Hi all i'am running a 460 with a c6 tranny.Now i'am having problems with what appears to be overheating.Now when I run the truck around town it runs darn near perfectly.as soon as i take her out on the highway or where i have to go over 45 mph she instantly gets ( to what I think is) hot and the valves seem to be clattering or the push rods rattle,but only when on the highway.After i take it home or to park it it will still clatter until it cools down then BOOM it goes away I have checked the oil pressure and am about to install a new temp gauge.The old orignal temp gauge says it runs in the normal range.Any help or input on this matter would be greatly appreciated.

P.S I dont have fan shroud but like i said it runs great in town only acts up when speeds pick up?

 

Radiator hoses collapsing due to bigger suction at higher rpm's?

 

I could almost guarentee that if you got a shroud, the problem would go away. Those big blocks like to run cool, if i remember correctly. My lower radiator hose has a spring in it to keep it from collapsing.

 

My lower and upper hoses both have springs in them however when they get hot they are pretty weal looking i will try changing them.As for the shroud i have looked high and low in 6 or 7 local scrap yards and have had no luck where could i find the right one for my truck?New or used?

sorry 28 inch rad

 

I'm going to an electric fan with a built in shroud. I'll let you know how it works. I like the idea of it spinning at full speed regardless of engine speed. Especially im Texas summers, AC blowing max, stuck in traffic on IH35 in the afternoon.

I went with a universal...I got this one because of the rubber surround shroud. It should get a pretty good seal, therefore pulling most of the air thru the radiator instead of just churning in front of the radiator.

http://www.jegs.com/cgi-bin/ncommerc...76&prmenbr=361


In case the link does not work, it's a Flex-a-lite Black Magic heavy duty Electra-Fan from Jegs.

 

For a shroud try the online store,but I didn't see any. Or your local ford dealership should be able to order you one,or give Denniscarpenters a call. They usually run around 100 bucks.

 

Greg, is one 15" fan enough?


Expys and F150's get dual 16" fans.

 

Guess I'll find out. It's labeled as a substitute for the mechanical fan for 4x4's and higher HP applications.

 

That seems to be to small remember i have a 28 inch rad,although the built in shroud sounds good.I also like the idea of it spinning at full speed regardless of engine speed.

460 CREW ihave tried to purchase many things on the online store however since I live in canada it says there is no way to ship to me,so I just go elsewhere.

 

Since it happens on the highway, it isn't a air flow problem. It is a coolant problem. On the highway your engine is turning at a high RPM. When you are in town, you are at a lower RPM and not producing alot of heat. Check your coolant level, check the thermostat, check your pump, check your hoses. Are you running 100% Antifreeze (coolant)? Antifreeze doesn't transfer heat as well as water does. Go with 50/50. Now you can even buy the coolant premixed w/ water. Don't buy a shroud. It isn't air that you need. Well you can buy a shroud but then send it to me. I have a 71 short bed with a 460/C6 that over heats in trafic. (no air) On the highway, I am great because I have plenty of air flowing over the radiator. I am going to be trying a electric fan from a junk yard and see how I do. I will have it turn on at 190F.

Good Luck
Austin

 

Two things come to mind, one was already mentioned the other seems logical. You fan may be on backwards.
I have used electric fans, but not for heating problems. It sure seems like a lot of people bail in here with heating problems and the fixes when ever the question pops up. My 2 cents worth, if your cooling system is in good order and you aren't towing, you shouldn't need an electric fan. A new stock 3 or 4 core radiator with a factory thermal clutch fan and a shroud should be all you need. Some people like the aftermarket flex fans but way too many of them are junk. The shroud is one of the key elements and should always be in place. Besides it is much safer when tuning if you don't have the meat grinder to deal with. Also if you live in the hotter climates you don't need 50/50 and can get by with less antifreez in the mixture. A wetting agent can also be used. We use it on dirt track cars but I don't remember the name.
Other things to check, the rubber seal between the core support and hood. Ignition timing, too much advance can cause over heating. And a good backflush on your engine can't hurt, you wouldn't believe how much crud can build up in there over the years.

 

Thanks willowbilly3.The info relly helps however i'm not sure how to do a backflush.Do I simply run water through the hoses backwards?with or without the truck running.also if you know where to find a shroud i would literally jump for joy!!


dablack
do you have any idea how much horse power your truck has?Also what year is your engine.Mine is c9ve wich stands for 69 lincon motor.Does anyone here run a lead additive and would that effect the temp at all?

 

I made my own backflusher. Take a section of 2 inch pipe about 2 feet long. Put a bell reducer on one end. T off that with a fitting for a water hose and a blowgun to hook to a compressed air supply. Now the only part I had to buy was the check valve in the water line connection. I didn't think it would be a good idea to expose my water system to 120 psi bursts.
To use this flusher you take out the thermostat and use a piece of radiator hose to connect the flushing device to the t-stat housing. Leave the top radiator hose connected to the radiator and point the end of it down. Now turn on the water and when the engine and everything is full and water is coming out of the top radiator hose you give it a blast of air. Repeat the procedure a few times until you don't see any crud coming out and only see clean water. I recomend pinching off the heater hoses with vice grips so you don't blow the heater core. I only ever had it happen on chevys but it is still a good saftey precaution. If you had to buy everything it would cost around $20 to build. I had everything laying around except the check valve when I built mine.
You will be amazed at how much crud will come out of your engine. I have replaced expansion plugs before and found a couple inches of crud in there.
I spotted a good shroud at the junkyard, it's off an air conditioned 72 with a 390 and it looked good but I didn't check the bottom. I will find out how much they want for it but it shouldn't be much as they are pretty reasonable. The bad part is it's about an hour and a half from here and the last two times we worked up there I was hauling the crew and really didn't have time to stop. We may be rained out tomorrow and I'll see about going up, they have the brackets, p/s pump, condensor and compressor for my 68. I also need to check on a brake booster.
I will keep you posted.

 

I don't think this was mentioned... check the radiator for a restriction. Drain some of the coolant out and look to see if there is any scale visible in the core. There might be enough flow for city driving but restricted at high speeds.

Joe

 

I was looking at them this week... Wally World (Wal-Mart) has a Prestone backflush kit. Right next to the Prestone AntiFreeze/Coolant, don't get the environmental friendly stuff, just get the regular. The book says the radiator holds 21qts (7 gals) and to run 30% coolant... get 2 or 3 gallons.

Shrouds... like the Holy Grail. My radiator (original) does not even have mounting holes for one... I don't think they were stock, for the most part. You can buy them, they even show up on eBay from time to time... they go high.