Spark plugs - change how often?
Humbug - 19/2/10 at 04:31 PM
As subject. The Haynes manual for my donor says change the plugs every 60,000 miles or 4 years. I've done 6-7,000 in just over 4 years. Do I
really need to change them? Will it make any difference? I haven't noticed any obvious ignition problems so far.
TIA
Simon
Marcus - 19/2/10 at 04:39 PM
I change my crossflow ones every year. The k series are long life, so they will be ok for years, BUT it may be worthwhile taking them out once in a
while to make sure they don't sieze in the head.
GreigM - 19/2/10 at 04:53 PM
quote:
Originally posted by Marcus
I change my crossflow ones every year. The k series are long life, so they will be ok for years, BUT it may be worthwhile taking them out once in a
while to make sure they don't sieze in the head.
I agree with this - change them every year - makes sure they don't get stuck and mess up your engine when you try to change them later
britishtrident - 19/2/10 at 05:15 PM
Depends --
K series can have copper core or platinum/iridium.
Copper core plugs won't last much beyond 15,000 miles with out risking a misfire. And should be re-gapped at half that mileage.
With long life platinum or iridium MG-Rover gave conflicting information exists depending on what model's service schedule one looked at.
Rover 75 & MG ZT - 60,000 miles
Rover 25 & 45 & MGs - 30,000 miles
Personally on a K series I would not trust platinum plugs beyond 30,000 miles and would re-gap at 15,000 miles,
Recommended plug gaps are
Rover K16 with coil packs & KV6 1.1mm (0.044"
Ealier pre 1999 Rover K8 & K16 with a distributor 0.8mm (0.32"
Personally I recommend also gapping plugs on cars with coil packs at 0.8mm to avoid excessive HT voltage taking out the coil pack.
NGK Plug types are
Copper Core BKR6E-11 or BKR6ES
Platinum PFR6N-11
-11 sufix on an NGK spark plug type indicates plug pre gapped to 1.1mm
[Edited on 19/2/10 by britishtrident]
britishtrident - 19/2/10 at 05:18 PM
quote:
Originally posted by GreigM
quote:
Originally posted by Marcus
I change my crossflow ones every year. The k series are long life, so they will be ok for years, BUT it may be worthwhile taking them out once in a
while to make sure they don't sieze in the head.
I agree with this - change them every year - makes sure they don't get stuck and mess up your engine when you try to change them later
Plugs getting stuck only realy happens to any degree on engines with tapered seat plugs such as the Fiesta Endura/Valencia engine and the early BL O
series.
This is the main reason tapered seat plugs went out of fashion with engine designers.
The K series uses washer to seal the plugs to the head so don't suffer from the problem.
In any event Platinum plugs are a bit to expensive to change too frequently
[Edited on 19/2/10 by britishtrident]
Humbug - 19/2/10 at 05:37 PM
Hmmm - thanks for the replies but I am not much further forward. To change or not to change? When I built the car I put in new plugs: Champion Eon1
701 like
, supposedly OK for "up to" 36,000 miles. They have done less than
7000 miles so far.
I suppose my original question should have been: do spark plugs deteriorate more with age (in which case the length of time is the key factor) or with
use (in which case I can happily leave them in for a while longer)?
britishtrident - 19/2/10 at 05:57 PM
Really not the plug I would have chosen for a Rover engine, but has they have been ok I would advise leaving well alone but change them around 12,000
miles.
If your car has a distributer just put a a set of either NGK BKR6ES or the X-Part equivalent plug in gapped to 0.8mm
If your car has coil packs X-Part Platinum plugs were originally fitted so either fit X-part Platinum plugs or NGK Platinum or Iridium.
ianclark1275 - 19/2/10 at 07:31 PM
i use NGK everytime
they do deteriorate
running rich fouls them up and it will misfire.
cliftyhanger - 19/2/10 at 09:07 PM
Another vote for NGK. I am surprised the champions have lasted this long
morcus - 19/2/10 at 09:23 PM
Spark plugs aren't expensive so why risk keeping them in too long?
britishtrident - 20/2/10 at 10:33 AM
quote:
Originally posted by morcus
Spark plugs aren't expensive so why risk keeping them in too long?
Actually good quality Platinum or Iridium Spark plugs are relative expensive about four times the price of copper core plugs.
On platinum and iridium plugs the rate of erosion of the spark tip is less than 1/10th that of conventional plugs.
Mazda dosen't specify any spark plug changes or plug re-gapping in its service schedules "the long life platinum plugs fitted should
last the life of the engine".
britishtrident - 20/2/10 at 10:45 AM
quote:
Originally posted by cliftyhanger
Another vote for NGK. I am surprised the champions have lasted this long
Champion are actually very good plugs but since the 1960's they have always lagged a few years behind NGK in technology. However they tailor
spark plugs more to individual applications than NGK.
Champion are particularly good for plugs for, lawnmowers, chainsaws and outboard motors. If you ever have have a US made two stroke outboard motor
don't use anything but oem spec Champion spark plugs in it.
My order order of preference when buying plugs is NGK, X-part, Champion, Unipart, Denso, Bosch and I don't touch anything else if it can be
avoided.
Champion actually make X-part and Unipart plugs but the X-part plugs for the K series engines are different from the plugs Champion sell for the K
series.
Mark Allanson - 20/2/10 at 11:53 AM
I think plugs have changed their technology in recent years, You used to be able to just brush them up , check the gaps and reuse for ages. Modern
ones seem to fail like lightbulbs, I was driving the Golf at a steady 80 and suddenly I was running on 3 cylinders, a new set of VW plugs cured the
problem - cheaper to buy OE than aftermarket