Water in the oil - troubleshooting

Discussion in 'Chevy C/K Truck Forum' started by Big6ft6, May 7, 2012.

  1. catmechanic07

    catmechanic07 Former Member

    Im confused! You all keep talking about him having oil in the coolant. The thread title says "Water in the oil"......Think about it: If you had oil in the water, you would possibly have an oil cooler, intake, or crack in an oil galley close to a water galley. Oil has more pressure that is capable of putting pressure into a cooling system. Your cooling system has less pressure than the oil system so.......you wont be as likely to have oil in your water. If you do, those are possible causes. Water in oil....as the thread says, more than likely is a bad head gasket (more than likely), possible intake gasket but not too likely, cracked block that the crack expands when block is hot. An engine with 163k miles is much more likely to have a blown head gasket or cracked head than any other issue.

    Does the oil look "milky", show streaks of oil/water mix on the dipstick, have a smell of antifreeze in the exhaust? I have seen large engines run with no smoke in the exhaust and have bad head gaskets. Just be careful with loosing water. Could sit on top of a piston and either lock the engine up or possibly do worse.
  2. Big6ft6

    Big6ft6 Rockstar 100 Posts

    Well, I pulled the lower radiator hose and let about a gallon of coolant run out. This was after the engine cooled down. I was dissapointed to not see any obvious signs of oil in the coolant. It was a darker green, like a forest green as opposed to the neon green of new coolant, but otherwise still fairly clean looking. Definitly not what I would expect if there were 3 qrts of oil in the coolant. Except since I let the engine cool down, is there any chance all the oil is floating up at the top of the engine. Still I would've expected some sign in the coolant that poured out.

    So much to my wife's annoyance, I did a compression check. She just loved holding the baby and listening to the engine cranking over for 5 seconds 8 different times. I'm happy to report that each cylinder was almost exactly 150psi...a couple were slightly less 145ish. All the plugs were very clean, a couple were chalky whitish.

    So get this....I get done checking the compression and now it won't start!!! WTH?? I did one plug at a time so no chance of swapping wires. The only other thing I did besides take out each plug was detach the primary plug wire from the coil. I hooked up my timing light to check for spark and have none!! It just turns over and over. What could I possibly have done during the compression check to cause my ignition to poop out?

    Anyway, back to the water in the oil. So now I'm questioning whether I really had water in the oil. So I poured the oil from the collection pan into a clear container to look at in the morning after it has a chance to settle and separate out, but it sure looked/acted like water when it was coming out of drain plug.
    Last edited: May 8, 2012
  3. Big6ft6

    Big6ft6 Rockstar 100 Posts

    This morning, the oil that I thought had water in it did not appear to have separated much...maybe there was no water (coolant) in the oil after all? But where in the heck did 3 qrts of oil go? I bought the truck 3 weeks ago and the guy said he had just changed the oil....I didn't ask, he just offered that in conversation so it seems unlikely he was lying. But the oil that drained out was black, seemed to be runny like water at times, and most importantly 3 qrts low!

    It seems the oil is going somewhere because I drove the truck for 300-400 miles before the low oil experience.

    So if no oil in the coolant and 150psi compression in all 8 cylinders and no visible oil in exhaust.... now what?...just drive and keep checking the oil level I guess.

    And for the truck not starting....somehow the ignition module failed during my compression test...could've been coincidence, or for some reason taking the primary plug wire off the ignition coil and cranking the engine during the compression testing killed the module. Every other ignition component passed the diagnostic, the module was all that was left. Luckily I had an old distributor in the garage and was able to scavenge the module from that distributor and it fired right up.
    Last edited: May 8, 2012
  4. catmechanic07

    catmechanic07 Former Member

    Your all over the place with this thread........
  5. Big6ft6

    Big6ft6 Rockstar 100 Posts

    Sorry Cat...I tend to write everything I'm thinking which is often too much. Let me re-cap:

    1) Bought truck about 300 mi ago, previous owner said he just changed the oil
    2) this past weekend, had oil pressure momentarily went to zero, checked oil very low
    3) Changed oil and only 3+ quarts drained out (and I had added one to get home meaning there was only 2+ in the engine at the lowest point) and it looked like lots of water in the oil
    4) I started brainstorming all the ways one could get water in the oil (start of this thread)
    5) I was hoping it was the engine oil cooler in the radiator since that would be the easiest fix, I figured if I found oil in the coolant that would add evidence that it was in fact the oil cooler in the radiator that had failed and was allowing water in to the oil
    6) I drained some coolant, saw no evidence of oil in the coolant
    7) Also after letting the old oil sit over night I also saw no evidence of separation of oil and water, so now I"m wondering if there was ever wateg in the oil to begin with.
    8) Even if there was no water in the oil, I'm still left with the fact my oil was very low....and I'm wondering why? Did the P.O. screw up his oil change? Or am I losing oil somehow? I have no external leaks and my compression checks out on all cylinders. Oil looked very black for having just been changed.

