beastpath Posted May 10, 2009 Share Posted May 10, 2009 Ok, so I'm gonna rip apart my engine to replace the head gaskets starting on tuesday. While I'm in there I'm gonna replace a couple of lifters to see if that will get my tap to stop, and will replace the timing belt with a new one JIC. Theres a few other minor things I'll take care of too. The closer it gets the more nervous I'm becoming, especially when it comes to putting it back together. I really dont want to mess anything up. Anybody have any tips for me they would like to share? Anything else I should look at when I'm in there? I've read a bunch of posts but just thought I'd ask anyways. Thanks guys. Link to comment Share on other sites More sharing options...
unccpathfinder Posted May 10, 2009 Share Posted May 10, 2009 may as well do valve seals, cam seals and remove any broken exhaust studs if you have any. Link to comment Share on other sites More sharing options...
MY1PATH Posted May 10, 2009 Share Posted May 10, 2009 may as well do valve seals, cam seals and remove any broken exhaust studs if you have any. valve seals? I'd like to know about this. Link to comment Share on other sites More sharing options...
Indigent Posted May 10, 2009 Share Posted May 10, 2009 Get yourself one of those parts organizer drawer things or ziplock bags. Write down where stuff came from. It only takes a few minutes to catalog the stuff, and it will save you a ton of headache later on. X2 on what unccpathfinder said. Make damn sure you have a good torque wrench for when you put the heads back on. The head bolts are 10mm hex, so what I did was take a 10mm allen wrench and cut it off. You can then use a 10mm socket with a breaker and the allen wrench to remove and install the bolts. If you have the money, I would buy new head bolts. They are not built to be re-used. It might not be a problem, but it would suck to have on of those bolts snap shortly after you get it all back together. Definitely follow the directions for loosening the head bolts. It is an aluminum head and can warp easily if loosened improperly. The picture in the chilton's/FSM is a bit confusing for the driver's side head so really look at and understand it before proceeding. It isn't that bad, but it can be tedious. Good luck and take pictures of things that are complicated when disassembling. Link to comment Share on other sites More sharing options...
Dowser Posted May 11, 2009 Share Posted May 11, 2009 Not sure how many miles on it, but might want to get a new Water pump and Temp sensor too, since it's gonna be all apart anyway. I think I recall the Nissan parts guy telling me the water pump has a life of about 160,000 miles or something but don't quote me on that. Not that expensive and that way you wont have to rip crap apart again for a LONG time. Link to comment Share on other sites More sharing options...
beastpath Posted May 11, 2009 Author Share Posted May 11, 2009 ok, thanks guys. one more question. would it be ok to leave my thorleys on the heads when i take the heads off? I've got no leaks etc and want to make this as little work as possible as well as not mess anything up. Link to comment Share on other sites More sharing options...
MY1PATH Posted May 11, 2009 Share Posted May 11, 2009 It will make working with the heads a little akward(90+ are short tubes) but you can. I would not think of doing so with my thorley long tubes (pre90 are long tubes) that would just be silly and clumsy. Now, UNCC how do you change valve seals? Link to comment Share on other sites More sharing options...
unccpathfinder Posted May 12, 2009 Share Posted May 12, 2009 valve seals you need a magnet and a spring compressor (valve spring compressor) compress the springs and pull the retainers out then pull the spring out and pull the valve out...if the heads are on the truck still fill the cylinder with air from compressed air so the valves don't fall into the cylinder...they're really easy to change with the heads out and the spring compressor Link to comment Share on other sites More sharing options...
beastpath Posted May 12, 2009 Author Share Posted May 12, 2009 valve seals you need a magnet and a spring compressor (valve spring compressor) compress the springs and pull the retainers out then pull the spring out and pull the valve out...if the heads are on the truck still fill the cylinder with air from compressed air so the valves don't fall into the cylinder...they're really easy to change with the heads out and the spring compressor where would i get a valve spring compressor? whats the point of changing the seals? is it bad if i didnt do that? Link to comment Share on other sites More sharing options...
beastpath Posted May 12, 2009 Author Share Posted May 12, 2009 also, just reading about the member whos cam sprocket slipped. burning through a head gasket wouldnnt cause valves to hit the pistons or anything would it? obviously ill check the piston heads thoroughly, but just wondering. Link to comment Share on other sites More sharing options...
unccpathfinder Posted May 12, 2009 Share Posted May 12, 2009 nah but look to see that the pistons aren't burned up. Valve seals are just one of those things that it's better to go ahead and do it while you're there esp if the heads are off Link to comment Share on other sites More sharing options...
