Steve_S3 Posted August 16, 2005 Report Share Posted August 16, 2005 I've had an intermittent problem over the past few weeks, where my S3 has been slow to pickup acceleration over around 4k revs - it feels like the brakes are on. I took it into Clive Atthowe Tuning in Norwich (as they have a 4wd dyno), and within 10 mins they had found an error code on VAG-COM: 16502 Engine Coolant Temp. Sensor (G62): Signal too high P0118 - 35-10 - - - Intermittent Their view is that this is putting the ECU into default mode and causing the poor performance. That said, my S3 still made 245hp and 258lb/ft. It goes back in tomorrow to have the new sensor fitted - I'll keep you posted on the result. Hopefully, it will be back to the full 270hp and around 290lb/ft...... Link to comment Share on other sites More sharing options...
neo283 Posted August 16, 2005 Report Share Posted August 16, 2005 Sounds like a faulty coolant sensor like you suggest. From experience, this shouldn't be more than a £20 part. Hopefully they won't try to part you from one of your kidneys! Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 16, 2005 Author Report Share Posted August 16, 2005 Yeah, the part is 25 quid and then it'll be 55 quid to fit and retest on the dyno....must admit, I was well impressed with Clive Atthowe Tuning - they know their stuff and do a thorough job. Full report to follow tomorrow's fixing!! Link to comment Share on other sites More sharing options...
Paul Posted August 16, 2005 Report Share Posted August 16, 2005 £25 quid sensor and takes five minutes without any tools to fit. If you can open the bonnet you can fit it. Link to comment Share on other sites More sharing options...
Mollox Posted August 16, 2005 Report Share Posted August 16, 2005 How would a coolant sensor affect performance? Link to comment Share on other sites More sharing options...
Drillslinger Posted August 16, 2005 Report Share Posted August 16, 2005 By giving false readings Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 17, 2005 Author Report Share Posted August 17, 2005 OK - just had the S3 back in for the replacement coolant sensor. This has cleared the fault, and another run on the dyno shows peak power back to 263.2bhp and peak torque at 252.8lbft. (I'll post the dyno sheet if anyone's interested - gives a good view of the results of the MTM chip) So, that's the good news..... But (and there's always a but), the sluggish acceleration is back. Speaking to the tuners again, they said the MAF was 0.2v out from default of 5v, and they think that this might be making the mixture too lean. The engine does have det sounds (pinking) on acceleration, so the view is that the knock sensor is retarding the engine and putting the ECU into default mode. Does anyone have any experience of something similar? How easy is the MAF to change? I hear it's about 90 quid exchange, but don't want to "invest" in another replacement part unless I'm very confident of a fix..... Link to comment Share on other sites More sharing options...
Paul Posted August 17, 2005 Report Share Posted August 17, 2005 [ QUOTE ] How would a coolant sensor affect performance? [/ QUOTE ] Mollox, this sensor has a huge amount to do with fueling calculations apparently. Even my 2003 S3 had an old black version that was throwing up intermittant faults. Link to comment Share on other sites More sharing options...
Mollox Posted August 17, 2005 Report Share Posted August 17, 2005 Is this the one that causes the "low coolant" warning alarm? (particularly when cold in winter in my case) Link to comment Share on other sites More sharing options...
Paul Posted August 17, 2005 Report Share Posted August 17, 2005 [ QUOTE ] OK - just had the S3 back in for the replacement coolant sensor. This has cleared the fault, and another run on the dyno shows peak power back to 263.2bhp and peak torque at 252.8lbft. (I'll post the dyno sheet if anyone's interested - gives a good view of the results of the MTM chip) So, that's the good news..... But (and there's always a but), the sluggish acceleration is back. Speaking to the tuners again, they said the MAF was 0.2v out from default of 5v, and they think that this might be making the mixture too lean. The engine does have det sounds (pinking) on acceleration, so the view is that the knock sensor is retarding the engine and putting the ECU into default mode. Does anyone have any experience of something similar? How easy is the MAF to change? I hear it's about 90 quid exchange, but don't want to "invest" in another replacement part unless I'm very confident of a fix..... [/ QUOTE ] your figures are good, im not sure the normal test of unplugguing the maf and see it it runs better would make any difference if you had vagcom you could try a throttle body reset. (teach throttle full open and fully closed) a log of the Maf airflows and log/ check the knock sensors (thiough whats aceptable and what isnt i wouldnt know) Link to comment Share on other sites More sharing options...
