#1 Exhaust head bolt missing, need opinion - Pic included Options

[Trevorg7]

So - I am under the car doing a valve adjustment this morning and notice something troubling. No sure why I never noticed before but one of the #1 exhaust head bolts is gone. I assume its been gone for as long as I've owned the car. The PO had the motor rebuilt within a year of selling the car to me so I guess it snapped then and the builder never said a word.

So my question is what is the risk of running the car like this? Keep in mind its must have 25k miles on it with the bolt missing.

Should I park it and replace? Drive it? Use this as an opportunity to by a Raby kit with new heads?

Let me know.

T

[Aaron Cox]

you need an exhaust stud.....

otherwise i guarantee you have an exhaust leak

[Trevorg7]

you need an exhaust stud.....

otherwise i guarantee you have an exhaust leak

Yeah no doubt I have a leak, known that for some time, I just didn't know the source until today.

Thoughts? Whats the risk?

Thanks

T

[jimkelly]

remove heat exchanger and drill/tap for a helicoil ???

jim

[Dave_Darling]

You may have lost that recently. If really was gone 25K miles ago, the head is history--not even worth considering saving. Exhaust gases, when they leak like that, will erode the aluminum head--seriously erode it, and probably the top of the heat exchanger and the gaskets too! But by that point, the leak would have been really LOUD and the engine would be running really oddly...

Pull the exhaust and inspect. If there isn't any erosion (yet!) count your blessings and get a new stud in there. Which will likely involve a helicoil or time-sert or similar thread repair technique, but that's less spendy than buying a new (or new used) head!

--DD

[Trevorg7]

Okay - I am finally going to get around to replacing this stud. Additionally I am going to replace the fuel lines and speedo cable.

The main question I have is the stud replacement. If I helicoil do I need to put in an OEM stud (8x53 for a 1.7) or would I use something else? I've never used a helicoil so I am just not sure.

Thanks

T

[DanT]

Trevor, have you been able to inspect to see if the stud is broken off or just completely backed out. If it is completely backed out you can just replace it with a stock sized exhaust stud and nut.
Might not be as bad as you think. (IMG:style_emoticons/default/smile.gif)

[Trevorg7]

Trevor, have you been able to inspect to see if the stud is broken off or just completely backed out. If it is completely backed out you can just replace it with a stock sized exhaust stud and nut.
Might not be as bad as you think. (IMG:style_emoticons/default/smile.gif)

Hi Dan, Thanks for the note. I believe it is broken. Either way, I assume I'll need to order a stud from Pelican (or other). Does that sound right?

Do you have a 1.7 stud laying around?

T

[DanT]

No, but I know who probably has one...local.

if it is broken you may be able to use and easy out and replace it with stock component.

get under there and get the exhaust off and see what you have then you know what you need to do. Hope it is better than you think.

[Trevorg7]

Sounds good Dan. I'll have it off today or by the latest tomorrow and I'll let you know.

thanks

T

[jasons]

if it is broken you may be able to use and easy out and replace it with stock component.

Be gentle with the easy out. I broke an easy out in an exhaust stud trying to do the same job. I ended up dropping the motor and pulling the head to fix the whole enchilada. Honestly, I don't know if there is any good way to get those out, with the motor in the car. I would say hit them with some PB Blaster, but it won't soak down anyway. You can try to get it good and hot before the easy out.

I think I would probably get some good drill bits, and drill the stud out. Start small and work your way up.

[Trevorg7]

Okay, I finally got around to pulling this thing off and here is what it looks like. The threads appear to be stripped and there is no evidence of a bolt.

What are the options? Heilcoil? If so, any recommendation for sizing etc.

let me know what you all think.

Thanks

T

[type47]

timecert?

[rhodyguy]

the other stud in the picture looks to have seen better days too. time to break out the Aerokroil and 12 or 13mm 1/4" drive sockets. take your time and try not to force the remaining fasteners. good luck.

k

[Trevorg7]

the other stud in the picture looks to have seen better days too. time to break out the Aerokroil and 12 or 13mm 1/4" drive sockets. take your time and try not to force the remaining fasteners. good luck.

k

Thanks for the feedback. you're right, in the picture the other stud looks bad or at least stripped. I just crawled under there and it actually looks good. Threads are fine. Are you seeing anything else that I may have missed?

T

[rhodyguy]

i see the carbon at the exh port but no burn/hot jet marks. make sure the old copper gasket is out before you put things back together.

k

[sww914]

The VW shops sell "step studs". They are normal 8mm on one end and 9mm on the other. A 9mm tap will just thread into the stripped out hole left by the missing stud, so you tap the 9mm threads and just screw the step stud in.
Really simple solution.

[Trevorg7]

The VW shops sell "step studs". They are normal 8mm on one end and 9mm on the other. A 9mm tap will just thread into the stripped out hole left by the missing stud, so you tap the 9mm threads and just screw the step stud in.
Really simple solution.

I really like that idea. I'll take a look.

Thanks!

T

[Trevorg7]

So, when it was all said and done I bought a 9/8 step stud (some think that is the original size but who knows) and drilled and tapped the hole. The 9/8 stud went in fairly easily. Bolted it all up and ran it. There is still an exhaust leak so I need to figure out where it is coming from. Seems that i can feel it puffing under the HE connections so I guess the HE are not seated. I'll look into that tomorrow.

T

[Trevorg7]

forgot the required pic.