Gevo

What other items would you recommend for me to change/check/adjust?

My (new to me) 1991 4Runner needs a lot of TLC. I started by changing the starter yesterday and properly heat-shielding wires and routing them.. etc..

Also, as I shared in another thread, I changed the broken coolant hose from the oil cooler to the block.

Now, I want to adjust the valves and change my injectors and generally once I have the manifold off I will clean everything accessible and reinstall with new gaskets.

Of course, I want to tap in to everyone knowledge and see what other items shall I consider while I have the top of the engine undone. Please, leave your thoughts.

Thanks!

For fun, here is a picture I took while changing the starter.. can you spot the foreign object? (tool)

Sturmcrow

V6?

While I had my cams off to adjust the valves I also changed out the valve stem seals. During the same teardown I also changed the front crank seal and both front cam seals. I would have changed the rear cam seals, but did not realize what they were, so did not have the parts on hand. I reinstalled them with liberal RTV instead.

Long story short, after changing all of those seals, my truck went from 1.5 qt of oil lost every 1000 miles to not losing a drop since April. I checked the oil level last night, and it is still right at the top on the dipstick marks.

I was not seeing much oil on the outside of the engine, so firmly believe that changing out the valve stem seals was the biggest contributor to fixing my oil losses. I will state, by the way, that the valve stem seals do not require much force to put back on, and I ruined one by pounding on it a little too hard (so basically I changed 11 of the 12 since I was then short one).

The valve stem seals are also very easy to replace if you have the cam off and have access to an air compressor. You do need access to a special tool to remove the valve retainers, but in my case it was totally worth the effort.

Gevo

This is gold Thanks.

YES! How could I forget, 1991 3.0L V6, VIN JT3VN39W..... So the 3VZE Engine (from what Ive been able to deduce)

I have a bit of experience working on jeep cherokee and grand cherkoees, and short of my dad owning a beautiful 89 SR5 Tacoma, I have no Toyota experience up until 2 days ago.

Keep any and all lessons learned and advice coming.

Thanks again!! I will post my work with pics for community fun as well

Sturmcrow

The valve adjustments on the V6 are a bit of a pain. You have to measure the cam clearance, then get the shim out, measure it and replace it with another one that will give you the correct clearance.

I found that it was very much easier to just remove the cams after getting all of the initial clearances measured. You do have to do a bit of RTV cleanup and reapply to the bearing caps closest to the ends of the cams, but it was really no big deal. That way you can swap around some of the shims to get the clearances you need and you may only have to buy 4 or 5 new ones. One of my local dealers had a box of shims in the back, the other did not. Highly recommend that you bring your calipers or micrometer along to the shop, as they were somewhat jumbled around.

You need an air compressor or a length of rope when changing the valve stem seals because otherwise the valve will fall down into the cylinder. Youtube is your friend for videos about how to do that. IF the valve falls into the cylinder, you are pretty much hosed, and will be doing a head job after all.

I used my compression tester as an adapter between the air compressor and the spark plug hole. You do have to remove the valve core that is in the compression tester in order for the air to flow the correct direction.

Sturmcrow

Just to be sure, are you planning to change the water pump and timing belt while you are in there? You need to pull the radiator anyway, so you might as well do a coolant flush and fill. Lots of opinions on here. I went with Peak Global Lifetime (http://www.peakauto.com/products/ant...obal-lifetime/) based on everything I could read. Toyota red is always an option, and will cost you about $100.

There is also a little U-shaped coolant bypass hose on the back of the engine that is known to leak. I made a judgement call that mine was still OK, but if I start seeing a puddle coming from back there, I will know what it is.

There is a valve under the intake plenum with plastic that gets brittle and breaks. It is supposed to open when the engine coolant gets hot and allows vapors for the charcoal canister to feed into the throttle body. Mine was hella broke, I did not want to pay the $60 for the part, and I did not want to wait to get the part. I just ran the vacuum tube straight from the throttle body to the charcoal canister. At least now my gas vapors are being burned up, instead of vented to the atmosphere as the PO had them doing. It is called the TVV, I believe, if you want to search on it.

