2H Oil Pressure

[jzmq]

Friday I finally got around to installing an autometer oil pressure gauge in my car. The original gauge had long stopped working- even at high oil pressure it read below the low line- and I thought it was time to have an accurate reading. One thing I had noticed in the past wwas that when the car was "cold" the oil pressure was significantly higher (normal) but that it took a long time for it to read on the gauge. I thought this was just a fault in the gauge, but now with the new mechanical gauge installed, it still does the same thing. Yesterday and today I timed it at about 30 seconds between starting the car and getting any reading, even though when the engine is cold it usually runs all the way at 60PSI. The pressure then stays around 40-60 PSI at idle for the first ten minutes or so before dropping to below ten after about 15 minutes. Idle when fully warm seems to be around 5-8PSI. I just had the engine rebuilt and changed the oil less than 300km ago, so I dont think it's bad oil.

Does anybody have any ideas on why the pressure takes so long to show a reading when I start the engine cold? I am using the included nylon tubing between the sending port and the gauge.

John

 

[brownbear]

edit: I re-read it again,


Maybe the relief valve stays wide open......... I dunno. No pressure builds up. Anyone know where the relief is located?

 

[roscoFJ73]

Friday I finally got around to installing an autometer oil pressure gauge in my car. The original gauge had long stopped working- even at high oil pressure it read below the low line- and I thought it was time to have an accurate reading. One thing I had noticed in the past wwas that when the car was "cold" the oil pressure was significantly higher (normal) but that it took a long time for it to read on the gauge. I thought this was just a fault in the gauge, but now with the new mechanical gauge installed, it still does the same thing. Yesterday and today I timed it at about 30 seconds between starting the car and getting any reading, even though when the engine is cold it usually runs all the way at 60PSI. The pressure then stays around 40-60 PSI at idle for the first ten minutes or so before dropping to below ten after about 15 minutes. Idle when fully warm seems to be around 5-8PSI. I just had the engine rebuilt and changed the oil less than 300km ago, so I dont think it's bad oil.

Does anybody have any ideas on why the pressure takes so long to show a reading when I start the engine cold? I am using the included nylon tubing between the sending port and the gauge.

John

Oil pressure at idle is not that important as long as is there is some pressure.
The more crucial figures are taken at say 2000-2500 where you should be able to maintain 30+ psi for a couple of minutes when warmed up.
Do the test outlined in the manual.

30 Seconds to get any oil pressure is a long time. Maybe the oil pump needs inspection

 

[brownbear]

editted my first post....

 

[jzmq]

I'm assuming that it has to be related to the pump, but can anyone think of any other possibilities? The biggest factor seems to be whether the enginge is cold or warm. Cold- takes 30 seconds to read on the mechanical gauge. Warm- I get an almost immediate reading.

 

[roscoFJ73]

The only 2 things I can think apart from a bad oil pump is the viscosity of the oil which is cured by a simple change of oil type.

The other thing is incorrect clearance between the crank and main bearings can affect oil pressure in strange ways.

Try taking the valve cover off,or if possible look inside through the oil filler hole and see how long before oil starts squirting and if it correlates with your dash gauge
Try a mechanics pressure gauge plugged directly into the oil sensor hole and see what readings you get there.
Maybe your new gauge is faulty

 

[brownbear]

does your 2H have the electric on/off motor(EDIC)? If so it should have a low oil pressure switch cutoff. Which the engine would not run if there was not oil pressure.

 

[Beast]

I have removed this pressure unit from the passenger side of the engine and ran my machanical guage from there. I have over 100psi at startup but it never dips below 30 warm and at idle. Where did you get you feed from?

 

[roscoFJ73]

I have removed this pressure unit from the passenger side of the engine and ran my machanical guage from there. I have over 100psi at startup but it never dips below 30 warm and at idle. Where did you get you feed from?

Hint ,you need talk in left and right hand terms as half have LHD and the other half have RHD.

 

[cruiserland]

sounds like main bearings worn; high pressure at start, then low pressure 15-20 mins.
little to no pressure on cold start
is this accurate?
my 2F has similar symptoms....

 

[Beast]

Hint ,you need talk in left and right hand terms as half have LHD and the other half have RHD.

Sorry, yes in my LHD HJ60T , I removed the sending unit for the EDIC and threw in my line for the mechanical oil guage.

 

[FJota]

My 12h-t has about 85 psi at a cold start up and then drops to the 35-45 psi. Is this high or normal for a cold start? At what pressure should the relief valve open?

 

[bigbrowndog]

I have removed this pressure unit from the passenger side of the engine and ran my machanical guage from there. I have over 100psi at startup but it never dips below 30 warm and at idle. Where did you get you feed from?

