Sweet smelling oil...additive?

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Oct 23, 2013
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I looked at a late 80's GMC with the 350 motor. I unscrewed the oil cap and ran my finger under the cover to check for sludge. A little came out, but the oil smelled sweet. The odometer says 125k. Is there an additive out there that will cause the oil to smell like that? Possibly to cover up a problem?
 
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Originally Posted By: bullwinkle
Antifreeze leak?
yeah that's strange. Antifreeze was my first thought too.
 
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Early on, the way to tell if you had the proper GC was the "gummi bear" smell...I've got some Caltex C3 synthetic 5W30 that when you get fairly close to it, smells of cheap confectionary also. In those cases, it's ester content...not sure how well it would travel in a used oil sense.
 
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grande prairie AB
I wonder what those oil additives in a can smell like. rislone, stp and the others like them. But coolant was my first thought. is the truck a good candidate for a crate motor swap or just a beater? I had an 81. Had a 350 in it. Nice truck
 
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Originally Posted By: tinmanSC
Originally Posted By: bullwinkle
Antifreeze leak?
yeah that's strange. Antifreeze was my first thought too.
+1
 
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IMO, Aromatics from burnt fuel, as a part of the blowby, that buildup on the oil. Maybe from toluene.
 
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01rangerxl

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IIRC, they have/had scented motor oil in Japan, but to my knowledge it has never caught on here. GM adds "grape scent" to their synthetic gear oil. I don't think that's what's going on here though. As others suggested, smelling a sweet smell in the oil on a late 1980s vehicle would have me concerned about antifreeze contamination.
 

MolaKule

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The esters I use for base oils have only this "fatty" smell to them. If it smells sweet, then it is coolant in the oil (head gasket leak), or an odorant was added(highly doubtful), or something like Rislone Engine Oil Additive was put in there.
 
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Joined
Jan 30, 2007
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Clovis, CA
Originally Posted By: 4wheeldog
Did it smell like wintergreen? MMO smells like that.
I always thought MMO smelled like Pepto Bismol.
 
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