head bolt torqueing 420A

[danny7481]

the short bolts only torque to 20 ft lbs. plus a 1/4 turn??? that isnt very tight.
please someone verify it thats correct, thanks.

 

[Locke]

20ftlbs +1/4 turn on the short head bolts is correct. Dont forget to tighten the head in the proper sequence.

 

[danny7481]

thanks.

 

[Doug99RS]

There was a revision to the original torque specs that came out with the use of the Multi-layer steel headgasket. The torque is increased as follows:

NOTE :THE 2.0L DOHC TORQUE AND TORQUING PROCEDURE HAS CHANGED WITH THE INSTALLATION OF A MLS GASKET. USE THE FOLLOWING PROCEDURES FOR THE 2.0L DOHC ONLY.

2.OL DOHC TORQUE PROCEDURE WITH MLS GASKET INSTALLATION

NOTE :THE 4 SHORT BOLTS ARE PLACED IN THE CORNERS.

A. Torque all center bolts to 34 Nm (25 Ft Lbs), Torque the 4 corner bolts to 27 Nm (20 Ft Lbs).

B. Torque all center bolts to 68 Nm (50 Ft Lbs), Torque the 4 corner bolts to 47 Nm (35 Ft Lbs).

C. Re-torque all center bolts to 68 Nm (50 Ft Lbs), Re-torque the 4 corner bolts to 47 Nm (35 Ft Lbs).

D. Tighten all bolts in the specified sequence (Fig 1) an additional 90°(1/4 turn).

Make sure you use these new specs when you replace your headgasket.
Doug

 

[Locke]

Hmmm. Good stuff there, Doug. Thanks.

 

[danny7481]

There was a revision to the original torque specs that came out with the use of the Multi-layer steel headgasket. The torque is increased as follows:

NOTE :THE 2.0L DOHC TORQUE AND TORQUING PROCEDURE HAS CHANGED WITH THE INSTALLATION OF A MLS GASKET. USE THE FOLLOWING PROCEDURES FOR THE 2.0L DOHC ONLY.

2.OL DOHC TORQUE PROCEDURE WITH MLS GASKET INSTALLATION

NOTE :THE 4 SHORT BOLTS ARE PLACED IN THE CORNERS.

A. Torque all center bolts to 34 Nm (25 Ft Lbs), Torque the 4 corner bolts to 27 Nm (20 Ft Lbs).

B. Torque all center bolts to 68 Nm (50 Ft Lbs), Torque the 4 corner bolts to 47 Nm (35 Ft Lbs).

C. Re-torque all center bolts to 68 Nm (50 Ft Lbs), Re-torque the 4 corner bolts to 47 Nm (35 Ft Lbs).

D. Tighten all bolts in the specified sequence (Fig 1) an additional 90°(1/4 turn).

Make sure you use these new specs when you replace your headgasket.
Doug

too late to do that, as i already have put the head back on.

 

[Kirby]

Take the VC off and torque them the rest of the way, it will cost you a new gasket but it's worth the $20. You don't need to take the cams and whatnot out again, but if you start driving it undertorqued like that you are likely asking for trouble esp if you used the new MLS gasket..

 

[Doug99RS]

You can't torque them "the rest of the way" in that manner. That's not how torquing procedures work. In order to do it properly you must remove the head bolts and reinstall them at which point the gasket MIGHT have to be replaced and possibly the headbolts as well since they are torque-to-yield bolts.

You'd be better off either redoing things or running it as is provided you aren't a speed demon. But if you drive it like you stole it, which most of us do, then fork over the $50-75 dollars for a new gasket, man up and re-do the job right so it doesn't come back and bite you in the ass.

 

[totaleclipse_05]

Is that process the same between the 420a and 4G63?

 

[Doug99RS]

Is that process the same between the 420a and 4G63?

No, you will need to refer to the service manual for proper torque procedures on the 4g63.

What did I screw up defiant?

 

[VelocitàPaola]

Yeah, I don't even see how "torquing" the headbolts would work with the camshafts in the way. Any swivel joint on your socket would throw off the torque wrench. That extra bend creates another factor that the torque wrench can't account for.

