My wife noticed while raging and waiting in a fast food line for 20 min. that our 90 190 E 2.6 started to run rough. She also noticed the smell of antifreeze when the aux cooling fans kicked on. The temp was at the line above 80 (Est. 100) I confirmed and was able to make the car do the same a week later. But the problem wasn't showing itself and I went into a wait and see mode.

I just got finished putting in a new modulator and adjusting it yesterday (the bladder was broken and was sending ATF up the vacuum line into the intake manifold), when the above problem came out in force. I changed all the plugs today with Bosh Platinum 4's and changed the air filter (no change). I didn't notice any plug that was cleaner than the others. Two days now it has started rough, stumbles at idle and seems to get worse when hot. My first thought was that I had pulled or cracked a vacuum hose somewhere else on the engine when I rotated the trans. Butttttttt.

The coolant tank started to overflow today after I drove for about 20 min. and was at idle for about 5 minutes. (temp was at est. 100 when it started the overflow). This coolant overflow has got me thinking the head gasket is cracked. I don't see any oil in the antifreeze. The antifreeze hasn’t changed color. I do smell sulfur like smell from the exhausts system that wasn’t present before. No smoke from the tail pipe. I think the Oil pressure is running high at idle-just above 2 while in park, but I don’t know what normal was. Engine stumbles just like a major vacuum leak.

What should I be looking for as to more tell tail signs? Could it be a cracked head? How can you tell the difference? Any suggestions on where to start testing? Will a compression check show anything yet or does the failed gasket have to open up more?

I've Done a post search and read them all, this is my best guess. Please tell me yours.