Diagnosing Coolant Smells and Leaks Coming From Your Car SUV or Truck

Okay, friends. We got the vehicle inside the shop, we got it on the lift so it's gonna be ready to go. Let's get under the hood so we can take a peek of what's going on. We're gonna make our way right over here, just give this a feel, make sure it's not super hot, okay? If it's not super hot and you're wearing hand protection and eye protection, you can go ahead and press this like this to relieve pressure. That looks good. Hey, friends. While I've got your attention, make sure you leave a comment, like, subscribe, ring that bell. Let's get back to what you came here to see.

Something that's always great to do is to check your freeze point on your coolant and you can do that with something like this. This is called a refractometer and it's just gonna measure the amount of ethylene glycol in the coolant to make sure that it won't freeze up when it gets a little chilly outside. So go ahead and take a look. If you look at that, you can see a little gauge and it's gonna say ethylene glycol over on the right-hand side. You want to be just below the negative 40. If you can get it to negative 32, negative 34, you're doing all right. If it's just sitting at the zero or anything worse than that, well, you need to flush out that system.

Let's just take a little sample. This is very low, it doesn't look very good already. Close this up, let's take a look. Here, take a look at that. The test for a coolant leak it's always great to have a tool that looks like. This is a pressure tester, it's gonna go right on here. Let's twist that on, make sure it's locked. That feels great.

Now we're gonna pump this up. You want to get it well over that 15, maybe even almost to the 20. Once you get it to that point, just let it sit hang out. I'm just gonna go right to that 19. Now we'll let it sit just like that and we're gonna watch for the gauge to drop. So we let this sit for a good 15 to 20 minutes and as you can tell, it really hasn't gone down very much. The only problem is we're still low on coolant, so we got to figure out where it's going. Let's get this off here.

Now it's time to check and test the cap. Take a quick peek at it and make sure that the rubber isn't torn or worn. This one does look like it's a little worn right here, it seems like it's been around for a while. Something that's important to pay attention to is right on the cap, and you can see where it's gonna relieve pressure. This one relieves at 18 pounds of pressure. So if we use this tool, it should hold pressure all the way up to 18 pounds, if it doesn't the cap is no good.

We've got a little tester on here, just an adapter to make this onto this. Nice. It should go right up to 18 and stay. So it looks like this cap holds no pressure. It should go right up to that 18 and stay right there. If I did go above it, it would go, you know, 20 and then it would drop down to the 18 and it should stop at approximately 18. It needs a cap. There are other places where coolant can escape from on vehicles, sometimes it'll be like a radiator hose where it connects on to maybe the radiator or the engine. It could leak right at the radiator, there's lots of seams along that radiator that could leak. Water pumps, water pumps go bad, they have a little weep hole and they'll let you know when they're leaking for sure.

There are some other areas maybe like a head gasket or an intake, that's very bad. Obviously, that's the worst that you can probably get. But something as simple as a radiator, that's an easy replacement. Coolant hoses, those are all pretty easy. Those are a couple of places, now let's have a look. If you look right along here, you can see your upper radiator hose. This comes right over here to where your thermostat's gonna be, okay? It can leak right along here and, of course, where the thermostat mounts onto here.

Also, you'll have your radiator which is very hard to see in this particular application because it's behind this cooling fan and all this crud. But generally speaking, you'll be able to smell it and you'll be able to see a drip. If you follow this hose along, you can see your heater core hoses. Sometimes you'll get a leak, you'll see it dripping right down along that firewall. Just visually follow those hoses around and check to see where they fit onto things and make sure there's no leaks on those as well.

All right, let's bring it up and check what's underneath. The water pumps right up here, it's a little hard to see. But if you see any fluid coming down, more than likely that's the issue. Right over here is where your lower hose connects onto the water pump. If you see any moisture coming down there, that could be the possible issue. We'll just follow that hose, it comes along over here to the radiator. That looks nice and dry as well. You can see the radiator right inside here, just keep following this and looking for moisture. Well, here we go. We got a little moisture on this side, look at that.

This right here is known as a petcock and that's also the drain for your cooling system. You would turn this to loosen it and coolant will come out of this. This one looks like it's in rough shape. If your petcock is doing this, you need to replace your whole radiator. If you look at the back of your vehicle, you can see your exhaust tailpipe. You'd want to pay attention to this, have somebody start up the vehicle and watch for any type of smoke. You probably see some white smoke billowing out, that would be a sure indication you have a bad head gasket.

All right. So, we finished testing our cooling system, we found that the radiator cap was no good, it wasn't holding any pressure. And at first, we seemed like we were holding pressure right here because it held for about 15-20 minutes and really didn't drop very much. But we figured we'd take a look. We've tested all those hot spots. We looked at all the hose ends, we looked at the firewall. We went underneath and we did end up finding the leak at that petcock. It was a very slight leak, just a little seep. Something like that's gonna cause the coolant to go low and it's also gonna cause running issues and maybe even overheating. So you want to make sure you get that fixed, get yourself a new radiator cap. If it doesn't hold and it looks like this, take it for a road test.

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