If you have over 100lb at start up I think this would suggest your pressure relief valve needs replacing , two things cause this as the spring loses tension and the valve wears the aluminium bore in the housing thus allowing the valve to sit on an angle in the bore. If the bore is ok just clean it up with some wet and dry and replace the piston and spring. If the bore is worn badly or scored it is best to use the longer aftermarket piston , the spring is the same. Last time I asked I think I was told a new housing was around $850.00. If this is not corrected the oil filter seal will eventually blow and it won't take long to pump the oil out at that pressure and volume. Often the filter bends or splits between the base and the sides. 2H oil pressure on idle can be down to 4.3psi and at 3,000rpm should be around 85psi. If I remember right the 12HT should be the same as I believe the oil pumps are the same.

 

[jzmq]

I have removed this pressure unit from the passenger side of the engine and ran my machanical guage from there. I have over 100psi at startup but it never dips below 30 warm and at idle. Where did you get you feed from?

I'm running it straight from the original sending units port. Unfortunately my Tachometer is also broken, so don't know the RPMs, but I never get above about 85psi. Once the engine is fully warm it doesn't seem to get above about 60psi- though I haven't driven it enough since the install to know for sure.

I'm more worried about the lag between cold starting the engine and getting a reading- it happened with the old faulty electric gauge and two original sending units. What weight oil are guys running in their rigs?

 

[bigbrowndog]

I'm running it straight from the original sending units port. Unfortunately my Tachometer is also broken, so don't know the RPMs, but I never get above about 85psi. Once the engine is fully warm it doesn't seem to get above about 60psi- though I haven't driven it enough since the install to know for sure.

I'm more worried about the lag between cold starting the engine and getting a reading- it happened with the old faulty electric gauge and two original sending units. What weight oil are guys running in their rigs?

This time lag could just be your line to your gauge and your gauge. You can fit a T piece and run your old gauge and the new one and thus run the oil low pressure cut off. Also not all oil pumps pump the same quantity and pressure this is why toyota give it as variable.I tried mine this afternoon twice and and it took 11 seconds the first time and 9 the second start. It takes my gauge a good 30 seconds to drop back to zero after turning it off.I also have my copper oil line coiled to cut down on vibration from the pump pulse. I run 20w 50 Penrite oil but it gets pretty warm here with high humidity plus running the turbo.

 

[FJota]

So the relief valve should open around 100psi ?

 

[Beast]

If you have over 100lb at start up I think this would suggest your pressure relief valve needs replacing , two things cause this as the spring loses tension and the valve wears the aluminium bore in the housing thus allowing the valve to sit on an angle in the bore. If the bore is ok just clean it up with some wet and dry and replace the piston and spring. If the bore is worn badly or scored it is best to use the longer aftermarket piston , the spring is the same. Last time I asked I think I was told a new housing was around $850.00. If this is not corrected the oil filter seal will eventually blow and it won't take long to pump the oil out at that pressure and volume. Often the filter bends or splits between the base and the sides. 2H oil pressure on idle can be down to 4.3psi and at 3,000rpm should be around 85psi. If I remember right the 12HT should be the same as I believe the oil pumps are the same.

There are 2 releif valves in my FSM. One above the oil filter and the other behind the power steering pump. Which one needs to adjusted?

Thanks

Paul

 

[bigbrowndog]

There are 2 releif valves in my FSM. One above the oil filter and the other behind the power steering pump. Which one needs to adjusted?

Thanks

Paul

Cheers Paul, It's the one in the oil pump behind the power steering pump. It is not adjustable. Also they are both different sizes and not interchangeable.You can change it with out removing the pump.After I removed the bung and springI found I could not get something in there to get the piston out so I just put a plastic bag around it and briefly hit the key and it shot out into the bag with a bit of oil. Be sure to clean the bore up before replacing it with a new one.cheers

 

[bigbrowndog]

cheers.

 

[Beast]

Cheers Paul, It's the one in the oil pump behind the power steering pump. It is not adjustable. Also they are both different sizes and not interchangeable.You can change it with out removing the pump.After I removed the bung and springI found I could not get something in there to get the piston out so I just put a plastic bag around it and briefly hit the key and it shot out into the bag with a bit of oil. Be sure to clean the bore up before replacing it with a new one.cheers

Hello bbd, I used a magnet on a flex shaft that I got from the local hardware store to pull out the valve . The valves had some scoring on both but they looked fine. How do I get my hands on the longer valves to replace these with? I will call Toyota to see how much new ones are.

Thanks

Paul