Oil in coolant reservoir

[hondaguy453]

Alright, so I have an ’05 Tacoma with a 2.7 (2TR-FE). These motors are notorious for blown head gaskets, which is why I performed the tests that I did. So, first test I did was a compression test.

Compression test results:
#1 cyl: 135
#2: 130
#3: 105
#4: 135
Compression spec’s are between 128-178. I added oil in #3 and it shot up to 130 like the rest, so I figured bad rings. Still didn’t answer my question of why there is oil in my coolant reservoir lol… After the compression test I performed a leak down, but I only did it on #3 and I heard the hiss from the oil cap after I took it off. Surprise surprise lol… Still haven’t found out my major problem. Oh, and I also tried to test for HC’s in my cooling system but I couldn’t even do that because my lower radiator hose did not get hot AT ALL, even after i drove the truck around for a while…
Ohhh, AND the truck has been eating oil for the past 15k. I added 3 quarts the other day lol. Any other ideas on how to pin this madness down? Thanks for the help in advance!

Topic

[hondaguy453]

I also wanted to add that I pressure tested the radiator to see if there were any leaks and the pressure did drop, but very gradually. As it dropped I removed each spark plug to see if there was coolant spraying inside the cylinders, but none had evidence. Also, if coolant is leaking inside a cylinder the top of the piston will usually be cleaner compared to the others, but they were all built up with carbon and dry… I also thought the “oil” could be transmission fluid coming from a possible leak in the tranny cooler, so I checked the level and that was also okay.

[Austin]

I was going to suggest tranny cooler, but you beat me too it. Do you know for sure its oil and not just dirty coolant? I would do a block test along with the leakdown. It should show up on the leak down if it was a head issue most times. Check your oil cooler and see if you have an issue there. That’s what I would do next.

[hondaguy453]

Oil cooler is what I first thought too, but it doesn’t have one :(. lol…. I seriously don’t know what to do anymore lol…

[hondaguy453]

I’ll for sure do a block test next! I forgot about that haha. Thank you!

[Author]

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