DCC Fan Controller and Mark VIII fan, overheating...

[MH88'Notch]

Just installed a Mark VIII fan controlled by a DC Controller. Had a stock fan/rad before and it would run around 195-200* on a hot day. Today, drove the car to work, cooling ok. Installed the fan and controller, seems to work well and cycle on/off ok, but the heat gets upwards of 200-210* cruising on the highway with the fan going, heater on high blowing hot air.

I'm kind of lost as to how this could be. I trimmed about a 1/2 of depth off the mark VIII fan shoud, I've tried reversing polarity on the fan connectors to see if it worked better than the other. It didn't.

I don't understand how the stock mechanical fan could be cooling better, when it seems as if this fan is moving a LOT more air.

Any ideas from people with similar setup would be much appreciated!

Thanks!

 

[HISSIN50]

On the highway, your fan should be off. If it's spinning the wrong way, that can be an impediment to ambient flow. Be sure the fan pulls air from the front to rear of the car (in other words, your waterpump should be getting scorched with hot air).

Be sure the temp setting for the controller is matched to your t-stat and that you use a balanced t-stat.

Good luck.

 

[LiquidGT]

x2

Get yourself a Stant Superstat 180* and set your fan controller to come on at 195-200*. If you set the fan to come on at the thermostat rating the fan will never go off.

 

[monte87]

I wouldnt waste my time with any type of Stant product. I only go Mr. gasket 180 T-stat. After testing them in a pot of hot water a STANT 180 openend @ 190 everytime and Mr Gasket 180 opened at 183 everytime and that was clcoking it with a heat laser gun. that pretty much prved it to me. Mr. Gasket for me-after that-everytime.

Later Ant & Good luck.

 

[baskin]

The fan isn't suppose to cool the car on the freeway, that cooling is provided by the low pressure behind the radiator and high pressure in front of the radiator from the lower air dam. If the air dam is missing, it needs to be replaced. The mechanical fan moves more air through the radiator at 2500 rpm than the m8 fan. If the controller is cycling on and off, then the thermostat is closing, indicating the controller is set too low, setting it higher will allow it to run at a constant low speed in lieu of cycling.

 

[LiquidGT]

I wouldnt waste my time with any type of Stant product. I only go Mr. gasket 180 T-stat. After testing them in a pot of hot water a STANT 180 openend @ 190 everytime and Mr Gasket 180 opened at 183 everytime and that was clcoking it with a heat laser gun. that pretty much prved it to me. Mr. Gasket for me-after that-everytime.

Later Ant & Good luck.

I guess all brands of T-stats are hit and miss, I had the opposite problem with the Mr Gasket, but I was lucky and it ran too cool. I put my Mr G 195 in water and it opened at 180 which made the car run at 170 on the highway. Not too long ago another memeber on here put in a MrG T-stat and he had mystery cooling problems, I called the T-stat and I was right. The Superstat is balanced and its the same as the summit brand T-stat.

 

[GreatWhite]

Has everyone had successful experiences with junkyard fans? I've had two now, and both of them seem to be crap. I had a Taurus fan and now a Lincoln fan and both of them have had problems cycling on. The Lincoln fan didn't kick on properly the other day and I had a puddle of coolant under the car when I came out of the bank... It comes on and runs great once it gets going, but for some reason it doesn't wanna kick on all the time by it self. But you give it a little nudge with your hand and it fires right off...

Sorry to highjack/rant... haha

 

[tmoss]

It comes on and runs great once it gets going, but for some reason it doesn't wanna kick on all the time by it self. But you give it a little nudge with your hand and it fires right off...

If these are DC motors that use brushes, the brushes may be worn down and the spring isn't strong enough to keep good pressure of the brush on the rotor. Check that out if you know how. These motors are Seimens motors and can be bought new for ~$60 last I knew.