My 98 Diamante has 165,000 miles on it. I have been having all the symptoms of a blown head gasket. It leaks oil and uses oil..1-2 qts about every two weeks. Rough Idle at start, BLUE smoke out the exhaust...oil is not milky, but regular oil (caramel) color. I have an appointment to have my mechanic look at it. He says it will be around $1200 to fix if it is head gasket. The water in the radiator is going somewhere, but I can't find any external leaks and like I said the oil is normal color. I don't know if its some kind of built in safety feature on this model car or what, but everytime I have an external water leak, the accelerator will stick somewhat when I stop at a light and then start up again. Anyone have any ideas?
RepairPal Certified shops can diagnose and repair your 1998 Mitsubishi Diamante. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
The symptoms of a blown head gasket are overheating, blowing coolant out of the radiator header tank, and coolant on the oil. The symptoms you describe are that you have oil leaks, probably from the valve covers for instance, a coolant leak which likely could be the coolant pump (you mantion 'external water leaks' - you mean coolant?), and sticky or collapsed piston rings allowing oil to burn in the combustion chambers and go out the exhaust. If the smoke is only at startup, it's probably just the valve guide seals are worn out - which would explain rough idle at startup since the plugs would be oil fouled. If it smokes all the time or just on acceleration it's piston rings.
And no, the accelerator pedal and the cooling system are not connected. There's something else entirely there.
Get your Mitsu specialist to look at it.
Here's a directory link for you:
http://repairpal.com/mitsubishi-repair-in-longview-texas
