Rephlex

So the $10m question. Do you have a lumpy idle still?

Babalouie

Well, it's the same as before

I think maybe what I might need to do, is to find someone with a proper Bosch Hammer, instead of the PIWIS brand tester that my mech uses

vagluv

what does your idle do? is it always off, or just sometimes? mine surges/hunts sometimes. sometimes only when the car is warm, sometimes only when its cold. and actually, its not just sometimes, its really most of the time when its cold, or when its hot.

Babalouie

Pretty common symptoms:

- doesn't really "burst" to life on a cold-start, sometimes requires a second go
- after a period of coasting off the throttle, has a bit of a dead-spot when you first apply power again
- doesn't actually stall, but sometimes seems like it's about to

ISV is new (which helped), but I think an idle adapatation would be a good thing to try next

beefa

I ordered one of these from Tore last month and it arrived here (North-West NSW) in <2 weeks. It can do adaptations (amongst other tricks).

Also, if you haven't got remote central locking, his T-LOCK is worthwhile. The remotes are nicely weighted and installation was pretty simple. Very impressed.

Babalouie

Oh really? So basically it turns your laptop into a Bosch Hammer?

beefa

No, I don't think that's the case. This has a limited set of functions. Have a flick through this thread.

I mainly wanted it for reading & clearing faults codes.

f3nr15

Hey Baba, Sydney Rennlister sml has previously undertaken a Hammer adaptation through a mechanic - might be worth messaging him to ask who he used.

sml

sorry, i'm not in syd

just call around the porsche mechanics and you may be able to find one .. and i doubt they will charge you for the adaptation (although they would be crossing their fingers for some future work).

i had incremental improvements with:
a) new ISV
b) wong chip
c) fuel cleaner additive things
maybe about the 5% improvement each, but the 85% solution was the hammer.

it is worth resolving the idle issue .. which may or may not be the hammer adaptation ... a car with a smooth idle is amazing (compared to 12mths with a dippy idle).

HiWind

SML/Baba - I've got a dippy idle, aftermarket fuel mgmt system (re the 3.8L), clean ISV, LWFW
but no AFM or TPS. Fuel mgmt system can manage the idle via a vacuum hose and airtemp sensor. But idle is dippy ..
ie when slowing down, if I put in the clutch and revs are at 3k, they fall to 300 and often stalls. Need a very gentle (ie hard to do) Heel & Toe.
When I plug in the ISV, car starts up 1st time even if cold... but idles at 2k, not 900 rpm. A bit loud/annoying and means oil guage cant work as idle too high.

post 8 re TPS
question and answer re ISV with Steve W

As sml says, there's nothing quite like having good road/traffic manners re stalling/having to H&T
everytime you slow to a stop ... is the hammer a resources I need? Any other suggestions?

sml

as your car is not stock, i would start a new thread and get some feedback from the experts ... your question will get missed here.

i have no idea if the hammer works with aftermarket mods, but as it is a free option, it is an easy potential solution to try.

Babalouie

At the beginning of January, I had Autohaus Hamilton sort out the oil leak from the power steering drive, which was getting really annoying. The leaked oil would coat the right-side heat exchanger, and when I stopped at a traffic light, a cloud of white smoke would waft past Thankfully Hamiltons sorted it out as part the major service, and two months later, the power steering drive housing is still squeaky clean.


However,m lately I've noticed an intermittent, and somewhat smaller waft of white smoke when I stop the car. It doesn't do it all the time, and isn't very repeatable. So up goes the car on stands for a look see.


First tell-tale is some oil residue on the heat exchanger intake pipe.


On a closer look, it seems as if the chain covers are leaking, and there is a conspicuous drip of oil on that conical round cover. I figure the smoke is from the oil droplets flying off that conical cover under braking, and dripping onto the heat exchanger, where it gets burnt and turns to smoke (a couple of droplets of oil can produce quite a surprising amount of smoke!)


When it comes to oil leaks, I find it quite confusing sometimes to separate cause from effect. My initial thoughts were that the chain covers were leaking, and that the oil was dripping down and collecting on that conical thing because it was the lowest point.

