View Single Post
  #1   IP: 74.88.0.97
Old 12-08-2019, 04:16 PM
nyvoyager nyvoyager is offline
Senior Member
 
Join Date: Jun 2012
Location: NY
Posts: 189
Thanks: 50
Thanked 16 Times in 14 Posts
Broken Exhaust Manifold Stud

I am sorting out a new to me late model A4.
The engine had been sitting in a garage for years, likely around 7 or 8 years.
While still sitting on a pallet under the boat , I pressure tested the block - it checked out.
Drained and replaced the oil. Spun it with a hand crank. All good.
Cranked it with no spark to get oil up and around.
Compression check revealed a stuck valve in #1 cylinder. Some MMO and a few more cranks and all well - compression on all 4 cylinders is spec.

Wired it up and it started on the 2nd crank.
Let it run for a minute and it sounds good with no smoke.
**** I did this with no water and pulled the impellor. I just wanted to get it started.

Fast forward:
I had to move the boat to another yard so the engine is sitting on the cabin sole knowing I have a few things to sort out and parts to switch over.
I have basically stripped all the accessory parts off including the exhaust manifold.
It turns out the center stud is broken and i don't believe it was by me. I used very little force to remove the bolts. The center stud just spun out.
Unfortunately I didn't take a photo of the threads but they look clean and in near new condition.
My thoughts are to pick up a reverse drill bit and easy-out
My questions:
What size bit and easy-out should i use?
Do i need to put sealant on the threads when reinstalling? - the threads are good.
what is the rust on this one port?

If this helps: the reason I pulled the manifold i because the exhaust flange bolt was snapped off. The other appears rusted in fairly well. The manifold itself appears in good condition but I have a new MMI manifold sitting here and will install it.
The next step will be to try and figure out why there is no thermostat in the housing
Thanks all.
Attached Images
  
Reply With Quote