98 Grand Prix GT 3.8 Burning Oil

Hello,

Having a lot problems with 98 Grand Prix GT 3.8 Series II. Mileages: 315345. Rebuilt Premium Long Block installed at approximately 170000 miles.
Currently, it is burning oil badly. Found a black film on the trunk (keyhole section) and rear bumper. While running a car for about an hour trying to locate a oil leak, it began to smoke badly leaving black spot s on the floor (had car on jack stand in front…was underneath when I observe this). Took to a mechanic (quick assessment), he indicated head gasket and heads rebuilt is needed.

Trying to determine if something I should do myself (no labor cost, no extensive experience).

Also is more investigation needed (periodically get a misfire from one cylinder, comes and goes)? Primarily check on plug, wire and coil is okay. Mechanic indicates probably same issue heads.

Any suggestions or comments are appreciated.

As always thanks in advance.

It's time for new valve stem seals, and valve cover gaskets.

If you go with an external PCV filter and plug the air duct works, she might not burn as much oil.

Be interested to know how you go about that with the setup on a 3800, with the MAP mounted on the PCV valve....

Unusual to see oil leaking out of heads, to create that much of an oil leak....sure it's not leaking out of the oil pressure switch and being flung up towards the head on the passenger side?

Plug the air duct work with the MAP sensor.

Hello,

Appreciate the response.

Daneilsatur, thanks for the suggestion. I will look into it. Also, correct.

Tech II, the oil leak is another issue (a long list). I am currently working on that as well. I recently replaced the oil pressure switch.

Performed the compression test last night. Most cylinders were 160 (two were lower). One was at 150. The one with the misfire was 60 and did not change with the wet test. Must be where the valve problem is located.

How evolve is the removal of the heads on the 3800? How long does it take?

Again thanks in advance

A bad PCV system could actually vacuum oil/gases from the crank case and contaminate MAF, or MAP sensors,thus burning more oil.

Compression looks good, the heads are a pain to remove, I would consider a ''In the car valve stem seal replacement''

You don't need to replace the Head bolts, gaskets, and waste time.

Daneilsatur,

Is the cylinder with 60, okay? You may have missed this portion concerning the cylinder with a misfire.

Thanks

60psi is bad, it could be a bad valve, or spring.

170K miles, you might get away with pulling one head.

danielsatur, thanks. Appreciate the help.

Can anyone recommend a good shop to rebuild heads in the DFW area?

Again thanks