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Oil for 4100

4K views 15 replies 6 participants last post by  carnut 
#1 ·
Hi all, the 4100 engine in my 84 Eldo has that thumping noise which is still very minor. Which leads me to two questions,

1. I am running 10w40 conventional oil, can I run something a little thicker which would hopefully get rid of the noise, or would that cause the motor to fail faster?

2. Once these motors start making noise, are they in danger of self destructing soon, or are they still fine to drive?

Thanks,

Darrell
 
#3 ·
Thanks for the reply. Good to know that it's just a noise I can ignore, unless of course it gets really loud. I will try that weight oil to see if it gets quieter. Would 20w50 be too heavy? Also, do I need to use ZDDP additive in these engines? Thanks again.
 
#4 ·
Motor oil already has zddp in it, just in lower percentages than in the past. I would only use a zddp additive in an engine that has flat tappet lifters. My thunderbird has flat tappets and I use Comp Cams break-in additive in the oil. I could be wrong, but I believe the 4100 has hydraulic roller lifters like the rest of the 4.x series..
 
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