I have a 2000 Volvo S70 GLT with about 145k miles on it. Its my first car and I don't want to get rid of it but I keep having issues with it. Back when I first got it back in August of 2016 a few months after I found that coolant was mixing with some other fluid. So i brought it back to where I got it from turns out it was transmission but what they did was flush the coolant but not the transmission. They had also put on an external transmission cooler. So a couple months later I decided to replace my radiator cause there was a crack. Come to find out they had snipped my transmission cooler lines and just plugged them. Not sure if they told me they were going to do that which is obviously something that shouldn't be done. So now i'm having transmission issues I have a P0740 and a P1618. It was shifting hard sometimes if I really slammed on the pedal but if I wasn't it still seemed to jump a little. Any other information needed i'll be happy to answer. Thanks

 

First thing I would do is check the fluid level and condition of the transmission fluid, and make sure they put the correct fluid in.

 

I have changed the fluid once but it became contaminated again never did a full system flush with a new filter last I had checked it was a milky sort of tan definitely not the color it should be. When i changed it out I added Lucas Transmission Fix

 

Did they actually install a transmission cooler? Hopefully they did not just pinch off the lines to the radiator. I used to do automatic transmission all day every day. If the cooler inside the radiator went, your transmission is done. Any water gets in and the clutch plates come unglued and the thing is done. I don't know why you'd bypass it. The radiators are not that expensive. The problem is the cooling system being pressurized will add water to your transmission fluid after the car sits while warm (the trans pump is not running then).

 

They installed an external transmission cooler.

 

You do at least need to get the transmission fluid to the color red. At least do that.