I've also posted in Heating and AC but this forum seems much more active plus it is an 87 truck.... So any help is appreciated

I've been on a mission to get my 87 F-350 with a 460 to stay cool in traffic. So far - new 4 row radiator, flex fan, heater core, thermostat, and just tuned up and also checked compression - everything fine. Also - the fan shroud is in good shape and positioned correctly (I think)
After the new radiator and thermostat I'm at or below the N in NORMAL while driving but stopped or in slow traffic, it quickly rises to the MAL range and you can tell it's warming up because the NEW A/C system goes from really cold to just cool.
I'm thinking the water pump is next - this truck sat for a few years and even though the water pump isn't leaking, some have told me that the fins can corrode and dissapear on the pump - especially on vehicles that have sat for some period. The local shop wants $220.00 to put a new one in - Am I on the right path or overlooking something else? Help Please!

 

"new 4 row radiator, flex fan, heater core, thermostat, and just tuned up and also checked compression "

Please remember this fact many shops get wrong: Now I'm not sure what you have in your cooling system, but most shops I've dealt with think 100% coolant cools the engine the best. This is wrong.

"Coolant" actually does a few things: it lubricates the water pump seals, it lowers the freezing temperature of the mix, and makes the boiling point temp. higher. It does not, however, help cool the engine better than the water.

A 50%/50% mix is almost your best bet for all-around use. Water pulls the heat, or transfers it, better than the antifreeze/coolant/whateever.

So that's a starting point.

Live in an area where freezing isn't a problem? You might try a lower ratio coolant-to-water mix to get more water in there, or just use the 50/50 and use a product called "Water Wetter." If you have an aftermarket temp guage I'm sure you'll be surprised at how much cooler it will run.
http://www.redlineoil.com/redlineoil/wwti.htm
(Please check the Aluminum block temp/seconds graph out)

I guess for max cooling I'd use a 30% antifreeze, 70% water with a bottle of Water Wetter.

(On the race tracks I, and others, use just water and Water Wetter - no coolant. But then those engines don't see freezing temperatures.)

As for horsepower I've heard some good things about flex fans, but I've also read some criticisms of different flex designs for cooling purposes.

Please post back with what you find out, I'd like to know what you have in there and what you end up doing to the cooling system.

 

How about hoses? Especially the lower one. I have seen where the inner liner of the hose will seperate and partially or totally colapse restricting water flow to the water pump. It sounds like you are ready to try anything.

 

Thanks for the replies - Yes, I'm ready to try about anything. I'll look at the hoses - I bought new ones with the radiator but didn't put them on because the ones on it looked good, but I'll replace them since I've got them. Also - I'm not sure about the mix of antifreeze to water - I'm in Florida so not overly concerned about freezing. SO I'll head to a higher mix of water and I'll let you know what happens. Thanks again for the responses.

 

I hate to say it, but it could also be a blockage in your engine block. If your water jackets in your block are clogged or partially blocked this could cause your problem.

 

try a 160 stat. :-staun did I say 160 I sure did I use 160 in my 150 5.0 efi and heat don't rise past the N even on hot days with A/C plus I picked up about 1/2 to 1 mpg . try it it works .I know what others will try tell you it won't work for whatevre reason. Trust me it works great I have did it with other car's & trucks Ford,chevy,mopar keep cool. Pushrod

 

Again, thanks for the replies - I did put a 160 tstat and it certainly lowered the temp but it still climbs in traffic. So if the engine had blockage - wouldn't it stay somewhat warm even when moving? I Can leave a stop light where it's crept up to A or L on the NORMAL on the gauge and 2 minutes later (if I stay moving) it falls back below the N.
I'm stumped if its not the water pump.

 

What happens if you rev. the engine a bit while it's hot when stopped? Does it cool down? Sounds like your pump isn't pumping enough coolant at idle or your flex fan is not flowing enough air through the radiator. Find a long hill to travel at speed, drop the trans into neutral to bring the engine down to an idle, if the temp rises it's a coolant flow problem most likely the pump. Also check to be sure the lower radiator hose has a coil spring running through it to prevent suction from collapsing it. I recently picked up a hose at AZ that did not have one.
Mark

 

Thanks Mark, there are not many hills in Florida big enough to let me try that but I haven't tried to run up the motor while stopped to see what happens - so that will be next. Also, the guy that put on the Flex fan kept my old clutch unit so I'm either going to buy a new one or replace with a better flex fan. Now that I'm really looking at everything hard - the fan looks a little small - there is about 1-1/2 to 2" clearance from the tip of the fan blade to the shroud. I also tried to measure it from the bolt to the tip of the blade and it's 9".
Maybe a bigger, better flex fan will do the trick.
I'll keep you posted.
Thanks again for the reply.

 

What heat range plugs are you useing. may want to back off one step. but most of the time backing off timing about 2.drg will stop a hot idle. Try it befor you flush the block . good luck !

 

2 more things:

You say you had a "tune-up", but I know the garages around here don't include checking the timing with tune-ups anymore, and if your timing is off it could make it run hotter.

Plus, believe it or not, higher octane gas has a cooler burn and will make engines run cooler. This might not be noticeable in a V-8 though, but it's awfully noticeable in 4 cylinder cars.

 

Just an update.. Installed the new factory fan and clutch. It did make a difference overall, engine ran cooler than ever but still have the creeping temps when sitting in traffic. I'm going to try the water pump next and last the electric fans

 

what about the timing?

 

Just had it tuned up - not sure where it's actually set at but he reduced it by 10 degrees... It doesn't ping with 87/89 octane. Has a slight hesitation when the gas is applied but runs very well.