Oil residue on inlet manifold
Oil residue on inlet manifold
Author
Discussion

lightweight73

Original Poster:

37 posts

106 months

Saturday 5th September 2020
quotequote all
The right-hand inlet manifold of my 94 xj12 seems to have a lot of oil residue on it.
Can anyone tell me where I should start looking?
Also do you think this level of impact damage will prevent the gasket from forming a good deal? I can only assume the ass hat that did other 'repairs' did it trying to fix the emission issues I am now looking at.

GreenV8S

31,025 posts

314 months

Sunday 6th September 2020
quotequote all
lightweight73 said:
Can anyone tell me where I should start looking?
I would look for confirmation that it was coming through the PCV system and then look for reasons for that.

lightweight73

Original Poster:

37 posts

106 months

Sunday 6th September 2020
quotequote all
I have cleaned the pcv filter and system so that could be the cause but it is on the left manifold and that one was cleaner than the right side.

GreenV8S

31,025 posts

314 months

Sunday 6th September 2020
quotequote all
Are you saying that the PCV system does not feed into the intake side that is dirty?

lightweight73

Original Poster:

37 posts

106 months

Sunday 6th September 2020
quotequote all
GreenV8S said:
Are you saying that the PCV system does not feed into the intake side that is dirty?
Correct, the pcv feeds the left bank. It was dirty but not as much as the right. It has been a while since I stripped down the left bank so maybe it was worse than I remember. I guess the other option is that more collected in the right manifold as it is the 'end if the line' for balanced air between the 2 sides. The right side did have a slightly collapsing airbox intake pipe so pressure from the filtered air could have been higher in the left side forcing more oily air to the right bank.

GreenV8S

31,025 posts

314 months

Sunday 6th September 2020
quotequote all
I guess that's possible.

Regarding the gasket surface, when you ding a surface like that it usually leaves a raised area around the dent. You will need to stone off any raised areas or burrs for the two surfaces to mate properly. The dent itself won't be a problem.

lightweight73

Original Poster:

37 posts

106 months

Sunday 6th September 2020
quotequote all
GreenV8S said:
I guess that's possible.

Regarding the gasket surface, when you ding a surface like that it usually leaves a raised area around the dent. You will need to stone off any raised areas or burrs for the two surfaces to mate properly. The dent itself won't be a problem.
Thanks, I will clean it up as well as I can.