While it’s not a M-B I’m sure many in this forum have opinions on motor oil. It’s an early 80’s Cadillac with the 4.1L engine that has a bottom end knock at idle when warm. I can’t hear it when cold or if I rev the engine so I assume its excessive clearance in the bearings somewhere. Since it doesn’t knock when cold at which time the oil is thick, why not have the oil thick like that all the time (discounting the cold start problems for now) by using 50 or 60 weight or even 70 weight oil? This is a cheap beater so actually fixing the problem is not an option.

i wouldnt go right to something that thick, but i would definately step up a couple of viscosity levels.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Hi there,
Those 4.1 engines had a problem with cam bearings. The cam bearings would come loose in the block and slide endways on the cam. My brother had one- the front cam bearing had come clear out of the block and the engine lost oil pressure because of it. It was still running ok but with a knock when I took it out and put a 4.5 engine in. They fixed the problem on the 4.5's. So it might not make any difference, or might not even be a good idea to put heavier weight oil in. If it's a leaky cam bearing, all the heavier oil will do is starve the mains. If you do go with a heavier oil, don't go TOO heavy, you might regret it!

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Richard Wooldridge
'01 ML320
'82 300D 4.3L V6/T700R4 conversion
'82 380SL, '86 560SL engine/trans. installed
'79 450SL, digital servo update
'75 280C

I'd try a nice 20w50 from Walmart. If its a beater you have nothing to lose.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

NO.

Here is where you need to post this question.

http://www.cadillaclasalleclub.org/

http://www.cadillacforums.com/



Have a great day.

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Yep, treating the symptom and not the disease is the way to go in beaterville.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

he said up front it is a beater... already.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.