Rounded head bolt during tightening!!!!

[Massimo]

I was doing the last sequence of 90 degree turns on the M42 head and I ended rounding two bolt heads. To say the least I am really pissed off that I could do something so stupid.

So bolt 6 and 8 the two at the front on the exhorst side. I got 6 trough about 3/4 of its last turn and bolt 8 was somewhere between 1/2 and 3/4.

I am thinking of just leaving them as I do not want to try and take them out and then ended fucking them up completely, as I do not know how I would then get them out.

What do you guys think? This is a DD so it is not drive hard on a regular basis.

Cheers Guys

[Dj Buttchug]

If you rounded the head bolts the torque on those bolts is not correct. Your going to have head gasket issues down the road im pretty sure.


Btw, did that cyl head ever make to you with the flooding and storms and all?

[KenC]

Two scenarios:
1. You used the wrong sized star socket.
2. Your torque wrench is not calibrated correctly.

Those headbolts won't round under proper torquing.

Take them all out, throw them away, and start over. They're one time use stretch bolts.

[Van Westervelt]

Youre going to regret not backing up and doing it right. Chances of leaks, leading to overheating or blown hg are likely. The right thing to do now would be to back up and use a new hg while you are at it.

[Ryann]

2. Your torque wrench is not calibrated correctly.

Can't see this being a factor since the last two steps are degrees vs. ft/lbs.

I was definitely stressed about this sort of thing when I torqued mine. The last 90 degree step was TIGHT, and tough to turn with my 3/8" torque wrench. I used a brand new Mac socket.

I agree, though. Take them all out and start over.

[AndrewBird]

These are your friend.

[Massimo]

LOL so when you guys mentioned am I using the right socket I though of course I am not stupid. But I suppose stupidity will prevail here and there, I was using an E14 socket instead of an E12.

Geez that is so stupid! I can't figure out how I even got the other bolts torque down correctly. Anyways I have backed them and out and will order some today.

Yeh the head came Ryan it is looking pretty spiffy now I have photos but ill will post them up on my thread when I have finished the job. I live in Adelaide there is never an issue with Mother Nature here, it has got to be the most boring town in the world. The most exciting it gets here is a bush fire.

How is the MS coming or is not yet?

Thanks again guys for the help.

[dakon]

can you re-use the gasket? isn't a head gasket a compression gasket? i would assume that the gasket would be a 1 time use item as well, and since most of the bolts got torqued the compression surface might not be re-usable?


i don't know for sure though just throwing that out there, would be a royal pain it the A$$ to get new bolts, and not get a new gasket should you need a new one.

Good luck man.... when i put my head on in the next week or so, i will triple check that i have the E12 on my wrench.

[Ceeker]

I was told u can re-use it. I had to remove my head on my M20 because I had timing slightly off and when I torqued the head down I bent a valve. I re-installed the same head bolts only because it didn't got through any heat/cooling exchange. the car is working fine and no problems. they are stretch bolts but when not under load they are fine. I also confirmed this with a machine shop before considering re-use.

BTW, I am NOT advising you...lol. I am just telling you my experience.

[Massimo]

Yeh I don't think I have an issue with the head gasket if the car was started and with heat expansion and all, there would be a problem but since I just torqued the head there should be no issue. But ill have a word with a BMW mech just in case.

Yes make sure it is an E12 LOL.

[Massimo]

Well got new bolts used the right E12 socket and put it all back together last night. So I turned it over by hand first all good, then I did a cold start sweet not valve hitting. So hooked the fuel pump up and started the car.................

It was not idling I assume this is the ICV and the chain tensioner was waiting for oil pressure with a lot of rattling. I gave it about 20 sec then I noticed a bit of smoke. So I turned the car off went and had a look and there is about 3lts of oil on the ground WTF!!!!!!!!!!!!!!

Turns out there is an oil plug on the back of the head that was missing. LOL scared the shit out of me! Anyways putting one on tonight, also noticed the expansion tank is leaking fuck sakes.

[dakon]

Gawd damn dude, i need to stop reading this thread.... i just got my head back, and will be bolting it on this weekend....


However, if you do keep us up, we will know what to look for.. i didn't even know there was a oil plug on the head..! however all of the holes in my head have something in them.


Good luck man.

[Ryann]

Turns out there is an oil plug on the back of the head that was missing.[/FONT][/COLOR]

This has happened to me twice. I now examine all machine shop workmanship with extreme scrutiny.

[Massimo]

Yeh make sure everything is plugged up. So I have ordered a new expansion tank, chain tensioner, and throttle position switch. The chain tensioner is not working don't know why, the expansion tank was leaking like a it was not even there, and the car is not idling so I have taken a guess that it is the throttle position switch as playing around with the ICV did nothing at all.

Hopefully have the baby going again soon.

[rjcaptsean]

Heres a pic of the back side:


Finally getting mine back together. Going slow and meticulous to make sure everything is torqued properly and not missing any oddball brackets. I've had to pull the A/C mount off three times now because I keep finding things that are behind it.

I will tell you what though, those head bolts added a few gray hairs. I swear I could feel them stretching on the two 90deg turns and I kept waiting for that sickening snap of a busted fastener. Once I got those done it was time for a cold one!