Radiator outlet switch leak

[Mtnman]

I have a slight leak in my cooling system. It is at the radiator outlet switch, which is located on the lower radiator hose. If you are leaning over the front of the car, looking into the engine bay, it is directly below you, to the left of the radiator, right above the plastic liner/guard. It is seeping. not much, but a little. If i press on the connection, it weeps a little more. has anyone had this issue? I ask only because if i remove the switch, it is going to start leaking coolant. Id like to know what im getting into before i remove the switch. Maybe there is a seal ring that is bad? Anyone seen this before?

[telijah]

Thats the coolant temp sensor, and yes, there is a little o-ring that is a known source for leaks. I think BMW did not sell it by itself, but many have found replacements for less than a buck at places like Lowes/Home Depot, but it was a specific color, and I cannot remember which. I am sure someone else will chime in with the right color.

[Newjack]

I think Dane said he got some at Lowe's. This thread is relevant to your interests.

[danewilson77]

[BCS_ZHP]

That was the source of my leakafter I did the coolant refresh, the coolant temp sensor, I tried to reuse the old sensor. It listed at $42 from the dealer, he sold it to me for $25 something (frequent customer discount, and E46 enthusiast parts guy). When looking at the old vs. new, you could tell the difference in diameter of the o-ring (which is green in color) and it was no wonder it was leaking.

And as long as you leave the expansion tank cap on when you pull this sensor, you won't lose much coolant, just a little. However, if you open the cap though, you change the pressure and it will pour out.

[JohnnyGraphic]

One other thing, until you get it replaced, don't wiggle the connector. I made that mistake. Made it worse! Then, thanks to Dane(Thanks bud!), I replaced the O-ring and no more drips.

Johnny

[danewilson77]

One other thing, until you get it replaced, don't wiggle the connector. I made that mistake. Made it worse! Then, thanks to Dane(Thanks bud!), I replaced the O-ring and no more drips.

Johnny

My pleasure. Those orings come on handy and work swell.

HTC Thunderbolt+TT

[shanneba]

ECS sells the BMW o-ring, 8mmX3mm from the Intake Air Temp sensor, it also fits the coolant outlet sensor- 96 cents today-

http://www.ecstuning.com/BMW-E46-330...43299/ES34373/

Other vendors should also be able to get these.

[Mtnman]

One other thing, until you get it replaced, don't wiggle the connector. I made that mistake. Made it worse! Then, thanks to Dane(Thanks bud!), I replaced the O-ring and no more drips.

Johnny

Ummm, yeah.....oops. Could have used that advise a few days ago. Ill be going to lowes for some o-rings this weekend. Thanks to all for the follow up

[danewilson77]

ECS sells the BMW o-ring, 8mmX3mm from the Intake Air Temp sensor, it also fits the coolant outlet sensor- 96 cents today-

http://www.ecstuning.com/BMW-E46-330...43299/ES34373/

Other vendors should also be able to get these.

Great info.......thanks