Oil weight question
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Racer
Joined: Sep 2010
Posts: 327
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From: se iowa
Oil weight question
Hello all I recently got my rebuilt tranny shoe horned back into the car and had merely to time it and adjust the tv cable and I was good to go. Things sounded good yesterday in the engine. This morning my Dad convinced me to drop my oil-5-30 and put in a heavier oil-15-40. When the motor was cold I had no issues. Since I put some miles on it now I'm getting a knocking from the engine. He says it sounds like a cam bearing.
This knocking is only present at higher rpm's-if i just sit there and idle I can't hear it. So I'm wondering if the heavier oil is causing me issues, did the cam bearing just decide this would be a good time to shoot craps or is the fact that I've been running on a mail order tune finally catch up to me.
This knocking is only present at higher rpm's-if i just sit there and idle I can't hear it. So I'm wondering if the heavier oil is causing me issues, did the cam bearing just decide this would be a good time to shoot craps or is the fact that I've been running on a mail order tune finally catch up to me.
Le Mans Master
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If the knock was internal to the engine it would be present all the time. I would start checking other items, especially ones you took off during the tranny repair.
Regarding oil weight, 15w-40 is way too thick for these engines. If its a stock or close to stock rotating assembly the bearings are setup for 30wt oil. Anything thicker is just causing more friction and more heat. I use 30 wt in my race car and I have had zero issues with oil temp or pressure under hard racing conditions. If yours is just a street toy 5w-30 is perfect
Regarding oil weight, 15w-40 is way too thick for these engines. If its a stock or close to stock rotating assembly the bearings are setup for 30wt oil. Anything thicker is just causing more friction and more heat. I use 30 wt in my race car and I have had zero issues with oil temp or pressure under hard racing conditions. If yours is just a street toy 5w-30 is perfect
