How can I reduce the coolant temperature?
- Thread starter prairiepegger
- Start date
Good question. I thought the same. I'm using an IR gun and the reading is pretty close. The thermostat housing reads 221 and the top of the rad (near the cap) reads 224 when the gauge reads 230 F. The gauge is a Classic Instrument (All American Series)
Good thought. I'm pretty sure that when I replaced the waterpump last year I matched the old one I took out. Replaced while replacing the timing chain.
Right now I'm beginning to question my memory.............
Yes.
This might be tough to determine. There is no indicator/pointer. Is there a way to determine without?
Sorry, forgot to mention that the engine did overheat. This is what led me to investigate. I thought 230 was normal until I ventured a little further in distance.
If you have an IR gun , shoot the outlet of the radiator too and see what temp the water is coming out of the rad. Then you can work out where the problem is. Is the motor making a ton of heat or is the radiator just not doing it's job well enough.
As Potvin Guy says, has the car ever been properly tuned.? Is it running lean? Vacuum leak?,Where's the timing at idle? and when you're cruising? All will contribute to it running hotter than you'd like.
Is it possible to put a larger fan on? It doesn't matter if it overhangs the tanks a little, as there will still be more area of the core with air moving over it. See if you have a decent size wire running too the fan , from the relay. Small wire will not help. And see if the fan is a reputable brand. Some of these offshore fans have puny motors that won't pull as much air as a decent fan. The size & weight of the fan motor is a good reference.
Those corrugated / universal/ "donkey dick" radiator hoses will slow water flow down, so change them to a decent smooth hoses if you can and you may be able to buy a larger crank pulley or smaller water pump pulley to speed the water flow up a bit?.
As Potvin Guy says, has the car ever been properly tuned.? Is it running lean? Vacuum leak?,Where's the timing at idle? and when you're cruising? All will contribute to it running hotter than you'd like.
Is it possible to put a larger fan on? It doesn't matter if it overhangs the tanks a little, as there will still be more area of the core with air moving over it. See if you have a decent size wire running too the fan , from the relay. Small wire will not help. And see if the fan is a reputable brand. Some of these offshore fans have puny motors that won't pull as much air as a decent fan. The size & weight of the fan motor is a good reference.
Those corrugated / universal/ "donkey dick" radiator hoses will slow water flow down, so change them to a decent smooth hoses if you can and you may be able to buy a larger crank pulley or smaller water pump pulley to speed the water flow up a bit?.
Something is not working at all. At a 40 mph cruise the fan should not be an issue. A marginal radiator, should still make the temp fluctuate with air movement. Just because it is easy to check, make sure the lower hose is not collapsing from heat and suction from the pump. Need to make sure you have a pump with the proper rotation. If you do not find something amiss in the cooling system, we may need more info on the engine. Since you put in a timing chain, I am guessing a stock, used engine? I will throw this out there because it is so easy to do wrong. If the heads have been off, the head gaskets are easily installed wrong and the result is overheating. It will not correct itself, even in Alaska.
Okay. I attached a vacu
I attached a vacuum meter and it was in the late timing section, not that far off from normal. I advanced the timing slightly and it now sits in the normal zone. Haven't tried driving it yet
You need to put a timing light on that thing, to confirm your timing method. If you can time an engine with a vacuum gauge, I will bet it applies to a stock, perfectly performing engine. If you have to buy a timing light, get one that has adjustable advance. You need to confirm base timing and total advance at what rpm.
roadmonster
Member
Why don't you have a pusher fan? That sounds like the problem. I have a pusher with a switch but leave it on. If I turn it off, it will soon overheat.
Okay. I checked for vacuum leaks. All was good. At idle RPM is 700 and in drive it's 590 to 620. Vacuum is 500 and mid way in the normal zone both in park and in drive. I got a very good Snap On timing light. I need to learn how to get the timing output to display.
I had a mechanic friend come over today. We started the car and removed the rad cap to determine if we were getting adequate flow once the thermostat opened and determine if flow increased once we accelerated. The flow was very good. It responded exactly as it should have when we accelerated. We installed the cap and continued to run the engine.
