3.4 Head Gasket Project
01-26-2010 | 09:30 AM
#1
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From: New Jersey
3.4 Head Gasket Project (Pics Added)
I will be starting my HG replacement this week and this forum has been a great help in getting me started. I also read the FSM sections twice to see what I was getting myself into. There are tons of 3.0 threads but not as many 3.4 threads that I found. If anyone has any good links saved please sent them my way. Here are some questions I have after my reading of the forum and the FSM. Please chime in with your $.02 if you have tackled this job. 
1. Did you replace the knock sensor wire while you had the intake manifold off?
2. My truck did not overhead so I am wondering how many people brought there heads to get checked even without overheating. Talking to a mechanic he said he would not do the job without sending the heads out. Did you send your heads out?
3. I read about others having timing (not starting) issues after re-assembly. If the three marks on the CAM gears are ligned up prior to installing the timing belt again is there anything to worry about on this front? Assuming the crank bolt has not been turned.
4. Do I need to completely remove the front exhaust pipe as it looks ike I can just undo the front bolts and not have to remove the 2 back bolts connecting it to the rest of the exhaust. The only reason I am looking to cheat this step is all my bolts are rusted to hell.
5. The FSM says to remove the heater pipe. I assume this is referring to the upper rad hose?
6. Do most people send their injectors out to get flowed when doing this job?7. I read a great tip about turning the cams to relieve spring tension and not put undo stress on the cam when removing.
I can take pictures of my progress if anyone is interested. Thanks!!!
1. Did you replace the knock sensor wire while you had the intake manifold off?
2. My truck did not overhead so I am wondering how many people brought there heads to get checked even without overheating. Talking to a mechanic he said he would not do the job without sending the heads out. Did you send your heads out?
3. I read about others having timing (not starting) issues after re-assembly. If the three marks on the CAM gears are ligned up prior to installing the timing belt again is there anything to worry about on this front? Assuming the crank bolt has not been turned.
4. Do I need to completely remove the front exhaust pipe as it looks ike I can just undo the front bolts and not have to remove the 2 back bolts connecting it to the rest of the exhaust. The only reason I am looking to cheat this step is all my bolts are rusted to hell.
5. The FSM says to remove the heater pipe. I assume this is referring to the upper rad hose?
6. Do most people send their injectors out to get flowed when doing this job?7. I read a great tip about turning the cams to relieve spring tension and not put undo stress on the cam when removing.
I can take pictures of my progress if anyone is interested. Thanks!!!
Last edited by BlueGTS; 02-07-2010 at 08:23 AM. Reason: Pictures
01-26-2010 | 09:47 AM
#2
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Joined: Aug 2007
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From: Vian, OK
send the heads off for sure, replace the knock sensor wire AND the sensor itself..(just for the sake of NOT having to go back in there)
heater pipe and radiator hoses are 2 different things, heater hoses usually run along the firewall, look for em, likely rubber hoses about 1.25" in diameter
you can send your injectors out if ya want, (i'm going to with my 3.0) but it kinda depends on your mileage, if you're under 100,000 i wouldn't worry about it...but it never hurts to be sure
good luck!!! i've never heard of a 3.4 blowin the headgaskets...what happened exactly?
heater pipe and radiator hoses are 2 different things, heater hoses usually run along the firewall, look for em, likely rubber hoses about 1.25" in diameter
you can send your injectors out if ya want, (i'm going to with my 3.0) but it kinda depends on your mileage, if you're under 100,000 i wouldn't worry about it...but it never hurts to be sure
good luck!!! i've never heard of a 3.4 blowin the headgaskets...what happened exactly?
01-26-2010 | 09:56 AM
#3
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From: New Jersey
Thanks for the tips. I guess it is not very common for the 3.4's to go, do I win a prize? 
My truck has 135k on it so I will prob. do some maintenance while I am in there. I had the WP and TB done 40k miles ago so I will be leaving those alone. Now that the Runner is not my daily driver I figured I would do the work myslef versus spending the $1300 in labor.
Here is why I think it is the HG. The truck is hard to start and idles rough for the first few minutes. Then when driving I get a lot of white smoke out of the exhaust. When I park the exhaust smells very sweet and I have no coolant left in the reservoir. The underside of the oil cap is white and milky. All of these things point to HG or cracked head to me. Do you think I am missing something?
