Technical Rough idle

[varesecrazy]

So to recap:

Its 93k with FSH
( so enough miles.. but general wear 'should' be minimal)

It ran great on purchase..

Had some drivetrain issues..

But this misfiring (rough idle) only started in last month

To be frank.. the clutch and gearbox should be unrelated.. unless they damaged something

Your coolant level will probably be key.. but as you mentioned 'dirty' plugs.. we can use that

Charlie

 

[rando]

So to recap:

Its 93k with FSH
( so enough miles.. but general wear 'should' be minimal)

It ran great on purchase..

Had some drivetrain issues..

But this misfiring (rough idle) only started in last month

To be frank.. the clutch and gearbox should be unrelated.. unless they damaged something

Your coolant level will probably be key.. but as you mentioned 'dirty' plugs.. we can use that

Charlie

Yeah im gonna get them out in a bit but i don't wanna replace them if they are gonna get fouled again(depending how they actually look when removed)

 

[varesecrazy]

A wash in petrol..or brake cleaner will be enough (after you have posted pics)

 

[rando]

This is what its looking like

 

[rando]

These are not in a great way but what has caused them to go like this is ny question

 

[jackwhoo]

These are not in a great way but what has caused them to go like this is ny questionView attachment 210300

Please post 4good pictures of the firing end of each plug numbering which cylinder they are from.

 

[rando]

1-4

 

[jackwhoo]

Is there oil leaking from rocker cover gasket into the holes the plugs sit in?

 

[jackwhoo]

Good pictures , thanks

 

[rando]

I've checked the holes for oil and there is none

 

[jackwhoo]

The part of plug we are interested in is the ground electrode , the centre electrode and the porcelain around the centre electrode.

The condition of the metal threaded part doesn't really give us any useful information.

 

[jackwhoo]

Plug 1 grey deposits on ground electrode and centre electrode indicate that this cylinder is burning some oil, though not so much oil that it is fouling the plug.
The plug electrodes are not wet with oil.
The colour of the electrodes look normal.

Plugs 2 and 3 look very clean possibly due to low miles they have covered.

Plug 4 looks ok too possibly a little grey deposits.

Ps deposites can be caused by fuel additives but would expect all plugs to look the same in the case of fuel additives

 

[rando]

The part of plug we are interested in is the ground electrode , the centre electrode and the porcelain around the centre electrode.

The condition of the metal threaded part doesn't really give us any useful information.

Let me know what more info you want whilst the car is apart

 

[jackwhoo]

Number 3 actually looks super clean ,

Is there any sign of cracking of the porcelain around the centre electrode?

Does the ground electrode have a slightly green tint?

 

[jackwhoo]

Let me know what more info you want whilst the car is apart

Those photos are good , I just wanted you to know which parts of plug I am looking at / talking about.

Good job

Jack

 

[rando]

Number 3 actually looks super clean ,

Is there any sign of cracking of the porcelain around the centre electrode?

Does the ground electrode have a slightly green tint?

Hi number 3 is in fair shape however it does have a slight green tint on the side and signs of the electrode being burned

 

[jackwhoo]

Hi number 3 is in fair shape however it does have a slight green tint on the side and signs of the electrode being burned

If none of the other plugs have the slight green tint on the side of electrode then it is possible that cylinder may have a very very small coolant leak into number 3 cylinder .
The super clean looking plug and green tint is a clue towards maybe coolant in cylinder.

Get a torch and look into number 3 cylinder so you can see top of piston, is it a lot cleaner than to of number 2 piston?
You may find it easier to see if 3 and 2 pistons at TOP of their stroke.

 

[jackwhoo]

Pictures of plugs after 10,000miles in a good engine

The yellow/green on the porcelain is normal.

If the electrodes are green that can be a clue .

 

[rando]

If none of the other plugs have the slight green tint on the side of electrode then it is possible that cylinder may have a very very small coolant leak into number 3 cylinder .
The super clean looking plug and green tint is a clue towards maybe coolant in cylinder.

Get a torch and look into number 3 cylinder so you can see top of piston, is it a lot cleaner than to of number 2 piston?
You may find it easier to see if 3 and 2 pistons at TOP of their stroke.

Don't want to sound like an idiot but how's best to look at this lol

 

[jackwhoo]

Don't want to sound like an idiot but how's best to look at this lol

Look straight down hole the spark plugs have been removed from , the thing you see is top of piston.