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Ok well I officially have a burnt number 6 exhaust valve. I called a reputable machine shop today and they will machine the heads and do the valves for $180.00 so that is the route I'm going to take and hope that its just a top in job that I need so I figured if I'm going to do this I'm going to go all out and wanted to get yalls opinions. I need to get new valves and what ever other parts I need to do this valve job, I'm assuming gaskets and seals for the valves? I figured while I'm in there I might as well change out the head gaskets too. Im going to change the water pump and timing belt also. I was even thinking about adding headers and was wondering what y'all thought. I'm sure I'm missing something so feel free to chime in. But I would like to get input on what all do I need to order for the valves themselves and what add ons do y'all recommend?
... I figured while I'm in there I might as well change out the head gaskets too. ...
Uh, yeah ... I don't think re-using old head gaskets would be a very good idea ....
Planning in advance is good, but don't expect to get it perfectly. You probably don't need all 6 exhaust valves (though they aren't that expensive, so your choice). I doubt you need any intake valves. You may need to replace some injector clips. You might break the Thermal Vacuum Valve when removing the head (lots of us have done just that). You'll need to look and see.
You will need a set of crush washers (dealer item); when you remove the fuel rail those all must be replaced. And I've never seen a gasket set that includes them. You'll want the machine shop to replace the valve stem seals, which ARE in the gasket set, so either get the set before the heads go to the shop, or get the gasket set FROM the shop, so they have the seals. You'll want the shop to adjust the valves, because they have the set of shims (and you don't). (You need to remove the cams to install the heads. DON'T turn the head over! The shims can fall out and you will get them all mixed up.)
you might even mark the shims. i had to do a valve job for someone after all the shims got mixed up by the prior mechanic. i marked them all. glad i did
Uh, yeah ... I don't think re-using old head gaskets would be a very good idea ....
Planning in advance is good, but don't expect to get it perfectly. You probably don't need all 6 exhaust valves (though they aren't that expensive, so your choice). I doubt you need any intake valves. You may need to replace some injector clips. You might break the Thermal Vacuum Valve when removing the head (lots of us have done just that). You'll need to look and see.
You will need a set of crush washers (dealer item); when you remove the fuel rail those all must be replaced. And I've never seen a gasket set that includes them. You'll want the machine shop to replace the valve stem seals, which ARE in the gasket set, so either get the set before the heads go to the shop, or get the gasket set FROM the shop, so they have the seals. You'll want the shop to adjust the valves, because they have the set of shims (and you don't). (You need to remove the cams to install the heads. DON'T turn the head over! The shims can fall out and you will get them all mixed up.)
Good luck!
I'm going to start ordering parts today. I'm pretty nervous about all this. I've never torn a motor apart before. Do yall think ill be good with the the top end? how do I know my bottom end is ok?
Well, that partly depends on what you mean by "okay." Will it develop as much compression as it did 25 years ago? Probably not, and short of re-boring for new pistons probably can't. Are the rod and crank bearings tight-as-a-tick? I doubt it. But it will run for a long time with just a little more clearance everywhere.
You start by looking. On mine, I could still pick out the factory honing cross-hatch on the cylinder walls. You may not be able to see that, but do you see any big scratches? If you do, you may have broken a ring, and the piston will have to come out. The only way to check the bearings on the crank would be to remove the pan and the bearing caps, and plastigauge them. That's a whole 'nother matter from replacing a head gasket. I didn't go that far. At operating temp, I probably don't get as much oil pressure as it did new, but I'm happy I stopped where I did.
You might think about replacing the head bolts. Toyota has a TSB that says you DON'T have to replace them, but that TSB was written for much younger head bolts. They aren't cheap, but aren't that expensive either.
Do you have the manual or some analog? Do you have a torque wrench? (You can't do much of anything without a 1/2". I recommend getting a 1/4" as well. The torque spec on the valve cover bolts is 48 in-lbf. That's just "gently snug," but it's a steel bolt in an aluminum head and very easy to strip.) Do you have a place to work? You can plan on doing this over the weekend, but as you've figured out, there's really no chance it will go completely to plan.
