesn't smell that bad but it does look kinda light (as in transparent and not very red). No flakes or debris. The car has 76K miles.

I added half a can (1/2 pint) of Trans Tune and it hasn't made a difference. I'd have to have to drop the pan, though. I might be able to stop in at my school and use their lift...

Here'* a quick pic, it'* very dark out so it'* kinda hard...


Nick

EDIT: The car has been sitting for about 4 hours and I did notice a sound (it sounds like the tranny) it'* like a rotary abrasive/sandpaper scraping-type of noise. It goes away about 2 minutes after the car is running. Could this be a fluid problem with the tranny?

If your going to go to the point of dropping the pan to change filter and fluid. I would say go a little bit more and drop the shift accumulator and open it up. Clean up the cylinder walls, check the O rings, and put it back together. Adding a shift kit wont hurt either. https://www.gmforum.com/t278802/

That fluid don't look that bad.

The sound you hear sounds to me like your idle air control. think of it as a choke. Lasts about a minuet

It sounds much larger than the IAC... It'* pretty noticeable even with the hood down..

Is this when your moving or parked?

X2... I see no evidence of burning. The fluid looks like it might be pretty new. You said you added 1/2 pint of Trans Tune? I can't tell from the dip stick, but make certain that the total fluid volume is between the upper MAX mark and the lower ADD mark.

If you know how to properly check your transmission fluid levels great. If not, here'* how to do it the right way.

Get your vehicle up to temperature and drive it around the block. Run it through all the gear selections, including reveres; and then come back, put it in park and keep it running and check the fluid level. Pull the dip stick out, wipe it off, place it back in and pull it out. the fluid levels should be between those two marks. If its above the upper or below the lower mark...your transmission will run like ka-ka.