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My 99v 1.0L polo has had starting problems for about a year now which the vw it appears are unable to fix. The car has done 57kmiles and for the first time it is started each day the engine needs to be turned over a great number of times and often the key needs to be turned off before trying again. When the engine does eventually start a great deal of blueish smoke comes out of the exhaust. Any ideas or help would be much appreciated.
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Please bear in mind that i'm in no way a vehicle technician, so my answer may be a little wide of the mark:
The bluish smoke on start up suggests that this is engine oil being burnt, which, assuming it doesn't occur at any other time, would suggest worn valve guides. During the time the engine isn?t running, it might be possible that the worn valve guides are allowing oil into the combustion chamber. So, when starting the car in the morning, for example, the oil coats the spark plugs so they no longer operate as effectively. This may be why it takes a while to get started.
IIRC, these Polo engines were fond of emulsifying their oil in colder weather. This may have lowered the lubricating qualities of the oil, which is what has lead to the prematurely worn valve guides. Do you have any oil consumption?
But VW aren't able to fix this. What have they said? I would have thought that the oil fouled spark plugs would have signaled a major problem, which they would pick up. Also, with fouled spark plugs, fuel consumption is high and the engine will have little power and may even misfire. Do you have any of these symptoms?
Like I said before, I?m no mechanic, so don?t be surprised if someone more qualified comes along and suggests something far more simple.
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The blueish smoke is the fuel that has not been burnt during extended cranking so at least its fueling. This now points to a spark problem. Remove and measure the resistance of all the HT leads particularly the King lead as this is common to all cylinders. VW leads are copper but with resistive plug caps and these are prone to overheating and resistor going open ect. Next would have to be a check of the coil and Ignition amp driver waveform, but I assume VW checked that. If you can arrange to bump start the car one morning I would try that to eliminate the starter current during cranking is not upsetting the ECU/ignition system. Come back with the results. Regards Peter
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Thanks for the help, I bump started the car today and it started straight away. Does this suggest that the current which the starter motor draws is not leaving enough power for the spark plugs to operate properly? I will ask for the resistance of the leads to be checked in a few weeks time. I don't think the car is using any oil so I don't think worn valve guides are the problem.
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Sounds about right.If it started ok-without any hint of rough running I would count HT leads out..Problem lies in battery running low over a period of time..As you stated. Not enough left to power the ECU
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Steve
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Earthing could be a problem here, using the starter motor could defeat a dodgy earth connection. Try connecting a single jump lead to a suitable metal point on the engine and the battery "-" when cold starting.
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The battery appears to have plenty of life in it, it can crank the engine over fine without any fading. Is it possible that the battery is not passing enough power to the spark plugs even though it seems to have lots of life? I don't understand the earthing issue. Thanks for the help.
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What Big John is saying.. Engine has to have substantial earth lead connected to it from chassis.If a connection is corroded either at engine point or chassis/not connected for some reason this may well cause your problem.I would try what he suggested to help either narrow the problem down or cure??
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Steve
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So we have a connection problem as bump starting works just fine. This could be an ignition switch problem so you need someone with a volt meter to check what is happening of of course a corroded connection. Remove and clean all earthstrap connections including the one from the bulkhead to the carb body. Regards Peter
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I tried the jump lead thing this morning, connected the ends as firmly as possible to the battery and a metal point in the engine bay. It still took a second or two of turning over to get it started but much better than before, but perhaps it wouldn't be as well earthed as with a proper earthing connection. I will try again another day to check that this is definitely the problem. Where would the proper earthing wire usually be located?
Thanks for all the help.
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I have tried starting the car with an earthing jump lead in place several times now and unfortunately this does not seem to make starting any easier. I am now thinking that it may be the worn valve guide problem which was the first suggestion. Although I haven't noticed any oil consumption the car does sometimes lose power and splutter during the first few miles of driving each day. I looked on the underside of the oil filler cap the other day and found a brown gunge, is this a signal of emulsifying oil? Sent car into vw over this starting problem about a year ago and they replaced the throttle cable, inc labour cost about £400, but didn't notice much improvement. Can worn valve guides be replaced? Would I have noticed high oil consumption if this was the problem? Thanks for the help.
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I would suggest getting the charge rate from alternator to battery checked out..It has been known for battery to turn starter. But not feed ECU and sensors.Discussion of which I have had several times.Though not here..I doubt worn valve guides or seals will give that much trouble unless severe
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Steve
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