Extreme Mechanic Solutions
Compartilhar
Light and heavy vehicles , fixed plants(engine powered) and mobile plant repairs.Root cause problems solution. If others have failed, it's time to get in touch
30/03/2026
Perkins 1104D 44TA engine
Problem: low engine oil pressure
Observation: 0 bars reading on oil gauge
NB- recently received overhauled engine
In most cases we would jump for the pump . I remember my hydraulics lecturer at college, ' in a hydraulic system the pump does not create pressure, it creates flow , what creates pressure is restriction, then valves come in to regulate the system pressure according to system requirements'. More restriction more pressure, less restriction low pressure. The system is made to safeguard against extreme high pressure and low pressure by valves and/pressure sensors.
In the case of this engine,the oil pump incorporates a pressure regulator valve. When the pressure increases above the maximum set pressure this valve opens to redirect the oil back to the oil sump.
This valve fails in two ways, stuck open or stuck closed.
When stuck closed it elevates the system pressure above the normal working range which also has adverse effects on the engine. If it gets stuck open the oil pressure drops below the system range which also has adverse effects on the engine.
So before you remove the pump check the pressure regulator valve.
NB-On some engines this valve is found on different locations e.g. on the block.
27/03/2026
Engine: CAT C9
Problem: mixing ,engine oil into fuel
The fuel system used on this engine is HEUI system. On this fixed plant, we have 3 filter bases, the first being the water separator through which fuel flows from the tank to the transfer pump. the fuel transfer pump is connected in tandem(inline connected )with the high pressure injection pump. From the transfer pump the fuel passes through the primary and secondary filters into the fuel rail in the cylinder head. Along this fuel rail we got our unit injectors which are actuated by the pressurized engine oil from the injection pump. The residual fuel then flows out of the cylinder head to return to the tank. Adjacent to the fuel rail we also have an oil rail into which the injection pump sends engine oil under high pressure. When inserted into the cylinder head the unit injectors will cut across both the oil and fuel rails, so to prevent mixing the injectors are mounted with O ring seal.
Objective: find out where the oil is mixing with the fuel.
- where on the engine does engine oil get closer to the fuel system with the possibility of mixing
Findings:
1-injection pump/transfer pump
2-oil rail/fuel rail
3-on the injectors( O rings separating fuel and oil galleries)
Elimination of possible causes to narrow down to the course
At this point the fuel in the filters has turned dark because of bent oil going into the fuel.
Steps-
-remove all fuel filters , drain them and clean out the dirty fuel with clean diesel
-remove fuel from the fuel lines
-find a clean contain with clean diesel
-re install the filters remove the suction line and put in the container with clean diesel and bleed the fuel system ( leave the return line connected to the main tank.
-run the engine for 15 to 20 minutes.
-stop the engine and remove the water separator filter pour out the diesel and observe the colour
-do the same with primary and secondary filter
Possible outcomes
-fuel in primary and secondary filter clean
-fuel in the primary and secondary filters dirty
Interpretation
Dirty fuel in filters- this means contamination is happening before the fuel reaches the cylinder head
Clean fuel filters (primary/secondary)- this means contamination is happening with the block.
Conclusion:
-if the fuel in the filters is found to be clean the problem is within the cylinder head ,across rails( crack in the head) or across O ring seals at the injectors
- if the fuel in the filters had darkened the problem might be contamination and the injection pump/ transfer pump assembly.
PS- WITH THIS ENGINE OIL WAS BYPASSING FROM THE INJECTION PUMP INTO THE TRANSFER PUMP, I REMOVED THE TRANSFER PUMP AND FITTED ANOTHER
NB- ON THIS ENGINE DO NOT REMOVE THE TRANSFER PUMP IF YOU DON'T KNOW THE PROCEDURE
My next post will be on the procedure to remove the transfer pump
A client brings a car/ machine with problem of oil from the exhaust or inlet system. After diagnosis you request the client to buy a turbocharger but after installing the new turbocharger you still have the same problem . Where did you go wrong?
First you need to understand how a turbocharger functions and how the turbocharger was designed.
The oil passes through the turbocharger for lubrication and cooling purposes . There are some holes directing the oil to the shaft connecting the impeller and the turbine. At the end of each side of the shaft just behind either the impeller or turbine there are 'piston rings like seals(metallic) . These seals are to prevent the oil seeping out on the shaft ends, because they are metallic they don't provide a perfect seal meaning oil can seep through.
Then what prevents the oil from leaking and the turbocharger is working? On the inlet side is the pressure of the incoming air and on the exhaust side is the pressure of the exhaust gas. Pressure difference between the oil pressure in the turbocharger and the pressure of the inlet/exhaust gases is used to supplement the poor sealing quality ot the metallic seals.
So irregularities that will offset the pressure difference within the turbocharger will cause it to leak oil e.g, blocked air filter, leaking exhaust manifold, blocked turbocharger oil return line, blocked crankcase ventilation system etc.
A GOOD MECHANIC IS THE ONE WHO GETS THE JOB DONE WITH THE LEAST POSSIBLE COSTS
29/09/2025
Battery health testing. There are four things to check out when testing battery health, voltage, internal resistance, SOC, SOH and CCA.
CCA - cold cranking amps-CCA is the number of amps a 12-volt battery can provide for 30 seconds at 0°F (-18°C) while maintaining a minimum voltage of 7.2 volts. NB batteries have different CCA according to size and the CCA is a specific to a type of battery
SOC-state of charge- a percentage indicating the remaining energy in the battery
SOH-state of health - current battery health compared to when it was new
Internal resistance-its own electrical resistance, which hinders current flow and is a key indicator of its health and ability to provide high-current starting power (CCA).
This battery that was tested here has a CCA of 725, compared to the 304 on the tester, it could even crank the engine
I got a P0192 fault code, "Fuel Rail Pressure Sensor 'A' Circuit Low". the engine is running rough and stalling sometimes.
Using my diagnostic I found the fuel pressure to be around 820 psi , the range for the pressure should be 1800-1900 psi.
The cause for this can be the following
1-faulty low fuel pressure pump
2-very low fuel causing air to be sucked into the fuel system
3-clogged fuel filter
4-obstructed fuel lines
5-faulty high pressure fuel pump
6-faulty high pressure sensor
7- problem with high pressure sensor wiring
8-faulty PCM.
9-faulty pressure regulator valve
The fuel system has both low pressure and high pressure sensors. Using that I can eliminate other possible causes from the list. Faults 1 -3 can cause low pressure in the low pressure fuel system. Fault 4 can cause low pressure in either low or high pressure systems depending on the position of the obstruction. NB any of the above faults will subsequently lead to low pressure in the high pressure system but faults 1-4 will trigger another code related to the low pressure system so most likely you will have a P0087/P008A code to accompany the P0192 code.
So with the information I got I will concentrate on 4-9 as I only have one fault code, P0192.
To further eliminate other possible causes I would use a manual gauge. If the gauge results shows normal pressure I would eliminate all except 6,7 and 8 from the possible causes, but if the pressure
on the gauge is low, then 5 and 9 can be the causes.
If I get the honour to repair your car, this is how I will do it, I won't throw parts at it and hope for the best. Extreme Mechanic Solutions is the game
Clique aqui para solicitar o seu anúncio patrocinado.
Categoria
Telefone
Website
Endereço
Tete
2300
