sorry for the delay in reply,, I went thru about 1/2 gallon per week, I followed the directions exactly, it worked flawlessly,,good luck on your car.

 

Out of curiosity do you happen to recall whether you'd determined beforehand if the coolant seepage/leakage from the head gasket had been definitely leaking into a combustion chamber? Just asking... and thanks again for the suggestion, and followup info.

 

Just wanted to double-check and hopefully get a comment or two in regard to whether cranking the motor without spark plugs could damage the electronic ignition? Should I be concerned about that and do anything like maybe cover the ends of the spark plug wire boots with electrical tape so that they can't "short-out" to any of the surrounding metal? Do I need to maybe think about grounding the plug wires so I don't do something like burn up the coils?
What would be the best way to ground the plug wires? Perhaps a jumper from them to a frame or engine bolt?

 

For the few secs needed to inspect for water, the spark plug leads could remain unconnected.

Alternatively, pull the electrical connector to distributor, so no spark is generated. This may set some codes that will need to be cleared by pulling BackUp fuse (7.5A) in underhood fuse box

good luck

 

There appears to be two electrical connectors with wires going to the distributor. Which should I pull? Both? The one on the right in this picture has only two wires going into the distributor (one of which is black with yellow stripe), whereas the one one on the left has up to eight or so.

 

Unplugging both will not hurt anything. The plug with the blk/yel wire likely only needs pulled, but I would unplug both.

 

I finally performed a cold coolant system pressure test. I pumped the system to 16 psi and did not observe any external leakage and no drips/drops down below the engine. However, after 10 or 12 minutes I noticed the pressure gauge on the pump had fallen to 15 psi. I pumped it again to 16, again watched for any external leakage and saw none, and then after 20 or 22 minutes thereabouts I noticed the loss of pressure down 1 pound from 16 to 15 again.
I was going to crank the engine with all the plugs removed to see if any water might squirt up out of any of the holes. However, to my dismay, the #3 plug seemed rather tight compared to the others upon attempting to unscrew it. When it seemed I had unscrewed it most of the way, it became harder and harder to turn almost like it was tightening again. Afraid to continue, I reversed ratcheted it and screwed it back down, and I'm fairly certain it screwed back down in all the way.
I figure at the very least at this point I might go ahead and try turning cranking the engine with three of the four plugs removed to see if I see any water squirt up out of any of those holes. I've got the spark plug wire connections lying around on top of the engine like shown in the photo below. Will that be a fine situation for the brief time I want to do the cranking and observing for water squirt?



Also I took a pic of the three removed plugs:



Any comment/advice about the plug removal issue I mentioned, and whether a brief engine crank with those plug wires lying there like that should be fine, and maybe in regard to the appearance/condition of those three plugs would be appreciated. Oh and I almost forgot, any comment in regard to the coolant sytem pressure loss as I described. Seems that at least a quart or more of coolant has been "disappearing" every few weeks, with quite minimal daily short distance driving of the vehicle.

 

Plug removal issue is likely carbon on the plug threads causing binding. You might try a good soak of PB Blaster and allow several hrs to soak through. Warming engine for 2-3 mins before attempting to remove plug may help also. Work slowly, loosen/tighten on plug to hopefully push debris out of the way. See following video:


If you reuse old spark plugs, clean threads w/ wire brush and use small amount of anti-sieze on threads.

Coolant system test was not a positive leak detection IMO. Loss of 1 lb is easily possible w/ small temp changes of coolant unless it was dead cold. This test may indicate head gasket is not the problem (good news!).

Agree you should test other 3 cylinders while plugs are out.

 

When I did the pressure test I did it with the system dead cold, so shouldn't have been any temperature change of the coolant to account for the loss of the 1 lb. Further comment please?

I checked the three spark plug holes for any coolant squirting out while cranking the engine a few times. No coolant observed squirting out of either of those three holes anyway. With the coolant loss I've been experiencing though (as I've mentioned), the coolant has to be leaking somehow but no sign of external leakage with the pressure test. Will try working the stubborn plug out following the suggestion(s) just posted previously. thanks

 

A 1 psi drop in 15-20 mins is a very small leak. You need something else to confirm head gasket. If coolant is leaking to combustion chamber, some gases should be getting in coolant. There is a chemical test for combustion gases in coolant that may provide confirmation of a leak. Following video may be helpful:


good luck