RS2 problems??

[alastairg]

Thanks for previous help!
Following on from previous post, can I seek futher advice
Polar RS2 77k new to me!!
1 Oil pressure gauge flips to >5 (pre engine start) and remains there. Is the fault the sender or something simple (recent oil change level correct)?
2 Tyres, humour me, why switch to 45 profile on downsizing 245 - 225 ?
3 Ext temp gauge Unlike diode failure(very familiar from S2 I have) the display shows - - - rather than faint figures Any ideas?? colud it be the sensor/connections rather than diode??

Thanks in advance I am trying to pre diagnose problems prior to service to ensure I can source parts in advance to avoid delay

[GlynRS2]

1. Check that the car hasn't been overfilled with oil. Otherwise could be the oil pressure sender.

2. The profile is the percentage of the width. Therefore a 245/40 section tyre is 240mm x 0.4 = 98mm in height from rim to the road. As you reduce the width to keep this height more or less the same you need to increase the %section - e.g. 225/45 section tyre is 225mm x 0.45 = 101.25mm in height from rim to road, whereas a 225/40 section tyre is 225mm x 40 = 90mm in height from road to rim. Ideally you want to keep the rolloing distance of the whole tyre&wheel as near as possible the same so as not to affect the gearing (or accuracy of speedo). As the rolling distance of the tyre & wheel is equal to the circumference, using the 2 x Pi x R rule, the circumferences of the different size wheel & tyre combos is as follows:
Standard 245/40 x 17 = 1972 mm
225/40 x 17 = 1922 mm (-50mm or -2.5%)
225/45 x 17 = 1993 mm (+21mm or +1%)
Not a huge amount in it, but the 225/45 is closer.

3. See this link. Look under niggles & ambient tempereatre display.

Hope this helps.

[Greg_S]

sounds like sensor on the ambient temp display is gone.

its on the passenger side by the horn inside the bumper if you want to check the connection.

Oile pressure, could be an earth fault or sender fault. If the engine isnt running there shouldnt be any pressure.

Greg

[s2driver]

@Glyn, this is a good rule of thumb but unfortunately I have experienced big variations between manufacturers interpretation of tyre sizes. The size on the sidewall is an indication only and all manufacturers interperate the sizes differently. Looking for tyres for my dads car recently I found that some 225/45R17 have SMALLER diameters than some other 215/45R17. www.tirerack.com collates the tyre manufacturer's data and usefully you can see the revs per mile, section widths, tread widths of all tyres that this USA site stocks.

HTH, Lee

[scillyisles]

@Glyn, this is a good rule of thumb but unfortunately I have experienced big variations between manufacturers interpretation of tyre sizes. The size on the sidewall is an indication only and all manufacturers interperate the sizes differently. Looking for tyres for my dads car recently I found that some 225/45R17 have SMALLER diameters than some other 215/45R17. www.tirerack.com collates the tyre manufacturer's data and usefully you can see the revs per mile, section widths, tread widths of all tyres that this USA site stocks.

HTH, Lee

This is correct and in particular the 245/40ZR17 Dunlop SP8000 OEM tyre for the RS2 was nowhere near 245 in width but was nearer to 225. This explains why on my car when I switched from the Dunlop Sp8000 to 225/45ZR7 Bridgestone Potenza the speedo became more accurate due to the circumference of the wheel increasing.

[alastairg]

Great feedback thanks
Car due to go to local specialist next week who following a quick test drive/check over gave same solutions and also checked the ECU re chipping(standard, always nice to know )
Additional minor issues are
1 Leak around rear key seal, which I guess is the cause of an intermmittent false autocheck bulb failure warning. Is the fix simple ie re seal or complex
2 Top mount bush wear, the clunk on full lock parking that heralded same on S2
3 Dreadful noise giving it all in low gears and lifting off intially I was dreading gaerbox failure however following test drive identified as exhaust contact. Know issue with known fix!
Finally which tyre make? I am keen to try Bstone SO2s. any thoughts?

