stepside trd

2001 taco w/2.7L sounds like a diesel. Don't have a man. to check valve specs to adjust. Was wondering if anyone knows adjustment specs., fealer gauge size, and order of adj.? Dealer says it should be done by them because it has variable valve timm., although there is nothing on my truck indicating this, any truth to what the dealer says?? If the valves don't need adj., could it be a weak or bad oil pump?? Anyone ever encounter this?? Knocking noise is not heard until engine is at normal operating temp. at idle.

97ltd4x4

Well,sounds like two things possible,valve adj,or timing chain guides/tensioner problem..

For the valves:
First off,they are right,you have to replace the shims with the correct thickness ones,to get them back in spec...There are like 40 differant thickness ones...The question is....if its a valve adj problem....Is it just one or two valves? Or is it most of them?

If one or two...(no one will know this untill the valves are inspected),have them adjust them....

On the other hand if its most of them,You have a couple of choices,first one is have them adjust all of them..and hope for the best...But

If most of them are out of spec..its because the valves are starting to wear into the seat and valve stem wear(shims will not wear)...

so you might want to think about pulling the head,sending to machine shop having valve seats cut/and or valve is starting to burn and have valve(s) replaced..have them install valve guide seals/shims,ect and reinstall head...Or buy remanufactured head.

I only say this because the 4cylinders sometimes have valve problems at higher milage(they start to burn exhaust valves).....

So its up to you.

If its a timing chain problem,guide/tensioner..its a strait forward repair.....Beware it is an interfearance engine with that timing chain,so I would really think about replacing t-chain componants...if it jumps a tooth it can bend all the valves....

stepside trd

Sounds to me like I am better off just doing a top-end re-build, as well as a timing chain/belt replace. The truck is an '01, but it only has 40,000 miles on it. I didn't expect to be doing this this early. I think I will just run it into the ground and then swap in a V6 w/ a TRD blower, upgrade the tranny, and swap out the IFS for a four-link sas. I may as well go balls out, that is if the wife approves. Or maybe just sell it as is and use the money to build the '08 FJ I just got her! Now if I can only convince her to get another ride!! Oh well, THANKS for the info, does anybody else have any ideas, be glad to hear them....

SoCalPaul

Take it to a mechanic for an inspection. Troubleshooting noises without hearing them is nearly impossible.

zlathim

^^^^^^^^^^

Listen to this guy. He knows what he is talking about. Every thing he has said rings true to me according to my experience with this engine.

My buddy had a high mileage 2.7l 4x4 Taco that he wanted to get rid of, but it had a burned exhaust valve. He asked me to fix it for him to sell. Obviously he didn't want to shell out for a complete overhaul of the cylinder head, so I fixed a couple of burned exhaust valves on cylinder #1, adjusted all the rest, and it ran fine.

Here is what those valves looked like after being too tight too long:



I bought two new Toyota valves and some lapping compound. I lapped in the new valves pretty good. Here is the result of that:



I filled up the combustion chamber with mineral spirits to test the seal on the vavles. I installed my spark plug adapter with o-ring to the combustion side of the head to act as dam on the spark plug hole. After ten minutes they were exhibiting no significant leakage:



If you can get away with merely an adjustment, it is still pretty involved. The basic process goes like this:
Obtain a copy of the factory service manual for your engine. Haynes and Chiltons have a decent section on the valve adjustment proceedure too.
In the sequence depicted in the manual, measure and record all valve clearances.
Then you need to know the thickness of the exhisting shim in order to consult the shim chart in the manual to find correct thickness of replacement shims. You have to remove them in order to measure, and you will notice that the manual says you need some special tools. You can buy the tools, fashion your own tool, or simply remove both cams shafts in which case the shims are easily removed. The cams sit right over the shim and bucket, so getting them out is a PITA:

Here is a crumby pic of the valve train:



Here is a picture with the cams removed. The valves on the right have the shims installed, and the ones on the left are empty buckets:



Purchase the shims from the dealer per piece. IIRC, they are about $6.00 each.

After the entire project I did, adjusting the valves was the least of my worries, but it is pretty involved. Get the manual and read through it a couple of times before you jump in.

