New sparkplugs

[guest1809]

Hi everyone,

I've recently bought NGK BKR6E-11 sparkplugs and did the change myself couple weeks ago. It was a 30 min job and went without any problems. However, in the meanwhile I've noticed that in comparison to the ride before the change, my car lacks power and MPG has gone down. I don't know what could be wrong since i did the change very carefully and only thing that comes to my mind is the following. According the manual the gap should be 1.1 and since the sparkplugs I've bought are pregapped tot 1.1 i thought it's a perfect fit BUT the gap of the old sparkplugs is  0.04. So was my choice of the above mentioned sparkplugs wrong, is the manual wrong or am i missing something?

BTW my car is GD1 , 2005, 1.4 dsi, (135000 km)

Thank you all in advance for you replies.

[culzean]

always gapped the plugs on my DSi to 1.1 mm - but one question how did you manage to change 8 plugs in 30 minutes      I always check the gap in pre-gapped plugs anyway just in case.

[guest1809]

I've checked the gap as well and it was 1.1 so no problem there. Regarding the 30 min job, well it wasn't  really hard and it went remarkably smooth.

[Pine]

You did change all 8 sparkplugs? 30 mins is quick for a DIYer.

[guest1809]

Yes I did, all 8

[JazzyB]

they say they are pre-gapped but I  have always found they are wrong and have to re-gap them

I suggest you re check them all to 1.1mm.

[guest1809]

Thank you for your reply. Before placing them i've checked and they are all pre-gapped at 1.1 mm. I wonder why the old sparkplugges , which were changed by the official Honda garage were gapped 0.4mm.

[dg]

wild guess, possibly ECU self-adjusted to 0.4 gap?
try and disconnect battery, reteaching ECU, 3 min at 3000rpm, driving around for 10 min, or something like this

[guest1809]

@dg:

Is that possible??? I have a ODB II reader connected to my phone by BT(torque app), and i don't get any error codes, and all read-outs seem fine.
I'll try to do what you suggest, it can't do no harm. Thanx!

[dg]

relearn procedure as described in hanes:
1) start engine and run at fast idle(3000rpm) until it reaches normal operating temperature
2) let idle with all loads switched off for 5 min and longer than this if radiator fan comes on during this time
3) drive approx 5 miles of varied driving conditions

[culzean]

Have never 're-taught' an ECU in my life, the best thing to do is just drive in your normal style for a few days and the ECU will soon adapt.  Modern ECU's are continually learning  and adapt to engine conditions and fuel 'as they are now', that's why when you put in higher 97 or 99 octane (remember 95RON is minimum octane for most modern high compression engines) the car adapts quickly and your MPG and general responsiveness get better almost straight away.

[culzean]

I wonder why the old sparkplugges , which were changed by the official Honda garage were gapped 0.4mm.

I am assuming you have got metric feeler gauges ?  it is just that 0.040 inches (40 thousandths of and inch) is 1mm

[guest1809]

@Culzean

Now that is possible, i will check it tomorrow, great idea. Thanx.

@dg

Thank you once more for the info i will try it tomorrow.


I have noticed that on the highway, driving 60mph, where in the past i was getting fuel consumption readout of  5l/100 km now I'm getting 7.4L/100km. So the problem could be in the ECU "learning" process.

[olduser1]

Like many owners I always ask what changed what did they change when faced with it wont go-
If this fault only appeared following the spark plug change - you can always reinstall the old plugs and see if the symptoms disappear - after all its a 30min task.

[guest1809]

Thank you all for your replies and tips.

I didn't reset my ECU as suggested but i made some longer trips on the highway and the consumption fell down to 5.3l/100km at the speed of 100kph so that's almost like it was before the change. However the consumption in the city is still quite high 8.5l/100km. So i think that if this issue has something to do with the learning process of the ECU that just driving should do the trick, otherwise i will put the old sparkplugs in as suggested and check if it gets any better. But this time I'll try to do it in 25 min