[nzenigma]

@ChipMIK
sorry if you took offence to my direct comment. Unfortunately, your equally strenuous rejection of the stop leak solution came at a time when, once again, we were not getting feed back from the member who had made the original enquiry.
 Gerard (tw) and I spend a lot of time trying to decipher member's vague fault descriptions. We are getting quite frustrated with the self interest of the many momentary members who make use of the site and make this a thankless task.

 The solutions we provide should always carry this caveat : 'we cant see or hear the fault, cannot work on the car and this is our assumption based upon logic and/or our past experience'. If we haven't had experience in an area, we say so and try to point the member toward a more appropriate advisor.

ChipMIK the vague fault description along with the mechanic's diagnosis of a "porous head" leads me to believe that coolant is leaking into the cavity/recess for a spark plug.
The mechanic's comment indicates that he could see the leak, otherwise he would have mentioned possible head gasket failure.
The spark plug recess is at atmospheric pressure. Ignition pressure has no influence upon the coolant system unless the head gasket fails or the head warps or cracks. In such a case, the evidence will be wide spread.
 

Fair enough Gary..My thoughts are the spark plug is wet where the spark happens, which off course is inside the cylinder (think we can agree on that one ;-) :-D )...But lets see if the guy returns :-)

Dazzler...I have read your comment again regarding translating Gary´s post to me & initially my translation of it made it look like you gave Gary right...As i now realize that you werent, but just translating to "nomal" forum language, thats the reaseon for my post to you as i didnt understand why you would speak out that way...So if sorry for that from me is the right word, this is my sorry to you for that :-)

 

We are all good again. I'm happy about that. 

[/quote]
Fair enough Gary..My thoughts are the spark plug is wet where the spark happens, which off course is inside the cylinder (think we can agree on that one ;-) :-D )...
[/quote]

You may be right, we need the guy to return and clarify.  but my initial assumption was that the leak is in the plug recess on the outside of the head. Therefore, (assumed) seepage keeps the plug and ignition lead wet and therefore permanently misfiring. Usually an internal leak will be cleared once the motor is firing on the other 3 cylinders and #4 will then operate normally.
As you say, we wait to see who is correct. Good Luck

[Dazzler]

@ChipMIK

Thanks, no problems. In hindsight my wording could have been better. I also forget English is not the native language of many of our members. I think our members do a great job communicating in english all the same. 

[tw2005]

@ChipMIK

Thanks, no problems. In hindsight my wording could have been better. I also forget English is not the native language of many of our members. I think our members do a great job communicating in english all the same. 

[eye30]

Was it ever ascertained whether the water is just lying on the plugs in the recess outside which you can see if you look at the plugs from the engine compartment?

[tw2005]

Was it ever ascertained whether the water is just lying on the plugs in the recess outside which you can see if you look at the plugs from the engine compartment?

No, and Frustrating

[nzenigma]

Was it ever ascertained whether the water is just lying on the plugs in the recess outside which you can see if you look at the plugs from the engine compartment?

  :

[/quote]

[Dazzler]

Was it ever ascertained whether the water is just lying on the plugs in the recess outside which you can see if you look at the plugs from the engine compartment?

  :

[/quote]

  I see where you are coming from there Gary.. If it was only that I don't really think the Op would have much of a problem!

[dickdes]

If your going to pay that kind of money then i've a bridge  you could buy ,its in Auckland harbour . Go find a reputable non factory aligned garage .Build a relationship & buy your parts online.In a nut shell the dealer is trying to screw you  .Probably replace the spark plugs through the sump. If the head is "Porous " & i doubt it a can of radweld in the radiator would fix it .