Signs of a bad clutch fan **UPDATE STILL RUNNING WARM**

[wayne]

Grim, Max speed was 45mph and it runs nice and cool. It's when I stop it heats up. It also heats up climbing a grade empty. It's not a matter of driving fast. Yesterday I took it on a 175 mile round trip and it never got above 195 or so going down the highway except when I hit a hill or stopped in traffic. It would just get up to 210 and then I would start moving and it cooled back down. Also before Friday it did not get above 200 no matter what I was doing.

 

[Mudzer]

My 454 Burb is running hot too. I have an infared temp gun and I checked the radiator and it was close. I realise the temp gauge checks head temp, but my radiator was within a few degrees of what the gauge was saying.

My Burban will heat up to the red when pulling a load.

I replaced the clutch with a used unit and it worked for a few days, but its now back to not doing its job. Another problem - my aux electric fan does not kick in ever. I am thinking about wiring it with a switch and relay.

I'm to the point of wanting to sell my Burban - there's no sense in having a tow rig that I cant get 40 miles from home with.

I'm considering jerking the 454 and installing a fresh 350 or something.

 

[wayne]

[ QUOTE ]
My 454 Burb is running hot too. I have an infared temp gun and I checked the radiator and it was close. I realise the temp gauge checks head temp, but my radiator was within a few degrees of what the gauge was saying.

My Burban will heat up to the red when pulling a load.

I replaced the clutch with a used unit and it worked for a few days, but its now back to not doing its job. Another problem - my aux electric fan does not kick in ever. I am thinking about wiring it with a switch and relay.

I'm to the point of wanting to sell my Burban - there's no sense in having a tow rig that I cant get 40 miles from home with.

I'm considering jerking the 454 and installing a fresh 350 or something.

[/ QUOTE ]

I never saw my electric fan kick in either. I am planning to switch the clutch one more time and if that don't work then I am going to try a solid 7 blade fan. I'll have to look into the electric fan. There is no reason it should get up to 220*.

 

[dyeager535]

With the new electric fan setup, it took some getting used to watching the temp climb to 220* and then drop back down to 200* or so when the fans come on.

220* isn't too hot for the engines unless they start pinging. That's well below even waters boiling point at 15PSI of system pressure.

At idle or climbing logging roads at low speeds in higher heat conditions with the old clutch fan, I didn't notice the temperature "swings" that I do with the electrics. Obviously GM didn't think 220* was a problem, or they wouldn't set the electric setups like that.

Interestingly, but somewhere around 210* seems to be the cooling "peak" under slow moving conditions on my truck. With the clutch fan it never got that warm, so I would never have noticed, but as long as I'm moving even a bit, the temp equalizes right about 210*.

At idle, it will climb to 220* in a few minutes if the vehicle is already at operating temperature, but even a single fan in 85* weather is more than adequate with my 3 row.

I don't like the large variation in temperature, so when I start burning PROM's for this thing, I will bump the coolant fan "on" setting to about 210*. Probably end up playing around with it until I can keep the temperature as steady as possible.

 

[mtnman210]

I don't know if this applies to your situation or not. But I've been fighting warm temps since I put the new 350 in last year. I've changed fans, new radiator, and gone through a couple gauges. I'd still see 220 all the time in the heat. Anyways last week I noticed my master cylander was leaking into my brake booster. Turned out the whole booster was ruined which created a huge vacume leak. This was causing bad brakes but also my high engine temp. So I replaced the m/c and booster and the brakes are perfect but more importantly the temp hasn't gone above 180 yet.
just my 2 cents

 

[diesel4me]

My brake booster was failing for quite awhile in my 79 C10--that coupled with my hot rod 600cfm edelbrock carb conversion is what I think helped blow the motor a few weeks ago--it always had a bad hesitation with the original 2 barrel vari-jet carb,and the edelbrock solved that problem,in fact it ran quite well with it almost 2 years,but now I wonder if the vaccumm leak at the power brake booster was the cause of the hesitation--I tend to think not because my van had the same motor and carb setup original and it ran the same way and had manual brakes,but maybe the vacuum leak raised the combustion chamber temp high enough to melt a piston(It seems like thats what happenned,I was smoke screening the highway REAL bad,and pinging and rapping!!)--wont know for sure till I do an autopsy on it after I'm done swapping in an 86 305 motor I got friday. /forums/images/graemlins/crazy.gif