The 89 Chevyvan 20

Hey guys I just got a reconditioned 89` chevy van 20, the 350 8cl gas beast. My mission is to drive it across Canada, then mayby down through the states into Mexico. Sangria and senoritas.... Trouble though. There is a problem with the coolant/pump? The radiator overheats on the smallest trips, I know its a new radiator. I dont know how much coolant should be in the engine or water in the Rad.

Reply to
Jimmy the saint
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The cooling system needs to be filled with a 50/50 mix of water and coolant, the short trip overheat is usually a thermostat problem, if it gets hot within a few minutes of starting it up cold...

You can open the radiator (cold) fill, and start the motor and watch what the coolant level does as the motor warms up...a healthy system will begin to surge coolant level up and down as the motor gets warmer, then after a few minutes the level will drop away, and you'll see flow through the horizontal tubes in the radiator core, which should increase flow a lot as the engine is revved...it may eject a small amount when it begins surging, but if it gets to where it is ejecting a strong column of coolant from the radiator, but the rad and upper hose still feel cool to the touch, the thermostat is not opening and allowing coolant flow out of the motor to the radiator...in this case be careful when you shut it down...it will most likey eject a large amount of coolant when the motor stops...you or anyone standing around could be burned...

Reply to
jeffcoslacker

Got new radiator hoses on it? DOes it have a fan clutch on the fan blade?

If you have not, put on new hoses and new fan clutch.

Bob

Reply to
Bob Urz

Reply to
jeffcoslacker

You need a 50/50 mix for the rad and engine of coolant and water. Auto parts stores sell an antifreeze tester really cheap. Well worth having.

Besides the thermostat, there should be a clutch on the rad fan. To test this clutch, heat up the engine fully and have someone shut it down while you watch the fan blades. If the clutch is working, it will stop the fan almost instantly. If the fan keeps on spinning, it's clutch is dead.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

How do you know it's overheating? Do you have a temp gauge? If so, what's it doing?

Why was the rad changed? Is it possible they put the wrong one (too small) in there?

Overheating can be caused by: thermostat stuck closed radiator plugged/leaking airflow - missing spoiler, plugged rad fan/fan shroud - wrong size, dead clutch fan, missing shroud water pump

I'm inclined to agree with starting by changing the thermostat.

Ray

Reply to
ray

Most clutch type fans you can also just fling them with the engine cold, and if they rotate more than 1/2 turn or so, the clutch is probably pretty weak...should be declutched, but not able to completely freewheel...seen a few you could just grab and hold stationary with the motor running (no, I don't recommend this!) and had slow rotation even when engaged...but like I said, if you run hot when moving, it's probably not the fan...I've set up large engines with on-demand electrics and eliminated the mechanical fan...they only run after idling for a minute or two at a stop, then cut off once the vehicle has moved more than a block or so....

Reply to
jeffcoslacker

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