1997 toyota t100 3.4L V6 206,000miles. Coolant has been flushed twice and still dirty. Doesn't appear the have oil in it. Maybe just dirty from the radiator. Also loosing coolant, don't know if leaking head gasket or what?? No coolant leaking on driveway, no fluctuation on temp gauge. No check engine lights.

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what did mechanic state or due --oil and coolant mix have a few reasons --head gasket - intake gasket- cracked block

Might want to recheck your head gasket is seated properly and that all cylinder head bolts are torqued properly. Sounds like you have oil mixing in with your coolant.

Have the codes read. I haven't worked on any thing to date that reduce power because of the coolant system or the oil. I have done some that will kill the engine because of both, but not reduced power. This could be from an engine hard part, sensor or wiring. Most times it's caused from a transmission problem.

hi there. sounds serious. my first would be head gasket. or warped
cylinder head. is your engine oil clean. look in your rocker box check
the oil. if its white and milky. then its almost certainly a head problem.
good look with that one.

your thermostat is stuck open. flush and replace part

Have the cooling system pressure tested ! 3.1 l engine These engines had intake gasket problems , have the radiator cap tested as well . Bad radiator cap will allow coolant lose . Does the oil cap have whitish or dirty color foam on inside ? Coolant leak into the oil .

Tighten all your clamps and clips, coolant can escape under pressure and is not noticable

Just drain and flush the coolant system real good then checkit. If you have not flushed the system for a while you may have to do it twice. other wise I think you will be fine after this id done. I hope this helps, Don't forget to rate my answer, thanks.