Exhaust manifold removal

[PhilW]

Before my engine goes back I decided to replace the gaskets on the exhaust manifold.  Nuts were rusted to nearly nothing so right thing to do.  Now got all 12 nuts off and soaked the area in WD40.  I am expecting the manifold to be stuck fairly fast  has anyone got any tips on free it off?

Thanks

[snowrx]

Penetrating oil or acetone/ATF blend around the studs for a good soak. Any sticking would be due to corrosion packed around the studs, I would think the iron manifold would pop right off the aluminum head.

[Barrykearley]

23 hours ago, PhilW said:

I am expecting the manifold to be stuck fairly fast  has anyone got any tips on free it off?

Rubber mallet

[PhilW]

Well its been soaking for all of February.  Will not budge.  Assuming it is corrosion around studs.  Now looking at heating the manifold around stud area but only have Mapgas.  Not sure it will heat quick enough before heat dissipates.

Any other suggestions anyone.

 

Thanks

[drdoom]

A wooden block struck judiciously with a substantial hammer would be my escalation exercise at this point. Impact shocks in a shearing direction, not so great as to bend the studs. Next level would be to, again judiciously, drive slim wedges into the gap between head and manifold, mindful of unduly marring the sealing surface of the head. Start with metal putty knife then move up to thicker implements. Wedging force is quite immense.

Best of luck

[Barrykearley]

Wood, smacking holy hell out of it with a mallet and plenty of swearing.

if you like soaking things and waiting - then drench it in brake fluid 

[910Esprit]

I had the same problem with mine originally, as in addition to the 8mm studs being tight in the manifold with rust, somebody had used some sort of sealant which further bound up the studs.   It was a ****ing nightmare!   Ended up bolting the head to the bench and attacking the manifold with baulks of wood, wedges, heat etc.  Hopefully yours wont be that bad!   When I refitted, I drilled the manifold holes to have slightly more clearance.   Since then I have gone for Alunox, which makes such problems a thing of the past!

NB - I would recommend using the HC laminated stainless steel gaskets on reassembly.

Edited February 28, 2022 by 910Esprit

[TAR]

Use the Mapgas to heat only the studs, this may have a better chance of shocking the rust into submission.  

[PhilW]

Thanks guys.  Suffering quite badly with COVID at the moment and I am never ill.  Probably have an hour on it later if I can face it.  3 jabs as well.  Dont want to think if i hadnt had a jab!

[Gis]

Hang in there and get well soon mate.

[Bibs]

Best wishes Phil, hope you get better soon. 

[PhilW]

Thanks guys.  Feeling much better but still testing positive.  last couple of days I have had a go at the manifold.  Got it off but what a fight.  Used brake fluid as mentioned and wedges, wood and a lump hammer.  All advise played its part.  Much appreciated