 

[Doug99RS]

I'd be more interested to see how you "torque them the rest of the way" if the last step of the procedure was a 1/4 turn beyond the original (wrong) 20/50 ft/lbs torque specs. It's not like you can put a torque wrench back on it and go 15 more ft/lbs than 1/4 turn

 

[danny7481]

thats a bunch of BS if you cant go by the settings in the haynes manual. torque settings should come with the gasket if there different than the manual says.

i couldnt go another 1/4 turn or so? the car hasnt been fired up yet.

 

[Doug99RS]

The information IS out there and has been for over 6 years now. The torque procedures come in the upper gasket from the dealer, I just picked up on today and I have the sheet in front of me. The steps listed above is from Alldata and can also be found on Mitchell on demand. They have not changed for quite some time and a search for Torque + 420A would have yielded numerous threads.

Below are some that are several years old. I know you're upset that the torque specs changed, the MLS wasn't on the car from the factory and that you can't just give the head bolts an extra umph and ACCURATELY know that you've still got it torqued properly. However, this is sometimes where cheaper parts like brand x vs dealer parts aren't always better and chilton's manuals vs buying a dealer service manual would have been better for you in the long run. Searching never hurts either.

http://dsmtuners.com/forums/showthread.php?p=151143332#post151143332

http://dsmtuners.com/forums/showthread.php?t=141271&highlight=Torque+specs

http://dsmtuners.com/forums/showthread.php?t=107786&highlight=Torque+specs

http://dsmtuners.com/forums/showthread.php?t=36983&highlight=Torque+specs

 

[Kirby]

Ha!

Yeah, I don't even see how "torquing" the headbolts would work with the camshafts in the way. Any swivel joint on your socket would throw off the torque wrench. That extra bend creates another factor that the torque wrench can't account for.

What swivel joint? IF you use a wobble extension which is what I do, your wrench will still get it damn close, granted the angle will throw off the torque a slight bit, but what do you think that last 1/4 turn is for? It's to make sure that if your wrench is off a tad that you still get there... Tq wrenches become less accurate after a while that is why craftsman only warrenty's them for a short period of time and not lifetime. Also on my torque wrench there was a chart for convirting things like wobbles and u joints... Not exacts but just genral FYI type of stuff.

I'd be more interested to see how you "torque them the rest of the way" if the last step of the procedure was a 1/4 turn beyond the original (wrong) 20/50 ft/lbs torque specs. It's not like you can put a torque wrench back on it and go 15 more ft/lbs than 1/4 turn

Are you kidding me? After that 1/4 turn they are still at some measure of torque. Maybe it is 25ft/lbs after that 1/4 turn for example. If you put the torque wrench back on it set it to 50ft/lbs it is going to take the current situation (25ft/lbs of torque) and it is going to tighten the bolt to the correct torque of 50 ft/lbs. Then you turn it a quarter turn. Did you think that a bolt looses it's torque if you are not wrenching on it at that time? Have you never used anything that required a re-torquing of bolts say after it warmed up or after it was used? Don't you re torque your lugs after a road course run? (after some needed brake cooling of course)

I'm not trying to be a jerk here, but you are going to have this guy pulling a head and spending money for nothing. Shit I remember one time I didn't tq my ARP studs to the right tq and I had to go back in myself and put them up to 90ft/lbs.. As long as you followed the proper sequence the first time and do that when you go back in all should be well.

 

[VelocitàPaola]

I don't see where anyone suggested pulling the head...

Maybe the cams, but not the head...

If you have the proper extensions and a fair knowledge of the compensated torque values for those extensions, then fine, finish torquing the bolts. Personally, I would do what Doug suggested; man up and do it the right way. That's just me though... I encourage you to make your own decision.

