Ignition coils melting...pls help

[Mr_E85Bim]

Gents,

Any idea why my coils look the way they do? Should I be concerned?
I discovered this while I was changing the valve cover gasket (was leaking oil into first park plug well) and spark plugs. I discovered that the spark plugs have never been changed

The front of the engine looked stained as in pic below. I assume this is another issue? Or the cause?

 

[Chris_D]

Blimey!
Lots of varnish at the front end around the vanos and the coils look like they've been looking at the business end of a blowtorch!
The intake vanos looks like it has a heat concentration due to the level of dark varnish. I'd suggest you have buggered seals causing excessive friction leading to an over-heating issue.
Is your engine running hot with the temp gauge higher than the middle point?
I'd suggest getting an OBD tool on it with live reporting. Get it up to your 'normal' running temp and observe.
You shouldn't be seeing anything more than 94-98 degrees C for the coolant temp, even under sustained load.
When was the last time you had a coolant flush/change?
What colour is the coolant and is the level ok?

It looks like you have a wide/varied selection of different coil types/brands there, suggesting someone has tried to remedy the over-heating issue previously by simply replacing borked coils.
In any case, I'd get it to a specialist rather than trying to diagnose it myself I think. Someone who can check if you have a vanos issue and the if the motor is down on power etc.

 

[Chris_D]

You don't mention what your mileage is but for comparison, here's my top end, sparkers and coils at 105k miles and in 'rude health' I would suggest.

 

[raymond.harper]

With the plugs getting older perhaps the coils allow more current to pass through which is why they are getting hotter. Hopefully, the engine oil is not the same age as the plugs.

 

[Mr_E85Bim]

Thanks gents!

Currently on 79k miles.
I did discover that the coolant was quite low a few months back. The floating stick was barely popping up it's head! Added sufficient amount of blue coolant. But judging by the spark plugs, I would be very surprised if it has ever had a coolant flush.
The temp gauge sits happily in the middle. Uave never seen it go past that point. Even at motorway cruise for a number of hours?

I will plug in the Carly and go for a drive later. Get a reading of what the running temp sits at.

Hopefully, the fried coils is just due to old plugs. I replaced the most damaged one with a new one. So will take a look at it next weekend. Should be plenty of time for it to fry a little if the problem still exists?

 

[Chris_D]

I'd suggest you don't really want to go 'destruction-testing' on a 20 yr old car.
Get it seen to by someone who knows what they're looking at.

 

[j3nks79]

I’ve seen them like that when the o rings let oil down the tube and it cooks the rubber on them.
Also the dark stains is because it’s not had regular oil changes. Seen it alot on the S54 engines

 

[Mr_E85Bim]

Thanks Chris. She's a relatively inexpensive project so I will take it slow and see how the new coil looks next weekend. If it looks torched too, even after replacing the o rings as J3nks suggests is the cause. I will get her to a specialist

Thanks J3nks! I can confirm oil changes have not been carried out on a regular basis

 

[j3nks79]

Check them in a few weeks but it’s all nothing to worry about