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.
|