Of course, you are going to want all new belts, a Toyota OEM thermostat, and the main radiator hoses too. Might as well change out all of the cheap stuff while you are in elbow deep. Speaking of, Rockauto.com has great prices and customer service, and a very wide selection of parts.

Last advice for now, when searching for things on the board, use Google. Be sure to put in yotatech and f116 and all of your results will be from this board. Much better solution than the forum search.

Gevo

Sturmcrow, thanks for the information on the valve adjustment. I will keep all of your pointers in mind. I will purchase a full set of valve seals and washers, I don't know, whatever else there is to change like that.

As for the radiator flush and other work, I absolutely will be doing it. There are some new hoses already, but I will not leave a single cracked or even 'dried' out hose under the hood. It's probably not worth it 10k miles from now

The issue is when it overheated on the way home (first day) some stuff came out of the radiator that definitely doesn't belong i.e. rubber gasket, other reddish particles that I would call rust but it wasn't... So, needless to say I will be rinsing the entire cooling system out in both directions until I am convinced the system flows as intended. My biggest worry is overheating, I want a 'perfect' running engine by the time I can say it's a road/track worthy 4Runner

Once I take the front end apart, I will inspect the timing belt and water pump. According to the previous owner her recently replaced those items.

I will just order the U-shaped bypass hose as well. I read on another thread in here all about it and it being beneath the plenum.

I've no idea what a TVV valve is, but sounds like something that would need to be replaced at 216k miles. lol.. damn!

Thanks for the auto parts store link, and the forum search tip.

Gevo

So I read up on the TVV valve on this forum and other places, and it seems like it is not mounted in a difficult to access area, i.e. under the plenum.... I assume the TV valve was a general suggestion not necessarily to do with the valve work? Or did you mean a different valve?

Gevo

Guys, and ladies.. I am really confused.. help!
How do I know which of the oxygen sensors in this list is the exact one for my 4Runner? There are many engine codes (i think) and none are 3VZE.... helP>>>

Scroll down to the list.. i'm sure this is a familiar site to all of you

http://www.toyotapartsoverstock.com/...xygen%20sensor

Gamefreakgc

Try www.rockauto.com and look for DENSO Part # 2344055 under emissions. $35 and it's OEM.

I will add that you don't have to remove the cams, if you've got good dexterity you can do it with these: http://www.ebay.com/itm/Toyota-Lexus-Valve-Adjusting-Adjustment-Tool-Pliers-/181213364733?pt=Motors_Automotive_Tools&hash=item2a312881fd&vxp=mtr. If you're not comfortable with engine work I recommend keeping the cams on. I didn't want to because my engine has a whole lot of miles and there's some seals and such that tend to disintegrate, so I've been told. But others took them off and said it was easier so if you want, go for it.

BTW, your local dealer will most likely not have a box of shims you can use. Sturmcrow, you got lucky... wish I had access to one! The rest of us have to special order each individual size and wait. Also, special order the copper crush washers for your fuel rails while you are at it.

As far as other things to change:

1. PCV valve on passenger side valve cover. Replace the grommet as well.
2. Any hose that appears cracked or damaged.
3. EVERY gasket you take off. Don't reuse them, they will leak.
4. If you want, knock sensor pigtail. They are known to get brittle over time (I didn't do this one though).
5. Water pump and timing belt if you think it need it but this one will run you $200 or so, or more. The pulleys can be difficult to take off though.

Gevo

Gamefreak, rockauto was suggested earlier and I am using their site right now and comparing to NAPA... wow, NAPA charges so much more for the same product.. what gives??? Also, I was looking at the BOsch.. not so worried about the price difference, but is there a known difference in quality between the two brands? Bosch vs. Denso?

anyway, thanks for the tip on not needing to remove cam.. I figure while in in there I may as well remove it and change all gaskets/seals that are accessible from there. I have done the top end gasket on my '98 Grand Cherokee a few years back.. here I am sitting where I don't belong for leverage to re-install the top end
Ignore the stupid smile and drunk face.. I had a few beers


As far as your listed items are concerned, I will be changing the PCV valve (bad experiences from jeep).. I was thinking about just putting new knock sensor, but it's pricey so I'm going to look up how to test it... if possible..
The guy i got it from supposedly put new water pump and timing belt.. we shall see once I open it up.

