Hey Guys, I recently replaced my radiator with a new one due to a leak on the drivers side. Replacement went well with no problems really to speak of. After replacing it and refilling with antifreeze, I took it for a test drive with heat, ac, everything to make sure it was working as designed and everything turned out fine.

Fast forward a few days and I have noticed something that doesn't seem quite right (or maybe I'm just paranoid). Whenever I start the truck and turn on the A/C or the heater/defrost, and then shift into either reverse or drive, it seems like the transmission or engine is hesitating. The normal amount of throttle doesn't make the truck respond like it did before the radiator replacement.

This evening I tried to duplicate the problem once I had been driving a little bit by stopping, putting the truck in park and then shutting it off. I couldn't duplicate the problem at all; so it must only be when the truck has been parked for a couple of hours or more.

I don't believe I'm losing any antifreeze (No Puddles, and reservoir seems to be at the same place), Engine is running right at 195 for operating temp, and oil pressure is right on. I was wondering if maybe any of you guys had suggestions on what this could be or am I just being paranoid? Thanks in advance!

 

Did you check the fluid level in the transmission after the radiator replacement? You could have been boarder line low prior to replacing the radiator and lost enough to cause your problem.

Remember to always check your transmission fluid after the engine & transmission are up to full operating temperature, with the vehicle on flat/level ground, with the engine running, and the transmission in park.

 

Thanks for the fast reply, I drove the truck for about 20 minutes in stop and go traffic and the highway, and then checked it as recommended. There is plenty of transmission fluid. The fluid was right above the thatched "hot" area. I checked all the other fluids and they are right on the money, or right above normal.

What else could I check for?

 

It sounds like it is a problem inside the transmission. I had a '97 Dodge Ram that had a problem with a check valve in the transmission not seating properly. If the truck sat over a weekend, the torque converter would drain out back into the pan and it would take a while for the pump to fill the TC back up and allow the truck to move. As a last whim, I put a bottle of Lucas Trans fix in and it unstuck whatever was sticking and allowed for proper operation all the time. Your mileage may vary, but it's worth a try.

Are there any codes present or pending?

 

if this is doing this only when cold . trans filter could be getting plugged up . they call it mornning sickness

 

I added a 3/4 a quart of transmission fluid, and the problem seems to be taken care of. Probably just like Kyle said with the fluid being borderline low and when I did the radiator I lost enough to make it low.

Although with 94K miles on the truck, it is probably due for a transmission filter and fluid change, so when I've got the extra cash, definitely will be changing fluid in the transfer case and the transmission along with the filter.

Thanks for the help guys, I'm happy it was something simple, I was a little worried when the theory that something was wrong with the transmission

 

Sometimes it may sound like an off the wall thing, but there is a method to this madness! Glad it worked out for you!!