Engine light on (again)
Posted: Thu Nov 14, 2019 10:31 pm
The car in question is a 2002, 1.2, 12V, Polo E, engine AZQ, no A/C, manual 122K on the clock.
It was a car my parents used to own but bought it back and was very clearly poorly maintained after it was sold by the new owner. Roughly 6000 miles were put on it in 2 years according to the MOT records.
The car has been sat for a long time (too long) as I get ready for my test (1.5 - 2 years) I have recently finished essentially overhauling the car to make it roadworthy, brakes all around, brake fluid flush, new filters (minus the fuel filter), new spark plugs, new auxiliary belt, coolant flush and refill with G13 (from VW), new coolant temp sensor, power steering flush with G004 000 (from VW), new battery, throttle body cleaned (on car stupidly), new airbox to throttle body seal as it was split and a set of 14" alloys from the Polo SE I believe (think they're called "Sao Paulo") to replace the old rusty steelies. It needs handbrake cables and tyres are being fitted but that's beside the point.
Its first oil change was very black and stank of petrol and the filter was black. New oil turned black almost instantly however filter was not so before I started driving it properly I performed another last week (oil and filter) and again the oil was black and stank (had about 10-20 hours total of run time) this time I let the car run before I drained it so as much sh*t came out as possible and it seems to have worked as new oil is only slightly discoloured.
However, during this time it has had 4 CEL's
First was a stored code for an O2 sensor which was cleared and never came back.
The second was an intermittent immobiliser and it ran like sh*t because of it (think it was running on 1 cylinder) which seemed to be caused due to low battery voltage (joys of letting a car sit) and it has never returned after being cleared.
The third was "MAP sensor signal implausible" which was easily fixed by cleaning the MAP sensor. In this case, the car would hunt quite badly and blew blue/black smoke and stank of unburnt fuel but would rev out fine still blowing smoke nonetheless. So the MAP was cleaned, plugs replaced and code cleared and ran great.
All has been well until today when I was out driving and the light came back on but the car seems fine no drop in performance but on that start, before the light came on it was again hunting but nowhere near as much as previously. There doesn't seem to be any smoke coming from the exhaust and no rich smell under the bonnet.
I'm having it scanned tomorrow to see what it is. If it is again the MAP sensor and when I take it out and its caked in deposits again what could be causing this?
It was a car my parents used to own but bought it back and was very clearly poorly maintained after it was sold by the new owner. Roughly 6000 miles were put on it in 2 years according to the MOT records.
The car has been sat for a long time (too long) as I get ready for my test (1.5 - 2 years) I have recently finished essentially overhauling the car to make it roadworthy, brakes all around, brake fluid flush, new filters (minus the fuel filter), new spark plugs, new auxiliary belt, coolant flush and refill with G13 (from VW), new coolant temp sensor, power steering flush with G004 000 (from VW), new battery, throttle body cleaned (on car stupidly), new airbox to throttle body seal as it was split and a set of 14" alloys from the Polo SE I believe (think they're called "Sao Paulo") to replace the old rusty steelies. It needs handbrake cables and tyres are being fitted but that's beside the point.
Its first oil change was very black and stank of petrol and the filter was black. New oil turned black almost instantly however filter was not so before I started driving it properly I performed another last week (oil and filter) and again the oil was black and stank (had about 10-20 hours total of run time) this time I let the car run before I drained it so as much sh*t came out as possible and it seems to have worked as new oil is only slightly discoloured.
However, during this time it has had 4 CEL's
First was a stored code for an O2 sensor which was cleared and never came back.
The second was an intermittent immobiliser and it ran like sh*t because of it (think it was running on 1 cylinder) which seemed to be caused due to low battery voltage (joys of letting a car sit) and it has never returned after being cleared.
The third was "MAP sensor signal implausible" which was easily fixed by cleaning the MAP sensor. In this case, the car would hunt quite badly and blew blue/black smoke and stank of unburnt fuel but would rev out fine still blowing smoke nonetheless. So the MAP was cleaned, plugs replaced and code cleared and ran great.
All has been well until today when I was out driving and the light came back on but the car seems fine no drop in performance but on that start, before the light came on it was again hunting but nowhere near as much as previously. There doesn't seem to be any smoke coming from the exhaust and no rich smell under the bonnet.
I'm having it scanned tomorrow to see what it is. If it is again the MAP sensor and when I take it out and its caked in deposits again what could be causing this?