2014 1.25 zetec petrol. 4 cylinder engine. 45,000 miles

Just checked the paper work with the invoices of when the car had a service back in 2021 ( it’s had another service 2 weeks ago by Ford).

But at the top of that invoice it mentions how They changed the spark plugs as it was only running on 3 cylinders. My concern is if it was running like that for a long time and if it’s caused any damage to the engine that might show up sometime in the near future.

i bought the car from a Ford garage so I’m hoping it’s ok. It seems to be perfectly fine when driving it but I’ve read that it can cause damage to the car if a spark plug goes and the car runs with 3 instead of 4 cylinders.

anyone got any thoughts on this?

thanks

 

3 minutes ago, Steven1212 said:

I’ve read that it can cause damage to the car if a spark plug goes and the car runs with 3 instead of 4 cylinders.

and where did you read that ?

It is very probably the reason that it went to the garage in the first place was because the owner knew there was a problem.

Just on a small point of interest the 1.0 Ecoboost 3 cylinder, actually runs only on 2 cylinders when not under load.

 

@unofix

A few online websites. Cos the fuel gets injected into the piston but doesn’t ignite and then ends up mixing in with the oil which leads to less lubrication so can cause damage to the piston rings / engine. Also something about the catalytic convertor. 
 

 

 

 

Plenty of modern engines use cylinder deactivation...VAG have been using it for a decade now.

Of course, they shut off the fuel injection to that cylinder to do so...but I'd expect the PCM on more modern conventional engines to do the same if it detects a constant misfire on one cylinder.  It's easy enough for the engine to detect a misfiring cylinder using a knock sensor and the lambda readings.  I don't know for sure whether the 1.25 PCM would or not, but I expect it does.

If the car passed the MOT emissions test ok then the cat was not considerably damaged by raw petrol through it.  And as you say it's running fine now, I doubt there was any internal engine damage caused at all.

 

Sometimes service history can cause more anxiety than it settles...  I once bought a car that had several parts replaced due to over-filled oil that blew oil seals all over the place...  I was always worried about the engine after seeing that in the history, but the engine turned out to be the most reliable part of that particular car!

@TomsFocus

ah thanks Tom 🙂 that’s kind of re assured me! Im only stressing as it was £8,500 which is a huge amount for me. And just want the car to last as long as possible. 
 

Thanks😊

 

Hi Steven, I was just curious to were you got the information about a non-working spark plug leading to long term damage. As Tom has answered the concern you had I'd say you have nothing to worry about.

20 hours ago, unofix said:

Just on a small point of interest the 1.0 Ecoboost 3 cylinder, actually runs only on 2 cylinders when not under load.

 

I thought it was the 1.5l Ecoboost in the ST, that had cylinder deactivation not the 1.0l. 

4 minutes ago, Jim H said:

I thought it was the 1.5l Ecoboost in the ST, that had cylinder deactivation not the 1.0l. 

No the 1.0 Ecoboost has it 🤣     The engine runs as smooth as silk, and absolutely no vibrations (well in the dreams of the Ford designers)

https://media.ford.com/content/fordmedia/feu/en/news/2016/11/29/ford-to-offer-fuel-saving-cylinder-deactivation-tech-for-1-0-lit.html

I’ve got the 1.25 not the 1 litre eco boost. And there’s several websites about how you shouldn’t run a car with bad spark plugs @unofix

I don't ever recall saying that you did have a 1.0 Ecoboost ?

20 hours ago, unofix said:

Just on a small point of interest the 1.0 Ecoboost 3 cylinder, actually runs only on 2 cylinders when not under load.

and there's several websites about how it makes no difference long term since as has already been said the engine will know there is a misfire and shut down the injector on that cylinder.

@unofix 

https://vehicleanswers.com/problems-change-spark-plugs/

https://vehiclecollege.com/can-bad-spark-plugs-damage-your-engine-all-you-need-to-know/

https://www.motorbiscuit.com/7-signs-you-need-to-replace-your-spark-plugs/

 

There’s  lots more online:)