Yellowish gunk in motor oil?

I checked my oil two weeks ago and it was fine (Castrol syntec). When I checked it again this morning, there was a thick gooey deposit on the dipstick, over and over (under a clear layer of oil). It had consistency of toothpaste and caramel color. What could it be and what's the best way to rectify this?Yellowish gunk in motor oil?
i own a repair shop,and it sounds like you have anti freeze mixing in your oil if this is the case then that means you could have a head gasket seeping a little bit on it,that's about the only thing that will cause that to happen to it,you may need to have a pressure check done on it to see if it has developed a small leak in a gasket,if it has now would be the time to get it repaired,if it is anti freeze,and you continue driving it like this,it will ruin the crank shaft in it and do more damage than its worth to it,you need to have it checked just to be sure good luck i hope this help,s.Yellowish gunk in motor oil?
your welcome. Report Abuse

Two possibilities come to mind,1st did you just make the change from organic to syn. If so it may be residual organic. 2nd could be an internal coolant leak(Like a head gasket) putting coolant in the oil.


Keep an eye on coolant level .
Water condensation, which for synthetics is common to have the two separated. If you are putting synthetics in an older vehicle, expect this problem, especially if you drive short distances. Driving long distances will allow the oil to heat up and boil the water out of the system. If you are a short distance driver, then you are waisting your money by using 100% synthetic oil. Change to a parasynthetic and save yourself 50% and get the same results.
Fix the broken head gasket or cracked block that is allowing coolant into the oil.
water, leaking head gasket
Sound like you may have water in the oil. Try changing the oil and if you see it again it means you need a new engine good luck
That happened to me too. Oddly I had a synthetic oil put in also. I would change the oil and go back with a regular oil. It never hurt the car that I had and it ran for years. I didnt change mine back, but would now.