2005 V70XC cooling fan performance question

[donoscituate]

Just bought a 2005 V70xc with 124K miles, lead a very good life with regular attention from Volvo dealer. with that said, 2 questions, the cooling fan responds nicely/comes on instantly when the AC is engaged, in fact once I shut the AC off, the fan will continue running to about 186F, and then shut off. So far so good, now here's the but, I put a cheap scanner on which shows water temp, and the fan doesn't seem to without the AC prompt want to turn back on, I let the temp go as far as 215F, so I think I saw somewhere that the fan doesn't engage until 220F?????? Question 1 is this true if so isn't this a bit high? Question 2 if 220F is the mark, has anyone toyed with the idea of decreasing the level down to 200F?

Why am I raising the issue, as I said this car was well-taken care of, regular oil changes, PVC service, timing belt, water pump, etc. I had looked at the oil fill car and it seems a bit "crusty", which kind of leads me to engine running hot, there are no codes. Living in the Boston area, I suppose in the summer folks keep the AC on most of the time, I usually don't, in the winter I doubt the temp is that much of a issue. Of course the temp gauge stays right in dead center from temps of 186 to 215F, so I don't have much trust there. This is my first car this new, the older cars seem to run a bit cooler.

[darrylrobert]

yes fan rarely comes on even on hot days, last time mine ran was after i towed another vehicle. The thermostat for the temp gauge in these cars dont show accurate temps, ive heard that the temp gauge will remain in the normal (12oclock) position when the car is overheating (coolant spilling from cap). The fan runs on a Pulse Width modulation signal (digital) so its not easy to test run, i have also looked into modding it by tapping the thermostat but many electronic forums ban talk about modding cars ..there are aftermarket warning systems available but i voted against it.

[jimmy57]

Cooling fan on and off temps went up 20 years or so ago most gasoline engine vehicles. When A/C is on the engine will run cooler due to fan running for A/C reasons. If you do not have a/c on it is VERY common to have the radiator or the remote tank boil over as the on temp can be in the 220+F range and it boils if no pressure is held to raise boil temp. The off temp is usually over 200F. The temps are measured at the hottest place as coolant leaves engine on way back to radiator. The higher temps increase the amount of evaporated oil contaminants that will leave through crankcase vent system in attempts to keep sludge build reduced. In older days with way less heat shedding capacity in old radiators the cooling systems needed to run cooler but not any more.

[Blacklab467]

I often wondered about that guage too. Mine sits at 12 o’clock on the hottest summer days with the A /C on in the parking lot for 1/2 hour at idle. Also, it warms up right away in the coldest of winter days, to the 12 o’clock position and blows nice heat. It never boils over so all I can assume+is that everything is fine.
A cooler running engine is not necessarily better, and 220 degrees is not overheating, or not enough to boil coolant at sea level in a pressurized coolant system. The engineers that designed the engine had an optimal operating temperature in mind. They also likely know what temperature threshold results in sludge and increased crankcase emissions. Your radiator and overflow tank are both pressurized so if they are boiling you may need a new cap.

[abscate]

I documented the hot weather cycle of my T5 while sitting in the border line one summer and the fan came on at 105c and off at 87c

105C is 221F so you were 1 F shy!


This is by design , and well under the boiling point of a 50-50 coolant mix under system pressure

[donoscituate]

thanks, seems counter to "old" wisdom, high temp is your "friend", the previous owner took very good dealer care of the car, I doubt he even knew much about anything going on under the hood. The oil fill cap seemed a bit crusty to me, probably why Volvo suggested a PVC service. I will probably run a quart of WD40 for 100 miles before I do an oil change along with a transmission flush, what a b*tch to get to the trans dip stick, see why volvo just deleted that on later models. The 2005 is one of the last years before all the crazy but nice to have features start coming on board. They, and all the Car manufacturers really don't want folks opening their hoods to even see what's going on, I predict in another 5 or less years only dealers will have the ability to service a vehicle. Anyway thanks as always for your feed back and dragging my butt into the 2005 era, my kids all get on me for owning old cars, 91 Miata with V8 Ford, 1992 Ford F150 straight 6, recently departed 1999 Volvo v70xc, a 2000 Porsche 996 Carrea, 2003 Miata (wife's car) and our NEW 2005 V70xc