Hi everybody, im new, just got a 78 ford f-150, with a 460, I came out the other morning and discovered the block heater had melted, so I got another one, mounted it, new hoses, and antifreeze, now when I warm the engine up to normal temp, I switch the heater on, and it feels like it's blowing colder air then the air that's outside(im in Utah) there is absolutely zero warm air coming into the cab, im still pretty new to this kind of stuff, ive done transmissions and interiors on Cameros, for 7 years, but I got this truck for a sweet deal, I did this guys Tranny on his I-Roc and he gave me this truck, so im really keen on learning all about it, it doesnt have A\C, so if somebody could throw a few ideas my way, I could go dig into it, if not, im just gonna have to kind of dabble around until I fix it, which works, but usually produces additional problems, thanx.

 

Verify the heater cables are adjusted correctly, https://www.ford-trucks.com/user_gal...=94681&width=0
Check the heater hoses in the engine compartment and verify near the heater core if the hoses are both hot.

 

I know about those Utah mornings-I used to live in Wyoming. Check the valve in the heater hose going from the engine block or water pump to the heater core. Mine is vacuum operated and it sticks closed sometimes. The heater core itself might be clogged.

 

Does the new engine heater mount in one of the heater hoses? If so, I would suspect a problem with that. Make sure it's mounted correctly (they only flow one direction). Water will not flow through the heater backwards. Keep in mind, antifreeze flows out the intake, through the heater core and back into the water pump.

Does the engine warm up to normal operating temp? With engine warm, are both heater hoses hot? Are the hoses hot on both sides of the inline engine heater? Let us know what you find.

Marty

 

I just went out and snapped a couple shots of how ive got it installed, the old heater laid down horizontal, where the new heater specifically said to mount it vertically, where would I post a picture of how it's set up? the only hose that's been hot (and ive checked them all) is the upper hose running out of the radiator, the engine warms up to standard temp, im not leaking anywhere, wheres this valve at? im totally new to this heater stuff, I couldnt even tell you where the core is! Im good as in once I call attention and identify all the parts I'll be able to bust it out, but as far as part locations I have to admit im really rather ignorant at it.

 

On the passenger side of the rear firewall, right below your windshield, and to the right of your engine. You can find 2 3/4 inch heater hoses, which connect to your heater core. On the heater hose running from your intake, you will find the heater control valve Katman469 mentioned. Check both heater hoses and check if they are hot.

 

Create your gallery and post the pics there.

So neither heater hose is hot? I would suspect you have a blocked flow, either the engine heater or heater core is blocking the flow. Is there a arrow showing flow direction on the engine heater? Try by-passing the engine heater and see if that helps - you can either disconnect the hoses from the heater and use a splice to reconnect them, or run a whole new hose.

The valve they are talking about is on a/c pickups. Your non a/c pickup will not have it.

Marty

 

okay Ive posted 3 pics in my gallery, man, im lost, all their is, is 2 hoses running out of the block, one runs into the heater, and then out into the firewall, the other one just runs straight into the firewall, yes their is an up arrow on the heater, and the heater warms right up, but I cant find anything else, at all, just those 2 hoses, you don't think mabey the new heater is bad do you? just a thought, but the arrow points up, ive got the flow right as far as I know, im really starting to get frustrated.

 

this can't be that hard, man ive figured out brakes, master cylinder, booster, tranny, ive installed new windows, mirrors, I just put a new floor in because the entire drivers side floor was rusted away, it was almost undrivable because their wasnt a floor, but Im going to get done in by a heater?? WTF?

 

It seems like there is some type of restriction on the line. Remove the heater hose and check for restriction at the heater core or the heater. Maybe the heater is hooked up backwards.

 

This is just a shot in the dark but make sure you dont have an air lock in the core. This can happen if the entry and exit points are both at a low point in the unit. Try detaching them both at the front of the engine and see if you can blow through them.

 

That's the problem. The arrow needs to point to the water pump. Antifreeze flows out the intake, through hose to heater core (firewall) then out other hose to engine heater, then to water pump. You need the flow arrow of the engine heater to point toward the water pump.

These pumps are made so the water won't flow backwards. Turn the pump around and it will work fine. I've learned this lesson the hard way too, I did the same thing to my '73 several years ago.

Marty

 

Great help fellas, you did a great job for this guy.

One thing though, This type of engine coolant heater is Not a *block heater* it is an inline hose flow heater and some styles actually circulate the coolant if they are so equipped with a small pump.

I prefer this style to the block heater as the block heater only warms a small amount of coolant.

The best install for colder climates is this inline coolant heater in combination with an Oil Pan heater for the Trans & Engine..... both available for Auto Owners.

 

Yes you guys did a helluva job for me, DAMM!!! thanx, I wish I could buy you all a beer, ive got heat so hot I forgot what not having heat was like already, once again thanks guys, god thats cool.

 

Ok, you are right, there is no way one should be 'done-in' by a heater problem. The first problem is, you added a part that Ford never had installed. Or rather, you REPLACED an aftermarket part that Ford didn't originally install. So, I am assuming that this is an inline coolant heater, not a block heater that replaces a freeze plug.

You had heat in your truck BEFORE you installed the new inline heater, then the only thing you changed was the inline heater, correct? That leads one to believe that is where the problem is. Logical? Always start with the very first variable when trying to solve a problem; The changed part. I believe what the others are saying, that this problem must be due to the flow being incorrect.

On my old '83 Lincoln Continental, I had an inline heater, but it was installed on the large lower coolant return hose. If that was a one-way flow and it was installed backwards, I imagine the car would over-heat in very short order. Sounds like your heater (I haven't looked at pics yet) is on one of your heater core hoses. The only problem you would have if installed backwards is the problem you are having; No heat in the cab!

Good luck, and please post when you got 'er heatin' up again. These old Fords had some of the greatest heaters ever made.

Mark