07 xc70 lukewarm heat am stumped

[jonesg]

in Maine ? now?
Maybe in 3 months.

[chrism]

Run CCM calibration (DiCE/VIDA required). You may have a faulty blend door actuator. Common problem.

I believe the specialist I took it to did that but going to text him to confirm. But that had we thinking about the climate control module and how to rule out if it's gone bad or not. Apart from ordering one online, swapping it and testing the heat, are there any other ways to rule it out?

You could remove the under-dash access panels and watch to see if the blend door actuators move when you call for heat, AC, defrost, dash vents, floor vents…….
If you are experiencing the same lukewarm airflow on both the driver side and passenger side that “might” mean there’s nothing wrong with the blend door motors themselves as it would be coincidental that both sides failed the same way at the same time.
Not to harp too much, but where is your temp gauge running?

[chrism]

As long as you don't blow a head gasket, then it is fine to pinch the hose lol.

Oh no, you would never want to hold it shut that long. An assistant could sit in the car and monitor the temp gauge while noting if the airflow gets warmer.

[cn90]

The problem with the temp gauge: it is buffered...so when it is at 1:00 (instead of 12:00), ppl are getting into the "danger zone".

Anyway, trust me, replace both Tstat + HC at this mileage and move on with your life.

PS: I don't recommend pinching the hose.

[vtl]

I believe the specialist I took it to did that but going to text him to confirm. But that had we thinking about the climate control module and how to rule out if it's gone bad or not. Apart from ordering one online, swapping it and testing the heat, are there any other ways to rule it out?

CCM calibration gives you steps counted end to end for each motor, including deviation from norm. Diagnosing dying motor is almost always a PIA. Driver side in my 05 was working after calibration, unless you or CCM itself set the temp to either of extreme (cold or hot). Then the motor derails again and looses coherence with the real position of the flap.

And you have 5 of them.

You want a full list of codes from your guy, even erased ones, if he erased any. And CCM calibration results.

Or get yourself a DiCE/VIDA setup if you plan to resolve the problem. Working on these Volvos can be tricky, but they are ancient now and every problem possible was solved by someone where on the forum.

[benbug]

Run CCM calibration (DiCE/VIDA required). You may have a faulty blend door actuator. Common problem.

I believe the specialist I took it to did that but going to text him to confirm. But that had we thinking about the climate control module and how to rule out if it's gone bad or not. Apart from ordering one online, swapping it and testing the heat, are there any other ways to rule it out?

The specialist I took it to actually didn't run a calibration I guess. He scanned it with VIDA and didn't see any codes for faulty actuators or anything else. Since I have the car back I'd like to hang onto it since his lead time is a little while but would you recommend a calibration regardless?
He also suspects it could be more than one issue as the air flow itself is louder compared to other xc70s. Like a door is maybe stuck or foam got lodged somewhere in a duct.

[benbug]

The problem with the temp gauge: it is buffered...so when it is at 1:00 (instead of 12:00), ppl are getting into the "danger zone".

Anyway, trust me, replace both Tstat + HC at this mileage and move on with your life.

PS: I don't recommend pinching the hose.

I'd like to just do that. No codes came up doing VIDA scan so idk what's going on. Core is definitely getting replaced but everything I have seen in terms of temp readings and the specialists notes suggest tstat "should" be fine

[benbug]

Hey to anyone reading, I replaced the heater core the other week and now the car is too hot to handle:)

Still hearing a louder than usual airflow sound and suspect a blend door may be partly stuck but for now I'm happy.

Thanks for the help

[scot850]

I still think someone has use liquid gasket repair and it may have blocked your old heater core. Keep an eye on the engine temperature into the summer in case the other water ways or the radiator are also gunked up.

Like most challenges like this, it can often end up unfortunately being a complex issue not just one.

Great start though!

Neil.