99 Regal tranny issue

99 Buick Regal 3.8L V6 (no supercharger). Often chugs on light acceleration in 2nd or 3rd gear and then shifts rather hard into overdrive. Usually only after driving for close to an hour or more and gone if left to cool off for a couple hours before being driven again. Check engine light comes on when problem exists and eventually goes off when driven without symptoms for a while. I read this in a local newspaper:

"It could... be the torque converter clutch locking and un-locking for some reason. A quick test for this would be to use your left foot to depress the brake pedal about half an inch - not enough to actually engage the brakes, just enough to activate the brake switch - and hold it at that point while you gently accelerate. If the chuugle disappears during this test, the problem is with the converter clutch or its 'command' from the powertrain control module."

First question would be whether the above seems reasonable. Second, of course, is if there's any kind of ball park on the cost to fix this - $200, $2000?

 

Well, before you go any further, have the codes read. That'll provide a starting point.
It gets regular service so it's got good fluid & filter in it I assume?

BTW, sorry about the Badgers getting knocked out of March Madness.

 

DTC's all always good, but here some info in the mean time.

Some owners of the above vehicles with a Hydra-Matic 4T65-E transaxle may comment on harsh upshifts or harsh garage shifts, soft shifts, shudders on hard acceleration, or shifts erratic. These conditions may appear intermittently or set a DTC P1811 or P0748. During diagnosis, a low or high line pressure (actual versus desired) may be observed.

The above condition may be due to any one of the following which may affect line pressure output:

• Sediment inside the pressure control (PC) solenoid valve, causing the PC solenoid valve to mechanically bind.

• Sediment in the valve body, causing the torque signal regulator valve to stick.

• Incorrect transaxle oil level.

This is some info of the of bulletin 00-07-30-002B

Fix to clean the valve body and replace the PC solenoid valve, if necessary.

As for Labor, you be looking at around 8 hours plus parts.

 

Transmission flushed and filled last fall. Had the code read once before and they said it was a generic transmission code.


Tow Guy: Haven't watched a college basketball game yet this year, so I wasn't even aware they were in. I'm finding these days that if it isn't NASCAR, I'm just not that interested in watching anymore.

 

What do you mean by Generic Code?

Flushing will not resolve issues with the valve body. I have noticed that alot of technicians prefer to replace a valve bodies then attempt to clean one (making sure not to have to do the job twice).

I don't know if GM considers Transmission Flush a Repair or Requirement. I have always viewed that as a get rich thing for your local Quick Lube. I'll have to remember and ask GM. The only thing I flush as per GM is the Trans Cooler after a Trans Repair. It's to insure that no trash is left behind.

Without Line Pressure readings or solenoids test, one can only assume.

Get a current DTC and I help to point you in the right direction.

P.S. All ECU and TCM DTC's would be great to insure it's not Engine related.

 

Just answering Tow Guy's question about good fluid and filter with the flush.

Just relaying what the shop that last looked at it with the 'generic transmission code' - maybe they didn't tell me everything....

 

I can't agree that the fluid was bad

 

one other thing that is not likely given the hard shift into overdrive is bad plug wires. I have seen it on the symptom of chuging, but given the hard shift my guess would be tcc, let us know how it turns out.
speedwrench

 

Didn't mention, but plugs and wires have been replaced with no effect.

 

the bottom line is that most all harsh shift complaints are related to abnormal line pressure (this is oil pressure that does "work" in the automatic trans...or a conmverter clutch that is not regulated properly. the converter can be released, partially released or applied during any operation including upshift at light throttle. it does need to have pressure test performed to zero in on the cause...altho in either case according to the bulletin posted above, cleaning or replacing the valve body is the fix for those specific causes. a competent and well trained trans tech should be able to sort this out for you.