I've got my '02 S-type 3.0L V6 intake torn down. The car is going on 94K miles. I have been getting some P0420 (and a single P0305) codes. So I decided to replace the spark plugs and coil packs. The coil packs were all original '01-'02 production based on the label codes (with the exception of one that looked to have been replaced with some cheap no-name.

I bought the car back in Dec. '08. So I am not too certain what all it has been through.

I took the upper intake manifold (plenum) off to get to the left side (Back 1) coils and plugs. I want to change out the PCV valve while I was in there. So I took the lower intake out to get to and replaced the PCV valve.

Someone had been in there before me. Both the top and the lower gaskets had some silver RTV gasket material on them along with the normal gaskets...

QUESTION: Is it suggested to use the RTV material with these gaskets??? If so, which is suggested? There are is a blue RTV that is made so it "will not foul O2 sensors". It seems like that would be a reasonable one. But is the RTV suggested/needed?

Thanks.
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BugDoc, the intake seals DO NOT!!!! require use of RTV. They will seal just fine on their own. So, clean up the surfaces, get all the old RTV off and reassemble the motor.

I hate to say it, but it sounds like the guy that was in there before you didn't know what he was doing. Hopefully he knew that and you are finding the only work he did to the vehicle.

 

Sounds more and more like bad DIY or the like before you got in there. The PCV valve may be OK - it's the elbow that tends to age badly. I've never seen one so am just repeating what others have written previously.

 

Might have been a DIY or a mechanic that knew that this plenum is notorius for air leaks. Not certain which.

The PCV valve was pretty oil clogged. I changed it out with a new one. At some point I will do a write-up with part numbers and photos and such. I am trying to take pics as I go but the hands are getting pretty greasy and pics require frequent glove changes...

The elbow, much to my surprise, looked brand new. It may be why they went in when they did. Not certain. The elbow is a bear to get off AND to get back on again. The PCV valve was not too easy either. If I had not had a pair of long needle nosed pliers, I am pretty certain I would not have gotten it out in one piece.

Hopefully I will get it all put back together correctly so the next to dig in here will not come along and say "What a hack! This guy did not know what he was doing!"

Back to the work shop!
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