stumbled on a gold mine of e30 parts

[cliff]

while researching the sheared head bolt issue on the 88 325i i discovered the left over part was finger loose (can remove by hand)...a great relief. next issue, finding a replacement bolt. called all around to dealers and autozones and machine shops and such....all said only a complete set for around 40 beans. then it occurred to me....a junkyard...called several and they said no BMW's...called another and they said they didn't know what they had, you had to come and see.
a u-pul-em place, as it is saturday i took a chance. drove about 15 miles and found this yard that is full of BMWs, Mercedes, Saabs, Volvos and virtually every Japanese make going. Found the exact make of the 88 325i with head in order and removed the much looked for bolts (took 2 even though I only need one) and went to pay for them. dude told me just to take em...free....saved me $50 right then and there...I intend to go back for mercedes parts after this is done....literally an easter egg hunt for those who are of such pursuasion....girl didn't like it first but she came to understand....

 

[E30m42cab]

You're using used headbolt? No, no, no. You use new headbolts all the time. Then they need to be torqued and degreed, in proper order. No used headbolts. Used ones will be stressed and stretched, should not be re-used. New bolts only.

 

[cliff]

no...not at all....1 out of 14 bolts?...not a big deal at all

 

[cliff]

the only reason you do all the head bolts in order is to settle a new gasket...this gasket is settled for sure. not a valve job at all, and the engine is fine. simply minimizing the potential for further issues at a minimum price is all.....

 

[echothreezero]

A used bolt is better than no bolt, but scott is correct in saying it is certainly not the done thing. Congrats on finding a decent wreckers yard and do what you like, but it'd be borderline negligence not to advise you to use a new bolt in this situation.

 

[E30m42cab]

The used bolt could quickly end up just like the broken one. You're probably right, it might not matter seeing as its only one bolt, but one used bolt will always be in the back of your mind when you're hammering the throttle and wondering if you did the right thing, or the cheap thing. $40 is a pretty small amount when it comes to the heart of your car.

 

[cliff]

appreciate the advice guys...nevertheless I applied the part today and I will have to live with the consequences I reckon. It was either $0 or $2000, I chose the former, and given my experience I shall have to live with it...I'm pretty sure I am right on this one...however...I shall find out shortly if I made a poor choice...I will most certainly admit if I did bad....this quick/fix will make itself apparent rapidly if I missed.

 

[M.Regello]

To reuse used headbolts or Not?

The head bolts used on that engine are "stretch" bolts. They are machined to a specific cross section diameter, which accurately controls the tension when the bolt is "degreed" after applying the correct torque to the bolt. When the bolt is "degreed" that cross section shrinks as the bolt is stretched, and does not return to its original diameter when the bolt is loosened. The bolt may or may not be able to be torqued to the correct specification, but if it reaches the correct torque, it should not be able to be stretched to the original tension without breaking! The broken bolt was probably reinstalled after being used once, and it wouldn't take the tightening. You can tell the difference between a new and used bolt by measuring the shank. The new bolt will be larger in diameter. Good Luck!

 

[Doughnut]

Bah, should be right.

When it comes time to replace that head gasket replace all your head bolts then.

 

[cliff]

Bah, should be right.

When it comes time to replace that head gasket replace all your head bolts then.

agreed, but I didn't replace the head gasket, just one bolt. the point was to avoid the expense and hassle of pulling the head. just checked repair (getting really good at pulling the valve cover) and all seems fine. car has 166K miles on it and the head has never been off. burns/leaks no oil nor coolant whatsoever and this thing has had the crap beaten out of it...deserts, mountains, harsh winters, everything, just spot on regular maintenance. why i drive these things to begin with, everyonce in a while something odd may show up but, by and large, they are bullet proof (the engines that is). thanks for the insight...appreciate it...