Leak coming from EGR valve during smoke test.

[Addicted]

Hello, I have a 1999 mercury mountaineer SOHC 4.0 V6 AWD which I was testing for any vacuum leaks using a smoke machine.

I noticed smoke leaking out of the bottom side of the EGR valve. There are holes or vents on the bottom side of the EGR were I see smoke coming out of.

This is all being done with the engine off. Is this normal or is my EGR bad and should be replaced?

 

[donalds]

They leak very little until they get vacuum And up to operating temperature
If its pouring out smoke .....like more than a lit cigarette ..... Then it has a torn diaphragm replace it

 

[Addicted]

The engine was not operating. Should I smoke test with the engine running?

And if the engine is running, no smoke should leak from the EGR valve during smoke test?


It wasn't a small leak, it seemed like a good amount was coming out from those holes underneath the EGR valve.

Also, the engine has 176k miles on it. This is the original EGR valve.

 

[donalds]

The engine was not operating. Should I smoke test with the engine running?

And if the engine is running, no smoke should leak from the EGR valve during smoke test?


It wasn't a small leak, it seemed like a good amount was coming out from those holes underneath the EGR valve.

Also, the engine has 176k miles on it. This is the original EGR valve.

You can't test it with the engine running lol

Replace it and re smoke test

 

[Addicted]

Thanks. I misunderstood what you were saying when you mentioned this.

They leak very little until they get vacuum And up to operating temperature

Thought you were saying to bring the engine to operating temperate to make sure it doesn't leak smoke anymore.


Nonetheless, I went ahead and purchased a new motorcraft EGR from Rockauto. Should have this on hand soon.

Before posting here I was looking at some other online forums were some of the members mentioned if you see smoke it should be replaced whereas other members were saying it was normal.

It was becoming a little confusing.

 

[donalds]

I'm happy you got it all figured out