I thought I'd stop hijacking the "synthetic oil" thread and create a thread to get some questions addressed. Let's start out with what @DannoXYZ mentioned:
I've done the valve-stem seals with engine installed on my VFR-750 and a friend's Supra.
The trick I use is to drop some smooth nylon rope down the spark-plug hole. Then rotate crank so piston pushes rope up against the valve faces. Adjust amount of rope as needed. Gives you firmer push against the valve-head than compressed air. Makes it easier to remove keepers & springs. You can use a deep-drive socket and hammer to remove, but I prefer a gentler pressing tool with more controlled motion.
The bike was too tight to fit the valve-spring compressor, so I just pulled the engine. The Supra was easy after removing the cam-towers. Made my own compressor with a triangle base that bolted to the cam-tower bolt-holes. Then a long lever with plunger.
For the Corolla, there's a tool that looks like a crescent-shaped cam at the end of a stick. Wedging the crescent and rotating it's increasing width over the springs compresses them easily.
So I'm considering whether I want to go through the effort of doing this job, and right now just trying to understand the scope of it. So I'll toss out my understanding of the procedure, and others can chime in to let me know if I'm on the right track:
Parts:
Assuming I can reuse the valve cover gasket I replaced last year, just need a few dabs of RTV.
My spark plug tube seals are also new, so those should be reusable. Same with the rubber gaskets on the valve cover nuts.
Although my cam seal is new it sounds like I might need a new one to do this procedure since the cams need to come off? I'm not sure if it's possible to reuse the seal without damaging it. I actually do have a spare cam shaft seal laying around.
I need 8 new exhaust side valve stem seals (90913-02089)
I need 8 new intake side valve stem seals (90913-02090)
Anything else?
Tools:
Either some nylon rope like Danno referred to above, or a valve holder to use with compressed air, like this: http://amzn.com/B000COC7ZU
A valve keeper removal tool for on-block removal and installation, like this: http://amzn.com/B0012S61IO. Danno - I couldn't find a tool like you described - any idea where you might get? How would you compare the tool I found here to what you mentioned?
I see that there are tools to remove the valve stem seals, but honestly I was hoping a pair of needle nose pliers will suffic?
The factory repair manual does mention a tool for installation of the new valve stem seals (SST is 09201-41020 "Starter Armature Bearing Replacer")... Is this really needed?
Procedure:
The factory repair manual only covers the procedure assuming you remove the entire head. So in looking at what's needed or not here's my guess at how to go about this:
Remove spark plug wires
Remove plastic cover for wiring harness to alternator/oil sender
Disconnect wiring harness for alternator/oil sender
Remove 4 nuts and 4 gaskets for valve cover
Remove valve cover
Remove timing belt covers
Set TDC
Mark position and direction of timing belt
Pull back timing belt idler pulley
Remove timing belt
Remove camshaft timing pulley
Remove intake camshaft:
Sounds like I need a 6 mm thread diameter 1 mm thread pitch 16-20 mm long "service bolt" to secure the camshaft sub-gear to main gear?
Remove the bearing caps and place them in order
Remove exhaust camshaft:
Sounds like the knock pin should be positioned at about 5:30 o'clock
Then removing front bearing cap and remove the cam seal
Then removing the other bearing caps and place them in order
Sounds like I then need to pick a cylinder to start, set the piston to top position with either nylon thread or compressed air to keep valves up
Using valve keeper removal tool, remove valve keepers
Remove spring
Using needle nose pliers, remove valve stem seal
Using some sort of tool position new valve stem seal on (how hard will this be?)
Using the valve keeper install tool, install valve keepers
Repeat for the remaining intake and exhaust valves
You could feel around the stems, especially around the keeper grooves. And if you find anything, just hit it with some emery-cloth or whatever. They're probably fine.
I pulled my replacement heads with unknown mileage from a junkyard, and probably should've replaced the seals, but cheapness, fear of facing the unknown, and laziness prevailed... What I did do was slip a heater hose over some of the seals and try to blow through it/them, while I was changing the valve springs. The ones I remembered to check all seemed tight.
I also pulled one or two valves out of the head, out of curiosity while doing this, and did feel some resistance as the tip and groove passed through the seal.
Use the rope, air is not so good!I f you push the valve in while the air is holding it then the air all escapes out and there's nothing holding it anymore! If you have a ton of miles the valve guides are probably worn as well, so really it's best to just pull the head and have it all rebuilt. It costs more and takes longer but you'll get a more satisfactory result for the labor involved.
The tool you want can be found with search terms of "Bluepoint ga317."