My truck has 135k on it so I will prob. do some maintenance while I am in there. I had the WP and TB done 40k miles ago so I will be leaving those alone. Now that the Runner is not my daily driver I figured I would do the work myslef versus spending the $1300 in labor. Here is why I think it is the HG. The truck is hard to start and idles rough for the first few minutes. Then when driving I get a lot of white smoke out of the exhaust. When I park the exhaust smells very sweet and I have no coolant left in the reservoir. The underside of the oil cap is white and milky. All of these things point to HG or cracked head to me. Do you think I am missing something?
Last edited by BlueGTS; 01-26-2010 at 10:08 AM.
01-26-2010 | 11:32 AM
#4
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Joined: Nov 2002
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From: Oklahoma State
Follow EB's special head bolt torquing procedure:
Quoted from EB:
Here's a another quote form EB, but I think he was talking about the 22re since he mentions retorquing after a full warm up, something that would be a major PITA for a 3vze.
One good link I know of:
http://www.ultimateyota.com/index.ph...6&topic=7462.0
Quoted from EB:
>>>*Morning!
*Quite a discussion. We always replace the head bolts on the 3VZE, mostly because of early on we had two cases of breaking them. This spoils a day quickly...
*Ever notice it is nearly always either the last one or the next to last one?...*LOL**
I personally won't make the studs, I do not own the equipment to roll the threads during the forming process. Sure, I could set up and cut the threads, this is much weaker than a formed and rolled out piece. *More work, too and I'm lazy.......All it takes is one little stress riser and the stud can break.
Usually breakage with bolts is due to the threads creating resistance, they stop turning. The same can happen with a stud if the nut end threads are not completely free and lubed. Once they stop slipping as they are torqued, you are now twisting the shaft of the piece. I have had a couple of cases of folks breaking brand new bolts, this is the cause of that.
If the shaft of the fastner is actually twisted rather than tightened into the block, it is not creating clamping force at all, even though the torque wrench may read accurate load.
Yep, it can break. So before we even think of going to maximum torque, we clean the threads in the block with a chaser, (NOT a tap)..Then we oil the threads and spin the bolt all the way in and out with our fingers. This assures they are clean and lubed.
Then we pull them to 50%, all of them. ... back off 1/4 turn and repeat, note each time it will turn a tad more before 50% is reached. This is because the threads are bedding in. We do this 5 times, then we go to 75%, then to 100%, all done. We do this with ALL new fastners...it assures a more even clamping force, inconsistant clamping force is the number 2 cause of early head gasket failure..(heat is number one)
It takes some time, sure, but it takes less time than pulling the head back off...Hope this helps.....*EB
*Quite a discussion. We always replace the head bolts on the 3VZE, mostly because of early on we had two cases of breaking them. This spoils a day quickly...
*Ever notice it is nearly always either the last one or the next to last one?...*LOL**
I personally won't make the studs, I do not own the equipment to roll the threads during the forming process. Sure, I could set up and cut the threads, this is much weaker than a formed and rolled out piece. *More work, too and I'm lazy.......All it takes is one little stress riser and the stud can break.
Usually breakage with bolts is due to the threads creating resistance, they stop turning. The same can happen with a stud if the nut end threads are not completely free and lubed. Once they stop slipping as they are torqued, you are now twisting the shaft of the piece. I have had a couple of cases of folks breaking brand new bolts, this is the cause of that.
If the shaft of the fastner is actually twisted rather than tightened into the block, it is not creating clamping force at all, even though the torque wrench may read accurate load.
Yep, it can break. So before we even think of going to maximum torque, we clean the threads in the block with a chaser, (NOT a tap)..Then we oil the threads and spin the bolt all the way in and out with our fingers. This assures they are clean and lubed.
Then we pull them to 50%, all of them. ... back off 1/4 turn and repeat, note each time it will turn a tad more before 50% is reached. This is because the threads are bedding in. We do this 5 times, then we go to 75%, then to 100%, all done. We do this with ALL new fastners...it assures a more even clamping force, inconsistant clamping force is the number 2 cause of early head gasket failure..(heat is number one)
It takes some time, sure, but it takes less time than pulling the head back off...Hope this helps.....*EB
>>>*Other than simple overheat, the #1 cause of head gasket failure is clamping force variations.
