302 ford will not warm up in cold weather??

Hello, I have a 65 f100 and the engine will not warm up in cold weather. I drive the truck everyday and am about to freeze. Any help is appreciated. Here are the detail, 91 5.0l 302 from a f100 pickup. The engine only had 41000 miles on it when I got it, it was torn completely down. I got the block honed, new freeze plugs,new cam bearings,new rings, new oil pump, and I bought a set of new gt40p heads. The engine has a b303 hydraulic roller can, edelbrock performer intake, carter 625 carb, and headers. The truck has a new vintage air a/c heat system. During the summer the engine will heat up fine but in the winter it will not even touch the first mark on the temp gauge. The air coming out of the heater is barely warm if warm at all. I have changed the thermostat 4 times with no change. Does anyone have any ideas? I used the 91 model timing cover and a old iron water pump so I could use v belts. I don't know if I have something mismatched or what. Thanks for the help.


Posted using the Full Custom H.A.M.B. App!

 

Back in the day we stuck a piece of cardboard in front of the radiator.... with openings in it as necessary. I still do it sometimes when the temp hits -30F

 

What thermostat? a 160, should use a 180-190. Clevelands need the type that's like a brass cup on the bottom, not sure about the Ws.

 

Bottom line----the thermostat is not getting warm enough to operate----- not all bad. Try cardboard in front of the radiator to restrict air flow. BILL RINALDI

 

Last time I changed it I went to a 195 to try to have heat, if the everything is working correctly I would not think blocking the radiator would be necessary, it rarely gets below 25 here. If it is below 40 the engine will not warm up.


Posted using the Full Custom H.A.M.B. App!

 

I was thinking that using some newer model parts and some older parts that the water flow may be bypassing the thermostat some way, I am a chevy guy, this is my first ford engine. So I did not know if I was missing something.


Posted using the Full Custom H.A.M.B. App!

 

I had a 65 F100 that I swapped a 302 into about 20 years back. It could be my faulty memory, but I recall there being a heater control valve, have you looked at that? Seems like I just removed mine.

 

belt on the water pump is turning it the wrong direction.

 

Serpentine W/P runs the opposite direction of the V belt one, but you did change everything over to V belt....

 

I changed the water pump over to a v belt pump and all the pulleys, i salvaged the parts for the v belt conversion from a 67 fair lane. I did use the aluminum timing cover from the 91 model truck. The newer timing cover does not have a hole for a fuel pump but I am using a carter electric pump.


Posted using the Full Custom H.A.M.B. App!

 

what about a blockage in the heater core. Engine at temp. but barley warm air sounds like no water flow.

 

I have been driving the truck for 4 or 5 years, but I did not drive it that much. It has now become my daily driver so having heat is a lot more of a concern than it use to be.


Posted using the Full Custom H.A.M.B. App!

 

Under normal circumstances, I would also say thermostat. It literally doesn't matter how big or cold the radiator and outside air is. If the thermostat is working correctly, the engine will reach operating temperature before flowing a significant amount of water through it. The only reason a radiator cover should be used is in places where it's so cold that not blocking the radiator will prevent the engine to reach operating temp. For anything other than a big rig, or living north of the arctic circle, covering the radiator should not be something that is in any way necessary. It might help a regular engine warm up quicker but the time is only a matter of minutes different.

I would guess the thermostat is being bypassed some way. That or you are getting a batch of crappy ones that don't work. The quickest way to test one (and you should, it's easy) is to take it and dangle it in a pot of water as you heat it to boil. Put a thermometer in the pot and watch the temp and the thermostat. There should be no movement until the water is at the point the thermostat should open. Since they are designed to open below boiling point, they will open while you can watch it.

I would suggest getting a cheap infrared thermometer and point at stuff as the engine is warming up. Find the cold spot, find the problem. The first things to get hot should be headers, then heads, then block, then intake. Point at different spots of the item you are checking to see if you can find a cold spot.

Without actually being there to see what is going on, I can't give a real response so this is a bump.

 

The engine is not at operating temp, it will not even warm up to 120, the heater hoses and heater core are new


Posted using the Full Custom H.A.M.B. App!

 

I agree diavolo, I believe the thermostat is being bypassed some way, I just do not have enough experience with sbf to know where. I do have a infrared thermometer and I will check that


Posted using the Full Custom H.A.M.B. App!

 

make sure the thermostat is not upside down also, should look like a tree, with the roots pointed at the block.

