I always hesitate to post on these sites because no one ever seems to answer the question posted. Many times I see people call names and argue. I hope that doesn't happen here.

I have a problem that has left me no where to turn so I will explain it here.


First; Hello and thank you for reading my post and I hope someone can solve the mystery of the Mysterious Green Goo Ectoplasm.


Every 1 - 6 months I have to replace my O2 upstream sensor. The reason is some mysterious green goo that fills up the connectors. I have had several mechanics look at it but no one knows what it is and where it comes from. There is about a teaspoon of it. There is no evidence of it on the O2 sensor wires or ANYWHERE else in the engine area. It ONLY appears in the upstream connector. This has been going on for a few years,I have had MANY people look at it. (I carry extra sensors because when it fills up I spray it out with brake cleaner and then blast it with air and let it dry but sometimes the sensor doesn't work after.)


This is bad enough but....


Yesterday I did my usual cleaning and the car ran well for about a block before ir coughed and hacked and lost mobility. I hooked up my analyzer and instead of showing the O2 codes (as usual) it displayed a MAF code.So I disconnected the MAF sensor and the car began to idle well again. I took it around my block and when I pulled into the driveway it started to cough and hack. I thought maybe the Maf sensor had to be replaced. I took off the air filter unit and when I looked at the MAF sensor connector it was full of guess what? Green Goo Ectoplasm! And like the O2 sensor it only appeared in the connector - not the wires and nowhere else ANYWHERE on ANYTHING.


So here's my question:

WTF ?


Does anyone know anything about this or is it really ectoplasm and the car is haunted?

 

Have you tried cleaning the MAF sensor?

 

Welcome to the site, green stuff can collect in electrical connections, perhaps clean with a quality electrical connection then apply a thin film of dielectric grease to keep moisture out.

 

Does it feel like vasoline? It may be dielectric. What O2 codes you getting? Maf?

 

to the forums!

Pictures might help.

What color is your coolant?

 

Thank you for your replies. Here are the answers.

I have cleaned the O2 sensor many times and also had to replace it regularly because the "goo" seems to cause it to fail. I probably cleaned it 8 times this year and replaced it 5 times. The usual codes occur every time the O2 sensor connector fills with the goo. I cleaned the sensor connection yesterday and the car ran well around the block but when I parked in the driveway it began to rough idle so I suspected maybe the MAF wasn't making a good contact. That's when I checked it and found the goo. Yesterday the codes were PO420, PO172. and PO137. (Not uncommon when the goo appears.) Today's codes were PO171 and PO420. I suspect the MAF AND the O2 have burnt out. I replaced the MAF almost 2 years ago. It was the 4th time I changed it during the 15 years I owned the car. There was no goo those times.

The green goo is the problem.
It looks like and has the velocity of coolant but I stopped using green coolant about 5 years ago when the "goo" began. (A mechanic suggested I do this to see if the goo would turn to orange. ) And it is NOT oxidation.
I have had many people go over the engine compartment and no one found any trace of the "goo" anywhere else. No sign of any capillary action on any part of the harness. No leaks anywhere.It only appears INSIDE the O2 sensor connection. It builds up at no particular rate and It will blot an entire half of a paper towel. (It will actually "spill" out of the connector when opened.)
Now it has appeared INSIDE the connector of the MAF.

It has been suggested ta few times to use grease to prevent the goo from making contact with the connector pins. This time I will try it.

How does it only fill up the O2 sensor which is BEHIND the engine and the MAF which is in front and under the air filter/engine shroud?

I brought the issue to this forum because I'm sure this group would LOVE to solve this mystery.

 

H

Here is a picture under the engine shroud of the MAF connector.The green fluid "spilled" out when I removed the harness connection. Most of it spilled into my hand as I was disconnecting it.You can see everything is dry elsewhere. The other picture shows how dry the engine is overall. If you look where the O2 sensor is you will see zipties. I (and mechanics) have tied up the O2 harness and connector every way possible to prevent it being "splashed" on. But it always fills up and there is never any sign of the goo anywhere else. Besides the goo just appearing, its bizarre that it would only appear in these two isolated places. When I replace these two sensors and the car runs again....because it will.....I will take pics of the green goo at the O2 connector.as it fills up again.... because it will.

 

P0420 is the #2 o2 sensor saying that the cat is not doing its job.
That green goo looks like the wrong kind of anti-freeze. The right kind is Dex-cool which is orange.O2 sensors have a hole through them.
Have you ever checked the coolant level under the pressure cap?

 

Any chance you paid someone to flush out the green coolant and refill with orange, but they used the green again anyway?

You stopped using the green coolant 5 years ago. The coolant is good for 5 years, it's time for another drain and refill.

 

Hello;
Thanks for your latest replies.

The coolant was replaced 5 years ago with orange Dex-Cool coolant and then again about 2 years ago. I did this myself. There is no green antifreeze in the engine.
The PO420 code always comes on when the green goo builds up and goes off once it is cleaned or the O2 sensor is replaced. There is never a problem with the downstream O2 sensor even though the connectors are right near the upstream one.
The antifreeze is always at the same level, the entire engine compartment is completely dry There's absolutely no evidence of a leak anywhere on the car.