It works really well on this engine.
Cam removal- You dont have to pull off all the covers, just the top one. Rotate the cams to where the cam dots line up and you can put the bolt in. I just slid my belt off the sprocket. When you put the cams back in do the reverse, then check the marks at TDC to make sure you arent a tooth off.
You will also need a magnet to pull the lifter out. One of those kind that extend to search for missing bolts is great for that.
DONT get the OEM seals, get a set of viton seals. I found mine for about $15 on ebay.
Pull them off with pliers. BE CAREFUL you dont damage the sides of the well that the lifter slides into. Installing the seal is easy with a 1/4" drive 10mm deepwell.
I didnt find any burrs on my valves when I removed the keepers, so your seals should install easily. USE LOTS OF oil when installing parts.
If your valves and rings are in great shape, then air is easiest for keeping valves in place. If you are able to push the valve down and lose air pressure, then use the cord.
Am I the only one that thinks 94RollaDad is crazy for considering doing this?
94RollaDad, recently you said that you burned 0.3 quarts of oil in 1200 miles. I wouldn't consider this bad enough that you need to change the valve stem seals. First, you don't even know if that is the point where you are losing oil. Second, the owners manual (at least mine does) will say that it's normal to burn a small amount of oil. The owners manual explains that this is from oil being sucked past the piston rings and valve stem seals into the cylinders during deceleration from the high vacuum in the cylinders.
Now at 0.3 quarts per 1200 miles you can make it 4000 miles before having to add a quart, so I don't see how this would cause any loss in performance or other problems, and it's certainly easier to add a quart (or less) of oil once between each oil change than going through the trouble of changing the seals with the head installed. So, I vote for putting it off until you do the next timing belt change.
Now if you really want to go through with it, you should check your valve clearances while you're at it. (I don't think you mentioned checking these during the recent timing belt change.)
I don't think the small spring compressor that Pete Shuman posted a picture of would fit around the springs in these cylinder heads. There is very little clearance, and like speedy25 said, you don't want to damage the sides where the shim buckets slide.
I definitely respect his attention to detail and how much he wants to restore this car to the utmost degree. I also appreciate that he puts up meticulous DIYs so the rest of us have a far easier time following in his footsteps.
However, I do think (for once) that this job is unnecessary.
Swap in 1/2 qt synthetic high mile ATF for 1/2 qt of oil for the next few oil changes and you'll see seal leaks diminish greatly. ATF is a gentle cleaner and seal reconditioner, I was able to really reduce my oil smoke at startup by doing this, at least bought me a few more years and a few more tens of thousands of miles. Rust and a slipping trans doomed it before a worn engine did.
I guess that's an option. I could also continue using high mileage oil. I don't have much more than 3000 miles in total of running high mileage oil. So it could very well be that I need to give it more time to fully recondition any leaky seals. Next month I'll do another oil change and at that point I'll swap back to the semi synthetic MaxLife to deplete my stock of it. I will monitor what the burn level is after swapping.
Next winter I could even try the Mobil 1 High Mileage oil I have sitting around too. I have too much oil sitting around from jumping on deals
Buy too much and it doesn't have shelf space either! I have a lot of 5 quart containers of full synthetic name brand oil that I paid $0 to $10 per container for after rebates.
You can up the ratio of ATF to oil without ill affect, or even use transmission stop leak for a short period of time (500 miles) in the oil for faster results. I prefer the ATF since it's a slower gentler process. I'd find it more likely that the valve guides are worn AND the seals hard as a rock. Seriously just consider pulling the head this summer.
Is the engine vacuum steady at idle or does it bounce a lot? Does it meat the specs from Toyota? Vacuum is a quick way to see how good the valve train is doing. Bouncy or low vacuum can show a poorly sealing valve or leaking valve seals. Also check the vacuum or pressure on the crank case at the breather. Pressure when revving can indicate worn rings and high vacuum during engine braking can indicate worn guides. I'm not sure what good or bad values are though, but if you're seeing like...20-30 inches while engine braking in the engine that's probably not good.
You can also datalog the MAP-sensor signal and plot it in Excel to determine manifold vacuum. It may present a sinusoidal wave.
At this point, I would do further texting before jumping into replace the valve-stem seals. Leakdown to see if your disappearing oil may be the rings. Otherwise it could be the valves. If so, I'd buy a whole engine from a wrecker and rebuild/blueprint it on the side to minimize downtime.
There's two ways I can remove the valve-keepers. One is with the same tool to inspect valve-clearance and remove the shims. There's the pliers type with crescent-shaped tip to pry down the lifters.There's also a pitchfork type with the crescent-cams at the end. I prefer this type because it pushes down on the lifters on opposite sides evenly.
