Spark Plugs.

[chuenyongman]

I own A Mitsubishi Lancer 1.8 litre engine. I have just completed 30 000 kilometers. Obviously it would have had new spark plugs when delivered. Around a month after taking delivery we had L.P.G. installed. We have had it regular servicing done at the Mitsubishi dealers. After about six or seven months when we took it to the dealers for a service they informed us it required new spark plugs. They fitted them. Last week whilst driving in the city, when setting off from being stationary the car was grossly under powered and stalled around 7 times. I returned it to the L.P.G,. installer. After inspecting the car he stated it required new spark plugs. The ones he fitted, on the spark plug box it stated they were suitable for C.N.G. and L.P.G. engines. Normally spark plugs last me at least 30 to 40 thousand Kilometers. Is there any motor engineers reading this post? If so could please throw some light on this post. I had a Mitsubishi Lancer 1.6 liter before this one. Completed the same kilometers before upgrading to this present car, The 1.6 car used factory installed C.N,G.Never changed spark plugs. Also to compare, my wife's niece bought a Proton vehicle at the approximately the same time as I purchased the 1.8 and she has driven around one hundred an ten thousand kilometers with only one new set of spark plugs fitted.

Thank you for reading this and your feedback. Gerry.

[Pomthai]

This is only an 'educated' guess, (though some might dispute that lol) I would imagine that C.N.G and L.P.G engines would have a tendency to run slightly hotter and / or leaner thus shortening the life of the spark plugs. Perhaps this is precisely why different plugs are specified.

[transam]

Having dealt with supercharged and nitrous injected V8's we found NGK plugs to be far better than anything else. Worth a try if you can locate a stockist......

[JAS21]

This is only an 'educated' guess, (though some might dispute that lol) I would imagine that C.N.G and L.P.G engines would have a tendency to run slightly hotter and / or leaner thus shortening the life of the spark plugs. Perhaps this is precisely why different plugs are specified.

No a bad guess ... run hotter so need a slightly harder plug .... even then the life of the plug will be reduced. You can use a slightly bigger gap when on LPG also.

[VocalNeal]

There are special plugs for LPG but here they are about B600 each. Solution use one grade harder than std and reduce the plug gap. The problem them becomes finding odd ball plugs so use normal ones with the gap less and change them every time you change the oil. Normal spark plugs are about B600 a set. Labour is inexpensive here.

Edited June 27, 2014 by VocalNeal

[BSJ]

Have your cooling system checked, including your thermostat, just to be on the safe side. Here in LOS the ambient temp is always hot. Plus your LPG engine will run hotter than a benzene engine. Plus your running the air con all the time.....and you have a p1ssy little radiator!

[ktm jeff]

When the main dealer (claims) he changed the plugs , did you see the old ones , and what new type did he re-fit . NGK iridium are the plugs to try ( code IEX ) and 1 number higher (hotter) than standard. LPG and CNG burn hotter (faster flame front).

[transam]

When the main dealer (claims) he changed the plugs , did you see the old ones , and what new type did he re-fit . NGK iridium are the plugs to try ( code IEX ) and 1 number higher (hotter) than standard. LPG and CNG burn hotter (faster flame front).

If I remember correctly the heat ranch numbers go the opposite way with NGK to other brands.

[Vacuum]

nigel jeffrey, on 27 Jun 2014 - 22:25, said:

When the main dealer (claims) he changed the plugs , did you see the old ones , and what new type did he re-fit . NGK iridium are the plugs to try ( code IEX ) and 1 number higher (hotter) than standard. LPG and CNG burn hotter (faster flame front).

That would actually be one number colder than standard.

[VocalNeal]

It is easy for NGK the higher the number the harder or colder the plug. So if the stock plug is say a BKR6E then for LPG use a BKR7E. The problem being is that unless the BKR7 is a common plug used in other vehicles it will not be super easy to track down. Which is why it is easier to continue with a 6 and change more often.

Have a 165,000 on one of our LPG trucks and have the plugs changed at oil change. Yes one can use "special" LPG plugs but the cost works out to be the same.

In the OP's case the stock plug for his car is Denso K16PR-U11 which is a NGK BKR5E rating plug. So it is easy as the Suzuki Carry uses a BKR6ES which is equivalent to Denso K20PR-U11 (and yes I know the NGK doesn't have a V groove)

So the OP can use plugs from the Suzuki set the gap down from 1.1mm to 1.0mm and change then at every oil change.

[transam]

https://www.google.co.th/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CDAQFjAD&url=https%3A%2F%2Fwww.ngk.com%2Flearning-center%2Farticle%2F225%2Fheat-range-conversion-chart&ei=3lyuU5zqHM6hugT404Jg&usg=AFQjCNHTCATZ_QdUSsOc2sPmFH47qOu7EQ

[Vacuum]

VocalNeal, on 28 Jun 2014 - 11:51, said:

So the OP can use plugs from the Suzuki set the gap down from 1.1mm to 1.0mm and change then at every oil change.

And the benefits of doing this would be ...............

[JAS21]

VocalNeal, on 28 Jun 2014 - 11:51, said:

So the OP can use plugs from the Suzuki set the gap down from 1.1mm to 1.0mm and change then at every oil change.

And the benefits of doing this

Read post No5 and then you can be as wise as the rest of us who have ....

Edited June 28, 2014 by JAS21

[VocalNeal]

VocalNeal, on 28 Jun 2014 - 11:51, said:

So the OP can use plugs from the Suzuki set the gap down from 1.1mm to 1.0mm and change then at every oil change.

And the benefits of doing this would be ...............

That you are following NGK's philosophy for spark plugs on LPG vehicles. You are using components that are already readily available.

Unlike me who can't easily find (so far) BKR7ES. I'm sure they are here but in Thailand when looking for stuff it is not so much where to look. It is who or what uses the thing you are looking for.

Edited June 29, 2014 by VocalNeal