[soceur]

hey guys i have a oil cooler, so of course i know i need to use more oil, but can someone think of why i would have oil pressure loss when lift engages(not that i feel it anymore because of the turbo), but i get a feelable hesitation and a loss of oil pressure at lift. I know im getting pressure loss because of the gauge. Cant remember what it dropped to...sorry.

 

[autxr]

Is it just a small dip than recovers, or is it a permanent drop when you hit lift?

Anyone know if there are any extra oil squirters for the "L" rocker arms, and the squirters only engage whe lift engages?

So long as you have 10 psi for every 1000 rpm I wouldn't worry about it anyway.

Scott

 

[soceur]

hey scott, so are you saying i should have 60psi at 6000rpm? Usually I have my guages read in bar(slowly being converted to ther evil ways)

 

[autxr]

Yes, you should have 60 psi at 6000 rpm (4.1 bar), honestly, on a healthy engine you should be seeing that well before 6000 rpm.

My freshly rebuilt motor in a '73 Celica shows 70-80 psi at 4000 rpm.

Scott

 

[Illusive]

VVL utilizes oil & oil pressure for lift to engage and stay engaged, that may take away from some of the oil pressure on your guage depending on where its reading from.

any oil leaks from the turbo? or rubber lines?

 

[Boosted2.0]

Anyone know if there are any extra oil squirters for the "L" rocker arms, and the squirters only engage whe lift engages?

Nope - you have the 2 sets - under pistons and in valve cover, and they all run all the time.

There is a decent load imposed on the lubrication system when lift engages - I would guess that Soceur's oil level may be a bit low or he has excessive wear on his rockers to where they are hemmoraging oil pressure. Could also be his lift bolt is snapped and the shaft is spun so that the oil feed hole is just spraying out into nothing instead of into the rocker.

 

[WAR]

Nope - you have the 2 sets - under pistons and in valve cover, and they all run all the time.

There is a decent load imposed on the lubrication system when lift engages - I would guess that Soceur's oil level may be a bit low or he has excessive wear on his rockers to where they are hemmoraging oil pressure. Could also be his lift bolt is snapped and the shaft is spun so that the oil feed hole is just spraying out into nothing instead of into the rocker.

the oil sprayers that are above the camshafts (attached to the underside of the valve cover) actually get more oil flow once lift is hit for extra lubracation of the rocker sliders.

If the lift bolt breaks, only the tip breaks off in the rocker arm shaft, all the threads are still engaged in the head and no oil can escape from there. This will not cause a loss in oil pressure, if anything is should result in more oil pressure since the oil holes on the rocker arm shaft may not be lined up with the rockers oil hole.

You will loose pressure drop across your oil cooler, however about 7000 rpm you should have very good oil pressure even with the oil cooler. I would suggest however that you rule out some of the easier answers before looking for at the tough ones.

1) replace oil filter, to make sure there isn't a block in it
2) swap a different oil pressure gage in to make sure the gage is reading right
3) remove/bypass the oil cooler. just to check that you aren't loosing all your oil pressure threw it.
4) try 10w30 if your using 5w30 now.

remeber that the oil pressure bypass valve is built into the oil pump, once that valve see's 72 or 75 psi (I can't rember which it's around 70 to 75 psi) it opens up and dumps back into the oil pan. So anything that you add to the oil system that restricts flow (like an oil cooler) will make the oil bypass valve open sooner. So you may have say 70psi before the oil cooler, but you have (lets say) 5 psi drop across the oil cooler, then if you read the oil pressure after the oil cooler you would only see 65 psi even though the oil pump see's 70 psi and is dumping the extra oil back into the oil pan.

rule out the easy stuff first before you start looking into the more complex senario's.

 

[soceur]

Originally posted by WAR
the oil sprayers that are above the camshafts (attached to the underside of the valve cover) actually get more oil flow once lift is hit for extra lubracation of the rocker sliders.