Usually when I mention this, the answer is "I torqued it properly!"
*Yes, very likely, but torque, which is a twisting force, means almost nothing when we are talking about clamping force.
Dirt or machinery debris in the bolt holes will throw the clamping force off as much as 50% and more, even though the torque wrench reads perfectly normal.
The same happens when installing new bolts. The very best bolts made will show a rough mating surface at the threads when inspected under a microscope.
When installing new or used fastners, first be sure the bolt will spin in and out ALL THE WAY freely with simple finger pressure. Be sure they are lightly oiled, not too much which can hydraulic lock at the bottom of any blind holes and spoil your day.
Use this simple breakin procedure for any new bolts: Tighten all of them to 50%, back off 1/4 turn, then to 75%, back off 1/4 turn. Then take them to 100%, back off 1/4 turn and repeat. Do a retorque after full warmup.
*This procedure simply assures that the imperfections of the threads seat to the bolt hole threads.
Yes, time consuming, but much faster and less costly than another set of gaskets, the actual clamping force will increase vastly, even though the torque load is exactly the same.
The alternative is you may be additional twisting at the top of the bolt after the threads have come to a stop from excess friction.
If any single one does that, head gasket failure prematurely is gauranteed, plus it weakens the bolt....*EB
Usually when I mention this, the answer is "I torqued it properly!"
*Yes, very likely, but torque, which is a twisting force, means almost nothing when we are talking about clamping force.
Dirt or machinery debris in the bolt holes will throw the clamping force off as much as 50% and more, even though the torque wrench reads perfectly normal.
The same happens when installing new bolts. The very best bolts made will show a rough mating surface at the threads when inspected under a microscope.
When installing new or used fastners, first be sure the bolt will spin in and out ALL THE WAY freely with simple finger pressure. Be sure they are lightly oiled, not too much which can hydraulic lock at the bottom of any blind holes and spoil your day.
Use this simple breakin procedure for any new bolts: Tighten all of them to 50%, back off 1/4 turn, then to 75%, back off 1/4 turn. Then take them to 100%, back off 1/4 turn and repeat. Do a retorque after full warmup.
*This procedure simply assures that the imperfections of the threads seat to the bolt hole threads.
Yes, time consuming, but much faster and less costly than another set of gaskets, the actual clamping force will increase vastly, even though the torque load is exactly the same.
The alternative is you may be additional twisting at the top of the bolt after the threads have come to a stop from excess friction.
If any single one does that, head gasket failure prematurely is gauranteed, plus it weakens the bolt....*EB
One good link I know of:
http://www.ultimateyota.com/index.ph...6&topic=7462.0
01-26-2010 | 11:33 AM
#5
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Joined: May 2007
Posts: 80
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From: Lexington, KY
Sweet smelling white smoke is a good indication that coolant is being burned, and the fact that your reservoir is empty after the truck is run. I've had this happen on two older Toyota's I owned, and ended up being the head gasket.
Your assumption should be correct. Only a few places where coolant will get into the combustion chamber. My guess would be a head gasket failure.
Your assumption should be correct. Only a few places where coolant will get into the combustion chamber. My guess would be a head gasket failure.
01-26-2010 | 05:14 PM
#6
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Joined: Apr 2009
Posts: 748
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From: Asheville, NC
Sweet smelling white smoke is a good indication that coolant is being burned, and the fact that your reservoir is empty after the truck is run. I've had this happen on two older Toyota's I owned, and ended up being the head gasket.
Your assumption should be correct. Only a few places where coolant will get into the combustion chamber. My guess would be a head gasket failure.
Your assumption should be correct. Only a few places where coolant will get into the combustion chamber. My guess would be a head gasket failure.
01-27-2010 | 07:05 AM
#7
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From: New Jersey
Follow EB's special head bolt torquing procedure:
Quoted from EB:
Here's a another quote form EB, but I think he was talking about the 22re since he mentions retorquing after a full warm up, something that would be a major PITA for a 3vze.
