Top End Rebuild

[gnomad]

So, I recently acquired a project '86 DX. I've been trying to track down a mysterious stalling/no start issue for a few weeks now and all the while I've become increasingly bothered by the layers upon layers (1/2" thick in some areas) of grime and the decrepit wiring, connectors, and hoses. I decided to try a new distributor (reman for 100.00 on closeout.. why not?) to solve the spark issue and while i was there i went ahead and ordered a top end rebuild gasket set. I know it's probably not necessary to get the van running but because it does have 300k miles and I plan on owning this van indefinitely i figured it was a good time for a face lift (or should i say head lift).. So here I am with the head removed (off to the machine shop tomorrow) and man was it a good call! I found brittle/disintegrating connectors everywhere, hoses ripping in twain, valve stem seal springs broken and floating loose in the head, rusted head bolt threads, massive carbon build up on the valves, etc, etc...

Now I'm looking for some opinions/advice..

Tim, you have mentioned you could provide some part numbers... I could use some of those . Preformed hoses and/or suitable alternatives would be great.. or what do you think about the flexible "universal" hoses? Also, I would really like to replace most of my wiring connectors: coolant sensors, injectors, and anything else with those silly wire retainers as i have broken most of them in one way or another. I can't find a source for connectors anywhere online.

And here's a general rebuild question... while i was removing the head i noticed some of the heavy, scaled build up in the head broke loose and fell into the push rod channels. I cleared most of it once the head was out but given the amount of build up in the head i dont want to risk clogging the oil passages further. i don't wish to do a bottom end rebuild at this time so is there a product anyone can recommend for flushing out the lower end? maybe spraying "gunk" cleaner down through the block... or pouring seafoam through several times?... any suggestions for a thorough bottom end clean would be appreciated!

that's it for now. i will keep this thread updated as i continue and i will try to take more photos and post a thorough walk through of the rebuild. Happy vanning!

[timsrv]

I am very sorry for the late response. My computer crashed and my life has been upside-down for the last week. I've resolved my computer issues and everything is up and running again . I somehow managed to go about 5 or 6 years without any problems, but the last few months I've made up for it. I finally just went out and got a laptop and of course I had to have something unique......yadda yadda........okay so I'm rambling, sorry. If anybody's interested I made some posts on the HP forum HERE.

Okay, back on topic. You mentioned you purchased a head gasket kit? You got a genuine Toyota gasket set right? There is a wide varience in quality when it comes to aftermarket head gaskets, so unless you're feeling lucky you should stick with Toyota here.......just saying .

The valve grind gasket kit for the 4y is Toyota Part #04112-73035. There have been different numbers used for this same kit over the years, so don't be too surprised if that number is superseded by another. As for hoses, I don't like flex hoses and will only use them when there are not other alternatives. I consider formed hoses to be far superior. There are a lot of formed hoses in the engine compartment. Most are still available but some are not. Last time I ordered these Toyota substituted some straight hoses for some of the formed coolant hoses. I ended up taking these back because why pay $15 for a piece of 18" straight 5/8 heater hose???

For the ones that are still available I marked up these break-down sketches from the EPC with part numbers. If I say "use bulk hose" it means you will either get bulk hose from Toyota at a very high price, or it is NLA (No Longer Available). For some of the smaller 5/16" hoses I found that Gates hose is actually superior to factory Toyota hose so I marked this up to show the locations this will work in. Some of the others are bent too sharp (bulk hose might kink) so I listed Toyota part numbers for those. There are some slight differences from 2wd to 4wd on some of these hoses so if you order make sure you copy down the correct part numbers.







Note 1: The EPC lists this hose as #99556-20300 for 2wd and #87245-95D12 for 4wd. The last time I ordered the one for 2wd Toyota sent me a hose in a package with the correct part number, but it was actually a 12" piece of 1/2" ID straight hose (not formed). So for this one I say save your money and just get a piece of 1/2" bulk heater hose for 50 cents (Toyota charged me $13). I'm not sure what you'd get if you ordered the 4wd hose, but it wouldn't surprise me if you got the same thing.

Okay, here's the air valve hoses and the ventilation hoses for the valve cover. The last few times I ordered the PCV grommet from Toyota there was a problem with the part number, but I found Dorman makes replacement ones that fit nice. Dorman has the racks marked "HELP!" in the retail section of most auto parts stores. You will find several rubber parts like this there, just use the part number in the picture below to identify the correct one.

