Temp/Running Hot

[rdhowe2006@yahoo.com]

Needing anyone who can point me in the right direction. My 1970 IL 6 250 Engine is running hot. I have had the radiator rotated out and repaired. Fresh coolant installed. While sitting in neutral on my carport idling the temp gauge rises to near the red zone on temp gauge. I have put a new radiator cap on it also. I'm need to this site so I'm looking to see if any of you may can let me know what else to check for. Thanks in advance.

[davepl]

Do you have ALL the factory equipment (fan, clutch, whatever came on it originally)?

Do you have the factory shroud in place?

Pic of engine bay might be good, showing the radiator setup.

[geezer#99]

What's your initial timing?
Retarded timing makes lots of heat.
Do you have a stock fan?

Do you have a fan shroud?
How far from the rad is the fan?
Is there anything mounted in front of the rad?

[rdhowe2006@yahoo.com]

Yes all original. Could it maybe the thermostat stuck?

[rdhowe2006@yahoo.com]

No shroud on it.

[davepl]

Originally Posted by rdhowe2006@yahoo.com

No shroud on it.

That's your problem, methinks, if it's OK at speed. Unless they actually made six-bangers without shrouds, but I've never seen a car without a shroud that didn't overheat at low speeds.

The shroud forces the fan to pull air THROUGH the radiator, instead of just churning air sideways.

[Grumpy old man]

6 cylinders didn't come with fan shrouds , replace the thermostat. Also check the lower radiator hose to see if it's collapsing thus reducing coolant flow and make sure the fan belt is adjusted correctly .

[rdhowe2006@yahoo.com]

See attached pics of set up.

[Grumpy old man]

That's a stock set up , you have generic aftermarket radiator hoses on it . Replace the thermostat . The hose coming from the valve cover should be going to the air cleaner spacer not hanging loose .looking at the thermostat housing at the end of the top hose it hasn't been changed in a long time . I would replace all the hoses with new correct ones NOT GENERIC including the heater core hoses that are mismatched and look old ,flush the heater core with fresh water by removing both ends at the engine and using a hose run clean water thru them until clear .reinstall new hoses add anti freeze and that should cure your problem .

[cdowns]

take a known good thermometer and take the tempature of the coolant and see how hot is too hot before changing anything

[Grumpy old man]

Originally Posted by cdowns

take a known good thermometer and take the tempature of the coolant and see how hot is too hot before changing anything

He's already rebuilt the radiator and fresh antifreeze , it is still overheating, the repairs I suggested are not only needed by the looks of it but just good general maintenance . Cost less than $50.00 and about an hour .I'd bet a donut the heater core is full of crud .

[cdowns]

Originally Posted by Grumpy old man

He's already rebuilt the radiator and fresh antifreeze , it is still overheating, the repairs I suggested are not only needed by the looks of it but just good general maintenance . Cost less than $50.00 and about an hour .I'd bet a donut the heater core is full of crud .

cost for my suggestions are less than $5 and takes aBOUT 4-5MINUTES

[Grumpy old man]

Originally Posted by cdowns

cost for my suggestions are less than $5 and takes aBOUT 4-5MINUTES

Hahahaha !! I thought I was the grumpy old man ?

[rdhowe2006@yahoo.com]

Thanks Grumpy. I will try this.

[rdhowe2006@yahoo.com]

Hey Grumpy, I didn't have a air filter assembly I got this one from a member on here. There is no place to hook the hose to the air filter assembly? What can I do on finding out the type air filter assembly I need. This must no be the correct one for my engine.

[geezer#99]

You need something like this to plug your breather hose into.
Different sizes, so measure yours.
This is just an example.
http://www.ebay.com/itm/1988-89-90-9...lVMAp~&vxp=mtr

[Grumpy old man]

Yep ^ you need that type of carb spacer just find the correct one for your carb , place a wtb ad in the classifieds .

