Viscous Fan - No enough cooling

thomasverfurth

New member
Hi, so the viscous fan clutch just decided it would be a great day to spit out all of its grease, and to add to woes blow a hole in the top radiator hose and boy did it get hot!!

ANyhow, so we replaced the hose, filled with water, and ordered a new fan clutch (DAYCO PN #115505). Clutch was fitted by the mechanic, and presto we drive off. ENgin gets nice and warm, then keeps rising - 90+ degrees C, just around the city, and a bit higher under some load... climb a mountain range at 45km / 2500rpm, and the temp rises to about 100 degrees. SOmething doesn't appear right.

Pull over, checked under the hood - no water leaks, turned off the engine, and the viscous fan spins about 4 times before stopping... hmmm that's no right ?

Drove home slowely, called the mechanic and he comes to look. takes the hub off, re-fits thinking the nut may not have seated correctly and tries again...

Upon starting, big massive woosh of air from fan - insane amount, but as engine heated this slowed! Fan did not increas when reaching thermostat temp (87C), took fir a test drive to try and increase temps.... same prob. look under hood little air movement !

Mechanic reckons faulty clutch, and ordered another replacement being - fitted today.

Could this be a faulty viscous fan clutch?
What else should I look for?

Are there benefits of going electric fans over viscous fans? And... can I get ordinary fans or are there ones out there made for mercs?


Prior to this my engine used to run at around 87C - Idle, 90C along city / highway, and up to 95C to 98C climbing the mountain dependant on day temp. A local Merc mechanic said that they are 'hot' operating vehicles here in oz, and anything around the 90's to 100 is fine. he said not to get concerned unless she climbs ovber 105.


My vechicle is a 2000 312D Sprinter. 5cyl inline 2.9L diesel
VIN: WDB9034632P987975

By the way.. Im in Cairns - North Queensland where daytime temps in summer are anywhere from 28 - 38 degrees.

I'm running 50/50 collant mix (suited to merc spec).


Advices are appreciated !!


Tom :)
 

220629

Well-known member
You have a bunch of stuff which I can't help answer.

I do have one basic question though, was the fluid which allegedly came out of the viscous clutch sticky, ugly, and silicone like in consistency? If not, the fluid you found may not have been the viscous clutch failing so you may not have corrected the original problem yet.

Just a question, not a diagnosis. vic
 

PeterInSa

Active member
RE
Prior to this my engine used to run at around 87C - Idle, 90C along city / highway, and up to 95C to 98C climbing the mountain dependant on day temp.

Our 313CDI TD 2.2Lt manual
Runs at around 80C - Idle, 85C along city / highway, and up to 90C to 95C climbing the mountain dependant on day temp.

Keep us posted with the fix

Peter
 

thomasverfurth

New member
Aqua: Yes the fluid was a silicone like substance, very sticky, greyish colour. was definately not any other oil - wasn't only easy to ruleout by sight, but a comparission from the dipstick confirmed this.


Replaced the Viscous clutch today again... yes this one engaged once the temp guage began to heat over 90 degrees while maintaining revs whilst in the workshop. Raised running temp to about 95 degrees and could feel fan slightly increase. Turned off engine, and fan came to almost instant halt!

Took out for a test drive / workout over some climbs whilst given some load (kept revs high at around 3500rpm and drove in 3rd & 4th gear to really work it in the local hilly streets), and took temps past the 95 degrees with a bit of effort, and flogging if it be known. We saw a slight drop in temps down to about 96 dgrees after the fan kicked in full force at approx 98 degrees (you can hear it engage!!). Engine temp did not go over 98C either during our test drive. Temps dropped when load was taken off and fan lowered its rpm accordingly.

This was all with both front & passenger aircon on full load too!


I'm yet do run into town, and then climb the ranges again tomorrow, but so far back to what we seem to perceive as 'Normal'
 

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