1997 850 glt woes

the 1 buchanan · Post by **the 1 buchanan** » 11 Feb 2013, 07:10

new to volvo, but have no fear. Working on a 97 850 wagon for my 17 year old daughter, 1st car. have some issues and looking for advice.
-Engine code telling me the engine temp is too low and I think it is effecting the fuel mileage, I am replacing the thermostat, any other advice for this issue??
- the ac/heat system is not functioning, it is flashing on start up but none functional after that. Wondering if I replace the whole control unit if this could fix the problem?

Post by **jblackburn** » 11 Feb 2013, 07:29

Engine code telling me the engine temp is too low and I think it is effecting the fuel mileage, I am replacing the thermostat, any other advice for this issue??

Change the coolant temp sensor and thermostat.

As far as the HVAC unit...troubleshoot first...the flashing lights could mean a number of things. Does the fan work on the slider setting? Is it maintaining temperature if the fan is set manually?

Post by **cn90** » 11 Feb 2013, 08:08

1+,

1. Tstat, stick to Wahler or Volvo brand, about $18 with O-ring
Replace the ECT, use only Volvo OEM for ECT $40:

https://www.matthewsvolvosite.com/forums ... hp?t=52203

2. HVAC Unit, likely ECC unit,
Search forum for some diode acting up.

Try these links:
https://www.matthewsvolvosite.com/forums ... =1&t=27239

http://www.volvoclub.org.uk/tech/servic ... m-Auto.pdf