2004 xc70 transmission issue

DLavallee · Post by **DLavallee** » 17 Jul 2024, 07:07

Hello, our xc70 is having a transmission issue. The other day when shifted into drive or reverse it wasn't engaging, was in neutral. Let the car sit for a while. (It was a very hot day) Once the car cooled down. Shifts normally. Checked the transmission fluid and it was very dark. We performed a fluid change and flush, after that seemed like it was shifting better than ever. Drove the car for about 20 mins and when I shifted it again it was like it was in neutral in every gear. Once again let the car sit for a while. Tried it again and it shifts fine. I really am trying to diagnose this on my own. It's my son's car and he can't afford a huge bill. Any insight will be greatly appreciated. Thank you in advance!!

Post by **jonesg** » 17 Jul 2024, 08:35

DLavallee wrote: ↑17 Jul 2024, 07:07 Hello, our xc70 is having a transmission issue. The other day when shifted into drive or reverse it wasn't engaging, was in neutral. Let the car sit for a while. (It was a very hot day) Once the car cooled down. Shifts normally. Checked the transmission fluid and it was very dark. We performed a fluid change and flush, after that seemed like it was shifting better than ever. Drove the car for about 20 mins and when I shifted it again it was like it was in neutral in every gear. Once again let the car sit for a while. Tried it again and it shifts fine. I really am trying to diagnose this on my own. It's my son's car and he can't afford a huge bill. Any insight will be greatly appreciated. Thank you in advance!!

DO you have vida ?
did you reset the adaption after the fluid change.?
if yes,
it sounds like you diagnosed it already, in the current trans condition the tranny fluid needs better cooling.

there are videos on youtube showing how to add aux coolers..
if it already has an aux cooler it might be clogged.
i would drop the belly pan and the front air dam to see what you're dealing with.
genuine volvo part is expensive but they're almost free at the junkyard, ebay used and other cheaper suppliers if you google it.

Post by **firstv70volvo** » 17 Jul 2024, 09:32

DLavallee wrote: ↑17 Jul 2024, 07:07 Hello, our xc70 is having a transmission issue. The other day when shifted into drive or reverse it wasn't engaging, was in neutral. Let the car sit for a while. (It was a very hot day) Once the car cooled down. Shifts normally. Checked the transmission fluid and it was very dark. We performed a fluid change and flush, after that seemed like it was shifting better than ever. Drove the car for about 20 mins and when I shifted it again it was like it was in neutral in every gear. Once again let the car sit for a while. Tried it again and it shifts fine. I really am trying to diagnose this on my own. It's my son's car and he can't afford a huge bill. Any insight will be greatly appreciated. Thank you in advance!!

Those are symptoms of a clogged inlet filter and to help confirm if it is actually a plugged up filter you should hear a whining type sound coming from the transmission pump being starved of fluid. This pump whine will change in pitch with the engine rpm. Do you hear any whining type sounds? If it is a clogged filter it's usually from a lot of clutch pack or converter friction plate wear. This filter is internal to the transmission so can't be changed without dropping and splitting open the transmission cases. Some have drilled a hole in the case and poke holes in the filter to get their cars going again but this is only a temporary fix and shouldn't really be done if you do plan on rebuilding the transmission. When I had this problem with my car I did clean the filter through a drilled hole in the case without poking holes in the filter and soon afterwards rebuilt the transmission. The clutch friction plates were worn to the metal backing plate so even though the filter cleaning got me going again the transmission was so worn out it wasn't going to last much longer anyway. The problem may also be due to a very badly worn valve body but I suspect a blocked filter. Draining and replacing fluid didn't help in my case, the particles are caught in the filter and don't drain out.

dikidera · Post by **dikidera** » 18 Jul 2024, 22:39

Pretty much this. The reason it drives for a while is that as the car is stopped, it is speculated that the gunk kind of separates and falls down from the filter, as you drive it slowly gets picked up again on the filter screen.

@firstv70volvo I am actually thinking when I finally have the time to drop the oil pan and use compressed air and atf or something else to blow it trough the return line in hopes of getting some gunk out of the filter. In addition to cleaning out the linear solenoids.