Mk3 GT6 Coil

[Guppy916]

Help please I ve just been out for a spin round the block about 20 miles and the car started to pop, bang & miss very badly, no power and didn't like ticking over, so I let it cool down and me calm down, 5-10 min started it up and drove off i only made 1-2 miles and it started again I just made it into  a lay-by, bonnet up the over flow bottle was full and over flowing a little, temp gauge working and showing normal temperature fan cutting in and out fine, so i thought has the dizzy moved timing out a bit nope ! all was tight, i grabbed hold of the coil and nearly lost the skin on my hand, so i let it calm down for 30 mins help arrived and followed me home and it started to pop and bang again my friend who was following me said it stank of petrol and black smoke , any idea's please

[Dannyb]

Check float bowls. Are they over flowing. Could be the float valves are sticking.

 

[Paudman]

If the coil is that hot, it may have failed. I had one on my MK3 that split and leaked oil everywhere. Try a replacement, and see if that cures things.

[Dannyb]

Forget my last post . I did not read the symptoms correctly. That's the problem when looking via my mobile. No coil should get that hot. I had a leaking coil but never got that hot so I expect it never lost enough oil. 

[Guppy916]

Thanks Daniel, i'm just going to check the resistance of it now

 

[Guppy916]

Right guys, I have 12.5 ohms across the + & --   and 8560 ohms across the + and ht connection, this is all measured cold, then with the engine running  13.5v  across the + and the battery neg

 

[glang]

Something is wrong with the coil as across +- should be around 3 maximum

[sparky_spit]

Agreed... primary resistance is 3Ω (1.5Ω if a ballasted system) and the secondary should be about 8KΩ. 

[glang]

A poor connection inside the coil with high resistance thats getting hot and causes a poor spark? Could also get worse as the coil heats up.....

[Guppy916]

that would explain the missing, no power, and a very very hot coil, i have ordered a new one from AccuSpark I will keep you all updated when it arrives 

Lucas 3 Ohm Gold Classic Sports Ignition Coil

DLB105 - £19.95

[glang]

With a bit of luck your ignition unit shouldnt have suffered as the current through the coil was low not high as in the case of shorted turns in the winding of the coil (this shows as a low resistance across the terminals)....

[Guppy916]

New coil fitted engine runs fine, just spotted the rad cap is  rated at 7Lbs a new 13Lbs is now ordered, This could be the reason my overflow bottle dumped some on the road.

will this make much difference running with Evans Waterless Coolant.

Are our engines  thermo-syphon cooling system, or what does this mean.

then I see at the bottom of Rimmer's Evans Waterless page this little comment 

' Not suitable for engines with a thermo-syphon cooling system.'

[nang]

No, our cars have a water pump. Thermo syphon is an old system which uses the principle of hot water rising and displacing the cold. (or something like that) 😆

Tony.

[glang]

shouldnt be any problem with waterless in our systems. However the bottle overflowing can be down to it being too full in the first place. About a 1/2 full when cold is good so theres room for the water in the system to expand into and the bottle wont overflow. With waterless of course as it doesnt boil the rad cap rating no longer matters..... 

[Guppy916]

Thanks guys, why dont Rimmer's and Evans, explain so simply, i'm off to the garage to play while the boss is shopping