Engine not warming up
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Engine not warming up
So I found out that the reason I'm not getting hot heat, is that my engine is not getting up to operating temp. I can't figure out why.
New radiator, thermostat, housing, hoses, heater core. Coolant is nice and clean. Water pump is not weeping, leaking, or making noise. I let the truck idle for about 15min, drove for about 15min, let idle for another 15min. Needle got just past "C" line. I originally thought the water temp sender wasn't working, but I think it is and the engine just isn't getting warm. I can pinch off the top radiator hose and feel coolant flow back into it when I let go, but the bottom hose never gets warm.
Any thoughts or ideas? Could the water pump be bad?
-MK
New radiator, thermostat, housing, hoses, heater core. Coolant is nice and clean. Water pump is not weeping, leaking, or making noise. I let the truck idle for about 15min, drove for about 15min, let idle for another 15min. Needle got just past "C" line. I originally thought the water temp sender wasn't working, but I think it is and the engine just isn't getting warm. I can pinch off the top radiator hose and feel coolant flow back into it when I let go, but the bottom hose never gets warm.
Any thoughts or ideas? Could the water pump be bad?
-MK
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I don't think it's the water pump. Reason being that the sending unit for the temperature gauge is on the block / intake. If the water pump weren't circulating it would get very hot very fast.
Remind me what kind of outdoor temperatures we are dealing with?
It sounds like you're dealing with a thermostat that is stuck in the open position. Now I know you said you've replaced it, but I wonder about the housing / intake. It acts like water is flowing through or around the thermostat anyway and thus causing your lack of heat.
On my truck(s) I if it is very cold I can actually watch the thermostat open and close by watching the gauge. The temp will start out cold of course then it will eventually creep all the way up near the P, then as the thermostat starts to open the temp will fall fairly rapidly back down to the E. It will then start creeping up again and if it is REALLY cold it might do this several times before it ever levels out and holds a steady temperature. See what happens is the heat from the block causes the thermostat to open but then the frigid water from the radiator cools it back off and closes the thermostat back, at least partially.
Remind me what kind of outdoor temperatures we are dealing with?
It sounds like you're dealing with a thermostat that is stuck in the open position. Now I know you said you've replaced it, but I wonder about the housing / intake. It acts like water is flowing through or around the thermostat anyway and thus causing your lack of heat.
On my truck(s) I if it is very cold I can actually watch the thermostat open and close by watching the gauge. The temp will start out cold of course then it will eventually creep all the way up near the P, then as the thermostat starts to open the temp will fall fairly rapidly back down to the E. It will then start creeping up again and if it is REALLY cold it might do this several times before it ever levels out and holds a steady temperature. See what happens is the heat from the block causes the thermostat to open but then the frigid water from the radiator cools it back off and closes the thermostat back, at least partially.
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I was about to say the same thing, my 400 did this, apparently what was happening is the coolant was leaking around the thermostat, which curculated enough that it would never come to full operating temp. The thermostat being to most obvious to check first, but it sounds like you covered that.
When you attemp to get it to warm up does the coolant system pressurize? You might pull the radiator cap and attempt to see if the coolant is circulating while cold, if it is, then i would venture the blame lies with your new thermostat not closing.
When you attemp to get it to warm up does the coolant system pressurize? You might pull the radiator cap and attempt to see if the coolant is circulating while cold, if it is, then i would venture the blame lies with your new thermostat not closing.
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So you're really not all that cold. You should certainly be getting more heat. Ok, here's a thought. If I understand the cooling system right, it will lead straight to your problem.
Wait till your truck is cold enough that the thermostat should be completely closed. Disconnect the upper radiator hose on the radiator end, and start the truck. If everything is working properly you should get little if any coolant out of there, maybe a VERY slight trickle. If you get more than that coolant is bypassing your thermostat somehow and you'll need to track it down.
Wait till your truck is cold enough that the thermostat should be completely closed. Disconnect the upper radiator hose on the radiator end, and start the truck. If everything is working properly you should get little if any coolant out of there, maybe a VERY slight trickle. If you get more than that coolant is bypassing your thermostat somehow and you'll need to track it down.
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So you're really not all that cold. You should certainly be getting more heat. Ok, here's a thought. If I understand the cooling system right, it will lead straight to your problem.
Wait till your truck is cold enough that the thermostat should be completely closed. Disconnect the upper radiator hose on the radiator end, and start the truck. If everything is working properly you should get little if any coolant out of there, maybe a VERY slight trickle. If you get more than that coolant is bypassing your thermostat somehow and you'll need to track it down.
Wait till your truck is cold enough that the thermostat should be completely closed. Disconnect the upper radiator hose on the radiator end, and start the truck. If everything is working properly you should get little if any coolant out of there, maybe a VERY slight trickle. If you get more than that coolant is bypassing your thermostat somehow and you'll need to track it down.
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I did drill a 1/8" bypass hole in the tstat based on another thread I saw on here, so I'm not sure that'll work so well.
I had a mechanic look at it last week and conclude that the water pump was working.
I had a mechanic look at it last week and conclude that the water pump was working.
