Thread: 98 GTP burning A LOT of oil

Hey guys,

I have a 98 GTP with about 156K. I bought about 4 months ago and have put about 4500 miles on it. I drive it on the interstate 95% of the time. I've noticed that I am consuming about 3/4 - 1 full quart of oil in that time. I am not entirely sure what would cause this. I was thinking bad intake gaskets as I know these are notorious for failing. However, I am not sure if those could cause consumption. Any help would be greatly appreciated.

On top of this, IF I had to replace the intake gaskets are there any other items I would or should need to do while doing it? The guy I bought it from said the front valve cover had been updated per a GM TSB, which I did confirm. However, I have a loud engine tick/knock on acceleration. It doesn't do it while at idle. This happens even when the oil level is full. I have been told that the lifters can flatten out over time and cause a tick? I am not sure on this. I was worried it was piston slap but it definitely sounds like it is under that front valve cover. Any guidance on this issue would also be greatly appreciated.

Thank you.

Ill try and post a video at some point soon. It's tough to hear from directly under the hood unless I have my ear to the valve cover or a stethoscope. It's very prominent inside though. I'll see what I can do.

And as for the oil consumption. A quart every 3000 is one thing, and I have actually heard that, but 1 quart every 500 miles is excessive. I'll probably end up resealing it this summer. I'm no master tech but I know enough to keep my head above water. I appreciate the feedback!

The ticking might be a leak/crack in the rear exhaust manifold. I'm pretty sure I have a crack in mine on my 00 GT. It'll wait until I pull the motor out to find out tho, lol.

pull the spark plugs and read em. theres a difference between a tick and a knock. if its a knock on acceleration that could be rather not good.
a video with quality sound could help us. if you could get us some sound from under the hood in park with it idling, then rev it up and let off a few times and also holding about 3k rpms.

get it up on stands/ramps and see if theres oil underneath from any location,too.

I did forget to mention the smoke. I guess I haven't paid a lot of attention to the rear on start up but I see quite a bit in the mirror when I accelerate. It definitely has the smell of burning oil from the tail pipes.

I know watched a video of a rather crude way to check for piston slap with a long object down a spark plug hole but IDK how accurate that is or if I can even get anything in the holes with they angle they are at.

I will do a little investigating when I get home for good in a few weeks and update on the issue and ask any additional questions. I appreciate all of the feedback! Great forum!

Originally Posted by FordMan77

The ticking might be a leak/crack in the rear exhaust manifold. I'm pretty sure I have a crack in mine on my 00 GT. It'll wait until I pull the motor out to find out tho, lol.

I don't believe it's an exhaust type tick. It definitely sounds like valve train. But I will do some more thorough checking in the near future. Thank you for the input!

Originally Posted by tomsteve

pull the spark plugs and read em. theres a difference between a tick and a knock. if its a knock on acceleration that could be rather not good.
a video with quality sound could help us. if you could get us some sound from under the hood in park with it idling, then rev it up and let off a few times and also holding about 3k rpms.

get it up on stands/ramps and see if theres oil underneath from any location,too.

I did pull a spark plug about a month and half ago and it looked brand new. However, I didn't pull all of them. I may do that and see what they tell me. Thank you!