Ran the engine for about 25 minutes and temperature climbed to 230. It went to 240 after 30 minutes at which point I turned it off.
I'm thinking that my speedway 14" fan rated at 1200 CFM is not big enough. I'm leaning towards buying a 16" SPAL. It is rated at over 2000 CFM. Is this a good choice or are there others that are better. I definitely want to stay with electric. Hopefully this will work without a shroud.
Good to see, checking the basics. Most electric fans come with a shroud. You should not need an additional one. With that said, I am not very hopeful of that being a cure. If you can cruise at 40+ mph that thing should not overheat. You do not have the rad blocked off with a tight mesh grill or anything, do you? I do not understand the 500 vacuum reading, but the idle rpm in neutral and drive do sound right. Your vacuum reading should be something about 20 inches plus or minus 5, or there about. I never did see a reply on any specs on the engine, head gaskets, etc. Do you have the vacuum adv hooked to the manifold vacuum. That will pull a lot of advance in at idle. If so, just pull and plug it and see what happens. Better get it done, Mike's site time is surely limited. Get the biggest fan that will fit. Watch the amp ratings, the higher the better, just wire it sufficiently.
Thanks for the response. I provided the metric version (sorry, even after 8 years away, the Canadian is still in me). This translates to ~20 inHg. Which is in the ball park, so to speak.
I took it out for a drive tonight and the temp continues to climb when accelerating. I'm in agreement with you that it should not overheat cruising at 40 mph. To add more salt to the wound, when the temp reached 230 F at a 50 mph cruising speed, droplets of rad fluid was hitting my face. Thankfully I was wearing goggles (still working on the windshield). Looks like the rad now developed a leak. Nothing leaking when I parked it but I could see where the fluid was coming out from. I'm thinking the pressure at higher temps is causing the fluid to escape.
The vacuum advance is hooked-up to the carb. I've tried it plugged but no difference noted. This 5.0L motor was a donor from a 1999 Explorer with GT40P heads. I didn't do too much to it. Essentially went old school - replaced the intake and opted to go with an HEI distributor.
In view of the leak - on a brand new rad to boot - I'll look at buying the biggest I can fit. Could I have a defective rad that is causing the overheating?
I truly believe the pump is moving the fluid efficiently I just can't understand why it's not cooling at cruising speeds. Not sure if there are surface tension or COF dynamics preventing further cooling when at 40+ mph cruising speeds.
The water wetter should correct any surface tension issues. Do you have a top tank rad? I do not know why that would matter, just trying to visualize what is going on. Need to see some figures on the ign timing. I do not know how to answer, whether the rad is good or bad. If it is moving water from top to bottom, wait maybe that is it. Is the water moving the right direction through the engine and rad. This would fall back on the water pump rotation. The bottom hose should be pulling. If you changed the pulleys from serpentine to v belt, or if someone sold you the wrong pump, or if you eliminated some of the accessories or pulleys off the front. If the pumps pulley has grooves it needs to be driven off the inside of the serp belt. If smooth, which I doubt, the outside of the serp belt. You might want to check you cap pressure, I would think 14 to 16 lbs would be suff. I hate to throw this into the mix, but you could be getting compression into the cooling system, ie blown head gasket. I have not heard of a heat crossover bleeding into the coolant on the intake, but stranger things have happened. I hope we can stay in touch until we find the issue. If you have to pull the intake, be sure to not use the all paper felpro gasket. Use the one with a metal layer in the middle. Keep it up, good luck.
roadmonster - I'm trying to understand what you mean by pusher fan. Are you saying that my fan needs to be attached to the front of the radiator and pushing fresh air towards the engine? The fan I currently have is attached to the inside of the rad and pulls fresh air in.
Just for comparison, I have a stock roller cam 302 engine in my T. It has a carb intake with a 1850 (600 cfm) and mallory ign. My rad is a 2 flue, top tank, brass 66 mustang, nothing fancy. My fan is probably a 12-14 inch puller, generic electric. It comes on with the switch. The only time it has ever gotten hot, the thermo stuck. I had drilled a 1/4 inch hole in the thermostat flange and was able to nurse it home. I think you need to dig deeper, before throwing more money/parts at it. Your engine is not a problem one for cooling.
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