Cooling issues
 

I'd suggest we move cooling temp issues to a new thread and out of my rebuild thread, which is essentially complete.

Today I drove up to the mountains and after climbing 3000 feet my coolant temp went through the roof and boiled over. I took out my belt driven fan for an electric one. Perhaps that is contributing.

Headed down hill, mostly idling, the engine wasn't warm enough to heat the cab.

Seems odd I can't cool enough when under full load and can't keep heat when idling.

Thoughts?

Sounds like air in the system or improper coolant flow. Air is not the best heat transfer medium hence the heater not working while idling. When you increase the engine speed the water must be circulating into the heater core better which would give you heat. Because of the heater situation an air pocket is likely. May be a good idea to pressure test before spending countless hours and dollars chasing the issue.

The other possibility is that the water pump is not operating within specs and not circulating the water which would result it high engine temps and poor heater performance.

I would check the following:
1) verify the cooling system is properly bled
2) headgasket is not faulty (pressure test system?)
3) blockage in radiator or heater core (flush system)
4) any possible coolant leaks

The cooling system is fine to 15psi. No leaks or bubbles, all bled out.
I am more concerned with the hot than the cold.
Only overheats when going up a the hill for about 30 min. If i turn on the heater core for the cabin, that helps a bit.
I just need to suck out more heat.
The cooling runs are longer in the pinz than a volvo.
Anyone every insall an auxiliar pump?
If i did that and mounted a larger fan up next to the radiator, i think id be fine.

My old cooling system posts
 

Here's a few posts about the cooling system I made in 2013:
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Here's some data from the "SAE paper 790206" - "New 5- and 6-Cylinder VW Diesel Engines for Passenger Cars and Light Duty Trucks" paper published in March 1979.

"The ratio between crankshaft and water-pump speed was raised to i = 1.1 (i = 0.85 in the gasoline engine). This results in a cooling water flow of between 140 and 170 liters per minute at rated speed, depending on the cooling-system flow resistance curve." (converts to 37 to 45 gallons per minute!)

That sounds like a lot of water moving through the engine.

My observation of the importance of a GOOD working thermostat is that when the engine is warmed up the back end of the thermostat must close the flow coming out of the block in the position right behind the thermostat, thus forcing all the fluid flow either out the back of the block or up through the water outlet on the head. The suggestion to use an 80C thermostat is probably a good idea since it opens sooner and thus closes that water flow coming out of the block. (I'm not convinced a cooler thermostat is better; as long as an 87 degree thermostat is working properly it will fully open and thus close the opening in the block. The hotter thermostat also allows the engine to generate enough heat for the heater during the winter.)
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On a trip a few days ago (September 2013) I drove over Donner Summit (Labor Day trip with temps at 95F in Sacramento and about 75F at the 7,200 ft summit) in 5th gear (4th plus overdrive) pretty much running as hard as possible. I wasn't towing anything and I'm using an 80C thermostat and a new radiator. When I got to the summit I pulled over at the rest stop and as fast as I could, felt the radiator temperature on the inlet and outlet sides. It was very hot on the inlet side and almost cool on the outlet side. I could place my hand on the plastic side of the radiator so it was probably no more than 90F. My conclusion: the radiator can handle all the heat the engine puts out; increasing the hot water (coolant) flow out of the head (especially the back of the head) would help.

I have to imagine the engineers that designed this engine had all the heat generation and cooling numbers at hand. They must have tested this thing under full load in hot ambient temperatures. There's a video somewhere on the internet showing a Pinzgauer running "wide open" in desert sand. If the cooling system can handle that type of heat generation.........

Cool. (pun intended)

I replaced the tstat when we rebuilt the engine, we know that is fine. WP was in good shape too.
When i get back to work on it weekend after next, I think I will:
- clean the whole cooling system put with Evapo-Rust.
- put in a Flex-O-Lite 293, 6000 CFM fan set, right behind the radiator; replacing the single 16" 2000 CFM fan at the back of the tunnel.

Other than that or finding a bug in the system, i think I will have to dial back the power.
Good news is that i can do 74mph on flat land in a 718 Pinz:
Yes, i know I am nuts.

http://i1311.photobucket.com/albums/...ps6c319425.jpg

If the rest of the cooling system is good it sounds like the fans located right behind the radiator might solve the problem.

I run Red Line's "Water Wetter" in my 1.6TD Jetta and Mercedes 180D, just water and additive in the summer then coolant and additive in the winter. I'm not a big additive user but I swear this stuff works. Both those engines are a little worn out and it does keep them cooler.

Sounds like a thermostat that doesn't close the bypass passage in the 'wide open' position, unless your whole radiator and lower hose were both scalding hot. Did you test that stat prior to install? How may times has it been overheated? It can harm them. I might be tempted to pull it out and measure protrusion of the blocking side, and maybe pin the thing open and go for a drive.

Seat o the pants dyno rates my belt fan at about -5 HP when it engages...might take a pretty big electric to duplicate.

Not quite an aux pump, but I did install an aux (honda) radiator on the belly of a 309D Mercedes bus i was working on, and it helped.

If you don't have any type of 'lip spoiler' around the bottom of the rad, fab up some ricyness.

Oh, and what is the track recorder there?

Yep, i use the Water Wetter too and also think it helps. Intuitively, i would guess it gives 10%~15% improvement.
Maybe I should try 50/50 mix of water wetter and antifreeze! Boy, that would be expensive.

What would you all make of this idea: i added a fluid air intercooler and pump the water to the back of the Pinz to a radiator and fan. They are on hinges so i can rotate in to warm the rear of the truck in winter, or blow it out in the summer.
What if i hooked up the oil cooler to this separate cooling circuit, post intercooler? That would suck some watts from the engine, and retard the cooling of post turbo air.
http://i1311.photobucket.com/albums/...ps6e935eaa.jpg

Hi Rob

Have you checked your radiator the normal sign that the rad is goosed on a Pinzgauer is what you are describing climbing hills when sections of the rad are blocked.

When antifreeze is not replaced every couple of years can cause these sorts of problems with the rads.

Very common on Pinzgauer

Is that intercooler cooler(sp?) big enough that you don't heat soak on long hills?

I despise the water to oil cooler, and advocate its elimination in favor of an oil-air unit. This also frees up a hot water line from the back of the head to go to an additional radiator if you so choose.