Hi,
I have a Megane Cabriolet 2001 1.6 16v that is running rough. I suspect it is the pencil coils that are breaking down. I have cheched them and I have 2 different makes. One been Renso and the other Sagem. What are the best pencil coils to use that dont give problems?
Thanks
Dave
It is difficult to judge the condition of a coils by testing its resistance simply because as it heats up its performance can change dramatically and won't be under load so to speak during the test. Most people either check the colour of the plugs or disconnect each in turn to see if there is any difference is engine speed. The ones that have the least effect when disconnected are the most likely to be duff
looking at my haynes manual. presuming yours is a k7m engine, (my manual only covers series 1 scenics,) the ht coil resistance
terminals 1 to 2 , 0.5 ohm
terminals 1 to 3 , `1.0 ohm
terminals 2 to 3 , 1.0 ohm
ht terminal to ht terminal . 10 ohm
does this make any sense, thats how its explained in the manual
looking at my haynes manual. presuming yours is a k7m engine, (my manual only covers series 1 scenics,) the ht coil resistance
terminals 1 to 2 , 0.5 ohm
terminals 1 to 3 , `1.0 ohm
terminals 2 to 3 , 1.0 ohm
ht terminal to ht terminal . 10 ohm
does this make any sense, thats how its explained in the manual
Thanks for the reply.
I have checked on all 4 coils and on the 2 low tension leads the resitance varies from 1.3 ohm to 1.6 ohm
When the car is running I have disconnected each coil in turn and it does not matter which one I disconnect the missing is worse so I am not sure which one is causing the problem. Either all or none.
Another problem that happns every now and then is that while driving, all the gauges drop as if the ignition is off and the reserver petrol light icomes on. This lasts for about a second and then returns to normal. Any ideas on what can cause this? I have reset the computer but this has not helped.
The only pencil coils I can get here in South Africa are the Sagem coils. I dont really have a choice unless I order over the net. Where can I order the Beru ciols from and what is a good price to pay?
The gauges dropping suddenly whilst driving is very unlikely to be a coil problem - it sounds very much like a sudden voltage drop. This could be down to a poor earth connection somewhere. I suggest you check out all battery terminals and fuses - plus check the engine earth strap is sound - it is usually situated around the gearbox area. Have you any way of getting the engine compresion tested
Thanks. I will check all the electrical connectors. With the miss file could it be the TDC sensor or the HT leads? If yes to the HT leads I need some assistance as I know the old style HT leasds from a distributor not on cars with pencile coils.
Te fact that when you disconnect each coil in turn and the engine runs rough would denote the coils are working OK. Its defefinitely worth checking the TDC sensor as it is a common problem and in many cases seems not to be detected by diagnostics
Theres no point in disconnecting the the coils one by one to check for a misfure as they are wired in pairs,so if you disconnect one you disconnect a pair.The way to check for a misfire is to reach down at the front of the engine and disconnect each injector in turn,this will show up the cylinder that has the problem.