Silver_Truck

Hey, as a few of you know I've been having problems for the last few months with my v6, its gotten better and worse and better and worse then finally took a turn for the worse about a week and a half ago when my fuel economy dropped from almost 20 on a trip to spokane down to almost 11 (same speeds, distance etc.) So I finally got around to doing a compression test and ended up with the following results;
1:150
2:145
3:160
4:150
5:145
6:20
So I'm figuring on a burnt valve as I'm not smoking (excessively), no coolant in oil or oil in coolant, no exhaust smell in coolant so I dont think its a head gasket. Any advice on taking on this task? It will probably be a little bit until we can get the 4runner v6 done and out of the shop, so I can get my truck in.

nunsa

The 3.0 is notorious for burning up #6 valve unfortunately! Don't just replace the valves do both heads with complete machine work, also if you take those heads off and this is real important: REPLACE YOUR KNOCK SENSOR, If not it will come back like a boomerang to bite you in the a** with a code 52!
Everyone always asks why #6 always burns up on the 3.0? The explanation I heard years ago when I worked for Toyota was that because of the restricted crossover! It maybe so, but they never did anything about it!
Good luck!

Morphine

I've got the 3vze and similiar (yet lower) compression results. I'm doing just like nunsa said. Full machine head work on both heads, oversized valves by engnbldr.com, new gaskets all around and since i"m this far into the engine new oil pump, water pump, timing belt and all it's accessories, knock sensor and wire, head bolts. Now to prevent this from happening again I'm going with Downey headers and new complete exhaust system including cat.

I'm no mechanic by any means and so far it hasn't been that bad doing it myself. OK I must give credit to all of the YOTATECHers here who have been helping me through the way, my thread is as follows:

https://www.yotatech.com/forums/f116/3vze-top-end-rebuild-w-pics-slowly-51371/

..But I'm making decent progress. If you need any help or have questions I'll do my best to help you or point you in the right direction.

-=Morphine=-

Silver_Truck

Nunsa: should I replace the sensor too, not just the wire. i dont want to if I don't have to its kinda pricey for the sensor. Planning on doing oversize valves, when I get to it. But I've got to get the 4runner out of the shop first so I can get my truck in there. Any one else pulled the heads etc. with the motor in? What kind of time am I looking at?
Thanks

Morphine

With all of the right tools and support you should have the heads off in about 4-5 hours. My actual time has been only 7hours but I'm borrowing tools left and right and only working a little here and a little there.

As to the knock sensor, from what I've gathered and those who've helped me, they've all said to replace both the wire AND sensor. You don't want to rebuild the top and then in 8k miles have a knock sensor code going off.

*******
Please correct me if I'm wrong on any of this as there are more experienced people on this board. This opionon is only mine from my current expeirence and research. Hopefully I can save you some of the headaches I've encountered.
*******

-=Morphine=-

Adam F

Whats an easy way to check compression myself?

Would this work?

http://www.harborfreight.com/cpi/cta...emnumber=39224

Silver_Truck

ya that would most likely work, I got mine at napa or some autoparts store like that. Its just a hose, gauge and a few diff adapters for diff threads.