"Symptoms:
- Engine will no
"Symptoms:
- Engine will not exceed 3600 rpm under load
- Engine beeps intermittently with overheat alarm but quickly cools off once RPMs are dropped to 1900
- Engine clacks on top rhythmically consistent with RPM after 1500 rpm (and higher) is reached (but not under 1500 rpm).
- Engine clacks whether under load (in gear) or not.
- No water or radiator fluid in oil
- No bubbling in radiator reservoir
Measures taken thus far
- Impeller new and clear
- Radiator hoses new and clear
- Radiator fluid proper 50/50 mix and not leaking, cap verified as not leaking.
- Heat exchanger inspected and verified clear of crap, impeller blades, etc.
- Fresh water flow very good
- Exhaust Manifolds removed and inspected (clear).
- Plug wires and spark coils have been swapped with my known good engine to troubleshoot integrity of those components.
- Oil and oil filter just changed to 20w50 synthetic.
- Injectors for suspect cylinders 4 and 6 have been pulled and swapped with known good cylinders. The problem stayed with the bad cylinders (did not follow the injectors).
- Removed valve cover and inspected rockers for any play. I could not move any of them. Everything looked very clean. No bent rods or valves noticed (but I did not remove the head).
- All cylinders and plugs are hot after engine runs (even 4 and 6)
Planned tests/maintenance
- Compression test has not been run. I am borrowing a tool tomorrow to run the test.
- Seafoam in oil and air intake.
Other notes
- This engine is a closed cooling system with a heat exchanger.
- 375hp Volvo Penta, 2001, 8.1 GiI-B, serial 4012064207, gasoline
- I have a MEFI4 electronic analyzer and I ran a balance test, disabling cylinders one at a time while running at 1500 rpm. When I disabled cylinders 4 and 6, the engine rpms did not change noticeably. Disabling all other cylinders individually caused the engine rpms to dip noticeably.
I hope I included everything but I'm sure there will be questions. Any ideas? Can we narrow this down to just a few components. I'm thinking head gasket."
- Engine will no
"Symptoms:
- Engine will not exceed 3600 rpm under load
- Engine beeps intermittently with overheat alarm but quickly cools off once RPMs are dropped to 1900
- Engine clacks on top rhythmically consistent with RPM after 1500 rpm (and higher) is reached (but not under 1500 rpm).
- Engine clacks whether under load (in gear) or not.
- No water or radiator fluid in oil
- No bubbling in radiator reservoir
Measures taken thus far
- Impeller new and clear
- Radiator hoses new and clear
- Radiator fluid proper 50/50 mix and not leaking, cap verified as not leaking.
- Heat exchanger inspected and verified clear of crap, impeller blades, etc.
- Fresh water flow very good
- Exhaust Manifolds removed and inspected (clear).
- Plug wires and spark coils have been swapped with my known good engine to troubleshoot integrity of those components.
- Oil and oil filter just changed to 20w50 synthetic.
- Injectors for suspect cylinders 4 and 6 have been pulled and swapped with known good cylinders. The problem stayed with the bad cylinders (did not follow the injectors).
- Removed valve cover and inspected rockers for any play. I could not move any of them. Everything looked very clean. No bent rods or valves noticed (but I did not remove the head).
- All cylinders and plugs are hot after engine runs (even 4 and 6)
Planned tests/maintenance
- Compression test has not been run. I am borrowing a tool tomorrow to run the test.
- Seafoam in oil and air intake.
Other notes
- This engine is a closed cooling system with a heat exchanger.
- 375hp Volvo Penta, 2001, 8.1 GiI-B, serial 4012064207, gasoline
- I have a MEFI4 electronic analyzer and I ran a balance test, disabling cylinders one at a time while running at 1500 rpm. When I disabled cylinders 4 and 6, the engine rpms did not change noticeably. Disabling all other cylinders individually caused the engine rpms to dip noticeably.
I hope I included everything but I'm sure there will be questions. Any ideas? Can we narrow this down to just a few components. I'm thinking head gasket."