Head Bolt Torque on Bolt Removal
 

I'm in the middle of replacing head gaskets on a 2001 DII and just removed the 20 head bolts. I was surprised that some of the head bolts were very highly torqued and required a breaker bar to loosen and some that came out easy like less than 20 lbf-ft. I would have expected them all to be of equal or close to equal torque. I guess the uneven torque could be due to the overheating that caused the failing head gaskets or it could be that's the way DII head bolts are. Or is it due to incorrect torquing by the shop that did the previous head gasket job? Has anyone seen this situation? Any ideas on whether this is typical? Thanks. Tom

How bad did you overheat? Did you drive for a few miles while it was in the red? If the heads or "even worse" the block warped bad enough while overheating then I suppose it could losen the bolts. Be sure you get your heads resurfaced.

My wife was driving it in a steep hilly area at about 50 mph when the double hose to the heater blew. From what she told me, it was likely in the red for a few miles. Actually she says it went into the red and then back to halfway and alternated like that a few times before she pulled over.

The heads go into the machine shop tomorrow.

I'm still curious about why the torque on the bolts was so uneven.

Ouch.
You should get the heads checked for warp when they are off.
I had to use a breaker bar to remove ALL my head bolts on a 2001.

But, you are probably stronger than me.
The double hose blowing may have been a bad thermostat
or a head gasket problem.
Or, the hose was just really old.

I would think though the excessive pressure had to take out the hose as it was the weakest link.

Next time this happens, tell your wife to stop ASAP and or she will pay for the repairs out of her own money!!!
How many miles on the engine, where are you getting your kit from and do you have the Rave CD or a shop manual?

Just removed the RH head. Both are going into the machine shop tomorrow.

As to the double hose blowing, I checked the part list of all the hoses the shop changed when they installed a new radiator and they replaced all of them but that pair. No wonder they blew. They are the originals.

Amen Mike. Unfortunately her back up car is my 1990 XJS convertible. Geez, maybe she purposely blew those head gaskets.

There are 140K on the engine. I'm using a Victor Reinz kit from Germany. I'm using the Rave CD.

Mike, with all your experience, is it likely I would find the head bolts unevenly torqued when I pulled the bolts? Today I removed the RH head. I followed the Rave removal instructions but this time I put my beam torque wrench on them to see how much torque I had to overcome to loosen them. #1 (front lower) and #2 (rear upper) were at around 90. Then #3 (rear lower) was only 20. Six of the bolts were around 20 and four were around 90. Was that likely caused by the overheat destroying the head gasket and reducing the torque in certain areas or did the shop that last did the HG job not torque them correctly? Just curious more than anything. It doesn't really change how I go about this job.

I don't know because i did not do the job myself, but its more likely that the previous shop that did the last HG job did not tighten to the proper torque specs. Maybe they got started and then went to lunch & forgot where they left off or did not do a re-check of torque before moving on. Sucks but there is not a lot you can do about it. Hope for the best on your heads, yikes.... set the alarm on the UG to go off at a certain temp so she knows to pull over and shut down next time.

you will find out when you send the heads to be trued, they will tell you it took one pass or 10 passes to get true them.

It is common for them to be uneven - but 20lb seems ridiculously low. Typically they will be anywhere between (approximately) 75 and 200 lb ft to remove.
As to why - well, probably the last garage didn't do it properly is the easiest answer. Perhaps they forgot the second angle rotation sequence? Why not make things better this time around and junk the stretch bolts and replace with a quality engineered solution - a set of ARP 124-4003. This way all torques will be equal when you install them, and all torques will be equal when you remove them. There are just too many variables with the bolts, studs are guaranteed more consistent.