Should I adjust the valves or not? That's my question. But it's not so simple, and I don't want to eff it up.

I'm nearing the end of a 3.4L build to go into my '93 pickup. I found a relatively low mileage (135,000 miles) 3.4L at an auto recycler out of a 2001 4Runner that had been rolled and sat upside down for at least several hours. There was some oil in the intake, and the heads. I took the spark plugs out and turned it over to clear as much oil as I could. Checked compression and averages were: 1:205 3:165 5:160 2:200 4:160 6:225 Why the high readings? Maybe the excess oil in the chamber? Anyways I tore everything down but left the heads on, got all new gaskets, oil pump, timing belt, water pump, oil pan, etc..., and checked the valves and six exhaust valves were out of spec which happened to be on the lower compression cylinders (3, 4 & 5) The lash was .016"-.018" (.002"-.004" out of spec). Only two intake valves were out, by .001" each.

I was expecting the exhaust valves to have tightened over time (Gadget's posts HERE) due to the valve seats wearing down. Which has me second guessing putting thicker shims in to tighten them up. Maybe some crud from the lower engine is keeping them from seating when it was upside down? I'd really like to cover all the bases while the engine is out, but I don't want to tighten them up then burn 'em up. The engine overall looks to be in good shape and I'm hoping to get another 150k out of it so I like to do things once, and do it right. WWYD?

 

I would not tight them any.

I bet your engine will run well for a long time.

Laying upside down should'nt have hurt it any; long as it did'nt run long while upside down.

 

The previous owner was a college girl who was drunk and somehow rolled it in a residential area. I'm assuming she didn't turn it off, and that either the engine ran out of fuel, which it still would have run for several minutes, or it would have locked up from being starved of oil. When I first got the engine home it wouldn't turn over by hand because of all the oil in the chambers. But feels smooth now.

 

Seconded on not adjusting the valves. I have NEVER adjusted valves on a 5vz. Had 3 with over 250k miles. 5vz is seriously that last GREAT motor Toyota built.

 

Ya- I'm going to hold off. I just rechecked the lash after rotating the cam a few more times, and I think there's some carbon crap floating around the seats that's giving me bad readings. I shot compressed air through the exhaust port and it changed the clearances. I'll check them again on down the road if I have the valve covers off, and give the engine a chance to burn off all the crap that settled in the top end.

thanks