Once the lifters are removed, I insert a hollow spacer tube of the same dimensions as the lifters. It's of the same diameter as the lifter with deburred ends and polished to not damage lifter bores. The valve-shim tool will now press down on the tube which pushes on valve-retainers and you can use a magnet-on-stick or precision screwdriver to remove the keepers.
The second type of tool is the lever-with-press that Pete showed. Instead of a generic sliding post for the fulcrum, I have a triangular base that bolts down to the cam-housing bolts. The pressing tube is then positioned on the lever to be directly over the valve, higher leverage-ratio for less effort needed. This is specific to the head and I haven't made one yet. I may have drawings for the 5M-GE head if you're interested.
I always deburr the valve-stems as regular practice. Most engines I deal with are high-RPM and tend to mushroom the end of the valve slightly to a larger diameter and create a sharp edge. I stuff a small piece of 400-grit wet-n-dry sandpaper into an 8mm socket. Position the sandpaper so it forms a bowl at the end of the socket and use with an extension like a valve-lapping tool to smooth the edge at the valve-stem end (use cutting oil on sandpapaer). This is where rope also has an advantage over air-pressure; holds the valve-face tighter so you can lap the other end. Clean off and remove old valve-stem seal with 45-degree needle-nose pliers.
I use a 10mm or 11mm socket to install new valve-stem seal. Should be large enough to push down on the outer body of seal, not the flexible tip. Use some heavy-oil/assembly-lube (non-moly type) on the valve-stem to help the seal slide on.
I always deburr the valve-stems as regular practice. Most engines I deal with are high-RPM and tend to mushroom the end of the valve slightly to a larger diameter and create a sharp edge. I stuff a small piece of 400-grit wet-n-dry sandpaper into an 8mm socket. Position the sandpaper so it forms a bowl at the end of the socket and use with an extension like a valve-lapping tool to smooth the edge at the valve-stem end (use cutting oil on sandpapaer). This is where rope also has an advantage over air-pressure; holds the valve-face tighter so you can lap the other end. Clean off and remove old valve-stem seal with 45-degree needle-nose pliers.
What happens with the particles that come off the sandpaper? Will they fall into the valve guides and into the cylinder? Are they too small to matter? It doesn't seem like you'd be able to clean it up perfectly.
I think I've fulfilled my mission with this thread - namely to get an understanding of the scope of what's involved. Thanks again to all who contributed. I will NOT proceed with valve stem seal replacement for now as it is pretty involved. I will keep all this in my back pocket though, as I might determine to pick it up at a later time.
For now I'll just continue to chug along with High Mileage oil and see where it gets me
Since you accomplished your goal, it's time to derail this thread!
I was having a conversation with someone somewhere else about aftermarket vs OEM. I mentioned you (not by name) in that we use pretty much only OEM parts for anything significant. I even bought OEM exhaust studs. But yeah, apparently we're weird.
When I see all the headaches caused by aftermarket parts on these forums I can't help but think it's not you and I who are the weird ones in this regard.
In some cases OEM is cheaper over time because it lasts longer. In other cases I'm paying a premium for not wanting to research comparable quality aftermarket and for favoring reliability and peace of mind over parts cost. It's a premium I'm usually very willing to pay.
And I do have some aftermarket parts but I choose selectively. I think my KYB Strut Plus assemblies make much more sense than buying OEM.
And it appears Speedy25 is arguing for higher quality / longer lasting materials exist for valve stem seals in the aftermarket than the materials the OEM seals are made of.
So there are exceptions. I still think my OEM guiding principle is perfectly non-weird.
Oh the trouble I've had with hoses. The Corolla's PCV hose has different size inner diameters on each end, so a universal hose won't fit well. I gave up and bought an OEM hose.
The Miata had a leak in a thin coolant hose. Couldn't fit a universal hose there, one size was too big and the next size down was too small to get on there (I bought two sizes just in case). Plus I realized that it had two 90 degree bends to loop around an accessory belt... brilliant engineering. So I went and bought the OEM hose... again.
Same deal with the MR2, PCV hose is long and makes two curves. I'm not bothering with trying aftermarket hoses, just going straight for OEM.
They might not fall off but you WILL still have grit on the valve stem. Only hot soapy water will remove it all.
As stated before, I HAVE found burrs on valve stems in the past but found NONE on my 300k Corolla head. OR the 180k head I got when one of my NEW exhaust valves broke. (Now theres a aftermarket vs OEM argument!!)
-SP
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