Spark plug change

[paulred33]

Hi everyone. Last night I tried to change my spark plugs.  I followed a guide for the vw up.  Got the air filter off and removed the 10mm bolt holding the coils on. But i've found it impossible to get the rubber boot off the spark plug. Pulling as hard as i can the coil pack comes off the rubber, but the rubber is stuck firm on the plug.  Tried using pliers and a squirt of wd40, but no movement it just stretches. Does anyone have any advice to remove it?

[ronime]

Silicone spray and then a hot engine.

[Hyphons]

Was the same with me, @Updown789 changed mine, think we ended up pulling it off with pliers 

[Updown789]

Literally just keep pulling until it releases I think, although as Hyphons says I think I grabbed hold of the rubber with pliers

[paulred33]

So everything started well.  I went to Tool Station and bought pliers and silicone spray. 

[paulred33]

With the engine warmed up.  Spray applied, i pulled as hard as possible. Then disaster, the rubber part tore.

I have come up with a solution with might help others.

Compressed air! Put an air nozzle into the rubber boot this blows it up stretching the rubber off the spark plug.  

[Emil]

I wouldn't change spark plugs when aluminum cylinder head is hot. Not good for the threads.

Edited 4 September, 2017 by Emil

[ronime]

10 minutes ago, Emil said:

I wouldn't change spark plugs when aluminum cylinder head is hot. Not good for the threads.

 

In over 30 years of changing spark plugs I have never stripped a thread in the cylinder head. I have found it easier to remove the plugs when the engine is hot or very warm but will admit that at the pace that I tend to work at on my own cars the cylinder head is a lot cooler when then spark plugs go back in ...

Edited 4 September, 2017 by ronime

[paulred33]

I'm waiting for new coil packs to arrive. I put new spark plugs in and left them a finger tight. So engine will definitely be cold when torqued. Does anybody know what the exact torque setting should be. Spark plug box says 25Nm is this too much?

[Vitas]

I usually tighten them until you can feel the washer fully compress. (not sure if this is the right way but i've not had a plug come out yet). However, i'm in the same boat, don't want to damage my coil packs by pulling too hard. Does anyone know how to get that darned hose off of the bottom of the air box? i'ts been driving me crazy

Edited 4 September, 2017 by Vitas

[ronime]

12 hours ago, paulred33 said:

I'm waiting for new coil packs to arrive. I put new spark plugs in and left them a finger tight. So engine will definitely be cold when torqued. Does anybody know what the exact torque setting should be. Spark plug box says 25Nm is this too much?

 

On NGK plugs with a crush washer it used to be a quarter turn to compress a new washer and an eighth of a turn for a used plug.

Edited 4 September, 2017 by ronime

[Emil]

30 years ago spark plugs were replaced more often than for new modern engines. These days we go 60 000km or more with same same plugs. Wouldn't you agree that it increase the risk to pull the threads out when you remove spark plugs from hot aluminum cylinder head. Well at least I'm not going to change my way to change plugs. Then again, I have changed spark plugs only 30 years I guess. 

[Ootohere]

Even in these times of modern plugs and ignition coils i still use a Dielectric Grease sparingly as my Journeyman taught me in my first day as an apprentice.

(Apprentice Mechanic, not Custom & Excise.)

Edited 5 September, 2017 by Headinawayoffski

[paulred33]

Just looked on google for Dynatex dielectric grease and it's on eBay for £27 seems a bit steep. What about copper grease?

[Ootohere]

No to copper grease.

You only need the smallest tube of dielectric grease if you only change plugs or the likes once in a while on a 3 or 4 cylinder car or when there is a blue moon.

Use sparingly, watch Youtube vids on what it is.

£5 on Ebay. Amazon or a Local Motor Factors is plenty to spend on a DIY sized tube.

 

PS

Not for this application, ie Spark Plugs / Coils / Electricity, but when you need Grease for rubber, that is Red Grease you want.

Edited 5 September, 2017 by Headinawayoffski

[ronime]

According to the Dynatex TDS it is a dimethyl polysiloxane compound. In other words it is good old silicone grease. Plenty of silicone greases with dielectric properties available for much less than £27 e.g. 

 

http://cpc.farnell.com/dow-corning/2793695/silicone-compond-dc4/dp/ME18609

 

http://uk.rs-online.com/web/p/greases/0494124/

 

Red rubber grease is safe on rubber but is vegetable oil based, often castor oil which turns into a gummy mess after a few years. I switched from red rubber grease to Ceratec (another silicone grease) for brake caliper sliders some years ago.

 

Edited 5 September, 2017 by ronime

[ronime]

4 hours ago, Emil said:

Wouldn't you agree that it increase the risk to pull the threads out when you remove spark plugs from hot aluminum cylinder head.

 

Err ... No.

 

Why would the thread be prone to stripping when removing the spark plug? Unless it is corroded in, in which case hot or cold probably makes little difference to the outcome.

[Ootohere]

Ceratec is an alternative and properly so to copper grease, not really to Red Grease.

[ronime]

Yep, used as intended (as an anti-sieze compound for static asemblies) copper grease is effective and economical. Keep it off the moving parts though (and rubber).

[Emil]

16 hours ago, ronime said:

 

Err ... No.

 

Why would the thread be prone to stripping when removing the spark plug? Unless it is corroded in, in which case hot or cold probably makes little difference to the outcome.

 

 

Err...  Have you ever heard heat expanding?

 

And big no for anti-seize for the threads. Except if car manufacturer recommend to use it, which I doubt. 

[ronime]

19 minutes ago, Emil said:

 

Err...  Have you ever heard heat expanding?

 

 

I sure have. I am also aware that aluminium and steel have different coefficients of thermal expansion.

[Emil]

Spark plug hole is smaller and spark plug is bigger when engine is hot. What it might cause? Let's think about it. 

[Breezy_Pete]

Wrong. Everything gets bigger, the spark plug hole more so.

[Emil]

Let's agree we disagree. 

[Breezy_Pete]

Ok, but I suggest you research the matter.