I have a 2002 Pajero (Montero in US I think) 75W with a 6G74 3.5L V6 engine 24valve…. (Jap import)
does anyone know where I can get or look at an engine oil flow diagram... I am trying to figure out where the oil comes from to set the pressure for the pressure switch?
Am I right in saying the the oil sits in the sump and then gets sucked up the oil pickup pipe... through the rockers and then down to the oil pressure switch?
would that be correct?
Thanks
[quote="rogerbotswana"]I have a 2002 Pajero (Montero in US I think) 75W with a 6G74 3.5L V6 engine 24valve…. (Jap import)
does anyone know where I can get or look at an engine oil flow diagram...
Am I right in saying the the oil sits in the sump and then gets sucked up the oil pickup pipe... through the rockers and then down to the oil pressure switch? would that be correct?
No definitely not
Oil is drawn up through the pick up in the sump by the pump. From the pump it is presurised and sent to the oil filter. The oil pressure switch is normally situated in the oil gallery right near the filter. From the filter it will split and supply the crankshaft main bearings and then big end bearings. At the split it is sent to the cylinder head to supply oil to the camshaft and hydraulic lifters. From the cylinder head it simply runs down back to the sump.
I am trying to figure out where the oil comes from to set the pressure for the pressure switch? ..... ???????????
I don't know who told you this but it is incorrect. The oil is not set for the pressure switch. In the oil pump you have a pressure relief valve which will dump any excess oil above a certain pressure. You have to remove the oil pump to get to the pressure relief valve.
Let me try and explain. You are probably getting advice from different sources. Please understand that you are dealing with the "heart" of the engine here. You cannot take a chance from here on forward and this has to be done properly otherwise you will suffer mechanical damage. You made one oversight by not servicing the engine as you should, do not make another by trying a shortcut. Hopefully you will not have damaged anything (till now) and we can help you get going again.
Believe me, we do this job in our workshop quite often and if there was a safe shortcut we would know. If say you could somehow get something into the oil system and blow air, petrol or oil backwards towards the (presumed) blocked the oil sieve, how would you know it is properly / completely clean? You are going to try and pump something past the gears in the oil pump ???- It will not work. Remember also now there is still going to be an odd bit of "koffie korrels" floating around the system that you are not going to find. ie the sieve will block up again slightly depending how well you clean up - so you need to get that sieve absolutely clean first time round. Pumping something into the engine oil supply (what I believe you are thinking) is like plumbing into your blood supply !!! Dangerous!!!!!
does anyone know where I can get or look at an engine oil flow diagram...
Am I right in saying the the oil sits in the sump and then gets sucked up the oil pickup pipe... through the rockers and then down to the oil pressure switch? would that be correct?
No definitely not
Oil is drawn up through the pick up in the sump by the pump. From the pump it is presurised and sent to the oil filter. The oil pressure switch is normally situated in the oil gallery right near the filter. From the filter it will split and supply the crankshaft main bearings and then big end bearings. At the split it is sent to the cylinder head to supply oil to the camshaft and hydraulic lifters. From the cylinder head it simply runs down back to the sump.
I am trying to figure out where the oil comes from to set the pressure for the pressure switch? ..... ???????????
I don't know who told you this but it is incorrect. The oil is not set for the pressure switch. In the oil pump you have a pressure relief valve which will dump any excess oil above a certain pressure. You have to remove the oil pump to get to the pressure relief valve.
Let me try and explain. You are probably getting advice from different sources. Please understand that you are dealing with the "heart" of the engine here. You cannot take a chance from here on forward and this has to be done properly otherwise you will suffer mechanical damage. You made one oversight by not servicing the engine as you should, do not make another by trying a shortcut. Hopefully you will not have damaged anything (till now) and we can help you get going again.
Believe me, we do this job in our workshop quite often and if there was a safe shortcut we would know. If say you could somehow get something into the oil system and blow air, petrol or oil backwards towards the (presumed) blocked the oil sieve, how would you know it is properly / completely clean? You are going to try and pump something past the gears in the oil pump ???- It will not work. Remember also now there is still going to be an odd bit of "koffie korrels" floating around the system that you are not going to find. ie the sieve will block up again slightly depending how well you clean up - so you need to get that sieve absolutely clean first time round. Pumping something into the engine oil supply (what I believe you are thinking) is like plumbing into your blood supply !!! Dangerous!!!!!
peterpot
Thank you for your detailed response and it really helps....
I think I am at the very least going to start be removing the sump and the rocker covers and look at the real condition
I guess I am trying to avoid a complete engine strip or buggering around with the timing or crankshaft as its pushing my expertise to limits....
If the pickup sieve is still completely blocked then I will clean... and see what I can do with the rockers... if that isn't an obvious help then I may have to strip to at least the oil pump and try to clear all oil ways properly.
The theory about how the pressure switch is activated is just me thinking out loud and trying to understand it... your explanation is perfect...
I guess I have a lot of work to do...
I just hope that my second car ... a Land Rover.... stays in one piece in the meantime.
Thank you for your detailed response and it really helps....
I think I am at the very least going to start be removing the sump and the rocker covers and look at the real condition
I guess I am trying to avoid a complete engine strip or buggering around with the timing or crankshaft as its pushing my expertise to limits....
If the pickup sieve is still completely blocked then I will clean... and see what I can do with the rockers... if that isn't an obvious help then I may have to strip to at least the oil pump and try to clear all oil ways properly.
The theory about how the pressure switch is activated is just me thinking out loud and trying to understand it... your explanation is perfect...
I guess I have a lot of work to do...
I just hope that my second car ... a Land Rover.... stays in one piece in the meantime.
For your sake I hope so (just change the oil - oh you dont have to on them they leak so much 
) I got rid of mine due to its need to frequent the workshops.
I kept the Land Rover jacket though they are very nice and work very nicely.
) I got rid of mine due to its need to frequent the workshops. I kept the Land Rover jacket though they are very nice and work very nicely.
For your sake I hope so (just change the oil - oh you dont have to on them they leak so much ) I got rid of mine due to its need to frequent the workshops.
I kept the Land Rover jacket though they are very nice and work very nicely.
) I got rid of mine due to its need to frequent the workshops. I kept the Land Rover jacket though they are very nice and work very nicely.
Agreed...
The Landie does leak a little... not too bad... I actually live in the Okavango Delta and this ZAR60k land is a tank and goes in a straight line anywhere I point it.... can't tell you how many ZAR 500k T Cruisers I have pulled out of trouble in it...
The Landie does leak a little... not too bad... I actually live in the Okavango Delta and this ZAR60k land is a tank and goes in a straight line anywhere I point it.... can't tell you how many ZAR 500k T Cruisers I have pulled out of trouble in it...