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Help ! 4.0 SOHC head bolt torque


tcbberger

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I have a situation here and I need a FACTORY correct answer if possible. I have a 2003 ford explorer with 4.0 SOHC motor and I replaced the head gaskets, I purchased new head bolts, but I have some confusion about the torque sequence. Everywhere I look online says first torque to appox 25 lbs, the turn 90 degrees, then turn 90 degrees again. I have a Ford Manual on cd I purchased from ebay many years ago, and it says ; Tighten the bolts in the sequence shown in three stages.
Stage 1: Tighten fasteners 1-4 to 32 Nm (24 lb-ft).
Stage 2: Tighten fasteners 5-8 to 32 Nm (24 lb-ft).
Stage 3: Rotate an additional 90 degrees.

The manual only says (1) 90 degree turn, I have already installed the head bolts as per the manual with a little blue thread locker on them, this was done about 36 hours ago. If I do need to turn another 90 degrees, can I still do it?

Thanks
 


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ghost798

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the bolts are stretch to yield .the bolts are made to stretch one time then throw them out
you do not need any blue thread locker on them. you can try to do the 90 degrees turn if they do not turn then you will have to get new bolts the head gasket can stay in place hope this was a help
 




2000StreetRod

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SOHC V6 head torque sequence

According to my 2005 Mustang SOHC V6 assembly instructions:

Position the RH cylinder head. Install 8 new M12 bolts and tighten in the sequence shown in 2 stages.
• Stage 1: Tighten to 12 Nm (9 lb-ft).
• Stage 2: Tighten to 25 Nm (18 lb-ft).
RightHeadM12.jpg

Install 2 new M8 bolts.
• Tighten to 32 Nm (24 lb-ft).
RightHeadM8.jpg

Tighten the 8 M12 bolts in the sequence shown (above) in 2 stages.
• Stage 1: Tighten 90 degrees.
• Stage 2: Tighten an additional 90 degrees.

A similar process is performed on the left cylinder head. The thread locker should break as you start the second additional 90 degrees. It increases the torque reading but shouldn't matter since you're stretching the bolt based on angle.
 




tcbberger

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Update

First I want to thank everyone for their response. Second, I bought an official ford factory used service manual, this manual was printed by ford for their techs, it's is about 3 inches thick. It says to do only one 90 degree turn. I am confused why this manual printed in September 2002 says one 90 turn and everything else on the internet says (2) 90 degree turns. This is why I was wondering if anybody on the forum was a ford tech who perhaps has done a head gasket change. It anybody knows a ford tech on this forum perhaps you can ask them to ring in on this subject. Basically someone who has had hands on experience .
I can attempt to turn the bolts and additional 90 but I fear two things, 1) bolt might shear off in the head, or I will pass the bolt twist spec and now it will not be as strong as it should be.
 




2000StreetRod

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inconsistent specs

I hate it when documented specifications are inconsistent. My 2005 Haynes Repair Manual states:

For MY thru 2000
8mm bolts 23 to 25 ft-lbs
12mm bolts 26 ft-lbs, +90 deg, +90 deg

For MY 2001 and later
8mm bolts 23 to 25 ft-lbs
12mm bolts 24 ft-lbs, +80 deg, +80 deg

My 2000 factory shop manual states:
8mm bolts 24 lb-ft
12mm bolts 26 lb-ft, +90 deg, +90 deg

Unfortunately, I have no hands on experience with the later engines. I understand your concerns.
 




Devan

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Update

First I want to thank everyone for their response. Second, I bought an official ford factory used service manual, this manual was printed by ford for their techs, it's is about 3 inches thick. It says to do only one 90 degree turn. I am confused why this manual printed in September 2002 says one 90 turn and everything else on the internet says (2) 90 degree turns. This is why I was wondering if anybody on the forum was a ford tech who perhaps has done a head gasket change. It anybody knows a ford tech on this forum perhaps you can ask them to ring in on this subject. Basically someone who has had hands on experience .
I can attempt to turn the bolts and additional 90 but I fear two things, 1) bolt might shear off in the head, or I will pass the bolt twist spec and now it will not be as strong as it should be.
I am a Ford tech and I'm kind of wondering the same thing now that im reading this lol but I am also aware that the workshop manuals on Fords pts website for most US Ford models (perhaps other countries as well) changed from 2002 to 2003. What I mean is the workshop manuals are like in a different format and some things like torque specs or wiring are different as well. I worked as a Ford tech for close to three years and then I outgrew the place but they didn't cancel my Ford pts login until like 2 years later LMFAO which was just like a year ago but then I used to use my buddys login for a while but then he left fordi think. So I was like damn what am I going to do but from what I seen on Alldata.com their Ford workshop manuals are official Ford workshop manuals or information cited from other reliable sources. however I've only used a few diff cars on there so I can't really speak too much to that. But the website itself is kind of clumsy but the information is great and the price per vehicle ain't so bad either. One more example I can give you is I have an 01 Cobra with a stage 8 ported eaton on it (plus tons of either custom goodies) basically the same setup as an 03 or 04 Cobra Terminator (dam i want that motor in my 2 dr sport bad, maybe someday or maybe ill build another 2dr in the last gen b4 mine cuz ive decided im prolly jus gonna keep this a v6 truck maybe even Cosworth DOHC swap or upgrade the Eaton M90 on my XPLR to my 2nd cobra Eaton M112 i got layin round) but that basically makes me a 99 to 04 mustang and explorer guru, i know all fords tho even the new GT350Rs so anyways that means whenever I was using ford PTS for like a problem with my 01 cobra I would search 03 04 instead because the whole intake manifold assembly is different some of the aspects of the workshop manual are different and plus like I said before the workshop manual changes from 2002 to 2003. Actually they started using color in their workshop manuals nd wiring diagrams in 2003. I think most of the old wiring diagrams were just black and white plus the labeling got a lot better and there might actually be wiring differences between 2002 and 2003 even if the vehicle is the same and the same trim and options.

I kind of came up on this post because I'm currently doing head gaskets on my 01 BoostedXPLR Sport and I just wanted to confirm what I was seeing on alldata plus I'm trying to find out if the cam sprocket bolt is torque to yield. And I think I would be able to replace the whole timing drive including the backside chain n guides n stuff without pulling the motor from the truck. Ill know once I pull the passenger side cylinder head to do the head gasket there, I just finished puttting the driver side back together. I'm 30 years old and usually I dont mess with timing drive stuff unless i have to and if its easy cuz I cooked a motor one time when I was young because I wasn't paying close enough attention to the workshop manual information I was reading and I didn't try to turn the motor over by hand before hitting it with the starter because I was too cocky. but this German made V6 with its 5 timing chains (4 on some) ain't so easy however I'm extremely familiar with the engine so it's no problem. But I was kind of wondering the same thing myself for a little bit about turning the bolts an additional 90 degrees.

But anways point is after all this bs i wrote that their could possibly be a difference in torquing procedure for the 4.0 between 2002 and 2003 according to the online Ford PTS workshop manual. Or maybe there could even be differences after 2004 even because that's when they started putting the 4.0s into the mustangs as well. I think they stopped using this motor in like 2010 or around tht all in all but I would imagine the hardware is all the same so the most recent revision would be what I would go with but I'm still doing further research and confirming other data and reading the rest of this post before I continue torquing my head bolts lol.
 




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