What oil are you running in your turboed 420a? I have a knock going on and I'm wondering if I use a thicker oil if it will help. I don't daily drive my car and just drive it for fun. I think this may help my problem until I can tear the motor down again.

I should have told you what oil I'm currently using. I'm running Penzoil 5w-30 right now.

Always 10w30 Mobil 1.

Thanks Dino, I was thinking of using some REALLY heavy shit to deal with the knock short term. Like 15w40 and some LUCAS, you think it may help?

Depends on what you mean when you say knock. Rod bearing? Nothing's gonna help. If it's fuel knock (i.e. detonation) then a thicker oil won't help.

Oh it's rod knock, when I first rebuilt the motor I checked 3 of the four sets of bearing and the set I didn't check was either bad or wrong and they scuffed up the crank. When I replaced them the crank was within .0005" of being out of tolerence. I took the chance that it'd be okay and I was wrong. After about 200 miles it started knocking again. I'm hoping that the thick oil will fill the void left between the bearing and the shaft. I'm not planning on taking the car far or to the track or anything. I had a friend die in a motorcycle accident a few weeks ago and there is a memorial car and bike show planned for him, I'd just like to get the car there and back home. I've got another motor built and waiting to put in the car and just haven't had time to put it in.

That heavy of oil may hide the knock for a bit, but it'll come back one nice cold morning with a vengeance. I wouldn't be surprised if you suddenly have a rod sticking out the oil pan

Originally posted by RoninEclipse2G
That heavy of oil may hide the knock for a bit, but it'll come back one nice cold morning with a vengeance. I wouldn't be surprised if you suddenly have a rod sticking out the oil pan

Yeah, I would expect that if I kept driving it. But I just need to drive it for an afternoon. Hell I've got new motor with JE's, eagles and new goodies as well as a portfueler and a new FMIC sitting here waiting on me. I need to get off my ass and get it done! lol

I run Royal Purple 10w-40 and it got rid of the lifter tick and other valvetrain noise I had.

Originally posted by flamineclipse

Originally posted by RoninEclipse2G That heavy of oil may hide the knock for a bit, but it'll come back one nice cold morning with a vengeance. I wouldn't be surprised if you suddenly have a rod sticking out the oil pan

Yeah, I would expect that if I kept driving it. But I just need to drive it for an afternoon. Hell I've got new motor with JE's, eagles and new goodies as well as a portfueler and a new FMIC sitting here waiting on me. I need to get off my ass and get it done! lol

It might make it like that. It might also be too heavy of a mix and shit itself right away because it doesn't want to push through the smaller oil passages. If you're just trying to limp it from one location to the other I would just try adding the Lucas to a 5w30 or 10w30.

Add warm fresh oil and some warmed lucas right before you get ready to go. Cold oil and lucas will likely spell a quick death. Either leave the oil and lucas in the sun for a while or warm each bottle in a pan of boiling water. Make sure to crank the engine a little with the fuel pump fuse pulled to get the fresh thick oil up in the bearings then replace the fuse and go.

Have a chase car to follow you in case of problems. I've seen cars with rod knock last a couple thousand miles and I've seen others not make it down the street.

I'm running castrol 20w50 at the moment. I haven't been driving everyday and only have about 300 miles on this oil but I'll be switching to mobile 10w30 one day next week. As far as the oil is concerned, I haven't had any problems out of it... but I haven't given it a real chance yet either.