How to clean out exhaust manifold?

J

jsurr

Cadet
Joined
Oct 12, 2008
Messages
11
I am having an overheating problem with a 1986 3 litre OMC. I pulled my exhaust and exhaust elbow and soaked in CLR, (a commercial house cleaning product used for Calcium, Lime and Rust stains, CLR) I literally got two hand fulls of crap out of them. I called a few machine shops to see if they could hot dip them for me and all three said that hot dipping uses solvent and would do salt build up any good. I have read about muratic acid but find it difficult to buy and/or dispose of.
Any suggestions on what to do with both to clean them of the salt build-up?

Thanx
Jeff
 
Haut Medoc

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: How to clean out exhaust manifold?

Those two handfulls of crap used to belong to the casting & your walls are that much thinner & closer to failure.......
I reccomend replacement.....;)
 
Bondo

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,524
Re: How to clean out exhaust manifold?

Ayuh,....

Throw it away,+ Replace it...... It's Junk....
 
T

TilliamWe

Banned
Joined
Dec 21, 2004
Messages
6,579
Re: How to clean out exhaust manifold?

jsurr, I am the cheapest guy you'll ever find, but if you got that much rust out of your manifold and riser, it's time to replace them. Sorry. And if spending $300-500 on new ones hurts too bad, just remember, if you reinstall them, they fail, and saltwater sits in your cylinder(s) for just a day, you're whole engine is junk and it'll cost you $1995 just for a long block, and you'll still have to replace the manifold/riser.
 
180shabah

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: How to clean out exhaust manifold?

The best cleaning method is replacement - your engine will thank you.
 
Capt.T

Capt.T

Cadet
Joined
Feb 1, 2003
Messages
27
Re: How to clean out exhaust manifold?

Fully submerge the manifold and riser (separately) in full strength muratic acid for 90 minutes, then rinse throughly. You can buy the muratic acid at Wal Mart for about $3.00 per gallon. You will likely need 2 gallons. Be very careful with this chemical, it is dangerous, read the label on the container. This will clean out the deposits, but you may have lost too much of the metal wall surface, and the life of the manifold/riser will be shortened. If this does not work, replacement with an original equipment manifold and riser will give you years of additional service. Good luck.
 
mkast

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: How to clean out exhaust manifold?

In the world of maintenance there is a term "consumables".
This term applies to items such as oil, oil filter, spark plugs, plug wires, distributor cap, distributor rotor, distributor points, (if used) and fuel, among other items.
Replacing these items is the price of using the equipment.
Replacing the exhaust manifolds is a requirement along with replacing the gimble bearing when it's serviceable life is reached.
 
R

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: How to clean out exhaust manifold?

wont be the first time I have had to replace the long block assy when replacing the manifold/riser assy.
funny thing is the manifold riser assy stayed the same price.
and they usually take out #4 cylinder and they can do it while running.
kinda like pistons in a 2 stroke. water pumps cost the same regaurdless of how many holes have to be bored or sleeved price of the pump job stayed the same.
 
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