Second coil explodes!

[Corderoy]

Sorry about the sensational title but it's what happened.

This is the second time in two weeks that a coil has "failed" on this car (95 Seat Cordoba).

First time was an original vw coil/ign module - at least a couple of years old- second time was the pictured Bosch MEC717 controlled by the ign module off an original coil - I bought it second hand off an Ibiza (I think) as it was all I could get quickly. It ran fine for two weeks.

First coil blew after I'd left the ignition "on" for a few minutes, second one the same (I was trying to get the VAG-COM software to recognise the cable I'd bought).

The heatsink that the ign module was attached to was hot enough to burn (and blister) my finger.

There is an ignition problem but before I start troubleshooting I need to know if it's the norm for the coils on this era vw's to cack it after a few minutes of ignition "on"?

[h100vw]

I'd say no. They last for ages usually. They don't overheat and fall apart like on cars with points from years ago.

Gavin

[Golf Loon]

I`m not liking the crimped on connectors you have on that unit. I`d probably put it back to genuine.

The other thing is make sure there is an earth from one of the bolts that hold the coil on, going to the engine block. I have seen this left off, resulting in massive amps at the dissy,which is also bad for your coil.

[Corderoy]

I`m not liking the crimped on connectors you have on that unit. I`d probably put it back to genuine.

The other thing is make sure there is an earth from one of the bolts that hold the coil on, going to the engine block. I have seen this left off, resulting in massive amps at the dissy,which is also bad for your coil.

OK so the coils don't explode as a matter of course, lol.

Yeah the earth strap is/was connected.

The car died on Fri and because there was power to the coil but no spark I assumed the coil had died.

I got a Bosch replacement (another $60) from around the corner but still no go. I then persisted with the old coil for troubleshooting purposes.

I tested the coil with test light and no blinking as motor was cranked so the no spark prob is before the coil.

Installed VAG Com software and just before the car burst into flames (ok, ok... slight exaggeration) I managed to glimpse a Vag Com reference to a "Halls sender"... Hall's something, anyway.

Whatever happened to ign points?

Anyway, here I am furiously searching for info on Halls senders but the obvious question is would the Halls sender thing in the dizzy cause
1. the car to just die - no spark from coil (I think that the answer is yes)

2. the ign module to get that bloody hot (and the coil to self-destruct)?

If so, is the Halls unit in my dizzy a replacement item or does the whole dizzy need to be replaced?

[Golf Loon]

Its usually a Hall Sender code when the car is not on and so no spark is being registered.

Vag Com will tell you bugger all about that car.

You can get the hall effect sensor for the dissy, but they are $150+ from Boshe, whereas a secondhand dissy will cost you $120ish.

I reckon change the coil and all will be well.

[Corderoy]

Thanks for following up, Matt.

I'm happy to change the coil if that fixes it but I'm a bit worried about an underlying cause.

The original coil did the same thing.



It may be coincidence but I'd sooner not have to take up a second job to keep the car in coils

[h100vw]

You can buy hall sender for $20 from Jaycar if you are a bit handy with electrics.

Gavin

[Corderoy]

You can buy hall sender for $20 from Jaycar if you are a bit handy with electrics.

Gavin

Cheers Gavin.

I'm a "bit" handy with a lot of things... unfortunately not really good at any of them

I'll grab another coil anyway, but I'll also have a look at Jaycar's offerings.

edit: I just had a look at the Jaycar unit... it's exactly the same - I've removed my distributor and the Halls sender. An easy job to replace. Cheers again...

[Corderoy]

So, Halls Sender replaced and coil replaced (thanks Matt).

Thing ran like a dog at low rpm.

Check timing... it was a tooth out, now runs perfectly.