Yellow oil

BMFB

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So, this is pretty neat

yellow-1.jpg


Motor developed a miss and I parked it. after some in garage work I fixed the issue (injector) This oil is pretty new (under 500 miles). I havnt lost any coolant that I can tell, and the engine runs likea top and still makes perfect oil pressure. stuff still feels like oil in my hands, except its this horrible yellow.

My first guess is water. The truck has green coolant in it and..ive never seen green collant do this to oil. Its usually a brown nasty color. Tonight when I get home I am going to drain the oil and do a pressure test of the coolant system. with teh valve covers off and see if I can hear it draining pressure into the block, or if its holding pressure at all. I do know the cooling system is making and holding pressure after its shut off so...its strange. I have no idea if the PCV system is actually working, although yellow is soemthing that hasnt happened to it before.

I did a compression test on the cyl. that was misfiring and it was fine. Also the engine runs like a top, doesnt seem to have any issues.

It does have some E85 smell to it (enigne runs on E85)

EDIT: some of you may rememeber my fram filter thread a while back. I do not think this is related as 1. the oil was not yellow. 2. the filter was missing the spring at the bottom of the can. the mottor ahsnt really run since then, its been parked mostly. This is what makes this so strage. it seems very sudden. I have no idea if E85 could do this to oil.
 

sy605

Member
Re: Yellow oil

From my experience you have water in oil. Cracked head, cracked block, blown head gasket. One of these happened. Do your coolant pressure test. Should reveal the issue.
 

BMFB

Not to scale
Re: Yellow oil

if it helps it wasnt foamy at all I dont think. It also was solid, as in no swirls or anything. It was like draining cheese colored...oil..out of the motor. it wasnt watery, it wasnt really sludgy either
 

Baythan

SY2TY2SY2TY
Re: Yellow oil

Obviously, you got cheese sauce in the block somehow. By the looks of it, i'm guessing Tostitos brand...but I'm no expert...
 

BMFB

Not to scale
Re: Yellow oil

I have no way to get into the garage today, and its 0F out. I manged to do an experiment at least. I took a bottlecap worth of oil and lit it on fire. It burned for a little while and boiled a bit. When it was done burning it was normal oil colored, and I couldnt set it on fire again.
 

BMFB

Not to scale
Re: Yellow oil

I did run it with a miss caused by a possibly stuck open injector for a few minutes
 

DanenGraham

Big in the rear
Coolant or water turns oil a white milky color. Alky turns oil yellow.


Stuck injector, or broken fpr would be the most likely, but maybe way to rich of tune, if he just did that.
 
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