But replacing the chain cover seals is no small job, as it requires the bumper, exhaust, engine mount plate, a/c bracket and crank pulley to come off! So I'm not too keen on doing all that. But after a bit of searching on the forums, I figured that the oil leak wasn't actually the chain covers at all. But first, the heat exchanger intake pipe has to come off, which it does easily, just 2 bolts to remove and a few hose clamps to loosen.


Once it's off, we can access that conical cover (which I've cleaned up first in this pic)


Undo the two nuts, and the conical cover comes off to reveal this. It's actuallt the cover plate for the chain tensioner.


The thing that looks like a coilover shock, is an oil fed chain tensioner, and the way it works, is that oil is fed into one of the holes in the cover plate, and it goes into that hole in the shock, which them extends its (spring assisted) piston, which pushes on a skid resting against the chain to keep it nice and taut. The excess oil just bypasses the tensioner and returns to the oiling system via that other hole.

So what really happens, is that oil is fed at great pressure into the conical cover, and the thing that prevents oil from gushing out everywhere, is this special gasket. You can't really tell in the pic, but the new gasket has three nice, soft and thick green o-rings bonded to it. And the new green o-rings stand proud of the metal gasket, whereas the old gasket's rubber o-rings have gone hard and are squashed permanently flat.


So...I figure that maybe, just maybe...the real culprit to the oil leak is actually the rubber seals on the old gasket being perished. The chain covers really just have to contain a smal amount of splashed oil, whereas the tensioner cover plate has to contain oil at great pressure (so that's much more likely to be a significant leak point).

Putting it back together is quite straightforward, although I have to say that it took quite a lot of effort to push the tensioner cover in place, against the tensioner spring, and it took quite a few goes before I got it pressed into position enough to get the nuts started on their threads. So if you are attempting this, make sure there's plenty of room for you to work, because you're going to have to muscle that thing back into place. But that aside...it was a pretty quick job, maybe half an hour or so. Once it's all buttoned up, start the engine...and if oil is not gushing out everywhere, then it's probably done


Now at this point, you're probably thinking that there must be another tensioner at the other side of the engine, and you'd be right. However it's location isn't symmetrical, and it's actually on the topside of the motor, inside the engine bay. So I figure that, by rights that one shouldn't have been exposed to the same heat from the exhaust, and hence the gasket won't be as far gone. But I do have a second new gasket, and I'll do the replacement in the next few days.

Fingers crossed this stops the wisps of smoke once and for all!

911Jetta

Aahhhh, a Friday morning (Eastern U.S.) Baba tech posting, with pics.
What a great start to my day, learned something new. Thanks.
It's going to be a good day!

John McM

Babalouie, you're an inspiration.

I brought my 964 book with me on my current trip to Sydney, but it's really your posts that have given me confidence I can do my own work on my new to me 1990 C4, when I be back to Auckland on Friday. Please keep on posting.

Babalouie

Well, a week after changing that gasket on the chain tensioner cap, and it's still dry. Also I notice that the chain covers are still dry too, so what looked like a weeping chain cover before, might actually have been leaked oil from the tensioner cap nearby...


However, I am still noticing some wisps of smoke when the car is stationary, and it always seems to be from the right side. So I keep poking around and...hmm...I can't believe I haven't noticed this before...


But the oil pipe going into the oil filter housing looks like it's leaking. I mean, it's not wet with oil by any means, but all that black dust sticking to it must mean that there's *something* going on there.


And the secondary muffler looks like it's had some oil leaked on it (and quite a lot, too!), judging by that stain at the seam. Needless to say, that hose sits right above this spot on the muffler.


So, the plan currently is to clean the offending pipe (which goes from the oil tank to the oil filter housing, so it's the feed pipe for the engine), and I'll keep an eye on it over the next few days. Hopefully any leaks will be easier to spot now that it's cleaned.


From searching the forum, it seems that there are two possibilities: one is that the pipe itself is toast, and needs to be replaced...and the easier alternative, which is that the pipe is fine, but a sealing crush washer (at the join where the pipe bolts to the oil filter housing) is corroded and leaking.

...fingers crossed it's the latter! But going by that dark colour on the first few inches of hose...I think what's actually happening is that the braided hose has gone bad where it's crimped into its fitting, so a bad hose is probably the cause here.