Zoenation87

Hello guys i have a 06 ml500 I’m having issues with. Recently my vehicle started forcing radiator fluid out the hose. Its lime it cannot hold the fluid in the line. I took the hose off and checked it, not dry rotted or anything. I put on the obd scanner and got a p0121 after some research I figured it was the tps. I really need some help it’s beginning to get pricey buying fluid every 3rd day. And for now its me and my family of 4 only transportation.

peter2772000

Which hose? I'm guessing the overflow from the expansion tank...

Zoenation87

It connects directly to the radiator

peter2772000

Sounds like you're over-pressure. Which is weird. Do you get a high-temp warning or does your gauge show higher than normal temps?

Zoenation87

No thats the weird part its not over heating or giving any warning i ran my icarsoft obd scanner on it and got a couple of codes but nothing as far as the coolant system. I was thinking could it be because i beed a new pedal position sensor, thats causing this. Or could it just need a new hose

Zuffen

Are you sure there isn't a small crack in the radiator tank just above where the hose couples.

Looking at the photo you supplied there is a sharp line of blue just above the hose.

If it leaks there under pressure it will blow back in the slipstream and cover the hose as shown.

If it were mine I wouldn't be driving it until I'd sorted it as an engine rebuild or blown head gasket/s isn't something I would enjoy.

Zoenation87

Its coming from the upper hose that connects to the radiator. It seems as if its dripping from where the hose meets the radiator,and the fan is blowing it

DanD.

Here is a good test. Helps find hidden leaks.

Zoenation87

Thanks I know where the leak is located. What im trying to figure out is why. Let me show you a picture its the upper radiator hose,where it connects to the radiator

DanD.

With all respect, this picture shows the result of the leak, fan blow over it, its dry.
I would start from finding exact place or just replace the tube and be done with it.

P.S. im not a mechanic just trying to help.

Zoenation87

No, thank you I really appreciate the advice I’ve located the leak,and will be buying a new hose Friday.

DanD.

As an idea, if hose is leaking potentially coolant expansion tank cup might not release pressure.
And test above will tell if cup is doing the work or not.

Zoenation87

Im definitely heading to my local Autozone to see if i can rent the tool