Non sensor safe......oops

fivemustangs · Aug 6, 2009

I pulled my header off because there was a small leak coming off the head. I replaced the gasket and also added a little red RTV silicone to help seal it better. When I put it back togeather I noticed the silicone was Non-sensor safe, I have not started the car yet and was wondering if this was going to mess up my O2 sensor or not when it is fully dried?

BlownFiveLiter · Aug 6, 2009

Probably not. I bet it means non-sensor safe, in a sensor such as a coolant temp sensor, not so much as one that's going to be exposed to extremely hot gases that would burn off any residue left by the RTV. I'd be more concerned with the RTV actually causing the gasket to leak. Is it the copper stuff that you used?

fivemustangs · Aug 6, 2009

It was the High Temp red rtv silicone from napa, I just used a little around both sides of the gasket to help seal, I didn't think it would be that big of a problem because I thought they make paper header gaskets? The silicone said it was good for up to about 650 degrees and wouldn't blow through.

GTA_V6_Mustang · Aug 6, 2009

You are probably going to have issues with the o2 sensors. What happens with non sensor safe rtv is that the vapors it gives off crystalize on your o2 sensor pretty much blocking it from reading.

turbogt · Aug 6, 2009

GTA_V6_Mustang said:
You are probably going to have issues with the o2 sensors. What happens with non sensor safe rtv is that the vapors it gives off crystalize on your o2 sensor pretty much blocking it from reading.

I highly doubt this...

maybe if he used it on the O2 sensor, but not from the header flange..

True 5.0 · Aug 6, 2009

fivemustangs said:
I thought they make paper header gaskets? The silicone said it was good for up to about 650 degrees and wouldn't blow through.

I do believe the gaskets are not paper but a ceramic material. Paper burns at 451 F and the exhaust temp is much hotter than that. The headers can actually glow orange especially during high RPM runs. I think the RTV will be toast in short order.

FWIW-

The ceramic header gaskets are notorious leakers due to shrinkage. I have had amazing luck using gaskets from Earl's Performance. They are made using an aluminum frame with soft graphite gasket material around the exhaust ports.

fivemustangs · Aug 6, 2009

The reason I put the gasket sealer on was because I beleave my headers (Long tubes) are from a fox body. They seem to leak on the drivers side under the exhaust ports on the heads between the header and the head. So I thought that a little silicone might fix it up. But I guess I will find out, The O2 sensors are old anyways and should be replaced soon so I guess I will run with it and see what happens, I will keep everyone posted, eather when the gasket burns out, O2 sensor stops working or if it works for a good while. Thanks!

fivemustangs · Sep 2, 2009

Been driving for a few weeks and it seems to still be doing fine, still getting sensor reading and the leak is still sealed. I would say good to go!

Non sensor safe......oops

fivemustangs

Member

BlownFiveLiter

have car, will race....wait, it doesn't run

fivemustangs

Member

GTA_V6_Mustang

Active Member

turbogt

Member

True 5.0

Member

fivemustangs

Member

fivemustangs

Member

Similar threads

Non sensor safe......oops

Member

have car, will race....wait, it doesn't run

Member

Active Member

Member

Member

Member

Member

Similar threads

Privacy & Transparency

Privacy & Transparency