Recently purchased a 95.5 4runner. Vin Decodes to a 3.0L. However the engine is a 3.4. Truck was not running when I bought it so I did a few basic diag runs (spark, fuel, compression, timing) and found that the engine was not building any compression. This along with the fact that I was uncertain of the engine size (yes, I know the 3400 on the timing cover should have been enough but call me cautious) I decided to tear down the top end. SO I have the heads off and found the intake gaskets were trashed and there was some dirt scoring on the upper cylinder walls.

https://www.yotatech.com/attachment....1&d=1407691724


I measured the bore and it is definitely a 3.4L but I am not sure the year of motor or if this makes any difference. I have to assume there were changes over time that will impact parts purchases so before I order $$$$$ worth of parts I wonder if anyone here can tell how I can determine the year of manufacture for the engine?

Secondly any advice on the compression issue? Any common issues to look for?
Thanks for any input and comment.

Hutsko

 

Would have been helpful to do a compression leakdown test before disassembly.

Did you verify that the valve timing is correct?? That would affect compression figures for sure.

 

millball... Yeah I did check the timing and it was bang on perfect. The compression test I did was using a compression gauge on each cylinder I turned the engine over several times until the gauge stopped going up. No cylinder made more than 30psi. It sounds really strange when turning over. There is no metal in the oil so I do not think the bottom end is an issue. Lots of oil leaks and grime so it is clear the previous owners did not keep up the maintenance.

 

You did have the throttle WOT when doing your compression test? I hate to see people make mountains out of potential mole hills.