Hi,

I am new in the Ford Truck field (rather more familiar with Mustangs).
However, I own now for 2 years a F250 XLT Lariat, 460cid / C6, 2WD from 1986 with A/C and ask for your help.

First I have to say I had never overheating issues. I believe that the temp gauge reads correct, as after 30 minutes drinving the needle comes into middle position and stays there, after the thermostat has opened obviously.

What I do not understand is, that the coolant Level (Looking from the Radiator cap inside, at Cold engine) is constantly about 4 to 5 Inches below the cap seat. When I fill the coolant (either from the cap Opening or the Overflow tank) the Level goes down again.
When the engine is hot, there is never something in the Overflow tank as well, which I am wondering about.
After filling the Overflow tank (About half way up) the engine cooling System sucks the tank empty as the engine gets warmer and warmer.
The Radiator cap looks good, as far as the rubber sealings is concerned.

I must say I have never found leakage under the car or on the hoses or elsewhere inside the engine compartment.

I have no idea, if I should leave this issue and go as Long as I don't discover overheating signs or if I should care About it in one way or the other.

I want to Mention, that my truck is a Survivor of provable 50tsd mls. So I don't think that there has been done a lot to it since 1986...

I also want to Mention, that I see since 3 month, that there is a lot of White smoke coming out of the vent System in the cab when I turn it on for the first time. The same, when I turn on A/C or heating.
So probably it is the heating hose System / heater core / heater plenum where all my coolant "disappers"?

I read here that probably burping the cooling System would be a first good step.

What do you think About this all?
I appreciate your help!!

thanks,
Greg

 

May have no effect, but you can’t tell by looking at the radiator cap if it’s bad. I’d stick a new one on; they’re only about $10. If that fixes your problem, great. If not, it doesn’t hurt to have a new cap.


I was mysteriously losing coolant and a new cap solved the problem

 

Thanks, seville009.

Just ordered 2 caps some days ago. This was also my first step of troubleshooting.

 

Smoke? Or steam?

Smoke will obviously have a burnt smell. Steam from leaking coolant will have a sweet smell. Since you've been losing coolant, I think we're talking steam.

Get thee a pressure tester for the cooling system. Pump it up to 13 PSI. Wait 15 minutes and make sure the pressure hasn't dropped more than a needle's width or so.

 

Does the inside of the windshield get covered with an oily film?

 

If it is the heater core leaking, it will be very easy to replace since you have a A/C truck.

 

So, today I saw some coolant dropping down the heater box in the engine compartment just at the firewall. And also I realised that there the floor carpet was wet inside the cab..also coming from the heater box.

It means to me that the heater core might be the problem most probably.

For exchanging it, I will look on rockauto.com for a new one. Any recommendations of brands?

How to do the exchange is now not clear to me 100%. But I might get the shop manual for my instruction.
If anyone can give me some instruction I would appreciate much!!!

Thanks for your replies so far!

Greg

 

All you have to do is take the glove box out, take that black panel off behind the glove box and it will be staring right at you. Of course you drain the radiator down about half-way, and then take the hoses off on the firewall side.

When you put the new one in place, put it all back together but leave one of the hoses off the heater core. Start filling the radiator back up till coolant starts to run out of the hose that is loose, and then quickly slip it on and tighten the clamp. Then continue filling the radiator. This won't get all the air out, but a lot of it.

Warning. Once you get it all back together and have no leaks, do not mess with the heater core hose connections again unless you can't help it. The hoses will stick to the heater core connections, and if you twist on the hose it always makes the core start leaking. If you have to take the hoses off the core later for some reason, take a knife and cut them off, no twisting or pulling on them.

 

Great help!
I will stick to that..

 

I find it to be easier if I use a razor blade or utility knife and slit the heater hoses where they connect to the heater core. This lessens the chance of damaging the heater core [if good], when twisting the hoses for removal. Since yours is leaking and needs to be replaced, this will not be an issue, but you might want to consider replacing both hoses at this point. They are not expensive and can be bought by the foot [~10 feet] at any parts store.