2000 4Runner Valve Problem

[owenjam]

Long story short, family member has a 2000 4 runner lmtd 4x4 that sat undriven for 4 years. Only has 46K miles. Covered in grime, put a new battery in it and it did fire up, but had had a dead miss. Got the vavle covers and intake off, had 4 stuck vavles. All came loose, but on driver side bank, one of the actual valve "caps" has broken off, valve itself is not compromised. Its a round flat metal cap on top of valve where it meets the over head cam lobe. Only found one small broke part on top of the head, rest is floating around in motor somewhere. put a scar on cam lobe and on the head near that area, but should not effect the performance if cap is replace and scars sanded.

Has anyone had one of these caps break????


Engine has good compression across all cylinders except this one. My mechanic thinks remove cam, sand down areas with damage and repalce the valve cap. Any thoughts?

 

[owenjam]

Pics

Here are the pics from today, Cam is off at last. Heres the outside.

 

[owenjam]

Valve and Cam close up

Here is the extent of the damage to cam and valve, cap is missing and only found a tiny metal part on top of head.

 

[owenjam]

More pics

Even better view of damage to head.

 

[KLF]

I've never seen that happen, but I don't have much experience with the 3.4L. Those "caps" are actually shims, you insert different thickness ones to set the valve lash. Generally they are difficult to get out.

I would definitely replace that cam.

That's messed up. But so is letting a nice truck like that sit for 4 years.

 

[raydouble]

x2 on never seeing that before.

 

[owenjam]

My assumption is the valve was stuck in the raised position and would not give when the cam lobe hit it thus causing the faliure.

 

[owenjam]

Shim is removed and ordered, $8.80 and includes overnight shipping. Seems I miss read the Odom, only has 43K MILES!!!!! Plan now, roll the dice, sand down cam and replace as to not upset other valve clearances, replace shim, and sand head near the edge. valve moves freely up and down and its possible to spin the sleeve. All but one part of the shim is accounted for, probably in the pan. One of the original parts found was lost, most others recovered today see pic. No need to drop the pan IMO. If future faluire occurs, then it will pull the heads time. Right now just going to get it running to asses any other issues present ie. trans, axels, etc..

 

[Jukelemon]

My question would be where did the broken piece go?

If it is in your pan, then I would treat it like a broken timing chain guide and at least try and find it by dropping the pan.

 

[owenjam]

Want to assess driveability, just below this particular valve is a large oil return port, all agree it went down that port based on the size of the missing part. If its in the pan, there is no way the oil pump would be able to pick up, ie screen and weight of the part. Plan would be run a magnet down the return port and see what comes up. Will drop pan after I am able to move it around and change oil but , it may slip out when we change the oil, missing part just might fit out the drain plug.

 

[Jukelemon]

I follow.

Just remember that it is not a matter of whether or not the piece would not go into the pump due to the screen. All it has to do is block the screen to create issues.

But if you feel the weight is enough and your guess is right that it is one piece and not several, that yes it will be fine more than likely.

Have you shot some oil into the cylinder walls just to assist in getting up to speed or did you already run it enough to lubricate the walls even though it was missing?

 

[owenjam]

Has been run sufficient to lube all walls IMO, but I will address before final run. Truck will not be operated on any extended term until oil has been changed several times. I feel cetain there are small shards in the mix, but not very many. This power plant will be filled, run and drained a few times before under any long term load.

 

[owenjam]

ITS ALIVE!!!! For now (knock on wood). Been running and test driving now for 3 hours, about to change oil, add some lucas, and wash the grime off. Ran a fuel system clean on it, but still a mild missfire on Cylinder #6. Cyl has good compression so we think clogged injector, (#6 is not the cyl we worked on). Right now has 1/2 tank new fuel and seafoam, and half tank of 4 year old crap. No drain plug on these rigs like the cruisers have. Updates soon, may drive home tonight.

 

[owenjam]

Total expense thus far $886.49

 

[Jukelemon]

Just siphon that old gas ( :

 

[owenjam]

I tried to get a tube down in the tank to get the gas out and cant get it into the tank, according to mechanic they have a srping loaded ball down where the filler tube attaches to the tank. Showing misfire on ALL cylinders now, so my guess is skunky gas. Runs decent, but still has a bad miss.

 

[owenjam]

The miss is localized on cyl 2-4-6, ran compression test and each one has 175 PSI and replaced plug wires. Thoughts now are bad or clogged injectors. Most of the old gas has been burned out at this point along with 2 bottles of seafoam in the tank. Any ideas on clearing injectors before I pull the intake, again, and start replacing them?

 

[Jukelemon]

Well, my thought is this:

The idea of cleaning injectors with anything other than a fuel rail cleaner system (attaches right at fuel rail) or taking them out and having them cleaned or you clean them is not going to be effective.

So, if you have access to one of those nice cleaners that actually attaches to the fuel rail (not gets shot into the pcv port), I would try that. You can get them for 50-75 bucks which is less than an injector rebuild/clean from a company.

If I were you, I would remove all of the injectors and just try to clean them up your self.

BUT first, did you replace the fuel filter?? That has to be done. You probably have mold deposits in a lot of your rail/filter due to sitting. The sea foam may have gotten some out but I doubt all of it.

You may have to run through a couple of filters befor you clear the fuel delivery system up.

 

[owenjam]

Yes it has a new filter, been looking for one of those injector/rail cleaners, have to be ordered by most of the parts places. All the shops I deal with dont have the actual machines anymore, too risky they say.

 

[owenjam]

Toyota Service Department

Wow, I had to snap a pic of all the Yotas lined up for a little service. LX 470-New valve cover gaskets.. 4 Runner-you know the story, have the cross over pipe from one fuel rail to the other off and inspecting for blockage. FJ60-Guy wrecked it 10 mins after buying it, getting front end repairs and new lights, grill, and custom bent hood.