89 Olds. Head Gasket or Intake Manifold?

My 89 Olds 88 with a 3.8 liter motor has either blown a head gasket or intake manifold gasket. There is antifreeze in only one of the cylinders by the firewall, the drivers side end one. I bought the car 4 years ago with 113K on it. It's never overheated and has 158K on it now. Seems kinda weird that the head gasket would go bad?

Can antifreeze get in the cylinder if it's a blown intake manifold gasket?

If it's the head gasket, can I replace just one side?

It's such a good running car, I hate to junk it.

More than likely it is the hd gasket as manifold gasket issue were not an issue in those years. I would do both while apart if you are keeping the car.

The intake gaskets on that motor will look like complete garbage... The old 3800's did not have as much trouble with them, but they still can go bad...

Drain the coolant, make sure you get all of the coolant out of that one cylinder and do a compression test.... See what you have... Head gasket failure on any 3800 is extremely rare... I would suspect the intake gaskets first...

Do the compression test to be sure...

I took the intake manifold off and the gasket is plastic. The rubber seals on the gasket in between the holes and such had deteriorated, and were like mush. I could see where the anti-freeze had been leaking into cylinder 6, cause the intake was really clean compared to the others. Installed new gaskets ($25), changed the oil, topped off the anti freeze and all seems to be well. It was blowing blue smoke for the first 5-10 minutes.....maybe the oil ring was stuck or rusted a little from the anti freeze in the one cylinder. I drove it hard for 5-10 minutes and it stopped blowing blue smoke.

Glad to hear you got it going... The smoke you saw was mostly from the moisture that had built up in the Cat Converter... Should be fine now...

Watch you MPG's tho... Its possible for the contamination to take out the O2 Sensor... If the MPG's start to drop you may need a new one... Steer clear of Bosch and or Standard if that happens...