Gamefreakgc

Glad to hear you know your way around. That will make this job a whole lot easier. Engines are engines, if you knew how to fix your Jeep, these Toyotas aren't much different.

DENSO are much better than Bosch. Our trucks don't like them all too much and in the case of an O2 sensor, it might lower your MPG's. DENSO's are tried and true on Toyotas. Different makes have different needs, if you had a BMW I'd be saying Bosch all the way.

Knock sensors very rarely ever go bad but the wiring harness can. Replacing the sensor would be a little over the top since I really haven't ever heard of one going bad.

Sturmcrow

DENSO O2 sensor is recommended by far on these forums.

You can also relocate your PCV out a little ways to make it easier to change in the future. You just drill out the old one to turn it into a reducer and get some hose and hose clamps to extend the new PCV out till you can reach it. Its easier to do than to explain.

You are right that the TVV is not under the plenum, but it is a lot easier to get to with the plenum off.

I may be wrong, but I think that the knock sensor pigtail is under the intake manifold. that is probably deeper than you will get, unless you want to, of course.

I have to disagree with gamefreak just a bit. I do not think there were any more seals to deal with when taking off the cams as you would with a decent valve adjustment anyway. The cam seals come to mind, but those should probably be replaced at 100K mile intervals anyway (complete WAG there, by the way).

Gamefreakgc

Hey no worries, it's good to have different perspectives when tackling a major project like this. I wasn't sure how confident the OP was on an engine so didn't want to impose more work than the minimum.

The last person who took the cams off my engine obviously didn't know what he/she was doing. They were put back on in the order of 1-4-2-3

Gevo

Great, thanks for the Denso vs. Bosch tip guys. I'm one to learn from the experiences of others

I figure things out as I go unless I've seen them before. My trusty electrical Engineer buddy is always there to catch my mistakes (I'm Civil & ~Mechanical Eng).

Well, Gamefreak, I won't go into the cam work blind, but I will be back here often enough with annoying questions

Well if the knock sensor pigtail is reachable without the head, I'll change it.. however, can someone point me to a site that sells it? I couldn't find it on rockauto.

Gevo

Question guys.. I am looking for the plenum gasket. I thought it would be just one piece, but although all of these look one piece and only one piece is shown as the picture, some of the items say "set" while others don't.. am I missing something? This is the one I'm looking to buy.
http://www.rockauto.com/catalog/more...562&cc=1272361

Gevo

Also, while I'm at it. The 'Intermotor' brand gaskets seem to be a few bucks more than the others, I am not familiar with gasket brands, is it worth the couple bucks extra?

Sturmcrow

I believe that my plenum gasket came with my valve cover gasket set. Make sure you don't accidentally buy two of them. I see that one of the DNJ sets on Rockauto has the plenum gasket too. I do not recall their being any other gaskets for the plenum, so "set" is probably a misnomer here.

I'm civil too, by the way

No advice on Intermotor, sorry.

Gevo

Thanks Sturmcrow, I will keep an eye on that.. at the moment I am trying to figure out which of the gaskets I need on this item.. I don't understand how to decide which from the list is the right one... on the following website, I want to get the part number 23802D gaskets, but that part number has two listed prices, both have the same car info with slightly different descriptions. I figure if im ordering by part number to the right, they are different, but by part number 23802D, they should be the same.. what am I missing???
http://www.toyotapartsoverstock.com/...rimLevel=18204

Gevo

Sturmcrow, do you currently work in the civil engineering field? although my education is both mechanical and civil, I chose the civil as a career path. It's been a great 7 years so far

Gamefreakgc

I believe it's a dealer only part.

That's the one. There's only one but like Sturmcrow said it might be a set with the valve cover gaskets. Felpro is a solid brand, I've never had any issues with them. I'd stay away from cheap-o brands.

Geez... that site is confusing! If you've got a Toyota dealer nearby then just buy from them. They'll know exactly what you need and you will know the quality is good. It'll arrive next day if you order before 3:00 PM (excluding Saturday). Prices are not the best but we're talking gaskets here, not going to cost you an arm and a leg (except for valve cover gaskets but those are easy).