Note: Rubber line (not shown) that goes from intake manifold to the metal line on firewall (brake booster vacuum supply) is Toyota #44774‑28080





Okay, last but not least is your BVSV (Bi-metal Vacuum Switching Valve) Toyota part #90925-05017 otherwise known as the "Oh crap I broke it valve". The plastic nipples on this valve get extremely brittle from the heat of the engine compartment and will break off if you look at them wrong. If you're pulling the head it's almost a given this valve will break. Last time I purchased one was about 2 years ago and at that time they were still available through Toyota. The valve's mission in life is to inhibit EGR operation when the engine is cold. These run about $40. Here is a picture of one.


As for your question regarding flushing out the lower end, I would advise against that. Nobody likes the idea of heavy sludge or chunks of scale floating around down there, but unless you tear down the bottom end, other than changing your oil there's not much you can do. Using crank-case flushing products on old engines is a bad idea. Scale or build-up doesn't do any harm when it's stuck to an engine surface. If the cleaning product actually works it will only serve to move the gunk from it's harmless position into a potentially bad one. When this stuff floats around in the pan it will typically end up stuck to the oil pump pick-up screen and if enough of it gets deposited there it can starve your engine for oil.

Chances are whatever fell down there during head removal will eventually drain out during an oil change or it will find a harmless place to deposit itself. Just try to minimize any further contamination and you should be okay. Tim

[llamavan]

Photographic tour of most coolant hoses (including part numbers)

Gwen

[timsrv]

Darn! I actually forgot about your killer post on these. I remembered all the pics and flow direction arrows but forgot you had part numbers . Oh well, redundancy is good and this shows break-down vs actual pics, so I guess it's good. Perhaps I should merge these threads?

And of course this reminded me of yet another thread with the same information . Here you go, eat your heart out: http://www.toyotavantech.com/forum/s...&p=296#post296

[llamavan]

I still have a few pics to take and add to my post, so I'll just take responsibility for merging and uploading it all to the library when I'm done.

Gwen

[gnomad]

That's great, thank you both. I also found the thread llama had posted on TVP about the interchangeability of late 80s - 90s volvo injector connectors so i went i picked up a bunch from the local pull-a-part. they fit perfect and are in great shape. i also found out that a number of the other connectors are also a direct fit: maf sensor, throttle position sensor, coolant sensors, and anything else with a wire clip... very cool. some of the connectors need to be modified slightly to work where the locating pins are offset.. but at $5 for 2 dozen connectors i dont mind the extra work. i will post pics of that in a couple hours..

i didn't end up going with genuine toyota gaskets. the head is at the machine shop and is getting toyota valves and guides. i got a beck/arnley top end rebuild kit. i know votes are in everywhere at 97% for toyota head gaskets but why? i've made gasket paper head gaskets for diesel engines and they held fine. i went with a reputable brand and the gaskets seem of good quality.. i got the set on closeout so i could get a toyota HG at least and not be losing to much. anyone want to try and convince me?

how about exhaust manifolds? mine is cracked almost all the way around #4 tube with another along the bottom. anyone have success with repairs? there's a cast iron repair shop a couple towns away, i figure that would be my best shot. if not, does toyota still sell them? can't find them at the other parts stores. anyone got a spare 4y exhaust manifold?

[timsrv]

i got the set on closeout so i could get a toyota HG at least and not be losing to much. anyone want to try and convince me?

how about exhaust manifolds? mine is cracked almost all the way around #4 tube with another along the bottom. anyone have success with repairs? there's a cast iron repair shop a couple towns away, i figure that would be my best shot. if not, does toyota still sell them? can't find them at the other parts stores. anyone got a spare 4y exhaust manifold?

There are at least 2 threads over on TVP where other van owners had their engines rebuilt or purchased rebuilt engines and the rebuilder did not use a Toyota head gasket. In both of those cases the head gasket blew in less than a year. I'm sure that you are correct about some aftermarket gaskets being fine, but I personally wouldn't want to risk having to do that job twice. Perhaps you could test the Beck Arnley head gasket for us and let us know how it holds .

