Thread: Disco3 Spark Plug Question

These motors have Iron block, Aluminium alloy heads.

Have replaced mine with NGK TR55 and no issues, so the plugs should be correct.

Clearly yours are contacting something on the way in, can you place a phone camera or similar through the open plug hole to check for any obstructions? I cannot see any way you could thread them in on such an angle as to deform the ground electrode like that.

Did all of the old plugs come out easily? Sometime they can partially disintegrate and leave a portion within the head. Rare but certainly possible.

Well I'm just bloody confused....

*A second pair of eyes on the job may well help.
*As a lot of plugs on petrols are long lasting, putting some anti-seize on the thread helps with putting them in by hand and removing them in another 100K.
*I have always used the Ford Motorcraft AGSF24N, they are easy/cheap to get from your local Ford dealer.

Thanks for the replies.I agree that a second (more experienced) set of eyes will no doubt help.

The plugs I pulled out were a little stiff on the way out but nothing ridiculous. I may try some sort of grease or anti seize to help the threading and hopefully that will be all it takes. I will also get the phone camera in to see if there's an obstruction. Plugs that came out look ok though and don't present like something has come loose from them.

Ive thrown my hands up and will put the car on a truck to the mechs on tuesday. Dont want to make any problem worse. Will just pray they dont tell me i new new heads!!

I will give you all the report when the mystery is hopefully solved. Thank you for your help

Sorry to hear of your dramas. Interested to hear the outcome. Good on you for having a crack anyway

Originally Posted by Disco3Cat09

Ive thrown my hands up and will put the car on a truck to the mechs on tuesday. Dont want to make any problem worse. Will just pray they dont tell me i new new heads!!

I will give you all the report when the mystery is hopefully solved. Thank you for your help

I'm holding off doing mine until I hear from you - not even looking at them at the moment!

Ok. So I got the car back from the mechanic today. Turned out he needed to do some work on some threads to get the spark plugs back in. No new heads thank god! New pugs, the labour and bonnet gas struts set me back $660. Not smiling but not crying. Was told that generally it was not an easy job. Most likely because of how long the plugs had been in there. A hot engine ended up being the trick apparently even if it ended up resulting in burnt hands (not mine at least!).

The downside is the car has been returned with an error message for an intermittent misfire on cylinder number 5. What this means in real terms is at idle the engine feels like sh%^&t. But when driving it's fine and runs at normal revs at speed. The car is back to the mechanic tomorrow to trouble shoot and will most likely result in a replaced coil pack and labour that will be another $500! : (

Out of interest, anyone know the cylinder numbers of the 4L v6? I checked online and thought it to be:

Firewall
3 6
2 5
1 4
Grille

I'm just curious which cylinder number 5 would be.