Check your Clutch Fan!!!

[Gauge]

Special thanks to RavenTai for helping me diagnose this.

All I knew was that in the summer months I would always have low oil pressure at idle and once in awhile the AC would kick off for no known reason. Keep in mind that during this time my water temp gauge always remained slightly below center - telling me that everything was normal.

After I did the Water Temp Gauge mod posted by RavenTai, it became apparent I had a problem. Come to find out my clutch fan was bad. Replaced it with a Hayden and my problem was solved. I just did a 1,500 mile trip to Maine and back and my gauge never left the center mark.

The pictures below are "before" and "after" installing the new clutch fan and taken under the same ambient conditions - (at idle with the outside temperature in the mid 80's)

 

[concretejungle]

How does the fan clutch effect oil pressure? Just wondering as i tend to have low oil pressure but my temps are fine.

 

[Gauge]

How does the fan clutch effect oil pressure? Just wondering as i tend to have low oil pressure but my temps are fine.

The viscosity of oil is largely affected by temperature. As temperature increases, oil becomes thinner. As it becomes thinner, it flows easier, which causes the decrease in oil pressure. That is why oil pressure is highest when the engine is first started and the oil is still cold. Cold oil = thick oil = high oil pressure.

 

[Tools R Us]

How does the fan clutch effect oil pressure? Just wondering as i tend to have low oil pressure but my temps are fine.

The clutch doesn't directly control oil pressure. If the clutch is bad it can cause the motor to run hot, hotter oil is thinner making lower oil pressure. This is why thicker oil is used in areas with high temps.

 

[concretejungle]

that makes sense. My oil pressure is always lower than my roommates which has had a fresh HG rebuild and has a SC. His is also a 95. So that has always had me a little confused. I had also heard that a worn motor will run lower pressure also.

I have not replaced my fan clutch but with the motor off if i spin it it will stop pretty quickly so i assume it's fine.

 

[landtank]

I have not replaced my fan clutch but with the motor off if i spin it it will stop pretty quickly so i assume it's fine.

bad assumption, the clutch could be junk

 

[cary]

I have not replaced my fan clutch but with the motor off if i spin it it will stop pretty quickly so i assume it's fine.

My old one stopped pretty quickly also, it was bad. No startup roar when you start the truck, the clutch is bad.

 

[Rookie2]

My old one stopped pretty quickly also, it was bad. No startup roar when you start the truck, the clutch is bad.

I'll do ya one better. If your rig is more than 8 years old (and they all are) and you have the original fan... it's bad.

I think it's pretty much a given, if you've got the original fan, it's not working.

 

[concretejungle]

OK. man the parts list is starting to pile up!!!!!

I do have the start-up roar along with the rattle

i need: starter contacts, fuel filter, valve cover gasket, head gasket, send injectors off to be cleaned, possibly front axle/birf carnage, rear axle needs rebuild (haven't touched it since i've owned it), new rear rotors, pads and ebrake shoes, fan clutch and a few other items. So much for buying a house.

 

[cary]

i need: starter contacts, fuel filter, valve cover gasket, head gasket, send injectors off to be cleaned, possibly front axle/birf carnage, rear axle needs rebuild (haven't touched it since i've owned it), new rear rotors, pads and ebrake shoes, fan clutch and a few other items. So much for buying a house.

BTW, after you get all these things done and the truck is running perfect, the deal of a lifetime will come along on a 100 and you will buy it and then sell the 80.

 

[Rookie2]

I do have the start-up roar along with the rattle

You've got the original fan and it roars on start-up?

The stop the fan gig while the engine is running to check the clutch is not as bad as everyone makes out. I rolled a towel up and let it rub against the tip of the fan blade and it came to a stop with very light pressure, so that's how I figured it was time for a new clutch.

I didn't think that anyone that had actually tested their original fan, found out it was still working.

 

[CreeperSleeper]

I didn't think that anyone that had actually tested their original fan, found out it was still working.

I bought a blue top 9 mo ago and that one isn't working.

 

[landtank]

I bought a blue top 9 mo ago and that one isn't working.

get in line.

 

[CreeperSleeper]

get in line.

I thought thats what I was doing?

 

[cary]

I didn't think that anyone that had actually tested their original fan, found out it was still working.

Mine was last year when it was hot out which was why I didn't replace it until a few weeks ago. I checked it during a hot day (100f) and it was locking up, I couldn't even slow it down with the truck idling. That one actually had no startup roar. I think it was on its last legs and only engaging when it was really hot, as it was not engaging this spring. BTW, it still didn't spin freely when the engine was off and cold, so that test means nothing.

I wonder what is going on with the Blue ones? I can hear my new one when it gets hot out, but definetely no roar from it when it is hot and the engine is at 200f. Maybe reindexing is a good idea.

Question for Gauge, are you able to hear your fan when the engine is hot with the new fan clutch. Can you hear it cut in and out?

 

[Gauge]

Question for Gauge, are you able to hear your fan when the engine is hot with the new fan clutch. Can you hear it cut in and out?

Yes I can. It is most noticable when I take off from a stop. It roars as the engine accelerates. I can hear it push the air with great velocity. Then after a short while the roar dies down.

It could be that the strong rush of air cools the sensor in front of the clutch fan and it cycles off.

It seems as though a lot of people are having problems with these clutch fans not working - even if they are new. If this one goes, I am going to find a solid steel replacement fan and to hell with the clutch. So I will get slightly less fuel economy. In the long run it is probably cheaper than replacing clutch fans at $75.00 a pop.

 

[Rookie2]

get in line.

I'm suprized C-Dan hasn't had anything to say about it, if the new blues are truely crapping out this quick. Maybe he's checking into it.

 

[cary]

Yes I can. It is most noticable when I take off from a stop. It roars as the engine accelerates. I can hear it push the air with great velocity. Then after a short while the roar dies down.

It could be that the strong rush of air cools the sensor in front of the clutch fan and it cycles off.

It seems as though a lot of people are having problems with these clutch fans not working - even if they are new. If this one goes, I am going to find a solid steel replacement fan and to hell with the clutch. So I will get slightly less fuel economy. In the long run it is probably cheaper than replacing clutch fans at $75.00 a pop.

Crapola, I had my truck idling yesterday, 103f, in a drivethrough. The engine got up to 210f and I threw it in neutral, reved it up and could feel some airflow comming back, but no fan roar. This is a two week old blue clutch.

 

[CreeperSleeper]

Crapola, I had my truck idling yesterday, 103f, in a drivethrough. The engine got up to 210f and I threw it in neutral, reved it up and could feel some airflow comming back, but no fan roar. This is a two week old blue clutch.

I'll do the ol metal fan / no clutch mod with you...

 

[semlin]

Special thanks to RavenTai for helping me diagnose this.

All I knew was that in the summer months I would always have low oil pressure at idle and once in awhile the AC would kick off for no known reason. Keep in mind that during this time my water temp gauge always remained slightly below center - telling me that everything was normal.

After I did the Water Temp Gauge mod posted by RavenTai, it became apparent I had a problem. Come to find out my clutch fan was bad. Replaced it with a Hayden and my problem was solved. I just did a 1,500 mile trip to Maine and back and my gauge never left the center mark.

The pictures below are "before" and "after" installing the new clutch fan and taken under the same ambient conditions - (at idle with the outside temperature in the mid 80's)

Gauge, are both those shots with the modded gauge? Also, it looks like it did not help your oil pressure much.