Need a DIY for replacing the oil fill tube

[Dale_K]

I've been searching around for a vacuum leak after I got a CEL with the 1126 code and I'm almost positive it's coming from the middle of the oil fill tube under the center section of the intake system. I can hear some hissing at idle and when I press down gently on the exposed part of the oil fill tube as it disappears under the intake the hissing sound gets louder and the motor starts running rough.

So if there's a DIY someplace with a bunch of pictures I could sure use the help.

[Jared at Pelican Parts]

What year? Boxster or Boxster S?

[harryrcb]

Originally Posted by Dale_K

I've been searching around for a vacuum leak after I got a CEL with the 1126 code and I'm almost positive it's coming from the middle of the oil fill tube under the center section of the intake system. I can hear some hissing at idle and when I press down gently on the exposed part of the oil fill tube as it disappears under the intake the hissing sound gets louder and the motor starts running rough.

So if there's a DIY someplace with a bunch of pictures I could sure use the help.

there are a couple of vacuum lines that run either over or under the oil refill tube that connect on the bottom of the rubber connector (which get brittle with old age) of the front intake manifold. Sound like you might be tugging on that tube and that would certainly make the engine run rough. Look for it it's a small tube

[Wayne at Pelican Parts]

See the coolant tank replacement article for information on disconnecting the oil filler pipe: Pelican Technical Article: Boxster Coolant Tank Replacement - 986 / 987

And then see Figure 13 of this article: Pelican Technical Article: Boxster Engine Conversion Project - 986 Boxster (1997-04) - 987 Boxster (2005-08)

-Wayne

[Wayne at Pelican Parts]

Originally Posted by Dale_K

I can hear some hissing at idle and when I press down gently on the exposed part of the oil fill tube as it disappears under the intake the hissing sound gets louder and the motor starts running rough.

You can also check by removing your oil filler cap in the rear trunk. If you remove the cap and there is no or little change in the running of the engine, then you have a leak in the tube (most likely).

-Wayne

[Dale_K]

The car is a 2000 S Tip. I've already done the AOS oil cap test and that seems OK. And thanks Harry, for the tip about a vacuum line. I should probably hold off simply ordering a new oil fill tube until I can see the actual problem. I'm thinking about taking the car to the independent shop in Little Rock instead of attempting to fix it myself. The accessibility looks pretty tight in there and I'm worried I'll mess up the job.

[BerneseMtnDog]

It's probably a good idea to have it looked over before ordering parts. I thought mine was split but it ended up that the joint where the two pipes meet in the middle was leaking. I replaced the spring clamp with a worm gear type and that fixed the problem.

Steve
2000 2.7L

[Dale_K]

Originally Posted by BerneseMtnDog

It's probably a good idea to have it looked over before ordering parts. I thought mine was split but it ended up that the joint where the two pipes meet in the middle was leaking. I replaced the spring clamp with a worm gear type and that fixed the problem.

Steve
2000 2.7L

How did you access this area? Is it necessary to remove the entire intake manifold system or can you get to the tube if you take out the throttle body and the middle couplings between the manifold halves?

[BerneseMtnDog]

On my car I thought I had a split in the flexible accordion area in the spot between the middle joint and the trunk bulkhead. I replaced that part only to see seepage at the middle joint. After replacing the clamp with a worm drive type all is good. The middle joint area is right on top of the engine and doesn't require removing anything but the engine cover. The section that goes to the trunk is fiddly to get at but you can also do it without removing anything. The section that goes from the middle joint to the engine I'm not sure about. Mine is still the original part. The main thing that's tricky is getting those dang spring clamps off.

Steve

[Dale_K]

I got the car back from the shop yesterday. They had some trouble finding the intake leak. They could hear something when they moved the rear (accessible) section of the tube by hand and it sounded like under the center of the engine but they said the leak actually came from the accordian section near the rear firewall. They showed me the old tube and there was deterioration but I'm not totally convinced that was the only problem based on how distinctly the sound seemed to come from another spot. No codes so far and the car runs fine so they could be right. The bill was a little over $300, which I'm happy to pay if it fixes it.