 

[silver eclipse]

Kirby is right. If the engine hasnt been started and heated, there is no difference in going back and adding torque.
It would be the same exact thing as going through and torquing in sequence, Ex: torque to 20 then to 30. They do that to allow the head to settle, and prevent cracking. as well as compress the gasket. So if the engine hasnt been started and the metal hasnt heated, going back through and adding some torque should not be any problem.
-Chad

You have to take the head off to change the head gasket, like suggested before. Thats probly where Kirby got that from.

 

[VelocitàPaola]

Kirby is right. If the engine hasnt been started and heated, there is no difference in going back and adding torque.

That is false, sir. If using ARP hardware, then sure... otherwise, that final 1/4 turn stretches the bolts. Even if the bolts weren't properly torqued, I'm sure the final turn stretched them.

 

[Kirby]

That is false, sir. If using ARP hardware, then sure... otherwise, that final 1/4 turn stretches the bolts. Even if the bolts weren't properly torqued, I'm sure the final turn stretched them.

No Sir, this ^^^ statement is False. (no offence) If a bolt is torqued to 20 ft/ lbs, it will take more than a 1/4 turn to reach the appropriate 50 ft/lbs of torque. There fore no stretching has taken place. What you still have is a bolt that has not reached the proper torque specs and can still be tightened to the appropriate specs. The point is that the final turn is not done until proper spec has been achieved, so if you are not to proper torque spec then the "final" turn is not final, it is useless! Does that make sense?
To the OP there is no reason to remove any more than necessary to resolve this issue. As long as the car was not started and driven around or started and let idle for a long period of time then you can still follow my advice. if you have driven it or let it idle for extended periods then the gasket may have already failed by allowing exhaust gases and or coolant or oil to flow through the gasket and that is where a replacement would be recommended.

 

[VelocitàPaola]

Um... I thought we were talking about the short bolts, which need to be torqued to 35ft-lbs..

Just for a little empircal evidence and affirmation of my original suspicion, I went out and torqued a small headbolt on my spare block to 20ft-lbs.. Then I set the wrench to 35ft-lbs. and began turning the bolt an additional 90*. It clicked about half way (45*), which suggests the 1/4 turn did indeed bring the bolt past its yield point, irreversibly stretching it.

Do what you want with the information; but at least make your own interpretation of the data, and know that personally, I would start over.

 

[Doug99RS]

I'm sorry to have to take off the wiseman gloves here and play hardball here but you mentioned your 8 years of working on 2gnt's and why you're right and everyone else is wrong. That's great and all but I've not limited my 9+ years of PROFESSIONAL experience to one motor, I've been trained by the factory to work on just about every engine Daimler-Chrysler produced. Now I have recently been working at an independent shop so my experience now is not just limited to DCX vehicles but I work on Hondas, Lexus, Mercedes, Fords, Chevy and anything else that rolls in the door.

Having worked with over 50 different mechanics in numerous shops in the past years I can tell you that even in one type of dealership there are not cookie-cutter procedures for doing things but one thing stayed constant and that's a torque wrench coming straight up off of the bolt with the shortest possible extension to prevent twisting and NO swivels. When you introduce a swivel in to the equation then there's no way of knowing EXACTLY what angle you have it at compared to the next guy and as such how do you know your 45* @ 50 ft/lbs didn't turn out to be 40* which reduced to... 40 ft/lbs??

The proper torque procedure is needed because this provides an accurate starting point for the torque-to-yield step. The 50ft/lbs is NOT the final goal at all. This is the last point prior to the 1/4 turn which is where the bolts begin to stretch and then squish the gasket in to place. It's important to torque the corner bolts to the 35ft/lbs because the corner is where it was leaking before so it should have a higher torque starting point than before. The 1/4 is the actual desired effect you want but without doing all the steps prior to it it's kind of like lacing up your shoes but missing half of the the eyes in the process.

If you don't beleive me, read these links.
http://www.xmission.com/~kd7olf/torque.html
http://www.tomorrowstechnician.com/tt/tt100506.htm

 

[Kirby]

Um... I thought we were talking about the short bolts, which need to be torqued to 35ft-lbs..

