Hi all, I have serviced my focus today and I changed the spark plugs. Euro car parts listed the Bosch HR8MCV+ plugs as fitting my car, I fitted them but the engine wouldn't start instantly there was a prolonged cranking and then it would stumble when it finally started. I have refitted the FoMoCo plugs that came out (probably the original 90k mile ones) and it's fine again.

Which plugs are actually correct for my car please?

It's a 2012 1.6 ecoboost.

Thanks in advance for your help :)

Ford part number: 1685720. https://ebay.us/m/RonG7Z

I'll bet the ones you have are for the 1.6 Ti-VCT engine. ECP only sorts by engine size, not engine type.

38 minutes ago, TomsFocus said:

Ford part number: 1685720. https://ebay.us/m/RonG7Z

I'll bet the ones you have are for the 1.6 Ti-VCT engine. ECP only sorts by engine size, not engine type.

Awesome, thank you for that. I don't fancy spending £80 on spark plugs though so I've googled the part number and found the NGK equivalent. They're on sale at GSF at the moment so I've got the four for £47, hopefully they'll be correct, they say they fit my car so if they give me the same issue I'll take them back and then I'll have to bend over and spend £80 on spark plugs. Quite the difference to the £20 for four that I spend on my other car 🙄

Bosch HR8MCV+ spark plugs are indeed ordinary copper/nickel spark plugs for the older naturally aspirated versions of the Sigma engine.

To be honest I have never had any good experiences with Bosch spark plugs in most of the Ford engines.

Personally, I always stick to using only the spark plugs that the engine was designed for or that the manufacturer specifies. The Sigma engine family was developed in the early 90's as a joint venture between Ford, Mazda and Yamaha. These engines were originally developed with NGK spark plugs and the original FoMoCo (not the horrible Motorcraft spark plugs) spark plugs are also rebadged NGK plugs.

The correct NGK spark plugs for the 1.6 EcoBoost are the NGK 94769/ILZTR6A8G. These are dual precious metal spark plugs with an iridium center electrode and a platinum ground electrode.




The original FoMoCo spark plugs even have the NGK ILZTR6A8G stamped on the spark plug body.

5 minutes ago, JW1982 said:

Bosch HR8MCV+ spark plugs are indeed ordinary copper/nickel spark plugs for the older naturally aspirated versions of the Sigma engine.

To be honest I have never had any good experiences with Bosch spark plugs in most of the Ford engines.

Personally, I always stick to using only the spark plugs that the engine was designed for or that the manufacturer specifies. The Sigma engine family was developed in the early 90's as a joint venture between Ford, Mazda and Yamaha. These engines were originally developed with NGK spark plugs and the original FoMoCo (not the horrible Motorcraft spark plugs) spark plugs are also rebadged NGK plugs.

The correct NGK spark plugs for the 1.6 EcoBoost are the NGK 94769/ILZTR6A8G. These are dual precious metal spark plugs with an iridium center electrode and a platinum ground electrode.




The original FoMoCo spark plugs even have the NGK ILZTR6A8G stamped on the spark plug body.

I have just edited my above reply but I've actually just ordered those NGK ones, I've always used NGK in my other car and been happy with them. They were £47 for four Vs £80 for the Ford stamped ones, I'm always happy to find out the original part can be bought cheaper elsewhere. Plus free delivery tomorrow and 4.3% back by going through top cashback, What's not to like?

Be aware that counterfeit NGK (and also other brands) spark plugs are a growing problem. These have been around for quite a while, but this problem seems to increase.

Especially the more expensive precious metal or dual precious metal spark plugs are being counterfeit because of their relatively high pricing. I therefore recommend to only buy the spark plugs from a reputable source and to avoid unknown eBay sellers.

There are numerous online sources about how to recognize the real and counterfeit NGK spark plugs.

Spark plugs arrived and fitted, all working as it should so thank you all for your help 😀