Hi all,

I was doing some work on the car and I noticed what looked like "gunk" behind the throttle body area on the intake tubes.

It looks sort of like road filth similar to what you'd see if you had oil sweating. I inspected it with the ol' Customs finger swipe but I couldn't smell any gas or oil smell.... I decided to pass on the taste test.

Any ideas what would be causing this? I'm due to clean the throttle body anyways.


Cheers
Aaron

 

The throttle body/butterfly needs to be cleaned occasionally. It's normal. If there's excessive oil, then it could be a bad Air/Oil Separator. After cleaning, you will notice a better idle at startup.

 

Ya, the AOS is my hypothesis as well. Luckily there is a DIY write-up out there and besides the general frustration it doesn't seem like that bad of a job.

Cheers
Aaron

 

if it was the AOS... you would be spewing black smoke!!

i doubt it.... mine was BLACK and full of crap when i took it apart to clean it!

BTW it would have been an awesome opportunity to due the AOS when our tranny was out....thats when i did mine....

 

It could be an early indication. I don't see how there can be a road grime/oil build up on the bottom of the intake ports/runners any other way than the AOS though... I'll clean the area and see if it returns.

There have been three or four upgrades done on the AOS since my production date and the life seems to be 30-50k miles on them.

Well could have been if there was a motor drop as part of the procedure. Otherwise you can get to the bolts from the rear wheel well and the difficult part is just wiggling it up through the engine bay other wise.

Cheers
Aaron

 

Clean it and see how soon the gunk returns. You're right, it may be an early indication. Or, it could just be normal accumulation that requires some periodic cleaning.

When I had idling issues at startup, I did some research and ended up cleaning the throttle body/butterfly, the result was amazing. But it didn't take long for the symptom to return, and I was cleaning the damn thing pretty regularly, and the oil accumulation got heavier over time. Eventually, I had to replace the AOS, case closed.

Oh, btw...you don't get Black smoke with the AOS. It's more like a blueish/whitish color.

 

your right... blue / white would be correct... but not too white because then its coolant!!

 

I'll keep a watch on it and if it looks to get worse, either exhaust color, oil accumulation, or TB cleaning issues I'll do the replacement.

It's not what I want to do on a weekend, but I will if it needs to...

Cheers
Aaron