<DIV id=post_message_17157>My mother-in-law has a 98 Grand Marque. It has been running very rough and the check engine light has been coming on. Also the heater is not working. I looked at it this weekend and there was antifreeze siting on top of the intake. It looked like there was a crack were the temp sending unit screws in on the left front side of the intake. She was also about 1 1/2 quart low on oil. So I toped off the oil and put some JB Weld on the crack. I also checked the coolant to make sure it was full. When I did this I noticed the coolant on top of the engine was green and the coolant in the resivor was a brown/rusty color.

Could someone have mixed the green antifreeze with the orange? Any one ever heard of these symtoms?</DIV>

You my friend have a cracked manifold. I had a 97 Grand Marquis with the same problem. From about 1996-2002 Crown Vics, Grand Marquis, and Lincolns all had plastic intake manifolds on them. You need to have it replaced. About a $400-$800 repair bill.