One good link I know of:
http://www.ultimateyota.com/index.ph...6&topic=7462.0
Quoted from EB:
Here's a another quote form EB, but I think he was talking about the 22re since he mentions retorquing after a full warm up, something that would be a major PITA for a 3vze.
One good link I know of:
http://www.ultimateyota.com/index.ph...6&topic=7462.0
I started the project yesterday after work. Just did some minor stuff like; removed battery, coil packs, throttle cables, drained cooland, upper radiator hose, fan shroud and pb blasted some bolts. The two bolts that connect the front exhaust to the rear exhaust are rusted to hell. The only way they will be coming off is with a cut-off wheel. I am hoping I can just remove the three nuts that connect it to the downpipe and leave the front exhaust pipes on.
I have not ordered any replacement parts yet as I want see the failed HG for myself before I start spending.
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01-27-2010 | 08:08 AM
#8
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Joined: Feb 2006
Posts: 1,485
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From: Austin Texas
[QUOTE=BlueGTS;51345584]
1. Did you replace the knock sensor wire while you had the intake manifold off? YES--might as well do the sensors also
2. My truck did not overhead so I am wondering how many people brought there heads to get checked even without overheating. Talking to a mechanic he said he would not do the job without sending the heads out. Did you send your heads out?--YES, And not just any joe smo--take them to somebody who is good at doing heads
6. Do most people send their injectors out to get flowed when doing this job?7. I read a great tip about turning the cams to relieve spring tension and not put undo stress on the cam when removing. YES, Send them out...even at ~80k, my injectors came in between fair and good
Label everything and take pictures to reference. The major parts are not that big of a deal to remeber where they go...but the little ones start to make you scratch your head..
I would think about putting in some better valves also (manely SS Swirl polished) and doing the "D" to "O" gasket mod. Really improves throttle response.
DONT USE COMETIC GASKETS UNLESS YOU GET THE BLOCK SURFACED ALSO--they are great gaskets, but you have to have both surfaces ubber flat--Try to AIM for an Average Surface Roughness (RA) of 50 or less IIRC.
Take the cams out little by little--do one bolt a little--then another--then another......
1. Did you replace the knock sensor wire while you had the intake manifold off? YES--might as well do the sensors also
2. My truck did not overhead so I am wondering how many people brought there heads to get checked even without overheating. Talking to a mechanic he said he would not do the job without sending the heads out. Did you send your heads out?--YES, And not just any joe smo--take them to somebody who is good at doing heads
6. Do most people send their injectors out to get flowed when doing this job?7. I read a great tip about turning the cams to relieve spring tension and not put undo stress on the cam when removing. YES, Send them out...even at ~80k, my injectors came in between fair and good
Label everything and take pictures to reference. The major parts are not that big of a deal to remeber where they go...but the little ones start to make you scratch your head..
I would think about putting in some better valves also (manely SS Swirl polished) and doing the "D" to "O" gasket mod. Really improves throttle response.
DONT USE COMETIC GASKETS UNLESS YOU GET THE BLOCK SURFACED ALSO--they are great gaskets, but you have to have both surfaces ubber flat--Try to AIM for an Average Surface Roughness (RA) of 50 or less IIRC.
Take the cams out little by little--do one bolt a little--then another--then another......
01-28-2010 | 04:56 PM
#9
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Joined: Apr 2008
Posts: 5
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From: Waterford, MI
Knock Sensor Wire Location 3.4
There is much talk about the 3.4 liter knock sensor wire. Can this be replaced without removing the intake? Where is this wire located, and since there are two knock sensors, are there also two sets of wires? I am getting the P0330 code and my truck runs horrible with the check engine light on.
01-29-2010 | 09:02 AM
#11
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Joined: Jan 2010
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From: New Jersey
[quote=hross14;51346672]
1. Did you replace the knock sensor wire while you had the intake manifold off? YES--might as well do the sensors also
2. My truck did not overhead so I am wondering how many people brought there heads to get checked even without overheating. Talking to a mechanic he said he would not do the job without sending the heads out. Did you send your heads out?--YES, And not just any joe smo--take them to somebody who is good at doing heads
6. Do most people send their injectors out to get flowed when doing this job?7. I read a great tip about turning the cams to relieve spring tension and not put undo stress on the cam when removing. YES, Send them out...even at ~80k, my injectors came in between fair and good
Label everything and take pictures to reference. The major parts are not that big of a deal to remeber where they go...but the little ones start to make you scratch your head..