    That is my summary...maybe not much better.....:neutral:
    Last edited: May 8, 2012
  6. catmechanic07

    catmechanic07 Former Member

    The only way your going to get oil in your water would be the oil cooler. Very doubtful any other cause.

    Water in oil will more than likely be head gasket. Also, if it were head gasket, you could take your reservoir cap off and see bubbles (90% of the time). Another thing about water in the oil, you will have a "gummy" looking substance all inside your engine and I mean EVERYWHERE!

    If it looked like water, it may very well have been a very light weight oil. Something cheap that breaks down quick. Your never guaranteed what your getting when you take your vehicle somewhere for an oil change.

    This is what I would do. Start off with a fresh oil and filter change. Put to the "T" the correct amount of oil in it. Check it again in 300 miles of whatever mileage you feel comfortable with. If its daily.....thats fine too. Keep records of how much/if any oil you add or see used. Once you have this info, we can trooubleshoot MUCH better. If it helps my opinion......I am a diesel mechanic and I deal with this everyday.
  7. Big6ft6

    Big6ft6 Rockstar 100 Posts

    Cat (I thought that might mean you worked on Cat Diesels)

    Thanks for the awesome info. So under my valve covers looks super clean, are you saying if I had water in my oil there would be gumminess under there?

    Another thing you said sparked an idea. You mentioned thin oil. When I had the zero oil pressure experience I stopped driving immediately and had a buddy bring my some oil. All he had was 10w-40. My truck is supposed to take 5w-30. I just put one quart of the 10w-40 in to safely drive 4 miles home then I immediately drained my oil. Maybe the "water" I was seeing was the warm 30 weight oil pouring out with the cool 40 weight oil.

    It was wierd though...I mean some of that oil dripped and "splatted" just like a water drop, it was supper thin. I even had two stream coming out of the drain plug at one point. One was supper thin and runny and the other was thick like I was used to. I was positive it was water and was just freakin' out. Maybe I was a little too paranoid?

    I'm following your plan exactly. I've been checking daily...although I've never felt good at reading dipsticks with fresh clear oil on a shiny dipstick....so far everything is good. Oil pressure has been up and stable. And like I said, I had 150 psi in each cylinder which I hope rules out head gasket issues.

    Also, this weekend I'm going to go borrow a coolant system pressure tester from Autozone's free tool rental. I'll pressurize the cooling system and see if it holds. Just so I can rule out any cooling system leaks.

    But I'm still left with what the heck caused my oil to get so low? We could spend many hours guessing, but like Cat says...first I need to find out if it really is getting low by watchign the level of my fresh oil change.

    I'll keep everyone posted.
    Last edited: May 9, 2012
  8. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    Did the oil look milky? White Streaks? If there was water in it you would see white. You did not check the oil before you bought it? Looking for dirty oil, water, level? If you checked it before you bought it and the oil looked good then, and now it only has 2 quarts in it, then I would be worried. But, if you were never positive that it was at the correct level then I would have to say that you may have not lost any oil and it was just never filled
  9. Big6ft6

    Big6ft6 Rockstar 100 Posts

    yeah...I checked the oil before I bought it, or at least I pulled the dipstick......I'm embarrassed to say that I think I just pulled the dipstick, smelled it for antifreeze and didn't even really look close at the oil level....almost like I was just going through the motions of what I'm supposed to do when looking at a used car. The truck looked so clean and the seller seemed honest, and he said he just changed the oi..... I must've been already thinking about my offer. But now lookin' back I don't think I payed close attention....wierd, embarassing..I know.

    When it was draining it was black...did not look streaky or or milky.
  10. catmechanic07

    catmechanic07 Former Member

    Seems like there is a VERY good chance the oil was very low when you purchased the truck to begin with. 5W30 will drain (after normal wear and tear) like black water. I noticed that when I changed the oil in my truck, I had 5W30 and it literally spewed all over the side of my face and down my arm where it was so thin. After adding a Diablo tuner and running higher horsepower settings, longer time on oil changes, and running on V-8 mode all the time, I have started using 10W30 Rotella. Rotella is a high quality oil (in my opinion.....we use 15W40 Rotella in our tractor trailers at work).

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