As for the manifold, you need a new exhaust manifold Toyota Part #17141-72010 (around $150 if purchased through a discount internet site). Usually when that runner cracks, the rear-most stud also breaks. Even if yours hasn't broke yet, I would strongly recommend replacing it now while you have good access. For this job you will need the stud Toyota Part #90116-10063, nut Toyota Part #90179-10051, and gaskets (which you already have). When it comes to extracting that broken stud I'd just let the machine shop deal with it, but if you feel the need to do yourself, here's a couple posts where I did that job. http://www.toyotavantech.com/forum/s...2197#post12197 & http://www.toyotavantech.com/forum/s...-exhaust-studs

As for cast iron repair, if your old manifold were the only one known to be in existence, then it would be worth a try. However, when new is available, welding a cast iron part such as this is a waste of time and would probably end up costing you more than a new one anyhow. Welding cast iron exhaust manifolds requires a special procedure. For there to be a chance of success it should be wrapped in asbestos (for insulation), slowly heated in an oven to an almost glowing temp, welded while hot, then cooled slowly to stress relieve. After all this, the surface that bolts to the head should be milled or surface ground to minimize potential leaks and future stress. Then after all your hard work, it will probably break again after a few heating / cooling cycles (this is why I recommend buying new). If you need it fast, check with your local Toyota dealer and have them order it as a critical part (will probably still take a couple days though) Note: Toyota's MSRP on this is $198.05, so if they try to charge more, call them on it.

If you get a new manifold, in addition to the parts I've already mentioned, save yourself some time and trouble by also getting these parts: Studs 90116-10058 (qty:3), Studs 92122-40610 (qty:6), Studs 90116-08128 (qty:2), Nuts 90179-06194 (qty:6), Nuts 90179-08059 (qty:2), and Nuts 90179-10070 (qty:3). You'll know why when you start putting it back together .

Avoid used manifolds. The 4y exhaust manifold is weak and tends to crack in the same place as yours at around 150k miles. If you're lucky enough to find a good used one I'm guessing it won't hold up very long. At least with new you should get about the same service your original gave. Tim

[llamavan]

I also found the thread llama had posted on TVP about the interchangeability of late 80s - 90s volvo injector connectors [...]

I can't remember who posted that one (and I do remember the post), but it definitely wasn't me.

Gwen

[timsrv]

BTW, I just came across THIS THREAD while surfing over at TVP. There are at least 3 or 4 others like it, but this one is a good example of why I don't trust aftermarket. Tim

[wayoffline]

About the exhaust manifold. I did not bother to check for a new one before tearing into a manifold gasket/broken stud replacement project(for some reason I thought they were unavailable). I enlisted the help of a friend who owns a muffler and welding shop. My manifold was severely cracked and very warped. It turns out both the front and rear studs had failed. He did not seem too concerned and proceeded to drill a hole at either end of the cracks (yes, there were more than one) and then grind a trough from one end of the crack to the other- connecting the holes. He then filled the trough with brass fillet. After surfacing the manifold, he was a little concerned about the reduced thickness in relation to the intake manifold. So far it is performing flawlessly but had I known a new one could be had for less than $200 I would have gone that route. I will try to remember to post an update a few thousand miles down the road.

[timsrv]

Glad to hear it's back on the road. I like these kind of experiments & wish you the best. I have done this sort of thing before on something with an exposed manifold, but it's quite a bit of work on a van. It will be interesting to see how long it lasts. Tim

[NEC]

I am running the Beck/Arnley hg kit I got on Rockauto at closeout price of around $20. This set is good quality and comparable to OEM. (remember, before it was on closeout it was a high dollar gasket set by a reputable brand) I have used lesser brands from china bought off of ebay. with lesser results.. Stay away from these brands. Beck arnley, Fel-pro, Rock, are all good brands for head gaskets. Tim I love your re-working of all the pns in the EPC. I bought all my rubber water and air hose from my dealership and paid over $400. The 4wd heater hose you mention is a molded hose.

[coronan]

I've repaired several things on my van including the hose of death. But not until I had my head off am i starting to comprehend the whole cooling system.

Am I to understand the the entire head is cooled via a 1/4" id pipe fed from the heater return????
Plumped like this: Heater return (5/8) > 1/4" T > under the intake manifold > Throttle body? > Hose of death > head.????

Correct?????

The water flow must be under significant pressure drop and flow restrictions on such a long journey.
No wonder our vans are subject to cooling issues.

Stupid question: How does the head get cooled if the cabin vent temp is set to cold??? (the water flow through the heater is shut off).

