cold running 145

[mo5]

So,the engine got to the right temp that morning because of a low coolant level,once I topped it up the gauge went down to cold again. The viscous clutch seems to be working as it should,turns with slight resistance when the engines off and cold. The fan blades don't look standard to me,wonder if they're too long, hoping that one of you could measure the length and width of your blades so I could compare them?
Thanks in advance

[B20F]

I don't think the overcooling is caused by the fan/viscocoupling. The themostat should close before reaching a too low temperature. What heatrange thermostat did you use? I should install at least a 82c or 87c thermo. Did you install it the right way round? The longest part of the thermostat with the visable spring should face downwards. Sure the're no airbubbles left in the system after installing the new thermo?
You can check if the thermsotat is closing properly. Check with cold engine, take of the radiator cap and start the engine. Watch at what temperature the coolant starts flowing in the rad. You shouldn't notice any flowing through the upper rad.hose untill the gauge reaches the right temp. At that point the thermsostat should start to open and the coolant starts flowing through the upper rad. hose. If you can get your hands on a infra red temp.meter you can check the temp. of the coolant when it starts flowing to rule out a defective gauge or sensor. The sensor for the gauge is in the back of the head above cil.#4, it has one wire attached to it

[arcturus]

You can also check it by placing it in a pan of water over the gas with a thermometer.you will be able to see it open and read the temperature.

[mo5]

Had to take a different route to work this morning and ended up going through the city,while stuck in traffic the temp gauge went to mid gauge and no higher but as soon as I got out of traffic the gauge went back to cold. Leads me to think that it might actually be the fan again.. Any thoughts?

[mo5]

The thermostat is 82 degrees,definitely in the right way around and I'm fairly sure there's no air left in the system..

[Michael J]

Is it supposed to be 82C? That seems a bit cold, especially in winter.

[mo5]

That's what it says in the book,I've tried an 87 stat but it just boils over..

[Michael J]

Oh. I am somewhat surprised. Which book? And does the cooling system hold pressure properly? (It shouldn't boil over unless it can first boil, which implies 100C and more when pressurised.)

The standard for all 240 series engines (I know, yours is 140 series, nonetheless) is 88C, according to my Haynes book - but that's American in origin so you need to be careful with some bits, they claim "opening temperature 190 degrees, fully open at 212 degrees" (Fahrenheit, obviously).

According to my original Volvo Owner's manual (1989) it begins to open at 92C.

[B20F]

Is it supposed to be 82C? That seems a bit cold, especially in winter.

82c is the correct thermo for the B20 according to Haynes. That's what I'm using in my ES too.

The thermostat is 82 degrees,definitely in the right way around and I'm fairly sure there's no air left in the system..

Sure you had the heater fully open while you where bleeding the system? The heater radiator can trap air if the heater valve was closed. I suggest you first bleed the system thoroughly, the symptoms you describe can very well be caused by trapped air. Just to be sure so you can rule it out as a cause.
Another thing that springs in mind is a leaking pressure cap from the expension tank so the system can't built up pressure which it should to function properly. Also check the cap from the radiator itself.

[Lesky]

Mo5 thank you for this post. My 164 is running cold as well and my thoughts are identical to yours as to why. Very helpful.