Car Heat Not Working Engine Overheating How to Diagnose Cooling System

So on this 03 Element, we have no heat inside, let's diagnose it. So let's talk about first couple of steps to go through real easy. Make sure the engine is cold, and check your coolant level. Even though your overflow tank on the side here might show some in it, I'm a true believer, if you have a problem, let's go right to the source. So let's take that radiator cap off and you want to make sure you have coolant in it. Well, I've already done that. And I've run it so now you want to run it. Once you've confirmed you have coolant, it's not low on coolant, put the cap back on and run it. I ran this thing for 45 minutes and I checked my upper radiator hose and lower radiator hose for heat and the gauge inside, that's the nice thing about an Element it actually gives you a gauge, the gauge goes right to where it should be right in the middle, the fans come on.

So run it till the fans come on, feel the upper hose, carefully feel it and grab it right up here. And you'll feel that you'll be like whoa, that's hot. If you don't actually have a temperature gauge that you can aim and check your temperatures. And then the one down below, the lower radiator hose. Well, I can get it right here. So you can also check it with one of these and aim it. This one actually has a red light on it, so it tells you right what you're hitting. It'll give you the temperature. And the same with the lower hose make sure you're aimed right at it, and the distance does matter. So I know for a fact because I've already done this, my temperatures are variance in like five degrees, that's nothing major.

But now I've got back here I have my heater hoses that go into the heater core, which supplies the heat to the cab. So you could check it real quick like this with your temp gauge on both sides of this heater valve see that right there. That's a heater control valve. This one's operated with a cable. And then you have the return right here. So goes in the heater core, and comes back out And goes into the engine. Well, these are ice cold, both sides, this one and this one, are ice cold after running for 45 minutes. There's a lot of problems out there with the actuator inside the blend door actuator, the outside inside recycling air door, that doesn't tell me why I don't have heat in there because those hoses should be hot. And then the heat would stop going in there because they wouldn't allow it.

So when this got real hot, like I said, all the hoses up there going to the heater core, all of them were cold. So I followed them down into the block and it goes behind the intake to the back of the water pump and the steel tube that comes out of the water pump, the rubber hose connects to it and goes up to that valve that heater control valve. And it was ice cold at the water pump. So first I was like whoa, does this water pump not working. And that was in the process while it was heating up. Then the fans came on, I check my gauge out my gauge was perfect right in the middle. So that would kind of tell me that the water pump is circulating. We're not having problems driving down the road and the car overheating. So that water pump is probably doing its job. So the way I figure is that this engines get nice and hot, hot upper, hot lower radiator hose, water pumps probably hot, it's just spinning. Back of it is cold but that's because this valve has not opened up to circulate the hot water or coolant should I say, the hot coolant. So we know the cable moves so the inside door actuator is moving, you can actually hear it when you're inside. I'm going to take the cable off, I'm going to physically move that butterfly with it hot and see if it changes. I don't think it's going to. Okay, so now I have easier access to everything. So I'm going to pinch both my hoses off so I can have least amount of spillage.

I'm going to take that heater control valve right out. So the good news is now that we have our heater control valve out, seems to be working right but the bad news is, is that looks like someone used stop leak on the system. So if you open and close it see how the valve works so it's not broken inside. I have seen that, this is working perfectly fine. What this tells me that this is working. That tells me that that heater core could be clogged. So I'm going to flush it out and see if we get heat. Well look what we found. Yeah, that's it, heater core is clogged. That is what we call stop leak. For me, it was one of the worst things they've ever invented. The only reason to ever use that is if you're stuck in the Sahara desert And you really want to get home. Other than that you just create bigger bills for yourself and more headache.

So I flush the system, put a bucket underneath there and three times until I got clear fluid, till I get meaning water, clear water and I did forward and reverse both inlet and outlet. I just kept flowing the water through and I got it all clear. So now I'm going to reassemble it, put the hoses and then heat the control valve. Now of course, you're going to want to flush your whole system, drain it, and flush the radiator, and everything. And if it's a used car or you don't have any reason or knowledge of why this stop leak is in there. If it's a used vehicle, you better hope that you're not going to find that the head gasket's been leaking. Always try to put the harnesses back to where you found them so that they don't hit exhaust and melt hoses go into brackets that are designed for them.

And we are ready to load this up with a coolant and start her up. So here we have a very inexpensive coolant filler device comes with a whole bunch of attachments, it's really inexpensive. If you don't have one, I strongly recommend it. So fill it up and now it's a burping funnel. So now I'm going to start her up, watch the coolant go down, leave it there until the fans come on. And air bubbles will come through and you know that you won't have any problems in the future.

So let's wrap up this no heat diagnostic. What I ended up finding was a clogged heater core due to what looks like someone put stop leak in the system. So I flushed the whole system out, flushed the heater core out by itself and put it all back together. I pre-diagnosed that heater control valve to make sure that wasn't broken. I went under the dash and looked at the heat actuator that opens the hot and cold door. They're known for that but this vehicle was working. So I moved forward took the system apart. That's when I found the clogged heater core. Flushed the system, flushed the core. I got some heat nothing great. So the next move is, replace the radiator and then possibly the water pump. Yeah, let's hope there's no head gasket problem with this one. So hopefully this video helped you out if you liked it subscribe if you're not already, thank you. Don't forget to ring that bell that turns on all your notifications and then you won't miss any more of my videos.