enginesilo
Petty Officer 1st Class
- Joined
- Jun 9, 2008
- Messages
- 355
The time has come to do some preventative maintenance and i'm planning on changing out the Exhaust Manifold and Riser on my 3.0L Mercruiser. The engine is a 2005 3.0L and an outer visual inspection the components look great, but I already know they rot from the inside out.
How difficult of a job is this on the 3.0L for a DIY type person? Anyone do it themselves recently? How long did it take from start to finish? The shop manual procedure seems straight forward. Anything to watch out for, or require anything more than what the manual states? I read a good tip that said to find some extra long headless bolts that you can put in place of the end bolts so the manifold is supported and doesn't go dropping off. Anything else to watch out for with the carburetor or anything?
I will be using OEM parts. Here is the parts diagram:
http://www.marinepartsplus.com/catal...860235A03_jump
-860235A03 Exhaust Manifold Assembly (Which supposedly comes with a lot of bolts and such)
-12076A2 Riser Elbow Assembly
Think buying these 2 part numbers will be all I need? I think so but i'm not fully sure. Should I be changing the exhaust shutter at this time or is it ok to reuse if it looks like its visually still functional?
All tips appreciated.
Here are the instructions from the shop manual:
Removal
1. Disconnect battery cables from battery.
2. Drain water from cylinder block, exhaust manifold and exhaust elbow.
3. Disconnect throttle cable at carburetor.
4. Disconnect exhaust hose and cooling hoses.
5. Disconnect fuel line at carburetor.
6. Disconnect crankcase ventilation hose at rocker arm cover.
7. Disconnect wires connected to electric choke.
8. Remove exhaust manifold fasteners; remove manifold assembly and discard gaskets.
9. Remove exhaust elbow.
Replacing Exhaust Manifold and Risers on 3.0L - Tips Needed
Installation
If exhaust manifold body requires replacement, transfer all parts (from old manifold) to new
manifold body.
1. Position new gasket on head and install manifold in position, making sure gasket is in
place.
2. Tighten fasteners evenly and torque to 23 lb-ft (33 Nm), starting in center and working
out toward ends.
IMPORTANT: After engine has been brought up to operating temperature, allow
engine to cool. Retorque manifold fasteners.
3. Install carburetor (if removed) and connect crankcase ventilation hose at rocker arm
cover.
4. Install exhaust elbow using new gasket. Torque to 25 lb-ft (34 Nm).
5. Install gasket as shown
6. Connect throttle cable to carburetor. Adjust as outlined in ?Removal, Installation and
Alignment.?
7. Connect fuel line and electric choke wires.
8. Reinstall exhaust and cooling hoses.
9. Reconnect battery cables to battery. Tighten securely.
10. Start engine, check for exhaust, water and fuel leaks and adjust carburetor idle speed
and mixture.
How difficult of a job is this on the 3.0L for a DIY type person? Anyone do it themselves recently? How long did it take from start to finish? The shop manual procedure seems straight forward. Anything to watch out for, or require anything more than what the manual states? I read a good tip that said to find some extra long headless bolts that you can put in place of the end bolts so the manifold is supported and doesn't go dropping off. Anything else to watch out for with the carburetor or anything?
I will be using OEM parts. Here is the parts diagram:
http://www.marinepartsplus.com/catal...860235A03_jump
-860235A03 Exhaust Manifold Assembly (Which supposedly comes with a lot of bolts and such)
-12076A2 Riser Elbow Assembly
Think buying these 2 part numbers will be all I need? I think so but i'm not fully sure. Should I be changing the exhaust shutter at this time or is it ok to reuse if it looks like its visually still functional?
All tips appreciated.
Here are the instructions from the shop manual:
Removal
1. Disconnect battery cables from battery.
2. Drain water from cylinder block, exhaust manifold and exhaust elbow.
3. Disconnect throttle cable at carburetor.
4. Disconnect exhaust hose and cooling hoses.
5. Disconnect fuel line at carburetor.
6. Disconnect crankcase ventilation hose at rocker arm cover.
7. Disconnect wires connected to electric choke.
8. Remove exhaust manifold fasteners; remove manifold assembly and discard gaskets.
9. Remove exhaust elbow.
Replacing Exhaust Manifold and Risers on 3.0L - Tips Needed
Installation
If exhaust manifold body requires replacement, transfer all parts (from old manifold) to new
manifold body.
1. Position new gasket on head and install manifold in position, making sure gasket is in
place.
2. Tighten fasteners evenly and torque to 23 lb-ft (33 Nm), starting in center and working
out toward ends.
IMPORTANT: After engine has been brought up to operating temperature, allow
engine to cool. Retorque manifold fasteners.
3. Install carburetor (if removed) and connect crankcase ventilation hose at rocker arm
cover.
4. Install exhaust elbow using new gasket. Torque to 25 lb-ft (34 Nm).
5. Install gasket as shown
6. Connect throttle cable to carburetor. Adjust as outlined in ?Removal, Installation and
Alignment.?
7. Connect fuel line and electric choke wires.
8. Reinstall exhaust and cooling hoses.
9. Reconnect battery cables to battery. Tighten securely.
10. Start engine, check for exhaust, water and fuel leaks and adjust carburetor idle speed
and mixture.
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