Alkorahil Posted May 12, 2009 Share Posted May 12, 2009 (edited) If you have the money, I would buy new head bolts. They are not built to be re-used. I would never re-use the old bolts! I am right behind you on the same project. New heads, and putting headers on whicle I have it apart. Edited May 12, 2009 by Alkorahil Link to comment Share on other sites More sharing options...
k9sar Posted May 12, 2009 Share Posted May 12, 2009 I have a set of heads sitting on my bench that I am rebuilding in prep for a summer project where I'll finally get around to installing my headers. I have some bad lifters and broken exhaust studs so it will be easier just to prep some heads (grind the valves, replace seals, fix/replace lifters,etc) and have them ready to swap in. In answer to your question about seals.... the valve seals keep oil out of the cylinder. If you have bad seals or blow one open, you will blow blue smoke like a crop duster. Link to comment Share on other sites More sharing options...
beastpath Posted May 12, 2009 Author Share Posted May 12, 2009 technically all the seals only have 24000 miles on them. So I have begun. so far have taken off all the belts, air box, bunch of wires etc. am waiting to take off intake plenium as i cant get the egr tube off the headers. have hit it with pb blaster and will try again a little later. what size socket is the main crank? biggest I have is 24, it looks like a 28? need to pick that up too. Link to comment Share on other sites More sharing options...
k9sar Posted May 12, 2009 Share Posted May 12, 2009 (edited) I'll check tonight unless someone else chimes in. I had to buy one when I did mine. and a quick trick to help loosen it.... make sure your coil is disconnected, put the socket and a breaker bar on the bolt, put a pipe on the end so it braces against the ground or frame member (make sure it's braced to prevent spinning clockwise) and hit the key to start for a moment. Lots of torque in that starter motor... let it do the work. Edited May 12, 2009 by k9sar Link to comment Share on other sites More sharing options...
beastpath Posted May 12, 2009 Author Share Posted May 12, 2009 Cool, I read somewhere on here its a 27mm? Link to comment Share on other sites More sharing options...
Indigent Posted May 13, 2009 Share Posted May 13, 2009 yes on 27mm Link to comment Share on other sites More sharing options...
beastpath Posted May 13, 2009 Author Share Posted May 13, 2009 ok, so I stopped for the night and went and picked up a few supplies. 27mm socket, scotchbrite, cap and rotor. They did not have a puller to rent so Im gonna pick one up at harbor freight for 12 bucks along with a few other things. Most likely wont be able to do that till thursday so until then am halted. More or less where I'm at. The upper timing cover is off too. One thing I'm stuck on is loosening the power steering pump. Ive loosened the adjuster, tightened it, completely undone it, but I cant get the pump to move so it loosens the belt. Can anyone help with this? Link to comment Share on other sites More sharing options...
k9sar Posted May 13, 2009 Share Posted May 13, 2009 (edited) you have to loosen the bolt that it pivots on, the bolt that holds the adjustment in place and then turn the adjustment bolt. Note... one of these you have to access thorugh the hole in the pulley. Either cut the PS belt off (if you are replacing it) or turn the engine by hand until you can get at that bolt Edited May 13, 2009 by k9sar Link to comment Share on other sites More sharing options...
Kingman Posted May 13, 2009 Share Posted May 13, 2009 My tensioner on my PS pump was stuck pretty good, I tapped it inwards (well knocked it pretty good) with the end of a long 1/2" ratchet through the fender well and past the frame. Link to comment Share on other sites More sharing options...
unccpathfinder Posted May 13, 2009 Share Posted May 13, 2009 oh one note when you go to pull the heads...after you pull the head bolts...each head has a 10mm screw on the outside of the casting holding it to the block...if the head won't come off that is what is holding it on...I seem to always forget about it Link to comment Share on other sites More sharing options...
beastpath Posted May 13, 2009 Author Share Posted May 13, 2009 you have to loosen the bolt that it pivots on, the bolt that holds the adjustment in place and then turn the adjustment bolt. Note... one of these you have to access thorugh the hole in the pulley. Either cut the PS belt off (if you are replacing it) or turn the engine by hand until you can get at that bolt ah hah, i had a feeling I had to loosen that bolt. may have to just cut it and replace. Link to comment Share on other sites More sharing options...
unccpathfinder Posted May 13, 2009 Share Posted May 13, 2009 no need to cut it...just put the (i think its a 16mm) socket on the pulley and slowly turn the PS pump over until it lines up...it may turn the crank a little bit but it shouldnt hurt anything...it hasnt hurt any of my trucks Link to comment Share on other sites More sharing options...
beastpath Posted May 13, 2009 Author Share Posted May 13, 2009 gotcha, ill try that then. will the cams move when i take the heads off? and when the heads are off can i turn the engine over to make sure its at TDC? If i did the above, how would I make sure the valves etc. are in the correct position when I put them back on? Link to comment Share on other sites More sharing options...
unccpathfinder Posted May 13, 2009 Share Posted May 13, 2009 oh yea...but its no big deal...you just need to loosen up the rockers and they'll spin freely so when it goes time to assemble everything back together it makes it cake to line back up and yes wehn the heads are off put the truck in N and the engine will spin super easy b/c you don't have to overcome the compression and thats how I found TDC on my engine since the crank was not marked wehn i broke my TB The timing belt and counting teeth will keep everything in time...the lobes on the cam are what opens and closes the valves so once you get the head gaskets changed put the heads back on and do the timing belt then tighten the rockers and this will open/close the right valves...just make sure to torque and loosen everything in the order listed in the FSM to be sure not to warp anything...the tightening procedure for the head bolts is pretty important to seat the head gasket and get the bolts to the strain condition Link to comment Share on other sites More sharing options...
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