jay-q

so 4runner was idling rough (violently shaking like v8 hot rod)..... took it to SD Trux here in San Diego (met John the owner, cool guy.... wish I had met him years ago)..... anyhow, they did a compression test and all cylinders were ~180 except #3 which was ~130psi....

reccomendation was valve job estimated at $1500-2000..... didn't want to put anymore money like that into it.... so suggested to john if a valve adjustment on #3 would help..... he said it would be a gamble, a little better that a 50/50 chance..... i took the risk since it would just be $200 on the valve adjustment....

they opened her up and found the clearance on #3 was at zero (0)..... so they shimmed it up to .0014"(.0001" above spec).... to see if they could get the compression up.... did another compression test and found no change to #3 still ~130psi .... told them to put her all back together and not to do anymore work....

funny thing, after i got her back.... i've been driving all day yesterday and some this morning.... the idle is back to smoooooooth again.... couldn't believe it.... i understand there is a burnt valve issue still, but its not as apparent as it was before.... runs nice

so here's my questions:
can i continue to drive it like this???
will anything else get ruined, other than the already burnt #3 exhaust valve??

john says there is a small chance (emphasized very unlikely) that the valve may reseat itself....

if i do continue to drive it as is, will the rough idle come back?
since they had to shim #3, is it going toward closing the clearance again, the more i drive??

lastly, what are your opinions on this: should i sell it now while it is running pretty nice (while i can still get someone to bite on it)??? as i'm thinking it would be hard to sell with the rough idle issue.... or should i just drive it for awhile??....
[i'm debating on this one, since i need a few months to save up for something new...]

please help..... any and all opinions are welcome.... i value and need everyone's wisdom on this.... especially the 3.0 experts...

thanks
JQ

1993 4runner V6, 4x4 Auto
158K currently
Original Owner

Tacoma Dude

I can't help you too much on your original question but I'd suggest getting a second opinion just in case. Last time I went to SDTrux I had an oil leak and they assured me it was the front main seal. Fast forward 2 months and I have figured out the oil leak by myself - a cork gasket on the oil pan and a bunch of loose bolts.

But it really seems to be hit and miss. There are some guys that really like SD Trux. Others prefer Pro Trux (San Marcos).

84sr5yoty

One of my buddies has driven his 1983 Cougar over 130,000 miles (and counting) with a burned valve with no problems. Still passes CA smog too. I wouldn't worry about it too much.

CoedNaked

I wonder if it reseated itself. Maybe go get the compression checked again to see.

wrenchmonster

Hummm. Sounds like a burned valve was never the issue in the first place. Lots of techs go after the valve job because it is such a common problem for 3.0s. There are lots of reasons for running rough... misfire, bad injector, etc. 130 is definately not balanced if you have 180 on all the rest, but 130 should still fire off. Heck, 90 psi will fire off.

Driving on a burnt valve will wash down a cylinder with gasoline. The gas will get into your oil and can do some real damage over time. You can disconnect your injector of course, but there is still added strain of driving without a cylinder firing, hence inbalance in the motor. I'd personally get a second opinion. I'd be willing to bet you have some other concern causing your rough running motor.

As far as selling the truck and dumping it off on someone else... that is an ethical and moral question you have to answer yourself. I personally believe in the golden rule and karma. That is: Do unto others as you would have others do unto you. And: What goes around comes around. Respectively. Loosing a little money is nothing compared to loosing your values. My 2 cents.

jay-q

ok.... so i decided to drive my 4runner for a few more months..... it is running pretty good considering the possible burnt valve issue.... was seriously considering purchasing a new vehicle already.... but am rethinking the issue due to the whole increase in gas prices.... don't think i can afford to have an SUV car payment and pay for gas too.... even though my 4runner now gets awful gas mileage, i can sustain because its all paid for....

thanks for all the comments.... and to wrenchmonster .... i totally agree with you on the carma of dumping it off to someone else....

JQ