Using PB blaster or liquid wrench or any of those things dont do crap on manifold bolts while the manifold is still in place.

Only thing you can do is put pressure on it and keep goin till she breaks free. Alot of people dont realize that when you spray the cleaners on the only thing you're cleaning is the head of the bolt, granted that most times the whole issue is the fact that the head of the bolt is seated so tightly against the surface of the manifold or whatever else you're working on, that it's almost like rusted togeather ? if that makes sense.

Like was mentioned earlier, the threads on manifold bolts and alot of other bolts on our engines start way far away from the head of the bolt, you've got damn near an inch of space between the head of the bolt and where the threads actually start, and the chances of the oil or cleaner getting that far into the groves is slim to none.

The only bolts/nut's that cleaner will help you with is the two studs in the middle of the manifold. most of the time you dont even take the stud out you end up just taking the nut off and sliding the manifold out and leaving the studs in untill you can get some vice grips and break them loose.


Just my 0.2 cents but all those cleaners and oils really only clean the surface when you're dealing with those types of bolts.

 

That's a good point yak, but some pentrating fluids will seep in between the manifold and the head as well as around the bolt itself if you tap on them. Kroil says it will seep into a space that is one millionth of an inch.

WD 40 - worst
PB Blaster - better but still bad
Liquid wrench - better
CRC Freeze off - better
CRC Knock'er Loose - much better
Cyclo Breakaway - as good as Knock'er loose
AeroKroil - I've heard it's as good as the two above
50/50 mix of acetone and ATF - Best (from what I've heard)