If you absolutely can't get ahold of a manual, pm me and I'll see if I still have the pdf file I used when I fixed my buddies truck.

littlecommando

lol what?
dont have a man, but has a wife?

stepside trd

Littlecommando, "man." is short for "manual", you would have gotten that had you read the complete sentence! Everybody else who replied understood it. A MANUAL, also known as a mechanics bible, a book you read to get information on repairing your vehicle correctly. Obviously reading is not a top priority in Powder Springs. Besides, I didn't come on this forum to have my writing skills critiqued. You do know what "critiqued" means don't you?? Try and keep up, and I will go slow for you. If you don't have any good info. (that's short for information, you still with me?), then please don't waste the space, someone else out there in cyberworld might have to help me. ZLATHIM, First off, that is a great job on the valve lapping, did you need to use both a course and a fine compound or was it salvageable enough to just go to the fine? I ask this because, wouldn't the valve grind affect the size of shim to be put back on. For example, if I miced. (that's short for, to use a micrometer for measurement, you still with me littlecommando?) the shim I took off the valve before I ground it to reseat it, wouldn't it require a larger/smaller shim to make up for it? So that the valve opens the same distance before the grind. I believe those shims are measured in the smallest of tolerances, aren't they? I am not loosing pressure in the chamber, or power at the wheels, I'm just getting a knocking noise (like the sound of a diesel running) that goes away when I put oil, which is why I thought it might be a weak oil pump. By the way, is 40,000 miles considered high mileage for a 2001? it is actually somewhere in the 37,600 miles range, I just rounded it off. Any and all info.(that's short for "information",you still with me LC,read slow now, but try and keep up) I need to look at this from every angle before I tear into it and I want to make sure I've covered all my bases. Living in an apartment complex sucks big time, so I need to get in and get out fast without the LL finding out. Thanks, if you have any other ideas or suggestions, or anyone else does, please feel free to add on. I'd like to hear them all........

zlathim

I'll try to answer all of your questions. I'm not good at diagnosing noises as described in writing, but your truck may have something wrong with it other than valve noise. Did the oil every get critically low? The one I worked on had a pretty bad miss, and a compression check showed #1 cylinder to be about 100 psi lower than the rest. I then did a cylinder leakdown test to isolate the compression leak to the exhaust valves.

Less than 40k miles and your truck is barely broken in. When I said my buddies truck had high mileage, I think it was in the neighborhood of 200k miles.

You are correct that the new valves would be almost impossible to gauge after lapping. I believe I just used the fine compound, but when I had it all assembled, I had actually just made a guess at which shims I would need for those two exhaust valves. I got 1 right and 1 wrong. I ended up making an extra trip to the dealership before I had it all adjusted correctly. I kind of forgot about that until you mentioned it because I did this repair a long time ago. I know that all in all, I worked on it for a total of about 12 hours over the course of 3 or 4 days.

Maybe someone else will chime in with more ideas. At this point I'm not even sure your problem is in the valvetrane. You may have a bad rod or main bearing from the sound of it, but it is hard for me to say really. 40k miles is pretty fresh to be having problems like that.

BTW- not trying to be a jerk or anything, but a less ambiguos thread title would probably get more views and responses. The first sentence of your original post sums it up pretty well and might have made a better thread title.

I hope you get it figured out, I will try to check in with this thread from time to time, and if I remember anything that may help I will post up!

stepside trd

zlathim, you are not being a jerk, I think the other guy was, but no sense in wasting space on that fruitcake. As for the oil press., no,it's never drop down too low. I have used plugs from Bosch plat., and just recently changed to E3's, which BTW, work really good. I have never exp. a miss, or a back fire, and the truck is not puffing smoke. I purchased the truck from a toy. dealer. in 2002, the truck is an '01 used, and have just never really drove it much even to this day. Although they assured me that it was toy. certified (whatever that means), the noise was there from the get-go.Thats how I found out about the noise disappearing when I added oil. The first oil change, I switched out to full synth. and it helped a little, but it is still there. The noise is definitely coming from the top end, so I know it can't be bottom end bearings. And yes, I do agree with you that diagnosing a sound is hard to do without actually hearing it for yourself. I can't tell you how many times friends have called me to ask why their vehicle is making a clanking noise, but if you have ever heard a diesel four cylinder at idle, I'd say that's what you are hearing. I have dealt with working with those shims on other toy. vehicles and I guess I was just hoping that someone else out there may have exp. the same thing I have and found a much easier way to fix it. In essence, I just want to avoid having to do all that work (especially here in the cold where I'm at) and wish I had a magic wand to wave over the truck and make everything all better. You know what I'm saying?! Hey, you wouldn't happen to have any spare magic wands laying around that you could lend me, would you?? Just thought I'd ask, THANKS a whole bunch anyways for the info. As for the thread title, in all honesty, I'm usually just a wallflower in these forums and don't participate much in discussions. This truly is my first time asking for help with anything pertaining to my truck and just didn't know how to start (never was good at writing as you can tell). My wife encouraged me to try something new for the new year, Oh ,BTW, happy new year to you and your loved ones. I'll keep trying to produce better threads.

zlathim

Happy new year to you as well!

I'll have to look around, but if I remember right, I am fresh out of magic wands

You seem competent enough, so I'm sure you will have that thing purring like a kitten in no time!

Take it easy!