[rdhowe2006@yahoo.com]

I started the engine up and after about 5 minutes the two hose going to the heater core against the fire wall was red hot and smoking. I had the radiator cap off while running and the temp got high very quickly. Any ideas on what is wrong? New to the form and not sure what I need to check. Thanks in advance

[firedemon]

if you have done all the suggestions and your still having problems I would suggest taking the water pump off and get a good look in the cavity you can see the cylinders . sometimes if an engine has sat for some time or maybe someone has put tons of stop leak in it , it can sludge up and reduce coolant flow . if everything else is ok or been replaced it must be plugged somewhere

[mrsmith]

Hi , I am new here ,but have a lot of exp with this engine. My first car had the same one. Your problem here is going to be one of a couple of things. Let me preface this by saying i am not a ASE mechanic , just a lifelong car lover.

If your car idles and is running in the red.
1. Could be bad thermostat. easy to check. a. top hose. b. run engine until it gets warm. c. squeeze the top hose. if it is hard or impossible to squeeze then you have a bad thermostat. To repair. a. take off the two bolt on the water neck where the hose connects. b. pull out old thermostat, and old gasket. c. new thermostat will come with gasket ,but use blue permatex to make sure it seals. d. do not over tighten it will crack. should cost like 10 bucks or so to get a new one. Some people ,especially those in hot climates will leave the therm out and just replace the neck. this makes the car take longer to warm up. If you are in a 100degree are this will not matter much. You could also pop the spring and plunger out of the old one and put the empty shell back in to give a bit of back pressure to it.

2. You could have a bad water pump.
to test this . a. start with cool engine. b. take off the radiator cap. c. start the engine. You should be able to see the water moving in the radiator , or it will over flow out of the top , both are ok that means the water pump is working generally. I am sure there are already instructions on replacing the water pump so in the interest of time i will leave that out.

3. Are you loosing coolant ? what i mean by that is once it warms up then cools back down do you have to put more coolant in the radiator? If it is eating coolant ,but not leaking then the worse case bad head gasket would be likely. That is the least likely though here.

I hope this helps. Good luck man.

[SparkyRnD]

Basics: if overheating while driving, could be core size or air isn't making it through the rad. If overheating while sitting, not enough air is being drawn through the radiator core (ie: fan isn't doing it's job).

That is assuming everything else is up to par. I would check the thermostat and waterpump to see if they are working properly and flowing coolant when they should. Also check for losing coolant as mentioned above, and check for exhaust gases in the cooling system (indicating head gasket). But again if its only at idle, that usually points to fan, tstat or waterpump.

We also make radiators here in the USA using domestically sourced materials by hand to fit your truck (and we can put the inlet / outlet wherever you need at no additional charge). They are all tig welded, no epoxy or glue either. Plus, we are a site sponsor. Let me know if you are interested.

[rdhowe2006@yahoo.com]

I ran it and I have hot water coming out of where the hose goes into the heater core.

[CST10]

One thing I notice in this thread is that the temperature has never been validated by a second source. I would get a cheap infared temp gun and check the temperature against the gauge. Your gauge or sensor could be off. If it's reading close to the same you then can trouble shoot your system with it.

Temperature at the thermostat once opened should be within a few degrees of the radiator inlet at the top, if the temperature is really higher at the housing vs the hose once up to temp it's a bad thermostat. The temperature at the bottom outlet hose nozzle should read real close to the water pump. Between the top inlet and bottom outlet of the radiator there should be a significant drop in temperature, like 40 degrees or so. Check that lower hose to make sure it's not collapsing when the rpms are raised.

If the temperature at idle is high but lowers driving, it's a lack of air flow. If the temperature is normal but increases with driving it could be the block is cruddy or fouled and may need to be flushed some more.

Also, are you sure you got all the air out of the system last time you worked on it. seen this as an issue in the past. Air gets trapped under the thermostat and then it does not see the correct temperature to open correctly and stays closed which leads to overheating. I usually jack up the front slightly to make the radiator the highest point in the system. If you end up replacing the thermostat, do yourself a favor and drill a small 1/8" hole somewhere in the thermostat to allow it to self bleed the air from the system.

Don't put anymore antifreeze in it till you get it straight otherwise your just throwing your money away. I'd also change the hoses if I had to go into it again.

[mrsmith]

CST10 had some very good input. I did not even think you could have a bad gauge. Good stuff there man.

[rdhowe2006@yahoo.com]

Well it did set up for sometime before I got it cranked.