Rav Posted November 10, 2021 Report Share Posted November 10, 2021 I need the help and advice of the techie sorts on here regards by 2000 Boxster S (Viola). I used the car yesterday and today to drive the long way from my home in Marlborough, Wiltshire to the Excel centre in London. Hotel rooms were £250 a night so i decided to drive the car. Tuesdays trip was great with exception of Waze taking me through the city instead of around the M25. I had to pay the ULEZ and Congestion Charge for two days - plus parking for two days. Anyway i digress. Today on the way in, slowly progressing through Knightsbridge - the car started to behave oddly. It was very jumpy, hesitant and then cut out a couple of times. It started fine on the key again, but the revs kept going up and down on their own. I was terrified that it would break down on a London red route or even worse in the Limehouse tunnel - can you imagine the headlines? Anyway - any help on what to look for much appreciated. I have the Torque app and a OBD2 code reader so will try to pull a code or two tomorrow. On a connected note - you might have read that I had the air con pipes replaced by Lee at Cotswold last month. I have noticed that: 1. The air con works well, but if i turn it off (i.e. snow flake symbol off) the car steams up almost instantly. Its so bad one cant see out of the car. Is this normal? 2. On occasion the air con make a hell of a noise. I cant describe it - its like a moaning noise. I guess that this is not normal? Many thanks. Quote Link to comment Share on other sites More sharing options...
mike597 Posted November 10, 2021 Report Share Posted November 10, 2021 Is it a tip? Quote Link to comment Share on other sites More sharing options...
the baron Posted November 10, 2021 Report Share Posted November 10, 2021 Rav, my first thought is the MAF sensor, easy way of checking is when the car is running rough pull the MAF and drive to see if it makes a difference. It could also be an air leak, so will have to get that tested, it could also be the coil packs. I presume no EML on? Cant help on the air con as my car doesn’t have it lol. if you want to pop over to mine I could help try and diagnose it. Quote Link to comment Share on other sites More sharing options...
Nobbie Posted November 10, 2021 Report Share Posted November 10, 2021 It shouldn’t steam up really quickly, maybe check bottom of doors and under the carpet behind the seats for evidence of water ingress. Often the top of the carpet is fine, but the foam backing is soaked. Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted November 10, 2021 Report Share Posted November 10, 2021 16 minutes ago, mike597 said: Is it a tip? It’s carrying a few extra sweet wrappers and needs a good vacuum, but that’s a bit harsh. 6 Quote Link to comment Share on other sites More sharing options...
milner Posted November 10, 2021 Report Share Posted November 10, 2021 Make sure that fresh air is coming into the car and not being recycled. Quote Link to comment Share on other sites More sharing options...
mike597 Posted November 10, 2021 Report Share Posted November 10, 2021 20 minutes ago, Menoporsche said: It’s carrying a few extra sweet wrappers and needs a good vacuum, but that’s a bit harsh. I was thinking the first set of symptoms could be a slipping auto transmission. Quote Link to comment Share on other sites More sharing options...
mike597 Posted November 10, 2021 Report Share Posted November 10, 2021 The second issue could be the heater matrix. Any smell? Quote Link to comment Share on other sites More sharing options...
Rav Posted November 10, 2021 Author Report Share Posted November 10, 2021 (edited) Thanks all - no its not a tip its a manual - but I love the joke!! I will check the carpets in the morning and also run the OBD2 code reader and report back. No EML light at all. Which is odd. No smell so I am not sure that it is the matrix, but it could be air recycle. I will check. Edited November 10, 2021 by Rav Quote Link to comment Share on other sites More sharing options...
Paul chocks Posted November 10, 2021 Report Share Posted November 10, 2021 Hi Rav, with the revs going up and down, I agree with the baron - check the MAF first. It’s dead simple to do. I didn’t even have to drive mine as it idled rough until I disconnected MAF. The noisy air-con can be an air pocket in the lines (apparently). Quote Link to comment Share on other sites More sharing options...
Rav Posted November 10, 2021 Author Report Share Posted November 10, 2021 Thanks Paul (and all the other replies) - I will have to make the car misbehave again, it seems to be fine (ish) on the journey home. Really occasional hesitation.... Quote Link to comment Share on other sites More sharing options...
½cwt Posted November 10, 2021 Report Share Posted November 10, 2021 +1 on MAF. Mine ran like a dog with a failed MAF, misfire and detonation in the exhausts. Quote Link to comment Share on other sites More sharing options...
