2002 C70 no heat

goldmandan · Post by **goldmandan** » 26 Aug 2015, 19:24

I redid the headgasket on the 2.3 T engine over the weekend. Got it up and running today. Runs great with no leaks etc............ I never tried the heater on this car (bought it about a month ago) and turned up the heat today.......... nothing. even after 5 minutes of driving nothing......... i suspect that either the evaporator or the heater core was changed out as the dash has been removed and put back in for sure! Any clues?

Post by **scot850** » 26 Aug 2015, 22:44

Maybe check that there is actually a heater core and someone hasn't by-passed it doe to a leak.

Do the ECC/fan functions all work otherwise?

It could be a stuck or out of sync heater flap servo motor.

Neil.

Post by **j-dawg** » 26 Aug 2015, 23:19

The dash doesn't need to come out to replace the heater core.

There is no valve or other element that normally bypasses the heater core; if the car is on, coolant is flowing through the core, and if the coolant is hot, the core is hot. Peek at the firewall near the left side of the car. You should see the two heater hoses entering a bulkhead fitting, stacked vertically. If they're not there or not passing through that bulkhead connector, your heater core has been bypassed.

If they are in place, touch the hoses when the engine is hot. If they too are hot, it would suggest something is wrong with the electronic systems governing getting the hot air to the cabin, as Neil said.

Heater core failure is not uncommon and leads to loss of coolant, which leads to core meltdown overheating and failed head gaskets. It wouldn't surprise me if yours has been bypassed. If that's the case, plan on replacing it and tearing up the interior to get all the coolant out of the foam under the carpets.

goldmandan · Post by **goldmandan** » 27 Aug 2015, 06:05

thanks for the heads up! I will check it tonight!

HenryD · Post by **HenryD** » 28 Aug 2015, 06:39

I have a no heat issue in a v70 1998 the heater core I replaced and the fan works on auto and manuel settings The cabin air t stat fan is spinning and the venting system pushes air to the selected locations. I think it may be the mixing motors but I cant find the info where they are located in the car and how to get them out or repair them.

HenryD · Post by **HenryD** » 28 Aug 2015, 14:45

as luck would have it I found the vents are above the heater core I finished replacing the heater core and the heat works fine. I think the old core was completely plugged up but it looked so new and clean i thougth there was no way. I am in the heat now.

goldmandan · Post by **goldmandan** » 29 Aug 2015, 13:17

Ok, So I checked the firewall last night. The 2 tubes coming from the heater core were open and there was a hose interconnecting the flow.......... so someone has bypassed it. Probably because it was leaking and they didn't want to fix it........ how easy is the job of changing out the core? Specially if there's no coolant in the old one.... I know I saw a Youtube video from "Robert" on this one..... just can't find the video right now..

Post by **abscate** » 29 Aug 2015, 14:41

The old one is probably still full of coolant.

This is an easy job if you still have all the parts, I would make a trip to Volvo and get the VIDA picture and inventory what you need to complete.

It's the flange and pipe bits in this pic you need to make sure you have