pete c

I have done my valve clearance check. All the intakes are fine at .010-.011. The exhausts, not so much. All are tight, some really tight! They range from .003 to .007.

Is there a clearance measurment where you can pretty much be assured that you've already incurred valve/seat damage?

This is the 3.slow, 1990, 120K in an RV with auto. In other words this engine has been working pretty hard for every one of those 120K miles.

I did a comp test last year. Was done with a loan a tool from autozone, so i don't know if it was accurate. All the numbers were on the low side, with a few particularly low. Don't recall the exact numbers.

It does run and sound nice. Only issue is an occasional slight stumble when applying throttle. Haven't driven it enough to have mpg numbers.

I will need to order the valve compressing tool. Recommendations for this as well as a good source for gaskets, T belts would be appreciated. I have seen some on feebay, but would like someones advice on which to get. Better yet, maybe someone has a tool they might want to sell me.

Thanks

Pete

scope103

http://www.antarespro.com/2667725-it...13d318d315d315

I don't know anything about these folks, YMMV. I got mine from a young lady who worked for a company that specialized in Chinese-made tools, but they don't carry it anymore (may be how I got it ...)

There are those on this list who claim they can pull the shims with nothing more than a small screwdriver. I sure can't -- the tool is definitely worth it to me.

Are you thinking of removing the head? (You asked about a valve spring compressor.) Consider taking it to a machine shop for the full spa treatment. They can flatten the head (you can't) and regrind the valves and seats (no, you can't, valve grinding compound won't do you anything). When they adjust the valves they'll have access to a full set of shims; you and I have to buy them onesy-twosy.

MudHippy

The exhaust valves are shot. I'll stake my reputation on it. They'll need replaced, and the seats will need ground minimally. You may also want to replace the seats too. But, it's not impossible that you could get away with just replacing the valves and lapping them into the old seats. You'll get a good seal, but it won't be optimal, or to factory specs(so it won't last as long as freshly cut seats and new valves).

For the 34mm valve clearance shims and the removal/installation tool see this link.
http://www.cylinderheadsupply.com/va...nce-discs.html

For gaskets and other engine parts.
http://ENGNBLDR.com
http://partsdinosaur.com

Good luck!

pete c

Well, that's not what I was hoping to hear. Thanks for the replys anyhow.

Here is what I think I will do....

Adjust the shims anyway, throw'er back together and cross my fingers. Remember, it's an RV that is likely to see just a few thousand miles a year. This might do me for a few years.

I will start looking for a 3.4 donor and do the swap. I would prefer that to yanking the heads off what ain't really the greatest motor to start with.

One other question.

Assuming I do this, what happens? Will the compression finally get to the point where it starts missing? Is it likely to leave me stranded 500 miles from home, or should I be able to limp home? I once drove my old supra 500 miles on 5 cylinders. I would think I could do it again if I had to.

sb5walker

http://www.toyotanation.com/forum/sh...19#post3137919

pete c

It seems that removing the shims, even with the tool, may be a serious PITA. I am contemplating just yanking the cams. Since I will need to remove all the exhaust shims, this might actually be a less stressful way of doing it. May take longer, but, that really isn't a problem.

What say you folks?

MudHippy

Adjusting the valve lash isn't going to do squat for compression. If you're trying to make it run better/gain compression, changing the worn valves/seats and/or re-ringing the pistons are all that are going to.

I remove the cams when I do it, BTW. That's only a "bad idea" if you don't know ahead of time to be careful removing them. It's all too common to damage the camshafts on this engine if you aren't familiar with the specifics of the issue. And I don't feel like elaborating on it right now. So do some searching for yourself, if you don't mind, on that one. Save me the hassle of doing it for you.

PS, the 3VZE is a great motor. Don't buy the hype!

sb5walker

Yeah, if you can remove the cams, that's a MUCH easier way to change shims. Of course be sure of your measurements first.

If lash is so small that when valves expand they don't close fully, that of course can have a big (negative) impact on compression, not to mention the fact that you're going to burn them. But by the time you get around to measuring compression, they probably will have cooled and shrunk.

I recommend loosening your cam cap bolts a little at a time, in reverse of the tightening sequence. Loosen them in several passes. Use an assembly lube containing moly when reassembling - Red Line makes a great one.

pete c

thanks for the replies.

so, looks like I will go ahead and double check my measurements, pull the cams and do it that way.

just out of curiosity, can someone give me a ballpark idea what a machine shop would charge to go through these heads, replace burnt valves/seals? I had 3 cylinders that measured .003-.004. I assume these will need new exhaust valves. The others measured .007, which is out of spec, but, hopefully not to the point of being burnt.