02 VVT oil pressure loss
#25
Thought I'd update and bump the thread.
I picked up a new #1 cam bearing and oil pipe (adapter; the part with the o rings) and installed those with no change. Not that I was really surprised but I started doubting my diagnosis and thinking about just getting enough flow to the rotating assembly to handle some RPM without worrying about the valve timing but also ensuring lubrication makes it to the cam bearing and the actuator.
I made 2 block off plates which sandwich under the supply line. The first one had a 1/8" hole drilled into it. This drill size was arrived at by measuring and closely equivalent to the opening in the oil control valve that allows oil to flow past to the moving parts.
Sketchy huh?
1/8" made little to no difference in upstream oil pressure! But at least it confirms my suspicion that the loss is down stream.
The second plate has a 1/16" hole = 1/4 the area of the first hole. This provides enough oil to the VVT to lubricate while providing 20lb @ 830 rpm and 60lb all the way to 7k rpm with >210* oil!!!!!!
Although this does not provide enough oil for the VVT to function at any level it does
1. Prove the loss is the the VVT system.
2. Provide flow/pressure enough to keep the reciprocating parts happy.
THIS IS A TEMPORARY EXERCISE
Any thoughts?
What would you do next?
I picked up a new #1 cam bearing and oil pipe (adapter; the part with the o rings) and installed those with no change. Not that I was really surprised but I started doubting my diagnosis and thinking about just getting enough flow to the rotating assembly to handle some RPM without worrying about the valve timing but also ensuring lubrication makes it to the cam bearing and the actuator.
I made 2 block off plates which sandwich under the supply line. The first one had a 1/8" hole drilled into it. This drill size was arrived at by measuring and closely equivalent to the opening in the oil control valve that allows oil to flow past to the moving parts.
Sketchy huh?
1/8" made little to no difference in upstream oil pressure! But at least it confirms my suspicion that the loss is down stream.
The second plate has a 1/16" hole = 1/4 the area of the first hole. This provides enough oil to the VVT to lubricate while providing 20lb @ 830 rpm and 60lb all the way to 7k rpm with >210* oil!!!!!!
Although this does not provide enough oil for the VVT to function at any level it does
1. Prove the loss is the the VVT system.
2. Provide flow/pressure enough to keep the reciprocating parts happy.
THIS IS A TEMPORARY EXERCISE
Any thoughts?
What would you do next?
#26
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1. It proves there is not enough oil volume coming from the pump to feed everything that currently needs to be fed. It does not necessarily villainize the vvt mechanism. The vvt mechanism does require a fair amount of oil, hence the size of the pipe compared to, let's say, a turbo oil feed line. The vvt may still be bad but I wouldn't consider this to be a conclusive deduction.
#27
Regarding your engine, I'd still try a 50W oil next. It will not flow as easily, thus whatever(s) in your engine that is leaking too much oil will leak LESS and this will result in higher oil pressure. Worth a shot. Otherwise you gotta tear it down and find out where the leak is.
#28
Sixshooter said it well.
What you need to understand is that the pump does NOT supply pressure. All it does is supply FLOW. It pumps a certain amount of oil. All the restrictions in the system (bearings, oil squirters, VVT thingy, etc) present a RESTRICTION to the flow, and thus the pressure rises because of this restriction. You have a big leak(s) somewhere causing a lot of oil to go to one place and not much going everywhere else, and this also means lower oil pressure.
You can do the same thing with a turbo car. Unhook the blow off valve from the charge pipe and watch all the boost go right out the hole instead of in the engine. No restriction, no pressure.
#29
Ok, granted guys. Using process of elimination, the squirters are installed with the copper washers and locating pins located and torqued to spec. The bottom end has a max clearance of .00225. The head has no cam bearings. So the head is left.
I guess clearancing all the saddles may point to a new head. Anyone know BP6D clearance? My search showed .006 max for 99 and before.
I guess clearancing all the saddles may point to a new head. Anyone know BP6D clearance? My search showed .006 max for 99 and before.
#30
Ok, granted guys. Using process of elimination, the squirters are installed with the copper washers and locating pins located and torqued to spec. The bottom end has a max clearance of .00225. The head has no cam bearings. So the head is left.
I guess clearancing all the saddles may point to a new head. Anyone know BP6D clearance? My search showed .006 max for 99 and before.
I guess clearancing all the saddles may point to a new head. Anyone know BP6D clearance? My search showed .006 max for 99 and before.
--Ian
#35
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My VVT engine has adequate oil pressure with the squirters.
So do tens of thousands of others.
So did yours, before whatever went wrong went wrong.
I'm trying to remember exactly what this area of the oiling system looks like. In the absence of the O-ring, would oil be escaping from the engine onto the garage floor, or merely escaping from a high-pressure area of the engine into a lower-pressure area (eg: the pan)?
So do tens of thousands of others.
So did yours, before whatever went wrong went wrong.
I'm trying to remember exactly what this area of the oiling system looks like. In the absence of the O-ring, would oil be escaping from the engine onto the garage floor, or merely escaping from a high-pressure area of the engine into a lower-pressure area (eg: the pan)?
#38
Try this: Put in 50W motor oil. If pressure goes UP, you have a leak after the pump. If pressure goes DOWN, you have a restriction before the pump (leaking/cracked/clogged pickup tube for example). Try something man! That or tear it down and start going through it.