Just for a little empircal evidence and affirmation of my original suspicion, I went out and torqued a small headbolt on my spare block to 20ft-lbs.. Then I set the wrench to 35ft-lbs. and began turning the bolt an additional 90*. It clicked about half way (45*), which suggests the 1/4 turn did indeed bring the bolt past its yield point, irreversibly stretching it.

Do what you want with the information; but at least make your own interpretation of the data, and know that personally, I would start over.

Now that is correct Paul, in all the excitement I did forget we were talking about the corner bolts which are at a 35 ft/lbs spec. Now that said, your sceintific research does yeild a simple solution here though. Again if the car has not been started/ driven then your analysis would dictate that he only need turn the bolt another 1/8 turn, as the proper torque was reached 1/2 way through the 1/4 turn. so again no need to start over, and the appropriate strech can still be achieved.

I'm sorry to have to take off the wiseman gloves here and play hardball here but you mentioned your 8 years of working on 2gnt's and why you're right and everyone else is wrong. That's great and all but I've not limited my 9+ years of PROFESSIONAL experience to one motor, I've been trained by the factory to work on just about every engine Daimler-Chrysler produced. Now I have recently been working at an independent shop so my experience now is not just limited to DCX vehicles but I work on Hondas, Lexus, Mercedes, Fords, Chevy and anything else that rolls in the door.

Having worked with over 50 different mechanics in numerous shops in the past years I can tell you that even in one type of dealership there are not cookie-cutter procedures for doing things but one thing stayed constant and that's a torque wrench coming straight up off of the bolt with the shortest possible extension to prevent twisting and NO swivels. When you introduce a swivel in to the equation then there's no way of knowing EXACTLY what angle you have it at compared to the next guy and as such how do you know your 45* @ 50 ft/lbs didn't turn out to be 40* which reduced to... 40 ft/lbs??

The proper torque procedure is needed because this provides an accurate starting point for the torque-to-yield step. The 50ft/lbs is NOT the final goal at all. This is the last point prior to the 1/4 turn which is where the bolts begin to stretch and then squish the gasket in to place. It's important to torque the corner bolts to the 35ft/lbs because the corner is where it was leaking before so it should have a higher torque starting point than before. The 1/4 is the actual desired effect you want but without doing all the steps prior to it it's kind of like lacing up your shoes but missing half of the the eyes in the process.

If you don't beleive me, read these links.
http://www.xmission.com/~kd7olf/torque.html
http://www.tomorrowstechnician.com/tt/tt100506.htm

I am also no stranger to different methods. I have personally re-used head bolts and I have had no issues in doing so, but notice that is not what I advised here. Now again Doug I am not talking about using a swivel, just a wobble extension to get the few degrees of clearence to keep off the cam, big difference there. Swivels are much less perdictible than the wobble extension, that's why I don't use them. Now since you were a DCX tech let me ask you this, did they re-issue the right rear head bolt to be shorter than the orignal? I'm sure you remember the right rear corner hole being a tad too shallow, causing most of the leaks there? Or does the addtional thickness of the MLS HG pick up the slack? As for the purpose of the torque to yeild I am aware of all that too Doug, but it is still true that this kid does not have to re-do everything. Even Paul's scientific experiment tells us the kid needs a max of an addtional 1/8th turn to put the bolt to the right place in "the strech". It's not a science project that will be torn down for exact examination later. He needs the HG to seal, and that is still possible.. Now when did I say not to torque to the appropriate specs Doug? Where did I say just turn it to tight and then do a 1/4 turn? When did I argue any points on torque procdure, I didn't. And since Paul's experiment was done we know the proper torque was achieved so torque is not even part of this discussion anymore. All I'm saying is it is fixable without re-doing the whole thing.

Now both of your points would be valid had the bolt been over streched, but remember in this case it is under stretched so it is not unfixable...

 

[Doug99RS]

Now again Doug I am not talking about using a swivel, just a wobble extension to get the few degrees of clearence to keep off the cam, big difference there. Swivels are much less perdictible than the wobble extension, that's why I don't use them.

