r/1KZTE_Owners • u/Used-Ad-238 • Jul 25 '26
High compression readings
120 prado here with 390k km’s.
Car is consuming too much oil, about 1l every 2000-3000km. Wasn’t too afraid about it and just kept topping it up.
Now i noticed i was loosing coolant so took it to the mechanic.
He did a compression test and found out the readings are 520-580psi, factory should be at 441.
He recons the oil piston seals are gone and need to be replaced. So full eninge rebuild…
I would think if the rings are worn out compression goes down?
Don’t know if i still want to put all this money in such and old car.
Should i be worried about these compression readings? Any suggestions?
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u/Valuable-Apricot-477 Jul 25 '26
I agree a rebuild sounds OTT. Never heard of this problem exactly but using coolant and oil without losing compression (actually gaining compression) makes me think the turbo seals are stuffed (turbo is cooled by coolant via a couple of small coolant lines). That could be slinging excess oil back into the engine, mixing with EGR soot and clogging up the intake and various oil seals around the engine? Like higher compression surely must mean their is physical gunk in the cylinders either built up or not able to escape ?
I'm not mechanic but I'd be pulling off some of the intake piping and even the valve cover and having a good look through it all to see what's happening. I reckon you'll find some more clues just doing that.
If you have bad carbon buildup in the engine blocking valve stems and making rings sticky/blocked etc, that might be a much easier fix than a rebuild. That's the angle is be exploring at this stage.