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One wouldn't think that an 1/8" hole would allow for enough water to circulate to cause the problems you are having, but then again it might. Why take something that is engineered to do a specific job and then go modify it without even giving it a chance to work the way it was intended?
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Oh I gave it a chance to work the way it was engineered. The first two thermostats didn't have bypass holes and yielded the same results. Furthermore, many modern tstats come with bypass holes. Helps rid the system of air, and provide a failsafe should the tstat ever stick closed.
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I have heard of a thermostat that is somehow designed so that if it ever does fail, it will fail open. Not sure how they can predict and design it to fail in that manner. Anyway it still sounds like you're getting more flow through the closed thermostat than you're supposed to, it's about the only explanation.
You may still try the radiator hose trick. A 1/8inch hole can't let THAT much coolant through. If you get a trickle or a small stream that is OK, if you get a gusher then it is bypassing it somehow.
You may still try the radiator hose trick. A 1/8inch hole can't let THAT much coolant through. If you get a trickle or a small stream that is OK, if you get a gusher then it is bypassing it somehow.
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I'll def. try your trick, however after 3 thermostats with the same results, I just don't think that's it.
I was looking around, and someone mentioned a heavier duty fan clutch possibly causing an engine not to warm up all the way.
Just another thought, but maybe somewhere down the line someone put a larger fan or different clutch in there. Hell I don't know...
I was looking around, and someone mentioned a heavier duty fan clutch possibly causing an engine not to warm up all the way.
Just another thought, but maybe somewhere down the line someone put a larger fan or different clutch in there. Hell I don't know...
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If water is somehow getting AROUND the thermostat rather than through it, what's to say that a dozen new ones wouldn't have the same problem? I don't buy the fan clutch explanation for a minute though. My truck doesn't have a fan clutch which means it's running at full engine speed all the time and it still heats up. It does so because there is no coolant flowing through the radiator until the thermostat opens up.
You said you replace the thermostat housing? At which point in the process was this? Maybe somehow that housing isn't sealing properly. Maybe you replaced a thermostat that was stuck open with a good one but you replaced the housing with a bad one and suddenly you have the same problem because you fixed one problem but created another. I don't KNOW that is what happened, but hey anything is possible right?
That's the problem with throwing parts at a problem, and trying more than one thing at a time. Just because a part is new doesn't guarantee that it is correct or not faulty in some way. And replacing more than one part at a time means that you can never tell the true effect of any one thing. I know it's extremely frustrating, I've been there, boy have I been there.
You said you replace the thermostat housing? At which point in the process was this? Maybe somehow that housing isn't sealing properly. Maybe you replaced a thermostat that was stuck open with a good one but you replaced the housing with a bad one and suddenly you have the same problem because you fixed one problem but created another. I don't KNOW that is what happened, but hey anything is possible right?
That's the problem with throwing parts at a problem, and trying more than one thing at a time. Just because a part is new doesn't guarantee that it is correct or not faulty in some way. And replacing more than one part at a time means that you can never tell the true effect of any one thing. I know it's extremely frustrating, I've been there, boy have I been there.
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I'm not sure how coolant could be getting around it. The housing is new, so the fitment is spot on. Once the thermostat is inserted into the housing, I put the gasket over it and it holds the thermostat in while I put the housing on the engine. The two times I changed it, the thermostat had not slid or slipped and was still in it's proper position inside the housing.
I'll have to pull everything apart again and make sure there's nothing I'm missing. I appreciate your help.
-MK
I'll have to pull everything apart again and make sure there's nothing I'm missing. I appreciate your help.
-MK
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Yeah I don't know how coolant could get around it either, but when all else fails.... that's why you've gotta check first to see if you're getting a flow out of that hose. If you're not then it's probably not leaking around that housing.
You know I just had another thought and I'm not sure how feasible it is.... I know for a Chevy there is such a thing as a reverse rotation water pump. It has to do with if your truck had v-belts or a serp belt. Apparently the routing of the serp belt makes the water pump spin backwards and thus you need a reverse rotation pump so it will still circulate properly.
I don't know if such a thing exists for Ford, and I don't know if it would cause your problem. It seems to me like it would make your engine overheat rather than run too cool.
You know I just had another thought and I'm not sure how feasible it is.... I know for a Chevy there is such a thing as a reverse rotation water pump. It has to do with if your truck had v-belts or a serp belt. Apparently the routing of the serp belt makes the water pump spin backwards and thus you need a reverse rotation pump so it will still circulate properly.
I don't know if such a thing exists for Ford, and I don't know if it would cause your problem. It seems to me like it would make your engine overheat rather than run too cool.
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New does not mean perfect in any sitiuation. There can be flaws in anything new or old. 1 out of 10 brand new spark plugs are bad, and that is sourced from Champion. Dont take anything for granted. Im pretty sure its the same issue i was having in my truck, i was 95% sure the water was getting around the thermostat just couldnt prove it. Try this maybe. Make a block off plate that goes where your T-stat and housing go, start the engine, see if it warms up. If it does. we are right, if it doesnt then there is something else wrong and way over my head lol.