[dkaile]

Spark Plugs Change - Comprehensive Guide - 40505kms - 17-04-2024

I had the Superb's original Spark Plugs lying with me for nearly 10 years now. They were the superior NGK Iridium Platinum variety, Made in Japan, part# PFR6Q which had a service change interval of 90k kms, just like the originals. So even though the originals were working just fine and still had more than half of it's life left in them according to their service schedule, I decided why to take any risk and get these changed anyways, as the car was 12 years old now.

So out came the NGK spark plugs. The main tool required to open up the spark plugs is the 16mm spark plug long socket with rubber grommet to catch the spark plug and 3/4" (or 1/2") ratchet and an extension piece -



This is the alternative Spark Plug part# if the above one is not available nowadays - PFR7S8EG for the 1.8TSI engine



First job was to remove the engine cover which is held by just 4 rubber grommets. You just pop them up to release -



Revealing the 4 ignition coils underneath -



Next disconnect the connectors at the back of each coil pack. Their locks are released by gently pressing the lock tabs as shown in the picture. I did it by hand -



After releasing the tabs you just gently slide them back as shown in the picture -



Now you are ready to take the coil packs out. Be careful not to bend them and exert equal pressure on the front and the back and very gently raise them to prevent damaging their insulation. Take the help (very gently) of a long screw driver IF necessary -



All 4 ignition coils are popped out as shown in the picture -



A view of them removed -



Their part# in case anyone is interested -



A view from the top after the coil packs are removed. The spark plugs are visible inside -



Now gently put in the Taparia ratchet wrench and the 16mm socket with extension and open anticlockwise to loosen the spark plugs fully. They clipped on to the rubber seal in my spark plug socket and I was easily able to pull them out.
Tip - You can also use one of the ignition coils to lift them out if you do not have a rubber seal in your spark plug socket -



All the 4 old spark plugs are out. Notice no yellowing or burn out of the white insulator part -



A closer look at their tips. Quite a good combustion color -



Here's the original Skoda/VW part# in case anyone is interested - 06H905601A -



The old and the new together -



A closer look -



Now I checked the resistance of both the old and new spark plugs, which is the best parameter to check the health of your spark plugs (as these are resistance based spark plugs). Here's the resistance of the 12 year old one, which is around 1.3Kohm, which is where it should be as per OE specs -



And then that of the NEW one; also around the same ball park -



Out came my trusty old WD-40 Contact Cleaner. This is an IPA based cleaner very similar to a Brake Cleaner. I used it to properly clean and store the old spark plugs for any emergency use, as they were still good enough -



Note the difference between the uncleaned one on the left and the cleaned old spark plug on the right -



Now the 4 NEW ones were ready to be fitted in the car -



But the 1st job always is to check the gap with my trusty old spark plug gauge. Although the new one's come gapped from the factory but still it is a good practice. The specs were to check the 0.8mm gap and only in 1, I found a very slight need for adjustment -



Next came out the Di-Electric Grease and the Torque Wrench -



Very little grease is applied at this point to provide a waterproof and air tight seal in the ignition coils, to prevent any corrosion -



I also had Anti-Sieze Lubricant which previously used to be applied to the spark plugs threads in older engines. But with modern engines which run on very very high voltage outputs (16~17k V), these can prove detrimental and best avoided, which I did -



Now torque wrench may seem to not be needed but is a very good idea. The perfect torque provides optimal heat transfer between the spark plugs and the cylinder heads. Too tight can lead to spark plug breakage and too loose can lead to compression loss and in some rare cases, the spark plug even blowing out of the cylinder block. The torque spec required here is 25Nm, just enough to the crunch the crush washer and I set my torque wrench to the minimum to achieve that -



The spark plugs were torqued down to factory specs -



The engine cover was put back on and the job was complete -



Final check was to crank the engine, which it did in half a crank (as earlier) -



Hope this helps fellow Skoda/VW/Audi/VAG car owners.

Cheers for now...

[jagdish_ker]

I would any day recommend replacing spark plugs early. I am not referring to the performance of the spark plugs. Over time, the aluminium cylinder head and the steel spark plug get galvanic corroded and disassembly becomes impossible. Worst case, you will have to end up removing the cylinder head to get the spark plug removed (spark plug breaking while trying to remove isn't a rare occurrence). This can be an expensive affair compared to replacing spark plugs more often.

[exhaustpipe]

Thank you for sharing this. I consider myself an amateur DIY guy when it comes to automobiles. I've been changing brake pads and undertaking 'normal' service on some of my cars. I find it therapeutic and fun.

On the subject of spark plugs, my C63s AMG recently started misfiring on 2 cylinders under hard acceleration. It turned out to be an issue of bad spark plugs. Which I had completely discounted because I changed them around 20 months and 7000 kms ago. They were replaced by Mercedes.

Comparing this fact with your post, it seems my spark plugs kicked the bucket way too soon. Any insights on why this happened?

[dkaile]

Originally Posted by jagdish_ker

disassembly becomes impossible.

Usually happens if they were never ever removed from the vehicle, unlike mine which were regularly cleaned and maintained. But once in 6 years should have been better, which is a OE VAG recommendation nowadays, even in a low mileage car like mine.

Originally Posted by exhaustpipe

Any insights on why this happened?

AMG's are performance vehicles and they will blow out spark plugs more frequently unless performance plugs are used. Seems normal to me.

Cheers...

[NomadSK]

Thanks for sharing.

A workman is known by the tools he keeps. It's good to see proper tools/instruments being used to do the DIY.

And the best part is you learn a thing or two while doing any kind of DIY's.

Just a suggestion use gloves/PPE while doing such stuff, fingers are the best tools (even eye glasses, if need be). I have hand gloves in my cars, at home for my gardening, for rescuing dogs and even in my gym bag, all for different needs.

[Jeroen]

Good job, well explained. Nice to see a torque wrench being used.

Jeroen

[Amrit@wheels]

Very well-documented post, dkaile. I am a big fan of your DIY guides and this is another excellent and very helpful post.