red dust on ignition coils (picture)

[friendly_jacek]

what is it?

long story: ignition coils are known to be defective in 2006-2007 RAV4 and fail frequently under 100,000 miles. i replaced them all a couple of tears ago before a long transcontinental trip. most of them had that red dust between coil body and rubber boot. note it's not rust and it's bright red rather than rust-like in this picture in full sun. i assumed this was sign of failing coils.

fast forward to last weekend (20,000 miles later), i was playing with a cheap ebay boroscope and noticed one of replacement coils has a small amount of this red dust. everything else is great and the engine is very clean, no leaks of any kinds.

what the heck is it?

 

[OneEyeJack]

You're looking at the results of a bit of moisture and dust, rust.

 

[demarpaint]

Originally Posted By: OneEyeJack
You're looking at the results of a bit of moisture and dust, rust.


Exactly. Mine have a rubber 'o' ring there and I put a little dab of dielectric grease on it.

 

[friendly_jacek]

A. the picture is misleading. it's bright red when inspected in person.
B. the dust is between plastic coil and rubber boot, so no metal, no rust.
C. the spark plug wells are very clean and mirror like as there are no leaks and they are covered by the coil seal from the top, so no moisture whatsoever.

anyone else?

 

[Mr Nice]

Same color on a Honda.

 

[MolaKule]

The SE US has a lot of iron in the soil.

Airborne, ferrous-rich dust would thus be attracted to the highest voltage point in an automotive HV electrical system.

 

[OneEyeJack]

Survey sez, dust and moisture even in the smallest amounts added to a very high voltage field = rust.

 

[friendly_jacek]

OK, why i don't see the same thing in the other (3) toyota cars i have with much higher miles.

also, do you see it in your own cars?

 

[Ihatetochangeoil]

Originally Posted By: friendly_jacek
A. the picture is misleading. it's bright red when inspected in person.
B. the dust is between plastic coil and rubber boot, so no metal, no rust.
C. the spark plug wells are very clean and mirror like as there are no leaks and they are covered by the coil seal from the top, so no moisture whatsoever.

anyone else?

Originally Posted By: MolaKule
The SE US has a lot of iron in the soil.

Airborne, ferrous-rich dust would thus be attracted to the highest voltage point in an automotive HV electrical system.



OK, you've played with a "cheap ebay boroscope" and seem self-convinced it ISN'T "rust." Now why not prove it? Go get a magnet. RUST is slightly magnetic. https://www.youtube.com/watch?v=rTR-Mm_lQA4 Have fun. It is or isn't magnetic? Maybe even use a magnifying glass to tell. Let us know.

If you don't see the same thing on your other vehicles, perhaps it is a pertinent question to ask, have all the vehicles been driven to the same locations?

 

[friendly_jacek]

Originally Posted By: Ihatetochangeoil

If you don't see the same thing on your other vehicles, perhaps it is a pertinent question to ask, have all the vehicles been driven to the same locations?


the answer is: yes.

now what?

BTW, the dust is gone, like cleaned away.

 

[Eddie]

+1 MolaKule

 

[BigD1]

Originally Posted By: MolaKule
The SE US has a lot of iron in the soil.

Airborne, ferrous-rich dust would thus be attracted to the highest voltage point in an automotive HV electrical system.



Bingo. I thought it was iron too when I saw it.

 

[circuitsmith]

It could be insulating material from inside the coil that's migrating out through some tiny gap.
Could be related to early coil failure.

Reminds me of high voltage "flyback" transformers used in vacuum tube tv's from the mid '70s and earlier.
They were impregnated with wax for insulation; and near the end of the transformers life the wax would drip out.
If I serviced a tv and it had a puddle of wax under the trans (along with stalactite/stalagmite) I would recommend preventive replacement.

 

[friendly_jacek]

Originally Posted By: circuitsmith
It could be insulating material from inside the coil that's migrating out through some tiny gap.
Could be related to early coil failure.

Reminds me of high voltage "flyback" transformers used in vacuum tube tv's from the mid '70s and earlier.
They were impregnated with wax for insulation; and near the end of the transformers life the wax would drip out.
If I serviced a tv and it had a puddle of wax under the trans (along with stalactite/stalagmite) I would recommend preventive replacement.


thanks, this makes a lot of sense. i googled some more and found this image of failed toyota coil:

from here: http://www.yotatech.com/f2/ignition-coil-comparison-192526/

 

[Ducked]

That was instructive.

Reasonable hypothesis gets elevated to a "fact" without any evidence.... OP gets treated to some sarcasm...then some evidence turns up and ....

.....OOPS.

The rest is silence.

Lesson for us all.

 

[friendly_jacek]

Originally Posted By: Ducked
That was instructive.

Reasonable hypothesis gets elevated to a "fact" without any evidence.... OP gets treated to some sarcasm...then some evidence turns up and ....

.....OOPS.

The rest is silence.

Lesson for us all.


well, the lesson is not not everyone who is vocal in internet forums is an expert, but we knew that, right? we also knew herd thinking is common.

forgot to say, thank you all for posting. i didn't appreciate the sarcasm part, but it's typical here, so i got used to.