Has anyone ever considered feeding the head off the 5/8 heater hose return line directly?
It would require a simple adapter plate threaded pipe 90 and a hose barb, And a hose barb T in the heater return line. There is not much room but there is room.

Buler????.....

[timsrv]

The head is cast with large coolant chambers & coolant flows throughout. It flows up through the block into these cavities, through the head, then out through the fill neck area to the radiator. The bypass system is used to supply coolant to the throttle body (prevent icing) then on to the air valve (controls idle speed when van is cold), then back to the heater hose return line near the back of the block. On the automatic 4wd vans, there's another tap here that supplies coolant to the engine oil cooler (mounted under the oil filter). The bypass system uses 8 mm (5/16") hoses & tubes to transport coolant & does not provide any cooling to the head. The plate/nipple(s) on the back of the head are simply the place where the bypass & oil cooler systems tap coolant from. Tim

[ninz30]

^ +1

[coronan]

Sweet. Too many late nights for me this week.
For some reason I couldn't remember seeing the coolant passages on the bottom of the head.

[Black Pearl]

I am re-doing the entire top end in my 87 4x4 . (This sure isn't a 22RE) I ordered hoses and gaskets according to the parts #s you had listed above. Apparently the heater hoses, numbers 87245-95D08 and 87245-95D15 are discontinued by Toyota. They look like formed hoses. Do you have any other suggestions as to what I can use instead? Also, I may have missed it in your threads, but do you have a recommendation as to what vacuum line to use?
Thanks

[timsrv]

It's been a while since I ordered those hoses, so I hadn't run into that shortage yet. Unfortunately due to the age of our vehicles this is happening more and more. When this happens, there's a few ways to deal with it. You can take out your old hoses, then go to a parts store with a good inventory and match it up to other similar hoses. Sometimes you can purchase a longer hose with a similar bend, then cut it down to size. If you go this route, please take notes as to which hose works (brand & part number) and post here.

If the bend isn't too severe, then perhaps bulk hose will work. At times I've requested the parts guy cut me a piece from the center of the roll as there is some natural bend from being rolled up this way. If your parts guy is willing to do that, it can help reduce the chance of a kink.

Another way is to purchase the metallic coils that are sold for making tight bends. I personally don't like this method (a bit bulky and looks trashy) but it works. You put the coil over the hose, then bend it to the position you want. The coil helps maintain the round shape of the hose and this prevents it from kinking.

Regarding the vacuum line (the small stuff like what runs across the top of the throttle body), this can be substituted for standard aftermarket sizes at the parts store but I've found the fit isn't perfect (either too small or too big). The small is more secure and less likely to fall off, but pushing it over the nipples stretches it a bit beyond it's design limitations (makes it prone to cracked ends). The other problem is the little looms that fit over the hose (for organization) don't fit the aftermarket stuff right. For this reason I prefer Toyota vacuum hose. Toyota sells it in predetermined lengths from 300 mm (about 1 foot) to 2600 mm (about 8 1/2 foot). Here's the Toyota part numbers & current pricing (at the time of this post):

• 90999-92002 300mm $5.46 (~$5.46 per ft)
• 90999-92003 600mm $2.53 (~$1.26 per ft)
• 90999-92004 950mm $13.33 (~$4.44 per ft)
• 90999-92006 1300mm $21.38 (~$5.35 per ft)
• 90999-92007 1650mm $36.78 (~$7.36 per ft)
• 90999-92008 2600mm $52.18 (~$6.14 per ft)

Note, this is current MSRP (what you'd pay if you walk into your local Toyota parts counter). If you order it via one of the discount Toyota parts sites, you can save up to 30% (before shipping), but as you can see, the cheapest way to get is purchasing in 600 mm lengths (about 2 ft). The good news about this size vacuum hose is Toyota uses it on almost everything they make so they're not likely to run out any time soon. Tim

[beetleswamp]

It seems 12262-73010 and 12261-73021 have been discontinued. My Pcv hose broke apart while disconnecting. What would be the next best option?

I am going through the top end preparing for an engine swap and changing everything that seems to be crusty and crunchy, and am surprised this van kept running for so long.

Okay, here's the air valve hoses and the ventilation hoses for the valve cover.

[beetleswamp]

Some vent hoses finally popped up online so I grabbed them. Not cheap but will save me the time of trying to mad max it. Wondering if maybe I should have bought 2 of each. Engine is almost back from the rebuilders. Exciting times ahead.