Swivel or wobble... there's little to no difference when you're talking about using a torque wrench which is meant to be used straight up from a bolt/nut.

Now since you were a DCX tech let me ask you this, did they re-issue the right rear head bolt to be shorter than the orignal? I'm sure you remember the right rear corner hole being a tad too shallow, causing most of the leaks there? Or does the addtional thickness of the MLS HG pick up the slack? ...

No, there has not been a revised bolt for the right rear corner for the head on the neon, cloud car nor the talons. There has not been a revised torque procedure for that SINGLE bolt nor has there been a written notification about any procedure to modify any techniques used when installing a headgasket on any of the before mentioned cars. There HAS been many RUMORS in the dealerships and training classes about cutting the bolts and using bottoming taps to insure that the bolt does not bottom out prematurely and that the block can fully accomodate the head bolt when you properly torque it down to the proper specs.

As for the purpose of the torque to yeild I am aware of all that too Doug, but it is still true that this kid does not have to re-do everything. Even Paul's scientific experiment tells us the kid needs a max of an addtional 1/8th turn to put the bolt to the right place in "the strech". It's not a science project that will be torn down for exact examination later.

You're right. It's not a science project where the guy gets to go to the store a buy $25.00 dollars worth of baking soda, vinegar, food coloring and newspaper. Instead when this little project fails because he over or under torqued something because he was guessing at how to do it or following bad advise he gets to buy a new headgasket kit, spend a whole weekend tearing the car apart again and if he's really unlucky gets to buy a new motor do to bend valves and rods in extreme cases.

He needs the HG to seal, and that is still possible.. Now when did I say not to torque to the appropriate specs Doug? Where did I say just turn it to tight and then do a 1/4 turn? When did I argue any points on torque procdure, I didn't. And since Paul's experiment was done we know the proper torque was achieved so torque is not even part of this discussion anymore.

You didn't say just turn it to tight and then to a 1/4 but you did say "Torque them the rest of the way" after it's already been turned the 1/4 turn,

All I'm saying is it is fixable without re-doing the whole thing.

But you fail to mention how to do it accurately without overstretching the bolts or undertorqueing them.

You've got to remember Kirby. You're providing information that is being read by people all over this country. How you do things for your car might be working well for you but as experienced as you and I are we need to be providing quality information and support to other people who don't have the same abilities. If you want to suggest the swivel technique to a veteran 420A as a "hey, if you're in a pinch, try this" that's one thing but it's very clear that this author needs the right information, the first time for a reason. When you provide short-cuts and questionable practices to the general public and pass it off as a perfectly acceptable practice for everyone then there will be even more people who will try and shortcut the shortcuts. Please keep that in mind when posting up in the future.
Doug

 

[Locke]

Why use bolts and have to mess with all this "torque" voodoo anyways. I say just squirt some Elmers on it and be done.

j/k, of course.

While I have never gone to Torque Wrench University, it has always been my understanding (and basic logic supporting) to use the torque wrench perpendicular to the fastener, with no (or as few as will permit) socket extensions, to assure the most accurate reading.

What are we REALLY discussing here anymore, anyways? The use of swivels and wobbles with a torque wrench?

 

[Doug99RS]

Why use bolts and have to mess with all this "torque" voodoo anyways. I say just squirt some Elmers on it and be done.

j/k, of course.

While I have never gone to Torque Wrench University, it has always been my understanding (and basic logic supporting) to use the torque wrench perpendicular to the fastener, with no (or as few as will permit) socket extensions, to assure the most accurate reading.

What are we REALLY discussing here anymore, anyways? The use of swivels and wobbles with a torque wrench?

The real question is should the original author remove the headbolts, gasket, replace gasket, retorque the headbolts the to revised bolt specs as layed out in the service bulleting or just give the bolts an extra umph and let it right?

That question then led to the question of how do you properly know how much extra umph to give it to match the missing 10 ft/lbs of torque that was missing prior to the 1/4 turn final torque step. That led to the introduction of the use of swivel or wobble sockets and their use with a torque wrench which also brought about the discussion of extensions.