Valve/Cam Problem 00 4R Lmtd

[owenjam]

2000 4Runner Valve Problem

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Long story short, family member has a 2000 4 runner lmtd 4x4 that sat undriven for 4 years. Only has 46K miles. I have tried to buy the truck for years and finally he let me pick it up to see if it would run or not, (pics to follow soon). 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]

More pics. I think for sure replace the cam, mech said he thought it would fly if smoothed out, but I aint putting that junk back in the motor. Main concers: parts of valve cap floating around in motor, damage to valve galley at the top. Valve should be out by this afternoon.

[owenjam]

I plan on keeping this rig for travel and family hauling, only 46K miles I like, but, I dont want to spend $2500 to get it going. Should I pull the head? Advice Please for a newbie to the forum.

[corax]

Looks like the missing piece is a valve lash shim, not much chance it went down the oil drain into the crankcase (give a good look around and see if it's there - if not, someone else already pulled it for some reason). The lash shim probably came off when the valves stuck open (how did that happen on such a low mileage 'runner?). Lash shims come in diffent thicknesses and the correct one has to be installed to allow a very specific amount of clearance between the camshaft and the valve cup (which the shim fits into).

Forget sanding down the cam lobes, hardening of the metal only extends a few thousandths of an inch (.001" = one thousandth). If you meant the bore which the valve cup rides in, I'd say leave it alone as long as there isn't any metal protruding into the bore (if there is, remove the tiny bits of metal that are).

Just looks like camshaft, valve lash shim and whatever gaskets are what you need. Still curious how that shim popped out in the first place on such a low mileage engine.

[BruceTS]

It appears that the valve shim came out when the valve stuck open, you can simply deburr that part of the head to allow it to move freely. Also there's a small burr on the camshaft that needs to be sanded down, other than that you just need to replace the shim and put it back together, don't see a need to replace the head, unless you can't unstick the valves. The Valve seals might leak, but I'd gamble and run it the way it is first....

[MTL_4runner]

If the motor really is that low mileage, then honestly I would pull the heads and take it to a machine shop to have them ensure the valves are all unstuck and that the valve lash is set properly. I would also pull the oil pan and clean out any metal debris that made its way down there too.

[owenjam]

Thanks for all the input, my gut does say just pull the damn heads, but what a PITA.

More history. This truck has mainly stayed parked since new. 4 1/2 years ago (last time truck was driven) the truck sat behind his girlfriends apt with Kudzu growing ontop of it and 3 flat tires, they used her car. (He does not "have" to work or be anywhere for that matter, so needs no vehicle of his own). He asked if I could have it towed and see if it would run, had been sitting in that spot for 2 1/2 years undriven. Last time however, new battery and truck ran perfect, I was shocked when I looked at the odom back then, buffed and waxed, 1 new rim, 4 new tires, good detail and it was nice. I drove it for 8 months (with his permission) and asked to buy it, he said no. The day he finally picked up truck and paid for repairs 4 years ago it was driven a total of 42 miles and parked. Photo of Odom for nay-sayers Monday. Thanks again for input,

[owenjam]

Shim is removed and ordered, $8.80 and 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..

[CJM]

Glad to see everything seems pretty good. Hope everything goes well and no more issues!

[owenjam]

Thanks, should be back together and running by Tuesday afternoon, will report back.

[owenjam]

ITS ALIVE!!!!! Running and test driving for 3 hours now, ran fuel system clean, but still has a pesky miss on Cyl#6, (not the cyl with damage valve shim). Thinking along the lines of clogged injector at this point. Still has 1/2 tank of old gas mixed with 1/2 tank fresh and seafoam. will continue the driving and post picstures to show how bad the paint is under the grime.

Total expense thus far: $886.49

[MTL_4runner]

ITS ALIVE!!!!! Running and test driving for 3 hours now, ran fuel system clean, but still has a pesky miss on Cyl#6, (not the cyl with damage valve shim). Thinking along the lines of clogged injector at this point. Still has 1/2 tank of old gas mixed with 1/2 tank fresh and seafoam. will continue the driving and post picstures to show how bad the paint is under the grime.

Total expense thus far: $886.49



Make sure to get some synthetic oil in that motor pronto, preferably 0W-30 to ensure all the parts are wearing in properly again. You may also want to change the fuel filter as well if it has been sitting that long and there may still be bad gas in it so run high test (91+ octane) for at least 3 tankfulls. Also do a compression test on all the cylinders to see if the #6 (or any others) have mechanical issues or if a potential problem lies elsewhere. For that year 4runner 43k is amazing so great deal on your part if the truck runs problem free from this point.

[owenjam]

I am on it with synthetic oil, going to run a few miles on the oil we just put in so filter can pick up any trash, then swap over to full synthetic in a day or two. Already put one fuel filter on and going to change it again after 4 tanks. Fuel filter has been replaced, and will replace again after some road time. Thanks for the input, clean pictures to follow.

[owenjam]

The miss is localized on cyl 2-4-6, ran compression test and each one has 175 PSI. Replaced all three 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?

[MTL_4runner]

The miss is localized on cyl 2-4-6, ran compression test and each one has 175 PSI. Replaced all three 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?


I find it interesting that you have a miss on all three cylinders and that they are all on the same bank (side of the engine). With just clogged injectors you'd normally expect the pattern to be more random. Are you getting any CEL codes at all? Does the miss happen only on the highway or at all speeds?

