Coolant Leak - Crossover Tube or Heater Core

[604-Allstar]

Hi,

I recently discovered that my passenger foot well was soaking wet. I tried to soak up as much of the liquid as I could, but it didn't show any tint of yellow/green. The car does have afaint smell of coolant though. I checked the coolant level, which was low, so topped it up. The next day i came back to the car and there was a small pool of coolant under the car which had dripped from the back of the engine bay. After some searching on this forum it appears I might have a blocked heater core or a cross over tube leak...

As neither job looks very fun to do, I want to make sure that i'm tackling the correct issue.

Couple questions
1. Will a leaking crossover tube cause the passenger foot well to be soaked?

2. Can a blocked heater core cause a coolant leak on the ground?

3. If I do a pressure test on the cooling system will that help pinpoint the problem or will both cause the same results?

Thanks for any help

[baja98]

Anytime i have found water/coolant on the passenger side foot well area its always been a bad heater core. Recently I had my coolant tube replaced in the back of the engine when it sprung a leak, that leak did not travel into the vehicle.

[604-Allstar]

Anytime i have found water/coolant on the passenger side foot well area its always been a bad heater core. Recently I had my coolant tube replaced in the back of the engine when it sprung a leak, that leak did not travel into the vehicle.

Do you know if a bad heater core could cause coolant to leak on the ground beneath the vehicle?

[604-Allstar]

So I believe my cross over tube is the culprit of the leak. Last night on the way home after a long drive on the highway my car started to over heat. When the car was moving the temp gauge would drop but as soon as I came to a stop the temp would spike. I had to pull over for 30-45 mins and wait for the car to cool down and then when i got home I put in almost 3.5L of coolant. I could see steam coming up right where the cross over tube is.

Fingers crossed the heater core isn't gone too...

[baja98]

Sounds like a bad thermostat. Our engines are different but I do believe yours has one in the cross over tube that maybe called a water control valve. Google or search here for that.

[JPK Omaha]

I had a leaky crossover tube earlier this year on my 03 Qx4, about 147k miles. I had the Nissan dealer fix it for about $1250. They had to drop the transmission to get at it.

I did not notice leaking in the interior footwell, or overheating. I just know there was a steady drip drip drip from the rear of the engine area onto my garage floor after I drove it.

[604-Allstar]

I had a leaky crossover tube earlier this year on my 03 Qx4, about 147k miles. I had the Nissan dealer fix it for about $1250. They had to drop the transmission to get at it.

I did not notice leaking in the interior footwell, or overheating. I just know there was a steady drip drip drip from the rear of the engine area onto my garage floor after I drove it.

Thanks, I have a feeling i might have two issues. I think I will tackle the heater core myself but the crossover tube seems like a real pain to fix.

[yeldogt]

I don't see how the crossover pipe could cause your leak inside the car. It sounds like two issues if you are sure of the crossover leaking. Also, some coolant may be able to leak out of the HVAC box through the drain for the AC evaporator -- have never checked the location of the components to see ... but if it can that could be your coolant leak to the outside. That should be easy to check.

[604-Allstar]

So I was able to do a pressure test the other day and when I did that I found the source of my leak... Coolant was pouring out of the freeze plug hole.

Has anyone had a leaking freeze plug before? I really don't think that's a job i'm going to be able to tackle by the looks of it.