 

Easiest thing to do would be to pull the thermostat, and put it and a thermometer in a pan of water and see where its opening up. Its either opening too soon, or not closing completely, or your gauge is wacky. While its apart, install a temp gauge with numbers on it that you can read. If the stat proves to be OK, then you need to look for a plugged heater core, or a path for the coolant to bypass the stat. Do you have an engine mounted and driven fan or is it an electric fan that might be running too early or all the time? You may have too much cold air coming into the car for the heater to heat. At least one of the heater hoses is coming from the motor side of the thermostat, right? Gene

 

I have a engine driven clutch fan, one heater hose is coming off the water pump and the other hose is coming off the intake. I just went and cranked the truck with it cold and did not see any water flow in the radiator.


Posted using the Full Custom H.A.M.B. App!

 

The water pump takes coolant from the bottom of the radiator and pushes it into the engine block from the front to the back, through the heads from the back to the front, into the intake manifold. From there it can go through the bypass hose on the thermostat housing back to the water pump to circulate back through the engine or it can go through the heater core or through the thermostat, through the radiator and back through the water pump. The bypass hose doesn't allow any significant opportunity for the coolant to lose heat. The heater core could cool the coolant slightly, maybe more if the ac is on but the engine heat usually overcomes the ac cooling capacity. The only way the coolant can get cooled significantly is by going through the radiator which would require the thermostat to be open or out of position so it doesn't block the flow.

You could try clamping the upper radiator hose to prevent any flow through the radiator.

Maybe enough heat radiates off the block. Try removing the fan to see if that helps.

 

I am thinking that the 91 timing cover is not compatible with the older style water pump. I thought the water pump and timing cover had to mate together in a specific way for standard rotation or reverse rotation,you have them mixed together. I have a 66 289, 71 302, and 89 5.0 and they are all different.

 

I have the same problem on my off topic 81 Toyota 4X4. If it gets below 35 or so, no heat. Above that it will run you out. I've flushed the heater core, and the radiator. I've ran water through all the hoses. I've tested the thermostat, and tried different temp ranges, and tested each of those. I've removed the fan, and drove it all summer, sometimes in 100 degree heat, and it never got above operating temp. even in traffic. The fan is still off, and has been for over a year. You can put your hand on any part of the cooling system, and the block, with the exception of the exhaust and not get burnt no matter how long you let it run. I've blocked the radiator, and that didn't help, it just won't get hot. I let it idle for about 30 minutes, then drove it about 4 miles, pulled the radiator cap, which is new, and was warm, but not hot, and put a thermometer in the water, and it dropped 20 degrees just sitting there idling. It was at 140 when I inserted the thermometer. This truck is all stock, radiator and all. Nobody can tell me why it does this. Sorry I don't have an answer for you. I wish I did, because it would fix mine too. It just doesn't get hot enough to open the thermostat. I even tried it without a thermostat.

 

K.I.S.S. it! you know the acronym right? oh the TIMES I usta WISH my Merc *would* run COOL -- in the summer of course I'd "cardboard" half the radiator -- was I you --

 

Call vintage air and talk to them. The switch that regulates the temp could be broken and your cooling the air from the ac side of the unit.

 

One possibility is that your radiator is too efficient. My 23 was that way, sbc engine and even with a 195 thermostat it wouldn't get higher than 170 on the hottest day in traffic. Going down the road it would go down to 150 sometimes. My top radiator hose would be very hot but I could put my hand on the lower hose and it was just warm.

As a test, do the cardboard routine.

Don

 

Did the Ford engine originally use quick connect fittings to attach the heater hoses to the to the heater core, engine and/or water pump? Did you replace these fittings with more conventional pipe nipples?

I don't know so much about Fords, but on a lot of GM models the fittings for the quick connectors often had a flow restriction built into them. My understanding was that the restrictions were there to help keep the coolant temps lower in the summer and/or higher in winter weather. If they weren't needed I doubt they would have been used in production.

Removing these restrictions might reduce the ability of the coolant to come up to operating temperature. If there are any of these restriction currently used in your system, make sure they aren't possibly plugged up.

 

https://www.google.com/search?q=for...er-hose-pics-86f250-non-a-c-351w.html;804;566 Shot in the dark!! Are your heater hoses crossed? Pete

 

The thermostat is supposed to be closed until the engine is hot enough to open it. With it closed the radiator shouldn't be involved in the problem

 

I agree with prpmmp that is easy to check. every body is overthinking this you have a water flow prob that is obvious now we need to find where. and I would bet is something simple . the water pump and housing if they were not compatible I don't think they would bolt together

 

I love it when someone remembers to NOT overlook the simple and obvious stuff. Which is usually my approach to tackling these kinds of problems...

 

Spitballing... Moving from socal to Wyoming and the resulting elevation change caused my chevy to run so rich that it NEVER went over 150. I rejetted it and it solved the problem.