Totaly rebuild 5.0l engine and no oil pressure
Discussion
Hello Pistoheaders!
First of all i am a new user here,and i apologize fpr my spelling and expression
because i am not from UK ,i live in Sweden...
History,
I have after a piston break witch resultet in a crack in the 8th cylinder and all the way in to the water canal,
So i bought me a new short block from Powers with big bearings at the crankshaft installed,so far so good,
I bulit it up with almost all new parts like new stage3 Warror heads and stealh cam new injectors and so on...
I have rebulid the oilpump ,because there is not possible to buy a new timing cover anymore (it's for me very strange)
i have also a stronger feather at the bypass.
The engine start immediately at first try ,but i get very low oil pressure the warning light is on and i get 10psi on the gauge,
,i have looked at the oil pickup is tighented i have try differens oils but nothing better.
so now i have start to tear it apart again to see if i have missed something
So is there any one here some have any idea? what i schould look for?
Of course I am very grateful for att suggestions!
Best Regards
Patrik
Sweden
First of all i am a new user here,and i apologize fpr my spelling and expression
because i am not from UK ,i live in Sweden...
History,
I have after a piston break witch resultet in a crack in the 8th cylinder and all the way in to the water canal,
So i bought me a new short block from Powers with big bearings at the crankshaft installed,so far so good,
I bulit it up with almost all new parts like new stage3 Warror heads and stealh cam new injectors and so on...
I have rebulid the oilpump ,because there is not possible to buy a new timing cover anymore (it's for me very strange)
i have also a stronger feather at the bypass.
The engine start immediately at first try ,but i get very low oil pressure the warning light is on and i get 10psi on the gauge,
,i have looked at the oil pickup is tighented i have try differens oils but nothing better.
so now i have start to tear it apart again to see if i have missed something
So is there any one here some have any idea? what i schould look for?
Of course I am very grateful for att suggestions!
Best Regards
Patrik
Sweden
You don't say if it a serpentine engine with the oil pump around the crankshaft or a pre-serpentine with the pump drive at the bottom of the distributor.
A serp engine will prime itself but the Pre-serp will not and either has to be primed using a tool in the distributor hole or the pump has to be packed with grease (vasaline).
Steve
A serp engine will prime itself but the Pre-serp will not and either has to be primed using a tool in the distributor hole or the pump has to be packed with grease (vasaline).
Steve
The serp pump is normally pretty bullet proof.
How much of the engine did you rebuild?
It is possible to mis align parts of the pump.
It is possible to incorrectly assemble the washers and drive gears on the front of the camshaft.
Does it have the correct oil filter fitted? Some filters have valves in them.
Is the pressure relief valve free moving? I have seen one jammed in the part open position.
Steve
How much of the engine did you rebuild?
It is possible to mis align parts of the pump.
It is possible to incorrectly assemble the washers and drive gears on the front of the camshaft.
Does it have the correct oil filter fitted? Some filters have valves in them.
Is the pressure relief valve free moving? I have seen one jammed in the part open position.
Steve
Op, how long have you run the engine? If it's more then 5 minutes the the 10 psi is unlikely to improve unless something needs to be primed fully like an oil cooler. I would think you have a leak somewhere inside the engine as you obviously have flow. Is the camshaft thrust plate fitted properly?
Does the pressure fluctuate with rpm's?
Does the pressure fluctuate with rpm's?
This V8 Overhaul Manual might help, it covers pre-serp' and serp' engines.
http://www.super7thheaven.co.uk/wp-content/uploads...
http://www.super7thheaven.co.uk/wp-content/uploads...
Some years ago I had an engine built by someone else which resulted in no oil pressure.
Turned out the oil pick up wasn't tightened properly so it was drawing air in which resulted in very poor oil pressure if any!
It is more than likely something very simple. You mentioned the oil pressure relief valve. Are you sure this is assembled correctly and free moving?
A silly question possibly but are you sure that all the cam bearings and big end shells are fitted and fitted correctly. I had a cam bearing fall out of position once which resulted in a 10 psi drop in oil pressure. Yours sound far worse than this!
Go through it methodically. As Steve said, not much to go wrong with your pump, if at all.
I think Camshaft assembly is a red herring. If you have lined it up properly with its drive I can't see how that can affect the oil pressure.
The oil pressure is dictated by the resistance in various areas of the engine It is just channels of oil being restricted at the big end bearings, main bearings, camshaft bearings and feed to rockers pretty much. If all is okay there then you can't go wrong, famous last words!
Of course, there could be a problem with the block but that is highly unlikely in my opinion.
Turned out the oil pick up wasn't tightened properly so it was drawing air in which resulted in very poor oil pressure if any!
It is more than likely something very simple. You mentioned the oil pressure relief valve. Are you sure this is assembled correctly and free moving?
A silly question possibly but are you sure that all the cam bearings and big end shells are fitted and fitted correctly. I had a cam bearing fall out of position once which resulted in a 10 psi drop in oil pressure. Yours sound far worse than this!
Go through it methodically. As Steve said, not much to go wrong with your pump, if at all.
I think Camshaft assembly is a red herring. If you have lined it up properly with its drive I can't see how that can affect the oil pressure.
The oil pressure is dictated by the resistance in various areas of the engine It is just channels of oil being restricted at the big end bearings, main bearings, camshaft bearings and feed to rockers pretty much. If all is okay there then you can't go wrong, famous last words!
Of course, there could be a problem with the block but that is highly unlikely in my opinion.
Mutley00 said:
QBee said:
....all assuming Patirk actually put any oil into the engine before starting it.
OK, that's the sort of thing I would forget.
After all the great advice you've given me Anthony and you now throw in this 'curveball' ! OK, that's the sort of thing I would forget.
Stranger things have happened but I wouldn’t think it would run for long and show zero pressure.
Are you checking oil pressure via a mechanical gauge O/P
Message Board | Chimaera | Top of Page | What's New | My Stuff