Paul Posted August 17, 2005 Report Share Posted August 17, 2005 [ QUOTE ] Is this the one that causes the "low coolant" warning alarm? (particularly when cold in winter in my case) [/ QUOTE ] no , that one is moulded in the expansion tank mate. needs a new expansion tank/sensor arrangement. The one were speaking of, is down RH said of engine in the pipes over the gearbox area. Link to follow. Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 17, 2005 Author Report Share Posted August 17, 2005 Thanks Paul - I'll try and get my local stealer to do a quick check with the VAGCOM. When you say that unplugging the MAF probably won't make a difference, just interested to know why that is.... Cheers! Link to comment Share on other sites More sharing options...
harminder Posted August 17, 2005 Report Share Posted August 17, 2005 [ QUOTE ] another run on the dyno shows peak power back to 263.2bhp and peak torque at 252.8lbft. (I'll post the dyno sheet if anyone's interested - gives a good view of the results of the MTM chip) [/ QUOTE ] Yes please.. Link to comment Share on other sites More sharing options...
Paul Posted August 17, 2005 Report Share Posted August 17, 2005 [ QUOTE ] Thanks Paul - I'll try and get my local stealer to do a quick check with the VAGCOM. When you say that unplugging the MAF probably won't make a difference, just interested to know why that is.... Cheers! [/ QUOTE ] your car is running well, Dyno proves that. If it was running like a dog,under performing, bad fuel consumtion etc, unplugging the Maf, and taking for a short drive, can sometimes make a smoother running car. If it did, the maf is most likely shot. But your car is pulling good chipped figures. MTM, always have been around the 250BHp mark, and sold as such. Link to comment Share on other sites More sharing options...
Paul Posted August 17, 2005 Report Share Posted August 17, 2005 Here is all the info required to change a temp sensor. If you can open the bonnet, you can follow this. Thanks to Wak. Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 17, 2005 Author Report Share Posted August 17, 2005 [ QUOTE ] your car is running well, Dyno proves that. If it was running like a dog,under performing, bad fuel consumtion etc, unplugging the Maf, and taking for a short drive, can sometimes make a smoother running car. If it did, the maf is most likely shot. But your car is pulling good chipped figures. MTM, always have been around the 250BHp mark, and sold as such. [/ QUOTE ] Correction - it WAS running well, but that stopped about 10 miles from the tuners. Now, it has zero power over 4k revs again, and the pinking(detonation) is still there. I'll certainly try the MAF unplugging - how far should I drive it like that? Could it cause other damage/problems? Link to comment Share on other sites More sharing options...
Paul Posted August 17, 2005 Report Share Posted August 17, 2005 just a short drive should be noticable. if you get any faults up on the dash that wont go away once reconnected, just drop the connection off the battery for 10 mins. this will clear them. Link to comment Share on other sites More sharing options...
neo283 Posted August 17, 2005 Report Share Posted August 17, 2005 I hassled the forum with MAF questions a month or so ago. Simple to replace, but not so simple to source. Apparently (you may already know this) Audi only do reconditioned/exchanges on their MAFs as they are so easy to fix. I got a replacement FITTEd by my local VAG specialist for £65, where as I had been quoted £70 for the unit alone form our friends at vagparts.com When replacing/ordering a new sensor, the while unit including the housing from the air intake is replaced. This is held in by a simple compression style metal strap. Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 18, 2005 Author Report Share Posted August 18, 2005 Neo - thanks for the info. When you say local VAG specialist, I guess you're talking about an independent? Link to comment Share on other sites More sharing options...
neo283 Posted August 18, 2005 Report Share Posted August 18, 2005 An indipendant with a VAG Com I guess. They're literally called AVW Specialists or something in Stonehouse, Gloucestershire. Found them infinately more helpful than any Stealer. Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 19, 2005 Author Report Share Posted August 19, 2005 Ok - another update. I unplugged the MAF last night, and drove the car for about 20 miles. The sluggish performance was all but gone, as was the det sounds (although it was still pinking a bit). Upshot of this is that I'll be getting myself a new MAF....more money into the Audi money pit Link to comment Share on other sites More sharing options...
Paul Posted August 19, 2005 Report Share Posted August 19, 2005 excellent. It wont be perfect running without the Maf, but if it runs better like you say it really does point towards it. Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 19, 2005 Author Report Share Posted August 19, 2005 Just been on the blower to get some MAF costs: Local stealer = £78.18 +VAT + £20 surcharge (refundable with return of old unit) Murrays Direct = £55-60 +VAT (depends on VIN) + £25 surcharge Don't think I'll get any cheaper than Murrays...... Link to comment Share on other sites More sharing options...
Steve_S3 Posted August 22, 2005 Author Report Share Posted August 22, 2005 Well, after reading several posts on the subject of MAFs, I decided to try cleaning it before shelling out for a new unit. So, I bought some Carb cleaner and a security Torx driver (why don't Audi just padlock the bonnet and be done with it?). A few minutes work to remove the MAF, a few seconds of blasting with the aerosol, job done..... Drove the car to work this morning - all I can say is "Welcome back, S3, where have you been???"" £8 rather than £70 - bargain. Link to comment Share on other sites More sharing options...
Jimbob_S3 Posted August 22, 2005 Report Share Posted August 22, 2005 Steve, Where did you get the "Carb cleaner and a security Torx driver" from ? Gonna get some myself and try this, got similar problems... Thanks! Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now