exhaust manifold leak
#1
Instructor
Thread Starter
exhaust manifold leak
I just changed out the exhaust manifold on my 86 951, including all the studs, new washers and nuts (rennbay kit). I also changed in new exhaust manifold gaskets.
Now with the soapy water test, it seems that I have a few small leaks at several nuts/studs. Also, some gaskets seem to be 'cooking', with tiny bubbles on the top edge. All nuts are torqued to 15 nm.
I'd rather not fail my MOT emissions test again. What is my course of action to solve this once and for all?
Edit: the car hasn't been driven since these changes, just tested. The soapy water test was done when the engine was cold. Can't verify if the manifold continues to leak after engine is warm since the water evaporates so quickly.
Now with the soapy water test, it seems that I have a few small leaks at several nuts/studs. Also, some gaskets seem to be 'cooking', with tiny bubbles on the top edge. All nuts are torqued to 15 nm.
I'd rather not fail my MOT emissions test again. What is my course of action to solve this once and for all?
Edit: the car hasn't been driven since these changes, just tested. The soapy water test was done when the engine was cold. Can't verify if the manifold continues to leak after engine is warm since the water evaporates so quickly.
#3
M8 fasteners should be about twice that. Did you maybe misread the spec? 15 lb/ft?
#5
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Porsche-noob-91 (01-26-2024)
#7
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#8
Instructor
Thread Starter
I rechequed the torque today and it was indeed torqued to 15 nm instead of 20 + 2 nm. After torqueing it to the correct value, I tested the car again with the soapy water test. No leaks! Thanks everyone.
#9
Three Wheelin'
What methods did you use to remove the studs from the head? My car needs all new manifold studs also. The rear stud on the #4 cylinder has broken off.
Tom
'87 951
Tom
'87 951
#10
Instructor
Thread Starter
I used the double nut method, and soaked all studs with pentrating oil beforehand. All studs came out easily.