blown head gasket???...... but oil dipstick looks good!!!

First of all this is about a 2000 3.4L 4-runner AT. I know this is a tacoma joint but its the same in almost every aspect as the tacomas. It is my soon-to-be ex wife's car. She called me up saying that she overheaded the motor. told her to check her coolant and WATCH the temp gauge constantly. She said she put some water in the radiator (don't know how much), and she said that she added some oil because it wasn't on the dipstick (oil on dipstick only shows after 3 quarts or so in this motor). I don't know how much oil she put in either. The main question at hand is that I figured that her thermostat needed to be changed out. got over to her house and started the job. broke the lower hose loose from the housing and then the fun started. What came out wasn't just coolant. It was white, thick, almost pepto bismol consistancy, and had an oily feeling to it. About 3/4 of a gallon or so spewed out of the line. At first I was like "that head gasket is shot" and told her that she had major problems. But after thinking about it for awhile, I figured that the oil would have been the same color if they cross contaminated each other. I haven't changed her oil yet or actually seen the oil color or texture out of the drain plug, but the oil on the dipstick and the oil below the filler cap looked good as far as I could see. This is leaving me boggled and anxious to find out what happened. Anybody seen this before or have an idea on what exactly I could look for to know for sure if its a head gasket issue, cracked water jacket, etc.???

 

oil and coolant make chocolate milk

 

Did your wife put oil in the radiator?

(I don't want to offend anyone by asking that, but I've heard people do this type of stuff all too often)

 

na.... I doubt that very seriously. I explained perfectly on the phone where to put the oil. I might be on to something in the past day though. I have heard rececently about something with the transmission cooler attached to radiator cracking or something with these vehicles causing cross contamination. That would explain the faint tint of pink in the coolant. anyone heard of this problem?

 

my radiator cracked on the POS plastic surround.
No cross contamination.

 

The engine head has several ports. It has coolant running through it, sure, but it also has intake and exhaust valves. Depending on where the head gasket is damaged is how it effects the outcome. If the gasket is damaged near a water passage and an intake port/valve, it will take the water in the radiator and allow it to be combusted and it will turn into water vapor in the exhaust system. The same is true if it is near the exhaust port/valve. It may or may not enter the oil jacket area, thus no milky oil.

Either way it will need to be repaired. Sometimes you can get lucky and only have to replace the gasket. I definitely recommend taking it to someone that knows what they are doing. A quality shop will actually do a throughout check of the head to check for warpage of the head surface or any cracks in the head itself.

Hope this helps.