Can anyone help me?

[DAlexander45]

Hey there guys, I’ve had my 95 pathfinder for three or four years now, my dad got it used but it had low mileage, and the motor had just been rebuilt by a local guy in town that rebuilds racecar engines, anyway back when it was cold I managed to blow the water pump out. Well I go to school out of town so I didn’t have time to work on it until this summer, my dad and I replaced the water pump and al the other parts you’re supposed to replace when you do the water pump, and it runs fine, except when you first crank it up, if you don’t give it ample time to warm up, you back it up and then drive forward and you out your foot on the gas, the engine will rev, and it’s like you’re going but you can tell its only partial power, and then all of a sudden the full power will come back, and it will go through this cycle until it first shifts, after that it runs great and shifts smooth. Any ideas what could be wrong with it?

[Precise1]

I'm assuming it is an automatic transmission...

 

How is the fluid level and condition?

Are you getting flow through the stock cooler (bottom of the radiator)?

Does it only do it when you are go in reverse first, then forward in drive?

 

B

[DAlexander45]

Yes! sorry it is an automatic, and as far as i can tell, but ive never had the oppurtunity to just put in drive and go, once it warms up there are no issues. Fluid levels are fine.

 

[Precise1]

So, do you have good flow?

Maybe park it in a manner that you can just put it in drive and go? Reverse needs the highest pressure and obviously uses different channels, so it might be telling to differentiate.

 

B

 

[Slartibartfast]

Is it like the engine's weak and not revving, or like the engine's revving but power's not making it to the wheels? If the transmission is slipping you'll want to sort that out ASAP.