I am new to the board having just picked up a 1993 4Runner SR5 4x4 3.0L V6 with 150k. The dealer I got it from had it tucked away in a storage area for quite some time and claimed it had a bad motor. Nothing specific, just a bad motor. Okay... The battery was completely dead from sitting so long, so I could not power it up. The body was straight with good paint, and it is pretty much loaded with power windows, locks, mirrors, sunroof, cruise, a/c, auto, CD, etc. with good 31s on Prime alloys. The dealer could not tell me what exactly was wrong with it, but for the price he was asking I really did not care, so I bought it and arranged for it to be towed home.
The next week I was going over the towing options and decided to charge the battery and try to crank it to see if it would work at all to get on a trailer or dolly. After warrantying the battery (it was replaced in April) and putting in a fresh one, I turned the key and voila!, it started right up! A bit shakey and after pulling plug wires, I determined the #3 cylinder was not firing, but hey, at least it was running. Good oil pressure, voltage, temp, tec. I opted to simply drive it the 20 miles home and it tuned out to be a completely non-eventful trip. Having retreived my beast, it was time for the troubleshooting...
Okay, #3 cylinder not firing, time for a compression check. Adjacent cylinder checked good, but #3 would only get up to 30psi. Not so good, but no wonder it did not fire. I suspected maybe the head gasket, but a check with Toyota confirmed the recall was already done. Also, no other signs like milky oil, white smoke from the exhaust, overheating, bubbles from the radiator, etc. Hmmm. Time to hook up the vacuum gauge. Interesting, quite a jumpy little bugger. The needle was boucing back and forth and the manual indicated stuck valves. A quick exhaust pipe test with a piece of paper comfirmed it, as the paper would alternate from being pushed out to pulled in the pipe. The exhaust valve must not be closing. Now we are getting somehwhere. Now I just have to get to the cams, ext...
What a pain to get the valave covers off! I suppose it was not so bad, but there were just so many hoses and fitting to remove as most of you already know. All told, it took me about 2.5 hours to get the upper intake and valve covers off. On the plus side, the valve cover gaskets were leaking anyway, so it was on my to do list. After getting the passenger side cover off I was able to check the valve clearances and see the #3 exhaust valve was no stuck but did not have any clearance, or technically had negative clearance since the valve was not closing. All the other exhaust valves were out of spec also with clearances ranging from .005" to .008". The intake valves were all within spec. After purchasing the special plier set and 6 new shims, I went ahead and justed all the exhaust valves to .014". After the adjustment, the troubled #3 cylinder has now come up to ~150psi (cold, so it may be higher when warmed up). Woohoo! I spent the better part of yesterday putting it all back together and now it runs smooth as can be. A quick wire pull confirmed that the #3 cylinder is definitely firing and the vehicle drives so much better now. It still deserved the 3.slow nickname, but it is not bad. Hopefully the engine was be okay for another 20k until the timing belt is due at which time I may redo the heads. Fortunately all the power accessories work, although the a/c and shifter bulbs backlight are out a night. Also, it looks like I need a little freon, as the sight glass it foamy when the a/c is one, but it does blow cold.

Now for some obsevations:
-All the shims appeared to be the factory originals, or at least they had not been adjusted in quite some time with all the clearances so far out. I suspect the problem of burning valves on these engines is directly related to neglecting the valave adjustments at the specified intervals due to cost, complexity, etc.
-IMO, the SST pliers and spacer are a must, but I did have to use a plain allen wrench to depress the R/H forward valve and the L/H aft valve due to lack of clearance for the pliers beacuse of wires and hoses in the way. I picked up the tools from a Snap-On truck that stops by work for $35, although I have seen them on eBay for as low as $20 plus shipping.
-I ended up grinding down one of the shims that I couls not remove beforehand to measure, miscalculated the replacement and the shop was closed yesterday. Light pressure on the side face of a bench grinder followed bu wet sanding over a piece of glass combined with constant thickness checks ensured a uniform thickness. Not the preffered method, but I did what I had to do...
-I am really not sure why Toyota decided to use such a difficult to work on valve layout. The engine obviously is not especially powerfull nor does it get good gas mileage. For such an application, I feel a traditional pushrod and rocker arangement would have been a better alternative. Just my opinion...

That is all I can think of for now and I wish to thank all those that posted info on this board, as it was quite helpful (along with the Chilton manual). I am sure I will have plenty of questions as time goes on. I'll work on some pics also. Now, on to the rear end sag.

-Chris
chrisaparker@hotmail.com

 

Welcome to the site! I'm guessing you got a screaming deal on your 4runner, since the dealer assumed the engine was bad. Nice job!

 

Nice going with the diagnosis....you just need to be a little smarter than the techs and you can get deals like that!

 

Nice job I will have to pick up a set of those plyers.
I was doing it the old way checking clearences removing the cams and prying off the shims micing them. That took for bloody ever.

 

last summer when i had my 4runner at the dealer getting the headgasket replaced, i asked about valve adjustments. the guy i was dealing with told me they never do the valves on the 3vze. he said they'd done it recently to the tune of $3k b/c the owner wanted to get rid of the tick ticking noise.

 

Anyone know where to get a set of those? Price?
Mine does tick a little bit and it would be nice to do.

 

Also call the dealer and check to see if your eligible for the Head Gasket Replacement Service Bulletin. I have a 91 and when i had mine done 8 months ago ($5,000 worth of work for free) they were just starting to phase out late model 91's (mine). They will tear your engine down to the bottom and check everything, and replace anything that's not to factory spec

Also at the same time there's an air condition valve replacement campaign that needs to be done. Just call your local dealer and give them your VIN number.

 

I checked and mine was originally done in '97. I got the plier set from Snap-On for $35, but I have seen them on eBay for $20 sometimes. I needed (wanted?) mine the same day, so eBay was out.