T-Bird 4.6L w/ hi mile oil?

[Tremo]

I'm going to be changing the oil for a friend. She drives a 95 T-Bird with the 4.6L SOHC engine. It has about 150k on the clock. I'm thinking of going to Wally's and geting Pennz 10W-30 High Mileage oil and a Motorcraft filter. Do you experts agree on this?

The car does have some consumption issues. It doesn't visibly smoke and I see no leaks on the concrete where it's parked, but the oil is going somewhere.

What say you? Thanks.

 

[williar]

I'd recommend Pennzoil 5w30 HM. It has the same viscosity as their 10w30 HM at 100 C., but a substantially lower vis at 20 C., with only a slightly lower HT/HS. If it's really going through oil like a fool then use 10w40 HM.

 

[Bdiddy]

I can bet the reason the Tbird is consuming oil is because the valve guide seals are shot. 94 - 95 4.6s are notorious for it. Alot of people seem to say that thicker oil won't really help, the only thing to do is replace the seals. Also, in my experience, my Tbird really does not seem to like thicker oils, I'm actually thinking of going with Ford's recommendation and switch to a 20 weight.

 

[darkdan]

He's correct. It's the valve guide seals.

I'm sure they're past the point that high mileage oil or autorx could fix them.

 

[dickwells]

Any oil higher than 5wx would not be good for this engine if it ever runs in a cold climate.

 

[JohnnyO]

I would go with the Pennzoil HM 10w-30 and Motorcraft. Just keep an eye on the oil level if you can since it's burning oil.

 

[Tremo]

The car will be driven in the California Sierra foothills. Coldest winter nights are about 25 degrees F. Is the 10W-30 still OK?

 

[darkdan]

Yeah, I use 10w30 in my crown vic's 4.6. No problems.

 

[MNgopher]

Yep, bad valve guide seals. This engine was made before the "fix".

In any event, in that climate, a 10w30 will work fine.