I just had my exhaust manifold replaced. The mechanic noticed something wasn't right. He did a test and it coded #1 cylinder. The results were 1 20psi, 2 95, 3 115, 4 125. The engine has 225,000 mi. (mostly highway Montana miles). He went through and checked all the usual suspects and said they were working (plugs, coils, etc...) I am on the fence about what to do or ask the mechanic to do. Any suggestions would be greatly appreciated.

 

The same thing has happened to mine, 60 psi in cylinder 1 and 90% leakage out of intake and exhaust valves. It has 190,xxx miles on it and it's had a cracked exhaust manifold ever since i bought it @ 130,000 miles. The mechanic recommended having the cylinder head taken off and the valves redone...cylinder head resurfaced. However that puts strain on the bottom end of the motor and it might blow eventually after spending 2g's. Pretty sure needs a new motor

 

Bottom ends in those engines are strong. As long as you have never over-heated and you kept up on oil changes, you shouldnt have any issues doing just the top end. I would do a timing chain kit though while its apart

 

X2^^. I had mine rebuilt and the machine shop said the 3RZ is very strong on the bottom end. Rods are stronger/thicker than some small diesels they build. Plus the 3RZ takes a turbo well, so if the engine has been maintained, I prob wouldn't sweat rebuilding the top end.

As I side note, when we pulled my engine apart, with 140K miles, everything was still near brand new. You could still see the crosshatch pattern from the factory on the cylinder walls. Bearings were dang near brand new in regards to wear, crank was flawless, and the chains looked brand new...

 

Thanks for the info good to know that I don't need a new engine! Would it be cheaper to buy a new cylinder head with the valves and everything in it, as opposed to having a shop-machine the head and put new valves in? I was quoted a price of $2000 to re do the vavles in each cylinder(even though only one is acting up) and the head machined. Thanks for the help in advance.

 

Is that all parts and labor included? If so, that price seems reasonable. Be sure your mechanic uses a good reputable machine shop. Don't be afraid to ask who they use and do a little research. I don't want to scare anyone, but that's a lot of money and unfortunately there are a lot of hacks out there. Oh and to answer your question- No. A new head from toyota is probably $1500. And thats a bare head with no valves or anything. Toyota doesn't sell assembled engine parts other than the short block.