L-Jet TPS is all oily, the bottom of the Throttle Body etc.... Options

[malcolm2]

Taking the TB off to be rebuilt and could not help but notice that the under side is covered with oily dirt. 20,000 miles since I put it all together, but this area has, by far, the worst build up.

The boot seems pretty stiff but no obvious cracks of holes.

1. I assume the oil is coming from the oil tower filler neck. But why would it blow out with air sucking in? 1st thought the stiff boot did not make a good seal and this is my vacuum leak. But again shouldn't it suck in? But the btm clamp screw on the boot was very tight.

2. is this normal?

3. are the "S" boots available new?

[pete000]

Taking the TB off to be rebuilt and could not help but notice that the under side is covered with oily dirt. 20,000 miles since I put it all together, but this area has, by far, the worst build up.

The boot seems pretty stiff but no obvious cracks of holes.

1. I assume the oil is coming from the oil tower filler neck. But why would it blow out with air sucking in? 1st thought the stiff boot did not make a good seal and this is my vacuum leak. But again shouldn't it suck in? But the btm clamp screw on the boot was very tight.

2. is this normal?

3. are the "S" boots available new?

Mine was also oily from years of use. I had it rebuilt.

[Dave_Darling]

The boots have been NLA for years. The good folks at 914rubber might be making them, though.

--DD

[Mikey914]

Got a pic or part #?
Mark

[malcolm2]

Got a pic or part #?
Mark

[malcolm2]

but seriously, do you think I am right?

Oil being sucked in via the tower, and then a leak is letting it blow or drip out when not running. It is the lowest point on the boot.

Any ideas on a better seal, short of an new $80 intake boot?

[Mblizzard]

PCV valve not functioning correctly?

[malcolm2]

PCV valve not functioning correctly?

Where would that be? I don't think i have one. A 1" pipe is in the funnel. That leads to the btm of the intake boot. The funnel tower is open to the case and the intake is open to the pipe.

[Mblizzard]

PCV valve not functioning correctly?

Where would that be? I don't think i have one. A 1" pipe is in the funnel. That leads to the btm of the intake boot. The funnel tower is open to the case and the intake is open to the pipe.

Not sure on the 1.8. But it would seem if you are pulling directly from the case with no filter or valve you would have to be pulling oil out.

[malcolm2]

PCV valve not functioning correctly?

Where would that be? I don't think i have one. A 1" pipe is in the funnel. That leads to the btm of the intake boot. The funnel tower is open to the case and the intake is open to the pipe.

Not sure on the 1.8. But it would seem if you are pulling directly from the case with no filter or valve you would have to be pulling oil out.

Seems to be the design. Pull the oil mist out and burn it.

I assume when the engine is off the mist stops flowing, cools off and settles til the next engine start. In the mean time i believe it had found a way out. I gotta get a better seal between the TB and the intake boot.

[Rob-O]

Are you missing any of the oil seals in the cap? That would allow a steady flow of oil misted air right back into the intake. There are two baskets on the cap. A lower, then a spring that circles the cap and then an upper seal. These are ON the cap. If the lower seal is missing or hardened, it would allow oil pass to the tube that runs to the intake. The upper seal just seals the cap, so oil doesn't get out of the top of the filler.

There are two other gaskets on the oil filler itself. The cork gasket that fits between the engine block and the oil filler housing. There is also a small o-ring that fits between the two pieces of the filler assembly (the oil filler neck and the oil filler housing).

[malcolm2]

Are you missing any of the oil seals in the cap? That would allow a steady flow of oil misted air right back into the intake. There are two baskets on the cap. A lower, then a spring that circles the cap and then an upper seal. These are ON the cap. If the lower seal is missing or hardened, it would allow oil pass to the tube that runs to the intake. The upper seal just seals the cap, so oil doesn't get out of the top of the filler.

There are two other gaskets on the oil filler itself. The cork gasket that fits between the engine block and the oil filler housing. There is also a small o-ring that fits between the two pieces of the filler assembly (the oil filler neck and the oil filler housing).

I didn't think about that, but this issue could also be that TOO MUCH oil is escaping.... I will look at it closer.

Turns out the cap does have 2 seals. Maybe 3. I can't remember if one sits at the very top of the funnel. Mine does not have the spring you mentioned.

Anyway one is and O-Ring, one is flat. I recently tried to get a new flat one. I thought 914Rubber had one, but it turned out to be for the gas cap.

my guess is that the oring seals the upper, larger diameter of the funnel and the flat one rests on the edge of the step from large dia to small.

