Engine Performance problem
1997 Buick Lesabre 6 cyl Front Wheel Drive Automatic 180 miles

Hi. i have a prob with this old lesabre i picked up for one of my kids to drive. and so far am stumped..
this car has a series 2 3800 .the engine overheated and would not start. after doing a lot of diag i found.
fuel pressure 45psi
spark good spark at all plugs
injector pulse on all inj.
removed inj and all have perfect spray pattern
compression 120 on all cyl
no blown fuses
.

removed timeing cover timeing gears fine.
new crank sensor and cam sensor.


only code showed up on mt 2500 no cam signal

exhaust is not plugged

removed plantum intake chamber full of oily anti
replaced plantum gasket.
car started and ran fine.


until we put coolant in, then died same thing cranks and no start. no water in the oil.


do you think the intake gasket could be blown and internally leaking into the conbustion chamber.


this is the only logical explanation i can come up with
for the oil and coolant under the plantum.

well any help would be appriciated. thanks billymac