Sharan/Galaxy/Alhambra - engine cutout for fractions of a second
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From: Calvin Sambrook on 3 May 2010 10:59 Hi, I wonder if anyone has any thoughts on a problem I'm having with my old-style (1995) VW Sharan. Every now and again the engine dies but only for a very brief period, less than a second I'd say although I've not been timing it. The effect on the engine power is as if I'd turned the key off, the car slows very quickly, much more quickly than simply lifting my foot off the pedal. At the same time all of the electrical stuff *except the rev counter* stays completely normal. The rev counter is weird, when this happens the rev counter dies away to zero almost instantly, clearly it's not reading properly as the car is still in gear and moving so the engine must be rotating. This fault is proving very difficult to diagnose as it only happens occasionally and only when it wants to. My guess is that if I can find out what the rev counter actually counts I'd be a long way to diagnosing it. Does anyone have any ideas?
From: JB on 3 May 2010 11:38 "Calvin Sambrook" <csambrook(a)bigfoot.com> wrote in message news:hrmoc7$cc3$1(a)news.eternal-september.org... > Hi, > > I wonder if anyone has any thoughts on a problem I'm having with my > old-style (1995) VW Sharan. > > Every now and again the engine dies but only for a very brief period, less > than a second I'd say although I've not been timing it. The effect on the > engine power is as if I'd turned the key off, the car slows very quickly, > much more quickly than simply lifting my foot off the pedal. At the same > time all of the electrical stuff *except the rev counter* stays completely > normal. > The rev counter is weird, when this happens the rev counter dies away to > zero almost instantly, clearly it's not reading properly as the car is > still in gear and moving so the engine must be rotating. > > This fault is proving very difficult to diagnose as it only happens > occasionally and only when it wants to. My guess is that if I can find > out what the rev counter actually counts I'd be a long way to diagnosing > it. Does anyone have any ideas? If it's like my old T4 Caravelle, it will be the brake light switch. (there are 2). One for the back lights and one for the ECU signal. Certainly the same symptoms. Worth �9 to find out too. Did you get a codes read? Know anyone with VAG-COM? If you're in the SW, I can do a scan for you no problem. JB
From: Duncan Wood on 3 May 2010 11:47 On Mon, 03 May 2010 15:59:19 +0100, Calvin Sambrook <csambrook(a)bigfoot.com> wrote: > Hi, > > I wonder if anyone has any thoughts on a problem I'm having with my > old-style (1995) VW Sharan. > > Every now and again the engine dies but only for a very brief period, > less than a second I'd say although I've not been timing it. The effect > on the engine power is as if I'd turned the key off, the car slows very > quickly, much more quickly than simply lifting my foot off the pedal. > At the same time all of the electrical stuff *except the rev counter* > stays completely normal. > The rev counter is weird, when this happens the rev counter dies away to > zero almost instantly, clearly it's not reading properly as the car is > still in gear and moving so the engine must be rotating. > > This fault is proving very difficult to diagnose as it only happens > occasionally and only when it wants to. My guess is that if I can find > out what the rev counter actually counts I'd be a long way to diagnosing > it. Does anyone have any ideas? > Plug it into vag-com & see what the intermittent fault (cam or more likely crank sensor) is.
From: Mrcheerful on 3 May 2010 11:59 Calvin Sambrook wrote: > Hi, > > I wonder if anyone has any thoughts on a problem I'm having with my > old-style (1995) VW Sharan. > > Every now and again the engine dies but only for a very brief period, > less than a second I'd say although I've not been timing it. The > effect on the engine power is as if I'd turned the key off, the car > slows very quickly, much more quickly than simply lifting my foot off > the pedal. At the same time all of the electrical stuff *except the > rev counter* stays completely normal. > The rev counter is weird, when this happens the rev counter dies away > to zero almost instantly, clearly it's not reading properly as the > car is still in gear and moving so the engine must be rotating. > > This fault is proving very difficult to diagnose as it only happens > occasionally and only when it wants to. My guess is that if I can > find out what the rev counter actually counts I'd be a long way to > diagnosing it. Does anyone have any ideas? crank sensor is the likely fault.
From: Chris Bartram on 3 May 2010 13:24
On 03/05/2010 16:47, Duncan Wood wrote: > On Mon, 03 May 2010 15:59:19 +0100, Calvin Sambrook > <csambrook(a)bigfoot.com> wrote: > >> Hi, >> >> I wonder if anyone has any thoughts on a problem I'm having with my >> old-style (1995) VW Sharan. >> >> Every now and again the engine dies but only for a very brief period, >> less than a second I'd say although I've not been timing it. The >> effect on the engine power is as if I'd turned the key off, the car >> slows very quickly, much more quickly than simply lifting my foot off >> the pedal. At the same time all of the electrical stuff *except the >> rev counter* stays completely normal. >> The rev counter is weird, when this happens the rev counter dies away >> to zero almost instantly, clearly it's not reading properly as the car >> is still in gear and moving so the engine must be rotating. >> >> This fault is proving very difficult to diagnose as it only happens >> occasionally and only when it wants to. My guess is that if I can find >> out what the rev counter actually counts I'd be a long way to >> diagnosing it. Does anyone have any ideas? >> > > Plug it into vag-com & see what the intermittent fault (cam or more > likely crank sensor) is. Seconded. Our Lupo has done this for some time, and has finally logged an 'implausible signal' for the crank sensor, so that may well be getting changed. The only answer is to get it on VAG-COM. |