Any of the other plugs have coolant on them?

 

No, I think they are losing compression between cylinders. But we also couldnt tell with those, as they all had gas on them. But you could smell coolant. Their is also and external coolant leak. Passenger side of car.

The two teeth off was verified by dodge dealership.

 

My 2000 Neon Two Intermittent coolant leaks turned out to be the water pump was putting a small grape fruit size spot on the ground in front of the passenger side tire. Never could find any signs of where it was coming from, but it was fixed after having the pump replaced while the garage was in there doing some of the 90K timing belt replacement, maintenance I didn't want to do. Its bearing had ever so little play in it. It had been intermittently leaking about 10K / 1.5 years before the 90K maintenance, so if your around, or past the 90K point, have the water pump replaced while in there to do the timing belt, tensioner & idler pulleys.

About a year later the Neon developed another coolant sipping problem I couldn't run down for about a year. Only once I found a small coolant sign drivers side front on one of the cam cover fasteners. Didn't make any sense where it was. Kept looking for signs every time I'd have to top up the over flow tank, but everything was dry. No internal signs, like milkshake looking foam behind the oil fil cap, or on the dip stick, or no foam on the dipstick & no sweet coolant smell on the dipstick, or from the exhaust, no signs on the spark plugs & no under hood stains.
The only thing I had noticed was the plastic radiator expansion tank had over the years begun to change color & texture, from a smooth glossy black, to a sort of light tan, non glossy cooked look on the drivers side top.

Came out one day to check things hot, after the wife got back from one of her severe service / short trip stop & go on a hot day drives & I let things Heat Soak about 20-30 min, Then raised the hood to have a look for weeps from the usual suspects, like the head gasket & smelled coolant. Looked all around found Nothing, but could smell coolant, standing there trying to figure out where it was leaking, I happened to look down at the drivers side top radius of the radiator expansion tank discolored tan cooked look area & caught a sign of a small area bubbling in that tan discolored area. It was in the airflow area between the hood & top of the radiator, so it could mist back between the engine & drivers side inner fender & evaporate, leaving no signs. I guess the one time I saw a tiny coolant collection just below the cam cover on that side that didn't make any sense for it to be there, was from it misting back after a engine shut down heat soak, with the vehicle parked with the front end up hill at just the right angle.
Anyway, if your radiator plastic expansion tank has any dull tan, cooked / grey look, inspect that area closely during a heat soak.

Turned out mine was leaking from a faulty knit line in the plastic part. The molder didn't have, or lost control of the proper mold, or plastic temp during molding, so as the plastic flowed around obstructions in the mold, it got too cool to knit where the flow met, so was weak there. The expansion tank flexes as it heats & cools, so over the years it sorta work hardened that area & it finally began to let go under a high temp / pressure, heat soak. The coolant would weep out in a really fine mist & evaporate, leaving no leak signs, but over time it would leak enough that the over flow tank level would slowly drop.

I had the same thing happen Twice on my 94 Taurus 3.8L radiator plastic expansion tank. That puppy had a bad part right from the factory & was replaced under warranty by the Dealer, then years later that tank developed a knit line leak just below the upper radiator hose attachment, but this time I caught the leak. Didn't use any more Ford tanks, replaced the Neon & Taurus with I believe it was American Radiator brand, from Advance Auto. Anyway their plastic expansion tank moldings looked fine to my eye, no molding error flow marks, or knit line flow marks to be seen, so looked like their molder had good control of his plastic & mold temps.

Long stories but good info for those of us that like to turn our own wrenches to look out for, when buying plastic molded parts, or assemblies with plastic parts, to check them for knit lines or signs the plastic has been cooked, or cold flow in the mold. Leave those plastic parts that operate under compression, pressure, or flex stress, on the shelf. The plastic parts shouldn't have any signs of material flow molded into them, they should be uniform all over, if the molder has good mold design & proper temp control of his material & mold.

 

We were smelling coolant on the other 3 plugs lol.

 

OK, well since the head gasket had supposedly been replaced, maybe check for a warped head especially if the engine has been overheated, or maybe the block isn't flat, or a faulty replacement gasket was used, or faulty work by the garage that did the work. Anyway sounds like you have a good suspect to move up to the top of your suspect list.

My previous long historical diatribe was to store in memory for possible suspect subjects, in case you, or others reading all this, turn out to have more than one coolant consumption problem, or develop another mystery weep coolant leak like I developed over time.

Keep us posted on how it goes.

 

It's still at the shop. I'm requesting they fix it. Properly this time.

 

BUMP:
Well Dave how is it going, 618 curious minds would like to know????

 

it went to another shop. Still no known cause yet. Although it's very strange. My compression data shows well below what the shop shows. The shop its currently at had well below standard compression but now it's back to just below normal.