hi i have an audi a6 1996, i checked my spark plugs today it has been about 15000 miles since i changed them all looked clean and fine but one of them was like i picked it up from mud really mud color brown with residue /sludge of some kind , i asked a mechanic he said the best bet is that the head gaskit is leaking and water is coming into the cylinder, well i changed the plugs to start off with i felt an almost 40 % increase in compression ( which i guess was due to that bad plug).

my question is should i use a block sealer and flush my cooling system if so please tell me what would work i would really appreciate it, thanks


awaiting your response guys,

 

Flushing you cooling system is always good practice, but what do you mean a block sealer? Is that an additive?

 

yes it is an additive used for repairing leaking headgaaskits and block seals, it supposed to prevent the block from leaking any anti freeze into the cylinder which is causing the sludgy sparkplug, thanks

 

You can use a sealer in the coolant yes, audi's DO NOT use antifreeze BTW. I don't know how much its gonna do for a leaking headgasket though. Just make sure you never use a sealer in the oil cause that can block your oil pick up tube and potentionally.........take out your engine.

 

i guess the best way to find out is that i should run the car as is for a week or so with the new plugs then i should check the level of the coolant and the condition of the same plug only if it is less i should mess wit5h the additive part otherwise jsut let it be what do you propose?

 

That sounds like a very good plan to me.

 

If you have a leaking head gasket and you keep driving it you can cause damage to it.The coolant in the cylinder will wash down the walls causing more wear to the piston rings. Once the coolant gets past the piston rings and into the oil, it will wash off the connecting rod bearings and you could "spin" a bearing. Not fun. I'd put in some bars liquid aluminum and pray. Otherwise the best bet is to get the head gaskets replaced (do both, don't ever just change one), have the heads milled, and probably since you are doing that, change the w/pump and t-belt at the same time since it's all going to come apart.

 

Ok, are you sure it's in the head, & not in the valve cover? If you have a leaking VGG, it will get on the plugs. Was it just the tip, or on the threads?

 

From what I've been told, the liquids you add to your coolant to "repair" leaks cause the gaskets to slightly swell. This may solve your problem inexpensively. I used it when I suspected an externalcoolant leak from the rear of the head gasket. That stopped the loss of coolant, but when I did my clutch (89k)it was discovered that the auxiliary coolant pump was leaking and it had to be replaced. The coolant was changedwhen the timing belt was replaced (96k). Car has not leaked any coolant since (just turned 100k).