Results 1 to 6 of 6
  1. #1
    Join Date
    Jun 2015
    Location
    hudson valley
    Posts
    1

    Default Optimum coolant temperature

    Hi all, I have an 01 xc70 120k miles.
    I recently purchased a scan gauge to monitor my engine temperature, I'm becoming obsessed. When driving at highway speed my gauge reads at 188f, in stop and go traffic it can read up to 225f. 225f seems high, should I be concerned?

    What is the optimum temperature range?

    I have also noticed my cooling fan doesn't start,if at all, until 220f. Is this an issue? Can the cooling fan cut in point be adjusted in anyway?, I have recently replaced the cooling fan with a used one, the previous owner had done a bad jerry rig fix.

    My cooling obsession is a result of the transmission issues I'm having, the car shifts beautifully when the engine is below 209f, above that temperature all sorts of crazy things happen.

    Any insight would be appreciated.
    Danpaco

  2. #2
    Join Date
    Mar 2005
    Location
    Pacific Northwest
    Posts
    1,927

    Default

    Never measured the exact coolant temp in all conditions. But here are some data for you

    - Instrument panel temperature gauge always have the needle in the middle once the car warmed up. Had 2 of these cars, both behaved identically. Only time it didn't do this (needle to the left or cooler) had a bad thermostat.

    - ATF temp is about 90C+ when warm which translates to about 200F. Since ATF runs through the cooler integrated with radiator, it likely indexes to similar temps.

    google shows most cars to be between 180/190F to 220-230F. FYI, most thermostat opens at 180/190F.

    If your dash temp gauge pegs in the middle, you are probably good. In any case, your sensor seems to be measuring correctly and car should provide warning if over spec.
    Past Volvos : 01 V70 T5, 01/02 V70XC, 02 V70 NA, 00 V70XC
    Current EV/Hybrid : 13 Tesla S85, 11 Gen3 Prius
    Friends cars under my care 17 Audi A4 Quattro DSG (B9) 05 Audi A4 Manual 6sp Quattro (B7) 04 e320 V6 Auto, 05 Accord 2.4, 08 Element 2.4, 08 Camry Hybrid
    Past Others : 01/03 VW MK4 Turbo/NA/01M. Gen1 Prius, Gen1 CRV, Gen2 Rav4, 02 Town&Country, 06 Corolla, 12 Audi A4 Quattro (B8), 07 Civic 1.6
    https://sites.google.com/view/howardsvolvos

  3. #3
    Join Date
    Feb 2013
    Location
    Boston, MA
    Posts
    1,196

    Default

    Coolant system runs under slight pressure, so boiling point is slightly moved above usual point. 225F in city traffic on a hot day would not concern me.

    You can install extra ATF cooler, as many of us did, it will partially remedy your transmission problem. Real fix is a rebuilt valve body and proper ATF change intervals.
    2002 V70 (sold)
    2005 XC70 (Telos Road took it. Did a chassis swap)
    2016 XC60 (sold, P.O.S.)

  4. #4
    Join Date
    Nov 2012
    Location
    Pacific NW
    Posts
    364

    Default

    Also, the temperature gauge is buffered; that is, after warm-up, it is designed to read in the middle, even when the engine temp rises, say up a long hill in summer with the AC roaring. The coolant temp is definitely higher, but the gauge doesn't display it. This is to prevent nuisance complaints to service. I have however wondered when, and if, the gauge will read up scale if there really is an overheating condition, before it is too late.
    PDX-Vancouver, USA

    2005 XC70 140,000

  5. #5
    Join Date
    Dec 2002
    Location
    TPE>BNE>DFW>AUS>TPE
    Posts
    1,464

    Default

    FYI, my OBDII register coolant temp from 90C (194F) in normal driving conditions, up to 110C (230F) when under heavy turbo boost pressure in the summer.
    It would always stay in the middle of the temp gauge.
    2002 V70XC w/volvoXC.com stickers! MTE Stage 3+

  6. #6
    Join Date
    Mar 2013
    Location
    musella ga
    Posts
    30

    Default

    had the same thing with my car, replaced the tstat and solved all that , sits on 186° to 209°

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •