I have a 2000 T/A, originally 2.73 geared, switched to 3.42's, stock computer tune, premium 93 gas. While breaking in the gears the torque converter lockup worked fine 1200 miles. Lately, I have been experiencing pinging when the engine is under load while the converter is locked, or the instant I go WOT while in OD with the converter locked. This has been constant thru four tanks of gas, two from Mobil, two from Amoco. I am getting up to 9 degrees KR and hear an audible pinging under these conditions:

-In Overdrive, around 40MPH, converter locked. If I give it 1/4 throttle, the converter stays locked and the engine will ping and pull timing, between 4-9 degrees. At the same speed with the converter unlocked there is no ping or KR.

-Going to WOT from OD with converter locked. While the trans is unlocking and downshifting the engine will ping and will pull between 4-9 degrees KR. Going WOT from any other gear when the converter is not locked produces 0 KR. I can go WOT from a stop all the way thru the 1320 and no KR.

I changed the plugs to stock platinum stock gap, changed fuel filter, PCV valve, air filter. All my sensors are working properly, the coolant temp never exceeded 190, outside air temp was around 70. The tranny is stock, no shift kit, no converter, fresh fluid, proper level <63K miles>. I have a handheld tuner <VHP> which I took out 10% timing and added 15% fuel for kicks and still had the ping.

I was told that my converter or TC lock up solenoid was "lazy" in unlocking my converter which is causing the pinging and KR. The converter has no problem locking up, and the unlocking does not seem to take long, although while cruising I have to give it atleast 1/2 throttle to unlock. The engine only pings and gets KR when converter lockup is in the picture. What do you think of this scenerio? Would the gear swap come into play with this <engine sees less load, converter takes longer to unlock>, or bad lockup solenoid, or converter, or???? Any insight would be appreciated as I would like to be a little informed before I take my car to a tranny shop.

 

Dunno. After swapping my 2.73s to 3.42s I drove mine on the stock tune (meaning without adjusting for gears) for several months without any such problem. Driveability did improve when I adjusted the shift points and lock-up points for the gears.

 

you know i forgot about your gear swap. i know the VHP tuner fixes the speedo. but i wonder about lock up. i'll ask roger about it tomorrow. you can try the "Enhance Trans Shifting" which raises the stock shift points about 300 rpms. Even on part throttle, it delays the shifting about 300 rpms.

 

Yea, did forget to mention that to you......I did use it to recalibrate my speedo though <that works great BTW!> Also, didn't mean to take anything away from you <being that you were the one that was doing all the testing> but for a posting purposes the paraphrasing cuts to the chase. BTW thanks again! I owe you lunch...let me know when you want to collect!!!

 

My truck does the same thing on the lower-speed / high-load unlocks.

I was/am able to get rid of it in two manners:

I "loosend up" my TCC unlock points, so that it doesn't require as much throttle...
or
I reduced timing in that higher load area of the timing table...

 

Would this be attributed to the gears then? I was wondering because this didn't come about until after the gear change.

 

Shoot, I'm really not sure... Mine's always done it though.

My gearing: 4.10's and 31.5" tires...

 

I was thinking maybe: less load due to the gears=torque converter staying locked longer........ You start giving it gas while cruising and the computer advances timing and adds more fuel but the converter doesn't unlock.......maybe??

 

Question for you.....the high performance/stock cam program raises WOT shift points 300.......and the "Enhance Trans Shifting" raises the WOT shift points 300.......would this be 300+300=600 raise in WOT shift points or would it still be 300? Just wondering.....

 

the hiperf stock cam raises the REV limiter 300 rpms. the enhance trans shifting raises the SHIFT point 300 roms. two seperate things.

and i don't mind you posting about it. i've been talking to dan98z about it as well. talked with joe vinci about the gear swap. so long as you corrected it with the tuner, it won't affect the lock up. because it depends on the speedo mph to lock/unlock.

 

Anyone else have some insight? The pinging seems to also be temperature related....the longer I drive the car/sit in traffic, the worse it is.....

 

well the hotter the motor, the easier detonation will become. but, again, this is only while the converter is locked up still correct?

 

Yes, it is only when it is locked up.....