Chocolate milkshake oil

I have an 05' 4RUNNER 4.0L , I do my own oil and filter changes, I decided to go to Costco to have my oil and filter changed 5w-30 Synthetic, after the oil change the guy doing the work called me in the shop and showed me my dipstick it was like a milkshake obviously coolant was in the oil.

I drove it to my house and did a block test, to see if there were exhaust gases in the radiator. ( no indication of gases in the radiator, the chemical was blue) before this, every couple of weeks I had to add coolant to my reservoir. This problem has me stomped ! So I decided to take it to the Toyota dealer to do a diagnosis, The Toyota tech. drained the oil and flushed it with a Toyota engine flush and replace the oil with 0W-20 and told me he pressurized the cooling system to 100 PSI, I said "You did what?" 100 PSI? why so much?, cooling systems are usually NO more than the 15-17 max PSI I told him" Even my little 13-year-old daughter knows that!" My 4RUNNER has 223K on it ,I bought it new and always changed the oil every 4.5-5K miles. It doesn't have a misfire and no white smoke out the tailpipe. Stomped ! The Stealership charged me $505.00 to do this work, to diagnose. And just took it right back to them after driving it for around 8 miles, and checked the oil and coolant in it . I'm thinking could it be the oil cooler gasket fail?

 

Reminds me of a engine block crack I had on an old car from the 70's. Hopefully its just a gasket.

 

I hope so too ! I don't even want to think about buying a used 4.0L, who knows how many miles it really has on it? Even though these used engine dealers tell you ie " it has 80K miles , how to know ? Cant !

 

Costco offers oil change service now?

 

If I'm not mistaken, '05 was around the time that the 1GR was known to have head gasket issues. Hopefully it's not the case, but it would be my first guess.

Did the dealership give you any sort of alternative diagnosis?

 

Yes, but not all Costco's , Here in Ontario Canada $70. full Synthetic with Purolator Filter. I heard they will not offer this after June 2023.

 

They said, there was no loss of pressure in the cooling system, It would be my first guess as well ( head gasket) , no miss fires,no smoke from the tailpipe. Oil was fine when I took it to Costco for an oil change, I'm sure they did nothing wrong as they do many oil changes per day. I'm thinking it could be the gasket in the oil cooler? The dealership flushed the engine with Toyota engine flush, and then used 0W-20 to fill it, and said No issues My engine takes 5W-30 I use Synthetic. Why would the dealership use a different weight? I asked them if they did a leakdown pressure test, and they said only the cooling system. ODD ?

 

Have you been checking the new oil? Any signs of more coolant getting in?

I have no idea why a dealership would use 0W-20 on an '05. I don't think I'd be going back there for any more service.

 

I had to take it back today, for their FOREMAN MECHANIC. after they charged me $505.00 to flush engine, and pressure test cooling system for 10 minutes. This is the biggest Toyota Dealership in the area where I live. That doesn't mean their techs are good ,I understand. I have always used 5W-30 Synthetic myself. I think 0W-20 is too thin !

 

I don't believe 0W-20 is even recommended for that version of the 1GR. . My '15 Taco took 5W-30.

The newer, dual VVT-I ones call for 0W-20.

Let us know if you see any signs of water intrusion in the new oil.

 

Do you make short trips in cold weather? I wouldn't be surprised if there was nothing wrong with the engine, just excess water in the oil from not getting it up to operating temperature long enough. I would just drive it more long distances and keep an eye on the oil by checking it every few days.

 

This oil was very milky, it's not normal condensation like under the oil filler cap sometimes. And I always warm it up properly in cold and warmer weather to give the transmission pump time. I am going to keep my eye on the coolant and oil, as I normally do.

 

Try doing a compression test of the cylinders (leak down test), sometimes if the leak is slight the exhaust gases wont visibly change the color of the test fluid. Maybe you have a coolant leak and another leak unrelated (like transmission).

 

Hi,Trekker I am going to do my own leak-down test, there are no leaks of coolant,and I have checked all over. Transmission can't be the problem, because when I bought my 4RUNNER brand new within a few days less than a week, I installed an external transmission cooler. I have a slight suspicion and I hope it's the oil cooler gasket. and not the head gasket? About every 2 weeks I have to top off the coolant overflow res.