[CutlassThunderbird]

Yes, I looked at the service records and it seems the old gentleman ran 20W50 in the 4.6. I guess mine has some worn valve seals? Since winter is coming, should I just switch to 10W40 plus a bottle of Lucas? I live in Arkansas so the temperature won't be too cold.

 

[XR7-4.6]

Bad seals or trying to mask a rod knock, I’d take it down to the recommended viscosity (5w30) and see how it behaves. Before you change it top it off with ATF for a few miles, it will swell the seals and the detergents will get out some sludge buildup. I did that before every oil change and it cut the oil consumption down quite a bit.

 

[SirRickyBobby]

Bad seals or trying to mask a rod knock, I’d take it down to the recommended viscosity (5w30) and see how it behaves. Before you change it top it off with ATF for a few miles, it will swell the seals and the detergents will get out some sludge buildup. I did that before every oil change and it cut the oil consumption down quite a bit.

I’ve never heard this before, but I’ll definitely try it because my Thunderchicken burns about a quart a week lol

No smoke though, weird.

Anyways how much ATF would you recommend putting in? How long would I leave it in for? Any certain types to avoid or to get?

 

[XR7-4.6]

I always put a full quart in the day before an oil change, and drive easy(it’s just about mixing it in and circulating it around) there aren’t any hard or fast rules with it. The detergent properties are all that really matter and any ATF will have them and have a swelling effect on the seals

 

[SirRickyBobby]

I always put a full quart in the day before an oil change, and drive easy(it’s just about mixing it in and circulating it around) there aren’t any hard or fast rules with it. The detergent properties are all that really matter and any ATF will have them and have a swelling effect on the seals

Thanks buddy, I love my chicken more and more every day. I just have to remember to check the oil. When I changed the oil yesterday only 3qts came out. Oops.

 

[racecougar]

Bad seals or trying to mask a rod knock, I’d take it down to the recommended viscosity (5w30) and see how it behaves. Before you change it top it off with ATF for a few miles, it will swell the seals and the detergents will get out some sludge buildup. I did that before every oil change and it cut the oil consumption down quite a bit.

^^^This.

And poor engine. 20W-50 didn't do it any favors.