If the lift bolt breaks, only the tip breaks off in the rocker arm shaft, all the threads are still engaged in the head and no oil can escape from there. This will not cause a loss in oil pressure, if anything is should result in more oil pressure since the oil holes on the rocker arm shaft may not be lined up with the rockers oil hole.

You will loose pressure drop across your oil cooler, however about 7000 rpm you should have very good oil pressure even with the oil cooler. I would suggest however that you rule out some of the easier answers before looking for at the tough ones.

1) replace oil filter, to make sure there isn't a block in it
2) swap a different oil pressure gage in to make sure the gage is reading right
3) remove/bypass the oil cooler. just to check that you aren't loosing all your oil pressure threw it.
4) try 10w30 if your using 5w30 now.

remeber that the oil pressure bypass valve is built into the oil pump, once that valve see's 72 or 75 psi (I can't rember which it's around 70 to 75 psi) it opens up and dumps back into the oil pan. So anything that you add to the oil system that restricts flow (like an oil cooler) will make the oil bypass valve open sooner. So you may have say 70psi before the oil cooler, but you have (lets say) 5 psi drop across the oil cooler, then if you read the oil pressure after the oil cooler you would only see 65 psi even though the oil pump see's 70 psi and is dumping the extra oil back into the oil pan.

rule out the easy stuff first before you start looking into the more complex senario's.

WOW! Good post, thanks guys....Major kudos WAR.

 

[Boosted2.0]

And if you want to try thicker oil you should try 10-40 for a turbo application.

New filter is never a bad idea, but its not going to cause a pressure drop in lift only.

Hey Soceur - do you maintain pressure at like 5750 RPM with no problem as long as you don't enter lift? And it drops off literally when lift engages? If so then I would still check the rocker shafts first. Checking for a spun rocker shaft is about as easy as it gets anyways - just yank the valve cover and pull 2 10mm bolts - takes like 10 minutes tops.

 

[soceur]

roger that! Ill give gas this link to check out...thanks !

 

[tirechirp]

Anyone else have a guage on a Celica? I don't but a friend has one on his VTEC Civic and the pressure doesn't drop at all when it kicks. I know it's a different engine I wish I had a Celica example.

 

[soceur]

hey guys do you think the position of the oil cooler could be the problem.
pics are in my imagestation folder...should be last pic.(only 8 or so)
http://www.imagestation.com/album/?id=4287406817

 

[soceur]

bump

 

[Black_TRD]

hey guys do you think the position of the oil cooler could be the problem.
pics are in my imagestation folder...should be last pic.(only 8 or so)
http://www.imagestation.com/album/?id=4287406817

pictures are of defi gauges, pistons and fuel rail, and more defi, no cooler

 

[Immo]

I can have an answer in 1.5 week, Gas is doing another st1 install and it will have a oil pressure gauge.
It is on a GT though

 

[soceur]

Originally posted by Black_TRD
pictures are of defi gauges, pistons and fuel rail, and more defi, no cooler

sorry wrong link! heres the correct one.
http://www.imagestation.com/album/?id=3716865093

Originally posted by Immo
I can have an answer in 1.5 week, Gas is doing another st1 install and it will have a oil pressure gauge.
It is on a GT though

??? I have a oil pressure gauge. My question now is the oil cooler position maybe affecting oil flow back to the engine.
thanks though!

 

[soceur]

bump

 

[Boosted2.0]

Bro - we would need to see where the hoses that go to the cooler come from and where the pressure sensor is mounted, not where the heat exchanger is mounted.

 

[WAR]

I have a oil pressure gage in my car and I do not see any drop when I hit lift. I hit a max of just over 70 psi at 3500 rpm and hold that constant all the way to fuel cut. But I do have a pro-drive oil pump, it's not suppose to pump more oil then the stock on as it is a identical design, but I thought I should mension it as is may for some reason pump a little more, I don't know.

 

[soceur]

Originally posted by Boosted2.0
Bro - we would need to see where the hoses that go to the cooler come from and where the pressure sensor is mounted, not where the heat exchanger is mounted.

ill try to get pics this weekened. Thanks