Jeff928S4

In my search to find a solution to a random idle problem, I started looking for vacuum leaks. Sprayed cleaner all around an no change in idle.

I heard you can also check leaks by removing the oil filler cap and see if the Idle Stabilizer Valve compensates for the extra air.

As I was about to try this, I remembered that my dipstick is not the correct one. It doesn't go down into the hole and seal, it just rests in the tube. Air is definately getting in here.

Will this affect vacuum at all?

Jeff

Gretch

absapatootlee....................

SteveG

Jeff: I think it would have to what with the connection that come off of my filler neck. My dip stick fits very tight, is sort of a PIneck to get out, but I assume that is for a reason. I had idle problem, and the hose from the neck that goes under manifold was toast. I could hear it hissing, couldn't see it. While I was in there I replaced the idle stalizer as well and other hoses; it wasn't all that dirty, but I wasn't going in there again anytime soon. HTH

Jeff928S4

I ordered a dipstick from Porsche, but it won't be here till next week and I'm doing a road trip this weekend.....anyone have a temp fix I could try?

Maybe wrap electrical tape around the metal part of the stick until it gets to the diametre of the hole, thus making a plug of some sorts? Is this a safe idea?

Jeff

Garth S

I put that one through 'spellcheck' and then thru 'synonyms': : It came back as - " righty-ho - you bet 'yer sweet a$$ bub".
Not having sufficient experience in the vernacular, I venture to speculate that it means an affirmative response.
This latter one transcribed by the anti- obfuscation league came back as "Yes, that is a certain vacuum leak!!" rolleyes:
Jeff, I've seen NOS* 928 dipsticks on ebay for $10-15 ( search 928, parts <$500)
* sorry, = 'new old stock':

Gretch

Yup, that is where I found this newest term in my vocabulary............Also : synonym for: "do wild bears siht in the woods?" and "does the pope wear little red shoes?". Even VB can't spell it wrong......

Shade tree mechanic explanation: "If you have a hole in the crankcase, the PCV system has to suck harder to pull a vacuum".

heinrich

A badly-seated dipstick is a bad thing for many reasons. As a temp fix you could carry the dipstick (if it's the wrong dipstick, what good is it?? length is likely wrong ... how do you know what your level is?) separately, and plug the hole with anything like a good unused balloon tied with elastic

Jeff928S4

Well, it turns out the dipstick is the correct one - it's just that the plastic piece that sits in the hole was broken off. I do get correct readings on the oil level.

I used some electrical tape and wrapped it around the metal part of the dipstick a few times until it was enough to make the dipstick hard to pull back out.

I also just did the Liquid Wrench (I don't use WD-40....sorry) into the breather hose trick to see if that helps too.

Took it for a spin and noticed a immediate difference in throttle response. It had a "lag" before - not quite a "miss"....but a lag (if that makes any sense). From idle, it revs freely and returns to 900-1000 rpms very nicely. Still looped the idle a wee bit when no pressure is applied to the throttle (that Liquid Wrench has to work it's way down), but that small loop even went away after parking it and restarting it (just to see if the idle would go back to 1200 - because it would idle fine until it was driven, and then would sometimes go up to 1200 and other times it would shudder around 550 and the amps would sit at 10 or lower).

So far - so good.....maybe tomorrow (when the Liquid Wrench works it's way to the ISV), it will work even better!

Jeff

Gretch

The system will suck the solvent through the ISV pretty quickly. I have seen here recommended that you squirt the solvent in (I use penefite) and let it sit overnight, and then go run the car. I suppose it depends on how "sticky" the ISV is. The advice I found here by reading the archives is to start out with small amounts of the solvent. let it sit for some time and then run the car for a bit. FWIW, I thought I had an ISV problem that turned out to be a vacuum leak. Look at the vacuum hoses that attach to the diaphram ends on the two dampers and the fuel pressure regulator. Take your air box off and follow the hose from the FPR to the "t" connector ans see if the "t" connector is ok. Make sure your oil filler cap is on tight. make sure the clamps on the y connector (from the drivers side manifold to the power brake booster) are tight. These are the easy leaks to find, there are other "opportunities".

SteveG

Oh, My, God,

not WD 40!

hacker-pschorr

Uh, Gretch, you just spelled it wrong....

Garth S

Jeff,
I had 30 seconds of spare time, so I did a Fault Tree Analysis via computer simulation of Heinrichs closing advice - to check for any unforseen risk.
quote "plug the hole with anything like a good unused balloon tied with elastic"
As you are dealing with a breach of engine vacuum, whether one uses a virgin balloon, surgical glove, or condom - there is an inherent risk in securing such a device to your dipstick (or to anyone else's for that matter); That is the the well known principle of " Vacuum Induced Displacement of Engine Oil", known as VIDEO in the simulation trade.
Specifically, what the risk is that on a long downhill run there is a tendancy to lift off the throttle and create an extended high vacuum period. The baloon-like device is 'inhaled' down into the dipstick: Knowing these things to 'stretch a mile before splitting an inch', this then forces the oil into the induction system. This leads to a forseeable oil starvation of the mains, and loss of bearings, etc. sic. -VIDEO!!
You will be at less risk using a cork - or tape on the dipstick.

Bill 86.5 928s

HA..HA..HA......Garth you floor me HA..HA..HA......Stop it....HA..HA...HA.......
V..I..D..E..O....HA..HA..HA......................................

heinrich

I second Bill's response ... Garth, keep your stick on the ice ;-)

Gretch

on purpose though.................