Who has heard the thin-walled cylinder 455 engine is prone to overheating.

So does it spin by hand when the car is cold?

 

Yes... Seems like once it gets engaged (hot) it stays engaged until it gets cooler. Turn off engine and let it sit.
Very strange. Vet

 

Clutch fans are not voodoo.

They are not complicated, (hard to understand) but they are complex. (several things that must work correctly for it to function)

When cold, the fan is likely to be hard to turn by hand. This is because it most likely was warm when it stopped and was in a "coupled" (locked up) state.

So, starting the car and letting it run for a minute or two, the silicon fluid (very thick/viscous) is centrifugally forced back into the reservoir.

Then the clutch "decouples" as the bimetallic spring is in its "contracted" state (cold).

As the coolant reaches a certain point (usually 160F or higher) and sufficient heat is applied to the the bimetallic spring (the coil on the hub) the orifices inside the clutch open, allowing the fluid to move to provide a hydraulic force, and the clutch/fan "couple" (lock up) and the fan essentially acts as a solid mechanical fan.

So, some resistance when cold and having sat, free wheeling after running and the fluid is forced back into the reservoir, then after temp is sufficient, then the fan "locks up".

If your fan never decouples, then the clutch is "stuck" in the "open" (coupled/locked up) position.
If the fan never couples/locks up, the the clutch is stuck in the "closed" position.

The problems above can be caused by either a bad bi-metal spring, loss of fluid, or the internal fluid gate in the clutch is stuck.

Hope that helps.

 

Appreciate the education.
You should have been a Votech instructor.lol

Seeing a new clutch fan will be at the shop tomorrow (Friday),
I'll see if we get a reliable one.
Roger over and out. Vet (Navy)

 

Every morning the one on my truck is loud till I drive it down the road and u can hear and feel it unlock.

The one on dually when it locks sounds like its going to suck the front of the truck off

 

Wow, that's crazy. Lol

 

That would be correct Hector..

The main reason I don't like to run a thermostat when it's not needed is that the thermostat is the most likely cause of overheating, when it sticks shut. And sooner or later, every thermostat will stick shut, and potentially damage your engine, it only takes once.. and how many of us actually watch the gauges intently every time we drive the car?

Speaking of that..

I have always disliked the term "idiot lights" to describe the factory warning lights. I have in 20 years had two customers whose brand new engines could have been saved by an "idiot light" for coolant temp. In both instances, they both threw the WP/Alt belt off, so the water pump stopped spinning.

The first engine I built in 2003, at that time this girdled 464 was about 14K..

And it was destroyed, he didn't notice the engine temp until the automatic trans started shifting strangely. That one score the cylinders badly and had to be overbored and custom pistons installed.. cost him thousands of dollars

The second one was built in 2020.. That Port injected EFI/Distributorless ignition 482 was north of 20K. It threw the belt in 2022.. It's fate is yet to be determined.. after it cooled down, the owner changed the oil and filter, and all seemed to be well..but then this spring, it stopped making oil pressure, and either had a cracked/loose pickup, an air gap between the block and girdle or a cracked block.. it has an air leak in the suction side of the pump. Customer is flying me to Juno Alaska next month to help him investigate it, and either fix it, or crate it up to ship it back to the shop. Again, we are talking thousands of dollars here folks..

Expensive deals that are avoidable.

Every Buick has two lights that can be used for dual purpose. Even those cars equipped with the factory gauge package. You have a "brake" light, as well as a high beam indicator. Both these lights are simply looking for ground to illuminate. Both can be wired to do double duty, meaning the new ground source will not affect their normal operation. Adding an extra grounding sensor (as all warning light senders are) and then wiring it in line (simply located the ground wire on the switch or pedal assembly, and solder on your new ground wire to the existing wire, and then run your new wire to the sensor), is a smart idea, that is the prefect solution for everything but the concourse cars. But most those cars are not really driven anyway... This provides you a warning light, as an indication to look at the gauges.. Use one for oil pressure, and one for coolant temp.

