Poor starting
QYou have helped me in the past with a Volkswagen Sharan that was overheating. Turned out the head gasket had gone so we sold it as spares/ repair as the front jacking points were rotting-out as well.
I have replaced the vehicle with a 2009 Vauxhall Zafira 1.9 CDTI with the 150bhp diesel SRI. It’s only done 75k. I bought it under six months ago and starting the engine was always first turn of the key. During the colder weather it’s taking a lot longer to start (10 seconds or so of turning over). It’s only the very first start of the day that’s like this. Any subsequent starts are pretty much instant.
I did wonder if it was the battery, though I have a music player in the cigarette lighter that shows battery voltage. It shows 12V with engine not running and 13.9V or 14V with it running which seems right to me. To try and rule out the battery I put it on a slowcharge and the charger said the battery was fully-charged after four hours.
The cold-start problem still persists with a fully-charged battery. I presume the glow plugs maybe on their way out. Would you agree that sounds the most likely cause?
Is there an easy way to test them? I presume the glow plugs must have a resistance within a certain range. Have you ever removed glow plugs from this engine? Just wondered if they’re likely to be a pig and is it worth dousing the glow plugs in
WD-40 a few days before attempting removal and using that loosen quarter of a turn and winding the plugs tight and then loose a bit more each turn so the
WD-40 can get into the threads.
Ian Turner
ALike many glow plugs fitted to more modern diesel engines the glow plugs in your 1.9 Zafira are the longer thinner variety which can have a tendency to sheer-off a little easier than the earlier short and stubby counterparts.
For this reason I would first advise that removal should only be undertaken if needed and if this is the case then warming the engine and soaking the thread of the glow plugs before removal should help ensure that the job goes smoothly.
Once the plug is loosened then periodic reversal of the direction should help prevent the thread catching and will assist in the smooth removal, but it should be remembered that once loosened off, if a tight spot is felt, don’t increase the force to remove the plug, but gently back off and work the thread back and forth easing the thread along.
The first check would be to see if all the glow plugs are being operated, from the wiring diagram I have for your Zafira it would appear that plugs 1 and 2 are operated from one side of the control module and that plugs 3 and 4 are operated from the other side. With this in mind checking that all four glow plugs are being fed when the ignition is first turned on may help eliminate the possibility of a control module problem.
If all four glow plugs are being fed then the individual glow plugs can be checked using an ohm meter to determine if they are operating correctly. By disconnecting the feed wires to all the glow plugs then using an ohm meter between the feed terminal and earth point of the glow plug, the resistance of the glow plug can be checked. An open circuit will be easily spotted as a failed glow plug and the reading should be between 0.1-0.7 ohms. All the readings should be equal and an odd reading from one glow plug will indicate a problem.
As the problem has developed with the lower outside temperature it is very likely that the fault is the glow plugs, but it may also be worth checking the readings of the air temperature and coolant temperature sensors using a scanner if possible to ensure that these are correct.