I did not replace the flat seal at that time. But I did flip it over, you can see an indention were it has been sealing since 1975. They were both pliable, the only damage looked to be the indention and that did not seem to be a failure. The cap is very tuff to turn and once loosened the seal makes it tuff to even pull the rest of the way out.

Now that I think about it. Why have the hose returning to the intake if you are gonna seal the cap so well?

[Rob-O]

I'll have to look at my seals to verify (or you might be able to find a pic through a search here), but I think that the o-ring fits where you have the flat seal and the flat seal goes at the very top of the cap, where it seals against the oil filler tube. So essentially they look flip flopped on yours. Although that would appear to be hard to do because your flat seal looks too small to fit at the top of the cap.

All that being said, to answer your last question. The center area of the cap is where the crankcase pressure is escaping, up through the center of the cap, past where that spring should be, and back to the intake boot. Think of the oil cap as a PCV. But if that spring is missing, instead of breaking up into a mist any air/oil, the oil has a better chance of just moving up the center of the filler tube, through the center of the cap, Past where the spring should be and into the intake. Also, if the lower of the two gaskets is wrong and not sealing, then oil can just run up the filler tube, past that lower gasket and right into the hose that leads to the intake boot. The design isn't that you seal the cap well and then pressure blows by the gasket. The pressure is coming up through the center of the cap and escaping out of the side of the cap where the spring goes.

So essentially would want to make sure you have the spring in place. You also want to make sure you have the proper lower gasket in place (to stop the oil from getting by). You want the top gasket on to help prevent a vacuum leak.

I probably did a poor job of jumbling up that explanation, but I hope some of this helps!

[Rob-O]

Y the way, I found it difficult to find the flat gasket too. Cork gasket and o-ring were easy, but the flat one was unavailable everywhere. Just bought a used one from a member here. All the ones I've seen are red in color.

[malcolm2]

Tuff to tell, but the cap and the bottom seal look a bit different than what I have.

2a is my set up.

2b would be the flat seal... seems to have a ridge on the btm of it.

and the cap does look like it has a spring. But that could just be the same design as mine with the areas to hold the seals.

Is there anyone out there with a late 1.8 that will pull the oil filler cap and take a photo?

2.0 might be the same, I don't know. If your funnel has the built in pipe, that would be the cap I need a picture of.

Thanks

[malcolm2]

Y the way, I found it difficult to find the flat gasket too. Cork gasket and o-ring were easy, but the flat one was unavailable everywhere. Just bought a used one from a member here. All the ones I've seen are red in color.

Probably not much of a market for them, but Mike at 914Rubber said he would take a look at making them. My guess is we can probably find a generic one. Or if he found a generic one, he could offer it up. Save them group from having to search for the proper spec generic flat rubber washer.

[Rob-O]

The 2.0L is just #2. It doesn't use the cap as a PCV. Instead it has vents on the heads and or a PCV like device on the base of the filler neck assembly (#7 in the diagram above).

[malcolm2]

The 2.0L is just #2. It doesn't use the cap as a PCV. Instead it has vents on the heads and or a PCV like device on the base of the filler neck assembly (#7 in the diagram above).

So #7 assembly would be both 1.8 and 2.0? I have never paid attention to what the btm of my filler box looks like. But Blizzard could be right. I sure don't remember a PCV device bolted to the btm.

[Mblizzard]

The 2.0L is just #2. It doesn't use the cap as a PCV. Instead it has vents on the heads and or a PCV like device on the base of the filler neck assembly (#7 in the diagram above).

So #7 assembly would be both 1.8 and 2.0? I have never paid attention to what the btm of my filler box looks like. But Blizzard could be right. I sure don't remember a PCV device bolted to the btm.

I think I have a 1.8 #7 assembly at home. I can check tonight if someone else does not beat me to it. But I seem to remember something being there.

[malcolm2]

The 2.0L is just #2. It doesn't use the cap as a PCV. Instead it has vents on the heads and or a PCV like device on the base of the filler neck assembly (#7 in the diagram above).

So #7 assembly would be both 1.8 and 2.0? I have never paid attention to what the btm of my filler box looks like. But Blizzard could be right. I sure don't remember a PCV device bolted to the btm.

I think I have a 1.8 #7 assembly at home. I can check tonight if someone else does not beat me to it. But I seem to remember something being there.

Mike, That would be great. BTW I am going to the big game Saturday. Looking forward to another BIG WIN! GBO

AA did not bother to clean this one they are selling for $35...


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