Well, that partly depends on what you mean by "okay." Will it develop as much compression as it did 25 years ago? Probably not, and short of re-boring for new pistons probably can't. Are the rod and crank bearings tight-as-a-tick? I doubt it. But it will run for a long time with just a little more clearance everywhere.
You start by looking. On mine, I could still pick out the factory honing cross-hatch on the cylinder walls. You may not be able to see that, but do you see any big scratches? If you do, you may have broken a ring, and the piston will have to come out. The only way to check the bearings on the crank would be to remove the pan and the bearing caps, and plastigauge them. That's a whole 'nother matter from replacing a head gasket. I didn't go that far. At operating temp, I probably don't get as much oil pressure as it did new, but I'm happy I stopped where I did.
You might think about replacing the head bolts. Toyota has a TSB that says you DON'T have to replace them, but that TSB was written for much younger head bolts. They aren't cheap, but aren't that expensive either.
Do you have the manual or some analog? Do you have a torque wrench? (You can't do much of anything without a 1/2". I recommend getting a 1/4" as well. The torque spec on the valve cover bolts is 48 in-lbf. That's just "gently snug," but it's a steel bolt in an aluminum head and very easy to strip.) Do you have a place to work? You can plan on doing this over the weekend, but as you've figured out, there's really no chance it will go completely to plan.
I can take some pictures and post them once I get the heads off and maybe yall can advise me. I can see a lot of black on top to the #6 piston with a bore scope which i assume is oil. But when I did a compression check when i added oil it only came up maybe 5 psi. the other cylinders were around 170
I paid for all this work just recently. Use only Toyota OEM valves per the machine shop. Aftermarket don't last. Change the knock sensor and wire. The shop pressure tested the cylinder heads, checked for cracks.
Ok just a little update, got the driver side head pulled last night and it appears that this truck has had a valve job done not long before I bought it. But it looks like they didn't have the correct shim in exhaust valve number six and it wasn't being able to close completely so it was just getting build up all in it. Even with the cam off the valve still doesn't shut. So my question is should I just check the clearences on the passenger side valves and if they are good just re work the driver side head seeing how the truck had valve job and head gasket done before I bought it?
Valves are cooled by sitting on the valve seat. If adjusted too tight (so that it doesn't sit all the way on the seat), not only does it leak, it gets fried. So if the valve doesn't close it's probably bad from overheating. Plus, you'll need to figure out why it didn't close; you may need a new valve guide (or at least ream the existing one).
I'm not sure why you think a valve job was done recently, but it doesn't sound like it was done too well. Once you've gone this far, I don't see any reason to not also replace the head gasket on the other side. If the head looks good, you don't HAVE to have the machine shop mess with it. But since you're hauling one head in anyway, I think it would be worth having the shop check for flatness (you need a precision straight-edge; that expensive ruler isn't straight enough) and pressure test it. If the valves look good, you can leave them alone, and that will save money.
Don't forget that you need a bunch of gaskets in addition to the head gasket. You'll probably be best off with a set, even if you don't use every part (if you don't mess with the valves, you probably won't replace the valve stem seals.) Which set? I'm going to stay out of that. Many swear by Toyota OEM, but I used an MLS set like this one: http://www.ebay.com/itm/88-95-Toyota...-/301048013912 It worked fine, but I don't have a LOT of miles on it.
This may seem off topic.. but I assure you it is good advice and I want to throw it out there before noone mentions it..
Do not skimp on the knock sensor. Get a Toyota Knock sensor with a Toyota pigtail. Make damn good sure that it is installed perfectly before putting the heads back on.
Otherwise you will be researching the code 52 threads shortly after you start her back up.
ok. I don't know much about heads and valves otherwise
This may seem off topic.. but I assure you it is good advice and I want to throw it out there before noone mentions it..
Do not skimp on the knock sensor. Get a Toyota Knock sensor with a Toyota pigtail. Make damn good sure that it is installed perfectly before putting the heads back on.
Otherwise you will be researching the code 52 threads shortly after you start her back up.
ok. I don't know much about heads and valves otherwise
I thought I just needed to change the pigtail? Most say the knock sensor don't bend to be changed. I mean I'll change it if y'all recommend I'm just confirming
06-05-2017, 04:38 PM
