If you have been following any of the VAG 1.8T / TFSI tuning scene over the last few months, you will have noticed a few posts on Facebook Groups such as 1.8T 20v Tuning and TFSI Tuning that there have been fake NGK spark plugs going round which have huge negative effects on stock and tuned engines. These are the ‘NGK Iridium IX’ spark plugs and the fakes are often found on eBay and other cheap online marketplaces. To a untrained eye, or someone who doesn’t check their spark plugs prior to installing them, these look the real deal and they are certainly very good fakes. However, we are going to highlight the differences between genuine NGK spark plug and the fake NGK spark plugs.
We have a couple pictures from some tuners who have highlighted this issue, so lets take a look at the findings.
The first one we shall look at is the top of the spark plug. If we look closely at the very top of the plug, we will notice that 3 of the 4 plugs have a small dimple/recession in them. These are the genuine NGK spark plugs. Look closely at the second plug from the left on the above picture. Notice the top is completely flat compared to the other 3? That’s the fake spark plug. This is a pretty good way of knowing whether the plugs you have are fake or genuine.
Lets have a look at our second image.
Plug number 2 (second from the left) if the fake one here. Occasionally, the threads on the spark plug will look damaged and it will generally look poor quality on the fakes with a poorer quality metal. A genuine plug will have a nice thread finish to them and the metal castings will be complete with no imperfections or defects. Another way to tell, which we haven’t got a clear picture of, is the stamping around the plug. The fonts are often different on the counterfeit plugs and the small line under the letter ‘P’ in Japan is shorter on the fake versions.
Here is a full body side shot of the plugs . Which one do you think is the fake plug in the picture above? You guessed it…. plug number 3 (from the left). Here we can see the detail in the top of the plug where the coil pack sits onto. If we look at plug numbers 1,2 and 4, we will see the shoulders where the coil pack sits onto are much more defined and have much stronger angles than plug number 3; which is the fake NGK spark plug. Eagle eyed readers will also notice the batch stamp number is different on the fake plug. M774 is the fake whilst the others are M71H.
Again, we have a close up picture of the shoulders of the plug where the coil pack sits onto. The fake plug, number 3 from the left, is much smoother compared to the other 3. Typically, the fonts and logos are much poorer quality than the genuine items, however, we don’t have any clear pictures of these on our sample set of plugs.
Here we can get a view of the sealing washers between the core of the spark plug and the threads that hold it into the cylinder head. We can see that the our fake plug (number 3) has a different sealing washer compared to the genuine items. The genuine washers tend to sit slightly down a touch whereas the fake will sit tight against the core of the plug.
This is a picture from Rich at Dyno-Daze in Leicester which was a plug from a Honda. We can see that there has been a catastrophic failure of the plugs threads and body of the spark plug, which again, highlights the cheap materials used in the manufacture of the counterfeit spark plugs. It was certainly a lucky escape for one customer!
Another common one which is worth looking out for is sooted up electrodes due to the poor spark produced by the fakes. This will lead to a build up of deposits around the electrode and could eventually end up in misfires or a rough running engine. The boxes the plugs arrive in also differs. ‘Usually’ the fake plugs arrive in a USA version of the packaging as opposed to the UK variant. Unfortunately we don’t have any pictures of this to show as a comparison, but once we get some, they will be uploaded here. Meanwhile, a quick google search between the two variants of packaging will show you the differences.
We hope this page has been of good advice to those who buy their spark plugs online through auction sites etc. If you are in doubt, you can always send images through to NGK customer support who will be happy to help and advise. Our advice is to always buy plugs from a reputable dealers or motor factors where you know the quality of the product is going to be right.
Our credit goes out to Niki Gower of R-Tech Performance, Leicester for supplying us and allowing us to use his images, with permission, of the fake NGK spark plugs.