Need help in diagnosing this

[2DR4EVR]

I was looking for thoughts on this one. Im still chasing gremlins out from my rebuild but this one I cant figure-

At freeway speeds, when gas is applied, I'm getting this wavy high frequency like rumble from the engine every few seconds. It comes and goes.........2-5 seconds of rumble, 45 seconds of smooth. Repeat. Foot off gas it goes away immediatly. I wish I could describe it better but its very noticeable to anyone in the vehicle.

I'm throwing no codes, I have a digital scanner hooked up to the car at all times. I get ZERO fluctuations in the RPM...Analog and digitial while its happening. Everythign remains rock solid.

What could be the source of this be??

I have new tires, replaced the U joints and this is a new engine. Entire fuel system has been replaced.

Thanks

 

[98 2-DOOR]

a/c compressor kicking on and off?!

 

[laredo1307]

I recently replaced the cats and the muffler on my 96 and I'm getting a droning sound between 70-80mph. I also replaced the tires at the same time but I'm almost positive it's from the new exhaust.

 

[BigWheelinBubba]

Did you have the torque converter out of the transmission when you had the engine out? If so it's possible you didn't correctly seat it on the pump of the transmission when re-installed.

 

[2DR4EVR]

Did you have the torque converter out of the transmission when you had the engine out? If so it's possible you didn't correctly seat it on the pump of the transmission when re-installed.

Bingo.

Just finally solved this. I was started throwing a transmission code. On a fresh rebuilt one. I still need to speak to the transmission guy. I was out of town and had my woman drop it off and pick it up. So she was trying to explain to me what he had told her. Not easy.

In any event...it was in and out in 1/2 a day.

Cheers