I recently purchased a used 91 940SE wagon. It's been quite well maintained and extensive checking finds only a few wear and tear items to deal with. However, I'm not too familiar with the warm-up characteristics of these turbo beasties. I notice that the temp guage goes from stone cold to fully warm (12:00) in a matter of about 2-3 minutes of driving. Never overheats, no odd noises or running problems and the heat seems to work properly. It just seems to me that this is extremely fast for a car to warm up.
If this isn't normal - ie the guage or sending unit is faulty - where do I start looking under the hood for electrical connections and testing?

Thanks,
Ben

Thanks for the input! The consensus seems to be that 1) these motors run hot as a normal condition and 2) having the water-cooled turbo is kind of like having "turbo-heated coolant"

Makes sense to me.

Thanks again1

Ben Vahl

That's just fine. My 740 warms up in about that same time. That 4-cyl engine has been around at least since the 240, I think much earlier actually, and it runs very hot (in case you haven't noticed yet, *40 heaters work very well :)). My dad's 960 takes 5-10 minutes to warm up, sometimes longer. I'm not sure why the newer engine runs cooler, save for better heat management in the block itself...any insight anyone?

I'll tell you why these cars run so hot, because they are made for Sweden where it gets bloody cold in winter, trust me. Anyone from North Dakota knows what I mean. Very nice on a crisp winter's morning....

George
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1987 745 GLE Turbodiesel Intercooler (D24TIC)/1988 745 Turbo Intercooler (B230FT/M46)

Keep in mind that you are essentially pumping coolant through your exhaust, which is hot right away.

Rene
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1988 745 GLE B23FT M46 (J-P Type combo). Toronto. 380000Km. Suspension upgraded and lowered . 1982 242 GLT project (B23ET LPT to be included) Also in charge of GF's 1986 244

Coolant through the exhaust???
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Regards,

David
1991 744 NA 139+K Miles

If you have a water-cooled turbocharger, the hot exhaust gases turning the impeller will quickly heat up the coolant traeelling through the turbo, and decrease the warm-up time versus a normally-aspirated engine.

Thanks. Learn something every day.
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Regards,

David
1991 744 NA 139+K Miles

That is just about right.