: Torque test and gas cut off?



kevinK
04-26-04, 01:19 PM
Hi,

When I do a torque test: holding brakes against torque (D, R, 1, 2, or 3), the engine RPM will not go above about 1800 rpm. It seems that the gas got cut off (reduced), and the front end of engine also vibrates somewhat. At P or N, it goes right up to 3-4000 rpm easily. The car drives OK but I feel it is less powerful than before, especially during acceleration. What could be the problem?

BTW, it was a new 98 Deville and I put 111K on it. It had plugs, wires, coolant, transmission fluid changed (DIY) according to advises from this board. The alternator was changed by dealer two years earlier, and battery changed a few months ago. Of course brakes too. The car also leaks little bit oil at the oil manifold gasket (according to dealer, and which would cost $2200.00 to fix. No, I did not do it, just add oil about every 2000 miles). Otherwise, it is a pretty reliable, low maintenance cost, POWERFUL AND CONFORTABLE car.

Any advice will be appreciated?

Thanks.

zonie77
04-27-04, 12:38 AM
I'm not sure how to answer you........
I've never heard of this as "torque test". Brake torqueing shows you the approximate stall speed of the torque convertor, in your case 1800 RPMS. It sounds like you got a normal result.

What did you expect to happen? What happened before when you did this?

Big Jim
04-27-04, 04:02 AM
Basically, you car is smarter than you are. It will not allow you to abuse the driveline with what you were trying to do. The ECM knows vehicle speed (in this case, 0) engine RPM, and transmission gear along with a bunch of other stuff. It just controls the injectors to prevent overloading things. You'll get similar action out of the traction control if all the speeds don't match up.

kevinK
04-28-04, 05:38 PM
I'm not sure how to answer you........
I've never heard of this as "torque test". Brake torqueing shows you the approximate stall speed of the torque convertor, in your case 1800 RPMS. It sounds like you got a normal result.

What did you expect to happen? What happened before when you did this?

Hi, I meant "brake torque test". A couple of weeks ago, my car had bad acceleration hesitation and jerking. There was no code. I did the brake torque test and showed similar jerking movement. I thought it could be the engine mount. It turned up to be two misfires. After replacing the plugs and wires, the accelaration problem is gone, but the brake torque jerking is still there. I am still concerned that there may be a mount problem. I do not know how a normal cadillac will do on brake torque test. Will it be more than 1800 rpm at the torque test without jerking? I tried the test on Lexus and the engine goes above 3000 rpm without much jerking. I hope it is like Big Jim said that the car outsmarted me by cutting off gas supply on torque test. But, I am not sure. Why the jerking? Can you please tell me what happens when you do a brake torque test on your cady? Thank you for your time.