YACT: Yup, its that time again!!! Take a look at this lower intake plenum

RGN

Diamond Member
Feb 24, 2000
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Originally posted by: Pepsi90919
looks like it either overheated a bit or the oil wasn't changed often enough.

hmm, could be. I bought the car cheap last year for a winter driver. It made it, but one of the fuel injectors didn't... :) No biggie I guess. Its got 146K on it nad it runs like a top. The oil probally wasn't changed enough.
 

toph99

Diamond Member
Aug 25, 2000
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did the intake manifold blow? you are going to get some oil in the manifold, especially on high mileage cars, through the PCV valve. What kind of car is it? that's one of the funniest looking lower intakes i've seen, especially that seemingly deformed port on the far left.
 

GasX

Lifer
Feb 8, 2001
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Originally posted by: Pepsi90919
looks like it either overheated a bit or the oil wasn't changed often enough.
You sure there was even oil in the engine?

:p

 

toph99

Diamond Member
Aug 25, 2000
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what does changing the oil have to do with what's in the intake? there is no oil flowing through the intake, only underneath in the lifter valley(looks like a pushrod motor by the shape of the valvecovers) and the lifter valley is what the lower plenum covers. i am 90% sure that the oil in the picture is from the PCV system, as to why it's over the surface of the plenum instead of just in the ports is what i don't understand. Are the runners isolated by the mating surface/gasket? now that i look at it it doesn't appear to be so, which explains the oil residue.

now if i'm way off base i'm sure one of the more experienced people will be able to correct me ;)
 

RGN

Diamond Member
Feb 24, 2000
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Originally posted by: toph99
did the intake manifold blow? you are going to get some oil in the manifold, especially on high mileage cars, through the PCV valve. What kind of car is it? that's one of the funniest looking lower intakes i've seen, especially that seemingly deformed port on the far left.

In theory the manifold didn?t ?blow? Although I?m guessing your referring to the gaskets right? I show my dad the pic, and he thought it might be gasket leakage but wasn?t sure. If this dirty/carbon buildup stuff I?m seeing could have been caused by gasket leakage, it won?t be a big deal as I have to replace the gaskets anyway. This is an ?89 Maxima, that really is a good car. It has a solid body because it came from Cali, but it is getting older. :)

And yes Mwilding, as long as I've had it there has been good oil in it. :p
 

RGN

Diamond Member
Feb 24, 2000
6,623
6
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Originally posted by: toph99
what does changing the oil have to do with what's in the intake? there is no oil flowing through the intake, only underneath in the lifter valley(looks like a pushrod motor by the shape of the valvecovers) and the lifter valley is what the lower plenum covers. i am 90% sure that the oil in the picture is from the PCV system, as to why it's over the surface of the plenum instead of just in the ports is what i don't understand. Are the runners isolated by the mating surface/gasket? now that i look at it it doesn't appear to be so, which explains the oil residue.

now if i'm way off base i'm sure one of the more experienced people will be able to correct me ;)

Here is a half pic of the inside of the upper: upper plenum

 

toph99

Diamond Member
Aug 25, 2000
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Originally posted by: RGN
Originally posted by: toph99
did the intake manifold blow? you are going to get some oil in the manifold, especially on high mileage cars, through the PCV valve. What kind of car is it? that's one of the funniest looking lower intakes i've seen, especially that seemingly deformed port on the far left.

In theory the manifold didn?t ?blow? Although I?m guessing your referring to the gaskets right? I show my dad the pic, and he thought it might be gasket leakage but wasn?t sure. If this dirty/carbon buildup stuff I?m seeing could have been caused by gasket leakage, it won?t be a big deal as I have to replace the gaskets anyway. This is an ?89 Maxima, that really is a good car. It has a solid body because it came from Cali, but it is getting older. :)

And yes Mwilding, as long as I've had it there has been good oil in it. :p

yes i meant intake gasket :eek: Am i right that the runners are accessing an open plenum area? The only reason i thought the gasket may have gone was because there was the oil one what i thought to be a mating surface

edit: ok so it is an open plenum. looks fine to me for a 14 year old car with 140k on it. Change your breather filter if you haven't already, that's what caused my friend's tempo to suck up a crapload of oil into his intake(stupidly designed airbox has the inlet for the breakther below the air filter, so it squirts the filter with oil on occasion) and check your PCV valve to make sure it's still good :) besides that i'd say it is fine... but again, someone with more mechanical knowledge than I should be around shortly i'm sure.