924Board.org

[blokhus]

hello,
I hope someone here can advise me.
My Porsche 924 /1976 is leaking oil from the dipstick hole. As soon as I start the motor up, oli comes up through the dipstick hole
I have checked the oil level that is ok. I have checked the tube that goes back to the air filterbox and steam comes out of it when the motor runs. When I take of the oil cap, the leak stops.
Any idea?

[ideola]

Not 100% certain, but it sounds like you may have a blockage starting to form in the breather attachment on the side of the block. When you remove the oil filler cap, it relieves the crank case pressure. Not an easy job with the engine in situ, but if the breather port is blocked you remove the line that goes to breather attachment on the block, and try flushing it out with some type of cleaner. Before you restart the car, you will want to change your oil.
_________________
erstwhile owner of just about every 924 variant ever made

[blokhus]

Thanks.
So what you suggest is the drain out the oil first.
Then find the breather attachment and clean it. How and where do I locate the Breather attachment.( I guess I just follow the tube that goes to the air filterbox ) Can I reach breather through the motor compartment or from under the car?
When I am at it, what type of motor oil would you suggest?

[blokhus]

How dos the breather looks like? any pictures? so I know what I am looking for.

[leadfoot]

below the coolant transfer pipe on the lower right hand side of the block, it is the round "UFO" looking item with the large hose coming off it.
You can pry it off the block and then give it a good clean, there is also a reducer in the hose that could be blocked.

be very careful if removing the breather to not drop anything into open hole. definately a good idea to give the area around the breather a good clean with compressed air to remove loose debris.
Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[ideola]

I would WAIT to drain the oil until AFTER cleaning the breather. This way the solvent you use (which will dilute oil) along with any of the gunk it removes will be drained out with the oil.

The breather attachment is on the side of the block directly beneath the intake manifold, near the rear of the block. Yeah. Not easy to get to. It may help to remove the entire airbox / AFM unit out of the way. Then you should be able to take hold of the breather hose and feel your way back to where it attaches on the block. It may have a hose clamp holding it in place, if so, you'll have to loosen it to remove the hose. The breather attachment itself is the half-spheroid shaped thing with a nipple sticking out of it. The OD of the nipple will be ~19mm or so, and the diameter of the spheroid portion is about 50mm or so.

As I'm typing this, another possibility has come to mind. I believe on the NA breather lines, there is a restrictor in the line itself. I believe it is nothing more than a short piece of dowel with a small hole drilled through it. It's possible that the tube itself is blocked, so as a first step, remove it, and repeat your test with the oil cap on and off and see what happens. Also inspect the tube, see if you can blow thru it or not, make sure the tube itself isn't blocked.
_________________
erstwhile owner of just about every 924 variant ever made

[blokhus]

It sounds like I have a busy Weekend.


I found this link http://www.924.org/techsection/technical.htm under engine point 4 there is a picture is that what I am looking for?
[/img][/i]

[ideola]

Look in the upper left corner of the above photo. See where the horizontal pipe along the top edge of the block splits into a Y? Directly beneath that, you can just make out the breather attachment, and you can see the breather line that attaches to it.
_________________
erstwhile owner of just about every 924 variant ever made

[blokhus]

Perfect.
I will take off the hose and clean it.
Try to fire up the motor with the hose off and see if I still have a leak form the dipstick. If I do I will clean the breather with gasoline and change the oil.
Does that sound like a plan?
Would it be easier to get to the breather through the engine or from under the car?

[Rasta Monsta]

There is a screen under the circled part, may need to be cleaned if the rinse doesn't work.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[blokhus]

What you have cirkled is the breathing attachement right?
So when you say rinsed you mean cleaning the hose that goes to the air filter, am I correct? and if thet does not work then clean the breathing attachement.

Sorry for my confusion, English is not my mother languish.

[924RACR]

Yes, make sure the hose is clean and also not bent shut; I had this once on the racecar, the crankcase couldn't breathe and oil came out everywhere, even the front and rear main seals! The only problem was that when I had last installed the breather hose, I had left it with a kink in it that prevented it from properly venting the pressure.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[924guy]

havent changed your head gasket lately have you? new HG + original worn rings= dipstick oil fountain...
_________________
Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
http://www.cardomain.com/id/924Guy
Performance by Pasha

[blokhus]

Thanks,
I thing I fix it, There was a extra extension hose attached to the original hose. the extension has a smaller diameter and by removing the extension it seems like the crank can ventilate much better.
I have not had time to take it for a drive, out so far no leak.

and yes I have a new rings, and head gasket.

Once again thank for the great help.

[datatrain]

Do the cars that meet California standards have the same crankcase venting system ?
_________________
'78 924 NA with Collector plate
33 year old car, with me for 21 yrs
Mint '92 318i BMW
Near mint '98 Buick LeSabre
VE7HFR