[scillyisles]

The clunk on steering full lock on both the S2 and RS2 is often caused by the front shock absorbers being slightly lose in their mounts - had the same problem on mine recently - took to my Audi dealer (Listers) and they retightened the shock absorbers and its gone away.
Tyres - I have Bridgestone Potenza RE40 on mine not S02s(which have been superceded by the S03.)
Wet weather grip is good and the tyres seem very resistant to aquaplaning. They seem to to wearing well too.
Big downside to them is the ride is very firm on Bridgestone. On my next change I'll probably look at Pirelli Pzero Nero and Rosso, Dunlop Sport Maxx and the Michelin Pilot Sport 2.

[s2driver]

SO-3s are not as good as the SO-2s in the dry but the later tyres have improved wet weather behaviour. SO-2s are still available in a few 16" sizes but mostly 18". I still get hold of mine in 235/40R18 which was originally a BMW M5 front fitment and I'll be sticking with the SO-2 until I change to 19's. Many Porshe ownrs who drive their car like it was intended didn't rate the replacement Bridgestone and have switched to Yoko AVS. If you own a Porsche I guess you generall don't care how long your tyres last! My steering clunk was a collapsed topmount bearing but you can easily check the tightmess of the top nut with a 7mm Allen key and a 22mm spanner (you can't torque it like this but at least you can check for loseness). If you have Konis the Allen key is a more friendly 6mm one! Should take you about 2 minutes to check.

[Doug_RS2]

Alastair - do you know how they checked the ECU?

A good sign of these cars not being chipped is to see if the wastagte has the small metal cap removed from the centre - if you can see a hex head it is more than likely been chipped.

You would have to remove the ECU and check the Boost and Fuel ICs to be certain that it isn't chipped - as it won't show up on the diagnostic tools(unless it is a really crap chip and lost comms)

Doug

[s2driver]

If you plug my car into the Stealers diagnostic equipment it would be impossible for them to tell that my car has been remapped. Opening the ECU would give nothing away either since the chips were socketed when stock. The only way to tell is to get a boost guage on mine. My wastegate has a stiffer spring which you could only tell by comparing it to a stock one side by side. Looking at the content of my remapped chips give nothing away unless you are a motronic expert and I doubt that any stealer is competent enough electronically to understand what is out of place in the EPROMS.

[Doug_RS2]

Lee - I agree that you might not tell if it has been remapped - but most tuners will use scramblers so their chips will be on a daughter board. If not they will probably have a sticker over the EEPROM window I don't know if original chips have this?), or at least something that the fitter will be able to distinguish the fuel chip against the boost chip. You will probably be able to tell from just looking the the ECU if the tabs have been messed with anyway.

Alastair - I think you should give me a shot just to make sure

Did your stiffer spring not get adjusted Lee? (do you still have the tab on top of the wastgate?)

[alastairg]

Plugged in diagnostic VAG unit Read no faults, code 4 I was told that USUALLY higher numbers indicate chipping and 4 is the usual non chipped number. I am sure those with greater knowledge can see flaws in this!!!!

[s2driver]

Don't forget Doug, I am still using the K24 so am only running 1.4 bar or so peak. We fitted the stiffer spring to reduce wastegate creep as it wasn't holding boost without it. I still have an absolutely stock looking wastegate with the circular tab intact. I agree that the chips might look a bit out of place to a more trained eye but my chips don't have scrambling sockets attached. If a stealer can't diagnose an S2 with problems unless fault codes are evident, I doubt they are familiar with the internals of the ECU. I also have an RS2 ECU which I had to open to recalibrate for the S2 MAF and swap the MAP sensor out. This is legitimate 'tab bending' and I think I still have the stock chips which can be whipped back in in about 15 minutes.

[Doug_RS2]

Lee - what were the chips I took out my ECU you borrowed? Mapped for a blocked filter?

Alastair - I'll have a look at your ECU if you want - Any excuse to see a nice RS2!

[s2driver]

Yes Doug, that set ran really rich once the filter was changed. It's all sorted now though. Despite what Audi say, the S2 and RS2 fuel filter ARE service items and they definately do not outlast the car!!