I might also make sure the timing marks on the cams are all lined up properly.

[corax]

I might also make sure the timing marks on the cams are all lined up properly.


Yep, cam timing is the main thing that cyl 2, 4 and 6 have in common - since the cam was recently removed, timing is the most likely culprit

[owenjam]

I am leaning towards a timing issue now myself, every now and then I will get a miss fire on 1-3-5, but not as consistent as the 2-4-6 miss. We had to have messed something up on that bank. CEL codes consist of system too lean and random miss fire mainly on 2-4-6. 2nd tank of gas and have not had the lean code yet today.

[MTL_4runner]

You may also want to pull the instake anyway since that will let you remove the valve cover and check the cam timing marks with a mirror. There's a pic of how it should look in my thread where I redid my head gaskets, see below.

http://www.ultimateyota.com/index.php?option=com_smf&Itemid=26&topic=2241.msg28026#msg28026

[owenjam]

I tend to agree with you, going back in this week.

[owenjam]

Well think now we have timing and or valve/cam issues. Calling in the big dogs to pull back down and start from scratch. Looks like a full head job is in order, no need to do one side without the other.... and have all injectors tested for good measure. After this pull down I am done ....... $1400 in so far....another $1000 to go.....

[CJM]

Even if it winds up costing you a bit, your still ahead of the game imho with it being in such minty shape.

[MTL_4runner]

Well think now we have timing and or valve/cam issues. Calling in the big dogs to pull back down and start from scratch. Looks like a full head job is in order, no need to do one side without the other.... and have all injectors tested for good measure. After this pull down I am done ....... $1400 in so far....another $1000 to go.....


Sorry to hear that, but I'm not surprised after sitting that long. Sounds like you're going to be doing the job right though and as a result you should have a very reliable vehicle for many years to come.

You might consider getting a set of used heads for rebuilding because of the damage done with sticking valves and the shim damage to the head casting and the cam. The biggest issue is that there may be other damage on the heads (valves, cams, seats, shims, etc) you haven't even found yet. It will also lessen the time the vehicle is in the shop since you can run the vehicle right up until the day of the HG job and they should have the work done and back to you in just a day (since the heads can be rebuilt before the vehicle even arrives at the shop).

My thread on replacing your head gasket will help alot with the process (process, parts, techniques, etc).

[owenjam]

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Well, after much confusion and dead ends we have resolution. Turns out after we pulled her back down, the cam was re-installed (in my absence) without taking into consideration it is spring loaded!!!! Mechanic that came in to "do the simple stuff" and install cam, valve covers, and intake after shim was repaced, did not line up the marks on the backside "firewall side" of the camshaft gear. Some how the bolt I put into the provided hole to keep cam in space was removed????? Off by 3 teeth to be exact. Once corrected, truck runs perfect with no miss fire or valve train noise. Stupid over sight and all involved were very apologetic. Good thing toyotas are non-resistance motors. Will post paint damage before and after pics soon. Thanks for all the insight!!!!

[MTL_4runner]

If you aren't used to working on these motors, it would be hard to know the cams are spring loaded to reduce top end gear noise. Glad it's back up and running with minimal out of pocket costs.

[paddlenbike]

What do you mean when you say the cams "are spring loaded?" Are you talking about something other than the lobes against valve spring pressure?

[MTL_4runner]

What do you mean when you say the cams "are spring loaded?"
Are you talking about something other than the lobes against valve spring pressure?


No, I'm not talking about valve springs. The cam gears are spring loaded too (see pic) but only on one side, the other gear is solid. If you don't put the service bolt in BEFORE you take out the cams, it's a major PITA to get the preload back on the gear again. If you don't preload the springs, your valvetrain will make an awful racket and you probably won't have the correct valve timing either as happened in the OP's case. Unfortunately it's also a very common rookie mistake.

[owenjam]

Great demo and pic MTL, with the cam out and no service bolt in, you can spin the opposite ends of it about 3 or 4 teeth, it is not a solid cam, it has 2 parts. I guess the idiot they trusted to re-install the cam said "huh, that bolt should not be in the cam like that" pulled it out and chunked it before setting the cam in place. The old saying goes, if you want something done right, do it yourself. I kept asking if they lined up the cam marks and they said yes we did, but I knew something was up.

[owenjam]

Before and after paint shots, also replace the MAF meter and corrected dead spot on acceleration and cleared up the Bank #1 lean code. Total expense to get truck back on the road:

$2244.34 :thumbup:

[rworegon]

You have nice rig there and you are on the road your $2500 target too. New paint or just a serious cleaning?

[owenjam]

Did not re-paint the truck, just washed it about 25 times and treated it with a special mixture to remove the grime.Paint is damaged pretty bad, but you have to be up close to tell. Pass side is the worst, but I will wax on regular basis and be done with it. Besides, if I get out on a trail I wont be so worried about a scratch or two.

[MTL_4runner]

Did not re-paint the truck, just washed it about 25 times and treated it with a special mixture to remove the grime. Paint is damaged pretty bad, but you have to be up close to tell. Pass side is the worst, but I will wax on regular basis and be done with it. Besides, if I get out on a trail I wont be so worried about a scratch or two.


If the paint on the truck isn't chipped, you should try a claybar on it to restore the shine.
Works amazingly well even on heavily damaged paint.

[owenjam]

I have heard about the clay bar, never used it however. Just might give that a try, thanks.