Rav Posted November 11, 2021 Author Report Share Posted November 11, 2021 I checked the Fault codes this morning using my torque app and obd2 reader - no codes stored. I also checked the fan and heater settings - the air re-circ is off - when i switch the air con off, the car steam up within a minute. The carpets and foam backing are all dry. Is it time to buy a 911? Quote Link to comment Share on other sites More sharing options...
dpg123 Posted November 11, 2021 Report Share Posted November 11, 2021 When I had my condensers and desiccator replaced, the air con made a droning noise from what seemed like under the frunk, somewhere around the bulkhead. I had it's regassed again and it went away. Maybe there's not enough gas / pressure / oil in the system (I read somewhere it needs quite a lot of oil as the compressor and pipes all lead to the rear of the car so it's a bigger system than normal). Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted November 11, 2021 Report Share Posted November 11, 2021 11 hours ago, mike597 said: The second issue could be the heater matrix. Any smell? Didn't someone have a problem behind the dashboard, not sure if heater matrix, front drain holes or similar, but I think eventually it led to damp in the footwell from the front, rather than the back as is most common. Quote Link to comment Share on other sites More sharing options...
mike597 Posted November 11, 2021 Report Share Posted November 11, 2021 5 minutes ago, Menoporsche said: Didn't someone have a problem behind the dashboard, not sure if heater matrix, front drain holes or similar, but I think eventually it led to damp in the footwell from the front, rather than the back as is most common. Logically if the windows are misting up, there is moisture somewhere. If it's heater matrix leaking then you'd expect to smell the coolant. I think I vaguely recall the issue you refer to, wasn't it seals around the pipes that feed the heater matrix that were letting moisture past them? Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted November 11, 2021 Report Share Posted November 11, 2021 Mike your logic as always is impeccable. I don't remember the details, just adding my vague recollections that it isn't always the carpets at the back. (Did we also have someone with a poorly installed replacement windscreen?) There are damp sensors sold in B&Q for damp plaster in walls, I don't know their sensitivity range but wonder if that would be an easy way to look for which bit of the carpet inside the car is damp. As ultimately that's gotta be the problem. Quote Link to comment Share on other sites More sharing options...
Shazbot Posted November 11, 2021 Report Share Posted November 11, 2021 (edited) When my heater matrix was playing up there was no smell and the window steamed up really quickly. Turned out the matrix had a small hole and the coolant was causing the steam by pooling under the matrix. i used to get what looked like smoke (steam) out of the centre dash vents occasionally which was very unsettling. Once I changed the matrix it was all good. Edited November 11, 2021 by Shazbot Quote Link to comment Share on other sites More sharing options...
GmanB Posted November 11, 2021 Report Share Posted November 11, 2021 Hope you sort it cheaply, that Viola is beautiful, can we have a picture please? Quote Link to comment Share on other sites More sharing options...
Rav Posted November 12, 2021 Author Report Share Posted November 12, 2021 Why of course..... 2 Quote Link to comment Share on other sites More sharing options...
Rav Posted November 15, 2021 Author Report Share Posted November 15, 2021 I checked this a little with my fault code reader over the weekend. The car behaved well all weekend, but then spluttered a little on the way to tesco. I used my terrible fault code reader and hey presto no fault codes in memory. Does anyone local ish to me (Wiltshire) have a Porsche system to plug in and read codes? There is no EML light on, on the dash. Quote Link to comment Share on other sites More sharing options...
mvw Posted November 15, 2021 Report Share Posted November 15, 2021 If it’s the heater matrix, you’ll get an oily residue on the windscreen too. Quote Link to comment Share on other sites More sharing options...
Rav Posted November 17, 2021 Author Report Share Posted November 17, 2021 Thanks all. I decided to take the car to drop my daughter off at uni this morning. It was fine until the M25 and then i started to feel a slight hesitation once in a while. We pressed on and thankfully when leaving the M25 it stalled at the roundabout. It started straight back up and we were safe. After the drop of it decided to play silly again near Ascot. Kangaroo jumping around all over the place. Even pressing the 'loud' pedal does nothing when it is one of those moods 🙂 I noted that idle can be a bit erratic before and after an episode. My daughter sent me a link to this: https://daseuropeanautohaus.com/symptoms-of-a-failing-porsche-mass-air-flow-sensor/ As some of you above have said - this is the likely culprit. Now where to get one that wont cost me £500!! Quote Link to comment Share on other sites More sharing options...
Nobbie Posted November 17, 2021 Report Share Posted November 17, 2021 41 minutes ago, Rav said: Thanks all. I decided to take the car to drop my daughter off at uni this morning. It was fine until the M25 and then i started to feel a slight hesitation once in a while. We pressed on and thankfully when leaving the M25 it stalled at the roundabout. It started straight back up and we were safe. After the drop of it decided to play silly again near Ascot. Kangaroo jumping around all over the place. Even pressing the 'loud' pedal does nothing when it is one of those moods 🙂 I noted that idle can be a bit erratic before and after an episode. My daughter sent me a link to this: https://daseuropeanautohaus.com/symptoms-of-a-failing-porsche-mass-air-flow-sensor/ As some of you above have said - this is the likely culprit. Now where to get one that wont cost me £500!! Try the MAF disconnect first to see if the issue goes away, but it sounds more like an issue with the fuel pump or fuel pump relay which may not throw a code either. Crank position sensor is another possibility, but you usually need to let the car cool down before they will restart if it was this. Quote Link to comment Share on other sites More sharing options...
edc Posted November 17, 2021 Report Share Posted November 17, 2021 It might also be worth checking or testing the throttle position sensor if there is one or the throttle body. If it's not reacting correctly to your input then it might explain some of the hesitation. Quote Link to comment Share on other sites More sharing options...
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