I would think about putting in some better valves also (manely SS Swirl polished) and doing the "D" to "O" gasket mod. Really improves throttle response.
DONT USE COMETIC GASKETS UNLESS YOU GET THE BLOCK SURFACED ALSO--they are great gaskets, but you have to have both surfaces ubber flat--Try to AIM for an Average Surface Roughness (RA) of 50 or less IIRC.
Take the cams out little by little--do one bolt a little--then another--then another......
Thanks for the gasket tips, I will buy the ones I need after this weekend. The plan is to take the heads off this Saturday. I hope everything goes smoothly as I would really hate to drag this project out. Infact, I am thinking about leaving the crank bolt and lower timing belt on as it was changed 40k ago. The removal and install of the crank bolt is a PITA step that I would like to avoid.
I normally have a problem with scope creap whenever I do a project. Be it home improvement or car related. For this reason I really want to just fix the problem without adding steps and headaches. I would really like for this to be a 2 weekend project versus something that drags into spring. Wish me luck.
1. Did you replace the knock sensor wire while you had the intake manifold off? YES--might as well do the sensors also
2. My truck did not overhead so I am wondering how many people brought there heads to get checked even without overheating. Talking to a mechanic he said he would not do the job without sending the heads out. Did you send your heads out?--YES, And not just any joe smo--take them to somebody who is good at doing heads
6. Do most people send their injectors out to get flowed when doing this job?7. I read a great tip about turning the cams to relieve spring tension and not put undo stress on the cam when removing. YES, Send them out...even at ~80k, my injectors came in between fair and good
Label everything and take pictures to reference. The major parts are not that big of a deal to remeber where they go...but the little ones start to make you scratch your head..
I would think about putting in some better valves also (manely SS Swirl polished) and doing the "D" to "O" gasket mod. Really improves throttle response.
DONT USE COMETIC GASKETS UNLESS YOU GET THE BLOCK SURFACED ALSO--they are great gaskets, but you have to have both surfaces ubber flat--Try to AIM for an Average Surface Roughness (RA) of 50 or less IIRC.
Take the cams out little by little--do one bolt a little--then another--then another......
I normally have a problem with scope creap whenever I do a project. Be it home improvement or car related. For this reason I really want to just fix the problem without adding steps and headaches. I would really like for this to be a 2 weekend project versus something that drags into spring. Wish me luck.
01-29-2010 | 10:50 AM
#14
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From: New Jersey
My cure is to step back and think about my last project. I have a way of turning little projects into big projects. While it sounds good in theory, getting this completed is more important to me now. Or maybe I am just getting old and lazy.
01-29-2010 | 10:52 AM
#15
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From: New Jersey
02-02-2010 | 12:19 PM
#16
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From: New Jersey
So I got the heads off last weekend. What was suppose to be a Saturday project turned into a full weekend in the garage. This project is not for the faint at heart. Hats off to people who do this everyday as I barely want to look at my truck when I pass it in the garage now.
I will post up some pictures and see if you guys can guess the issue.
The hardest part by far was breaking the CAM gear bolts off. That was a solid 6 hours of trial and error. One of them was on at maybe 200 ftlbs the other was on at 300+. If I had to the project again I could get the heads off in 1 day but doing it the first time is no walk in the park.
I will post up some pictures and see if you guys can guess the issue.
The hardest part by far was breaking the CAM gear bolts off. That was a solid 6 hours of trial and error. One of them was on at maybe 200 ftlbs the other was on at 300+. If I had to the project again I could get the heads off in 1 day but doing it the first time is no walk in the park.
02-16-2010 | 08:05 AM
#19
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Joined: Feb 2009
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From: Maine
I have to remove my intake manifold to replace the FPR and found this thread. I see that people replace the knock sensors as preventative maintenance? How often do they fail and what are the symptoms? CEL or sluggish acceleration? A quick price check shows them at $160 a piece! I'll replace a wire but don't want to spend an additional $300 for no reason right now. I'm currently at 102K in my 2001
02-16-2010 | 08:13 AM
#20
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Joined: Nov 2002
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From: Oklahoma State