Especially you guys that insist on running thermostats. I replaced hundreds of stuck shut ones in the 15 years I spent as an ASE Master Tech, in the repair side of the industry.

A word to the wise....

JW

 

So true Jim - My Dodge van has an "idiot" light that says "look at your gauge" when something is amiss! Literally!

 

I always add gauges, and keep the lights for the instant awareness.
Lights get your attention, right now.
Aircraft maintenance, doing engine runs and such formed a "scan gages every five seconds, and outside/around the jet" lifelong hard habit. But I still want them lights.(OCD can be yer friend)

 

My Speedhut gauges have bright led warning lights that can be set at whatever temperature you like, same on the oil pressure - a low, high pressure warning set point. Just a great feature these gauges have.

 

Yup, so do the 2000 Up GMT800 platform trucks.

Buzzer sounds, and the light or the DIC says "Check Gauges".

I drive trucks every day that have full gauges, and I rarely ever look at them, other than the speedo.

The "check gauges" light came in handy when my 2000 Suburban 1500 lost the water pump, and when my '05 3/4 ton QS stuck the thermostat.

JW

 

The Idiot lights have saved me a couple of times. Although the Oil Idiot light is basically too late IMO. If you see that one, just hope it's the sender or you have troubles.

 

Thanks JW

 

A bunch of years ago, I brought a 4-core radiator to a local radiator shop to be rebuilt.

They asked me "Do you want us to make it a five-core? It's barely any extra money"

One of the best investments I've ever made. And even though I've made a science project out of cooling my engine, sitting in 10-20MPH traffic on a 90-degree day with the A/C running it will still SLOWLY creep up to 210-220 degrees (which is not a problem for driving but you certainly wouldn't want to go WOT at those temperatures). If I get panicky I can turn off the A/C until the traffic jam breaks free (25-30MPH is enough to start to control the temperature again).

A couple of other thoughts: Antifreeze hurts thermal transfer, your best bet is 100% distilled water. BUT that's not practical since you need corrosion protection, maybe freeze protection in winter, lubrication for the water pump, etc. So I run about 25% ethylene glycol and also RMI-25 and Redline Water Wetter. But the higher the percentage of distilled water, the more heat transfer you can get.

And one more endorsement for the idiot light.

-Bob C.

 

Thank you Larry, I just ordered the Griffin Aluminum yesterday.
I didn't realize their company is located in SC.
The show owner how is working on my Buick, says Griffin is the best aluminum radiator on the market and it's made in the USA.
I'am sure this will cure my high water temperature issue.

Thank you so much for your help. Regards VET (Navy)

 

Perhaps part of your problem is you are using an HD thermostatic fan. They are definitely louder and lock up sooner. Try just a standard thermostatic fan. They still lock up but not as solid and aren't as loud. I've got Hayden units on both my GS cars.

 

Thanks, i'am using SD Thermostatic clutch fan. I bought it from Todd Miller.
I also found out that because my fan blade pitch is less 2 1/2 inch (2 1/8 in I have), i'am suppose to be using a SD fan clutch on an 18 inch diameter fan blade. You are right on, HD's lockup to long and also create a roaring noise that is uncomfortable.

Found all this info written by a Buick guy. Really helped me.

 

Detonation, sorry I had to correct yah.

Like JW mentioned, the reason the clutch engages full force is the excessive heat coming off the radiator, the fan clutch is working as it should, the radiator is not.

The old one was lazy.

I’d revisit your radiator.
I thought I read you bought an aluminum one??

 

That is true.
200/210 is not over heating, yes it’s hotter than optimal, but your not hurting anything.
IIRC the factory “temp” light was set to activate at 250/254/256 degrees.
My daily driver Tahoe always runs at 210, ac on/off, city/highway, dead of winter or middle of summer.