Read the plugs

[eltax91]

Hi all

I’ve had a bit of a rough idle issue in my 2.4 Accord. The old girl had 155k on the clock and is an auto, so the rough running also means a pulsating through the whole car when the car is creeping in drive/ pulling off the line slowly. As soon as I put 20% throttle or more down its fine and picks up just fine.

So as they was service time today I thought I’d change my plugs too. The rough running is slightly better now although not what I’d call ‘fixed’. I think I may have another issue.

However, I’ve pictured my plugs below. The plug on the far left (cylinder nearest the crank pulley and aux belts) came out with a small amount of oil on it above the thread where the coil connects. Question is, do the condition of these plugs tell me anything about the health of the engine. They’ve been in the car in for some time, 2 years and 50k+ Miles.

[J4CKO]

I just had an NGK R conk out causing mine to Misfire like mad.

[anonymous-user]

don't look too bad to me given the mileage

It's worth running some BG44k additive through the system. Swear by that stuff!

[grumpy52]

Give it a proper full service , if it has them dizzy cap , rotor arm , ignition leads , all filters ( inc fuel ) and stick a fuel cleaner down it . Give it a good hard thrashing , it's not called an Italian tune up for nothing .

[eltax91]

lord trumpton said:

don't look too bad to me given the mileage

It's worth running some BG44k additive through the system. Swear by that stuff!

Possibly. Car is gas converted though so I’m under the impression it burns much cleaner and in theory shouldn’t much of an issue? I’m not ruling out valve stem seals or anything else ultimately, but it runs flashlube to counteract the hotter temps of the lpg system and I’ve yet to try anything else yet, so not tried new coils or looked at the Maf/ map sensors yet

[eltax91]

grumpy52 said:

Give it a proper full service , if it has them dizzy cap , rotor arm , ignition leads , all filters ( inc fuel ) and stick a fuel cleaner down it . Give it a good hard thrashing , it's not called an Italian tune up for nothing .

Today I changed the oil and filters, incl the lpg filter. Can’t change the petrol filter as it’s sealed in the tank (barely ever runs on petrol anyway).

It gets a regular hammering to the redline, don’t you worry about that

[Squishey]

As mentioned above, at 155k the coil(s) and HT leads are probably starting to break down. I've had similar problems with high mileage petrol cars - new plugs, coils and leads have sorted it out.

[eltax91]

Squishey said:

As mentioned above, at 155k the coil(s) and HT leads are probably starting to break down. I've had similar problems with high mileage petrol cars - new plugs, coils and leads have sorted it out.

This engine is coil on plug, so no leads to worry about. I’ll look into the no doubt hugely expensive coils.

[sunbeam alpine]

Is it my eyes, or do some of the plug gaps look a bit on the big side?

[eltax91]

sunbeam alpine said:

Is it my eyes, or do some of the plug gaps look a bit on the big side?

Trick of the lens I think. They were all uniform. I’m sure there’s an issue elsewhere as this seems to have improved the rough idle but not taken it away.