Yellow Deposit

[Dick Whittington]

I'm just giving Christine a big oil service (1.6K SS) and decided to pop the cam cover to check the little yellow sponge by the Apollo breather. Needless to say it was not there.

 

But in doing so when I took the spark plug cap off of one of the spark plugs it was evenly covered in a yellow deposit. The deposit also evenly covered the outside of the well. The well is dry.

 

Immediately I thought HGF, but then when coolant evaporates it leaves a white deposit and it is not even. The colour is very similar to that found on a spark plug electrode.

 

Then I though that the spark plug must be loose, but it seems firm when prodded (I don't have a K-series spark plug socket yet). It looks like there is no deposit on the spark plug nut which would be exposed with the spark plug cap on, but it is difficult to see down there.

 

So I suppose the possibilities are:

 

1. The spark plug is broken or loose.

2. The spark plug has been broken or was loose in the past and the previous owner never cleaned up after fixing it.

3. Is is HGF.

 

Anyone seen anything like this or have another theory.

 

Dick

-----And all I ask is a fast car and a momo to steer her by

Racing is Life! Anything that happens before or after is just waiting

[Rob Walker]

Its is most likely that water has got down the plug hole in the head then dried out when the engine got hot leaving a fine rust deposit. This ususally happens when washing the car. Some owners put a dustbin bag over the cam cover when washing the car to stop the water getting in . Some also forget to remove it afterwards until it starts smoking. 😬

 

Rob

[Dick Whittington]

I'm not sure that can be right as only one spark plug is affected and the covering is too uniform. Also isn't a K-series mostly alloy except for the nuts and moving surfaces so no iron oxidation (rust).

 

Dick

-----And all I ask is a fast car and a momo to steer her by

Racing is Life! Anything that happens before or after is just waiting

[LazerBrain]

Which plug was affected, Dick?

 

I have a plug socket if you want to borrow it - I'm not far away.

 

cheers,

 

Darren.

[Tony Whitley]

Yellow? The deposit left behind by evaporated urine perhaps? I suspect "K Series Envy" by one of the Ford/Toyota crowd 😬

[Budjuggler]

Not me mate

 

Andy - 50% AR ReHaB

 

 

The Cat in front is a Toyota ....

 

 

[Rob Walker]

I think you will find that the threaded plug base is made from ferrous material. Go on worrying about HGF if it pleases you I don`t care

[Dick Whittington]

Darren, thanks for the offer I bought one now.

 

Rob, you are right 😶‍🌫️. I pulled the plug and there is a yellow ring around the machined top of the spark plug socket and around the next one along, but no coating on the well wall on that one. After nearly overheating on two separate occasions last year (both thermostats went) I think I'm a little HGF skittish. At least it is a 1.6, so it should be more resilient than the 1.8s.

 

I will post a photo.

 

Dick

---

And all I ask is a fast car and a momo to steer her by

Racing is Life! Anything that happens before or after is just waiting

 

Edited by - Dick Whittington on 1 Feb 2009 16:26:43