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Well, turbo's in and running, but still need to tie up a few loose ends. BUT, I can't do squat until I get my damn oil pressure issues resolved! Soooo...
Before the turbo install, pressure was about .75 bar (about 11 psi) at idle when warm and right about 4 bar (about 58 psi) at redline. Fired it up last night with the turbo in and cold startup pressure was 2 bar (about 28 psi). WTF?! Took it out for a spin and I'd peak at about 2.5 bar (about 35 psi). Double and triple checked everything and can't find sh*t! Changed the oil and filter to 15w50 and it did give me a bump, but very minimal. I'm still not even hitting 3 bar (about 43 psi) at redline! WTF!!!?!!?! I'm running a GReddy gauge so I don't think that's the issue, but I'm still gonna go pick up an el-cheapo mechanical gauge and see what that gives me (just to take the gauge out of the equation). Other than that, I'm focking stumped! I'm ready to try just about anything!
So, whadaya got for me?
TIA!
BTW - I'll by a twelver of your favorite beer to whoever helps me figure this damn thing out! lol!
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David De Anda
A buttload of black smoke....
I hate to say this... but thats what I got on my car before we found that the block had a hairline crack in it... we rebuilt it 2 times to find the same problem... Put a new block and VVL oil pump in it and all was good... you should be at 25-32psi of pressure at startup I peg the gauge at 100+psi at redline... (keep in mind I have the VVL pump now)...
Something is not right on yours.... I would hate to find your turbo trashed from metal shavings... I went through 3 turbos to find out that focking hairline crack was causing everything...
Erich, the strange thing, however, is that just two weeks ago (last time I drove the car) the pressure was fine! Around town I was at 3 bar and at redline I'd hit 4 bar. It just seems strange that just two weeks ago everything was fine, I stop the car to put the turbo in and now things are not good! Strange....
jacen99SE, I'm running a -3 line into a T3/T04E so it shouldn't need a restrictor. Besides, the turbo shouldn't be killing the pressure that much... Thanks for replying, though..
I'm no expert, but to contribute some logic, I would start where you made your modifications. Are you leaking anything around your oil lines? could someone chime in and answer if maybe the (or lack of) oil restrictor is causing this? man, I'll be bummed if my T25 makes my oil pressure drop like a rock.
Okay, eliminated the gauge being an issue - got a mechanical gauge in there and got the same exact reading. Now, I'm left with two items that I feel are the possible culprits - turbo and oil pressure relief valve. For some reason, I just don't think it's the valve, though - it would seem strange to me that the valve would just go bad all of the sudden from sitting for two weeks; I guess it's possible, but I just don't see that happening (SR pumps are damn near bomb proof!)...
The turbo... The turbo I'm running was used for a couple thousand miles and then removed - it's been sitting for about 1.5 years from that time until now. Could the turbo be bad enough to cause a pressure loss? Anyone seen this happen before? I guess I just don't understand how the pressure was fine two weeks ago when I shut the car off to install the turbo and now after the turbo's in, the pressure sucks! I know it's not the lines because I put all the lines in, drilled and tapped the block, and drove around for about a month before actually bolting on the turbo and never had an issue! So, in my simple mind, everything points to the turbo, but I want other opinions before I rip it out to send to get rebuilt.... Anyone.....?
Whoa, Pat! Damn, didn't know you were around here too! Nice!
Anyway, it goes out the back of the block (from where the stock sending unit used to be) into a -3 line into an OEC distribution block (same one I used on my last turbo SR). On the distribution block I have the stock sending unit, my GReddy sending unit, and the -3 feed line to the turbo. This is exactly how it was on my last turbo SR...
You might be getting low pressure readings from that -3 line going to the OEC block, it will act like a restrictor considering the main oil passages are about twice that size. If you can put a restrictor (0.040"-0.060") after the block going to the turbo and see what that does.
Wouldn't you think it would have given me issues since the day I put the guage in, though? I ran around like this for two weeks (with the current oiling setup minus the turbo) with everything operating normal (= normal pressure)... This is the exact same setup that I had on my Sentra as well and never had any issues then... I am curious, though, about using a restrictor - I might just go ahead and try it...
Could a damaged turbo center section also act like a huge leak and kill my pressure (not that I have signs of this happening, but it's just a thought)...?
Why not remove and plug the line to the turbo from the dist block as a diagnostic procedure? You obviously don't want to drive around like that, but I doubt that running no oil to the turbo at idle for a minute will hurt anything. I'm sure someone will hand me a banana loaf if I'm wrong.
For what its worth I have the same OEC block on my car with the supplied lines from the block to the D. Block... I saw no pressure drop problems... I'm beginning to think that the Distribution block in your case cannot supply the pressure needed for your turbo... I would venture to think that you may want to put a restrictor in your oil feed line to see if that brings the pressure back up as part of your elimination... you may even want to run a line directly from the block to the turbo to see if the distribution block is causing it... I'm just trying to help you man, its all a process of elimination... I would hate to see you where I was chasing oil pressure problems and going through 2 blocks and 3 turbos at the same time...
Cheers-
Erich
Last edited by Wicked R : 02-28-2005 at 08:05 PM.
Reason: Correction on name...
I've thought about that, but fear killing the turbo by running it with no oil.....
Anyone ever done this (run a turbo at idle with no oil)? I'd be willing to give that a shot, but like I said, fear killing the turbo.
DO NOT DO THAT!!! I drove around with LOW oil pressure for 1 block and the turbo was toast.
Check to make sure you didn't clog up the distribution block (teflon tape/paste, whatever you use to seal). And that -3 line going to the block might be too small.
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Khiem
'96 SE-R.... boost, brakes, suspension, etc... sold
'05 Evo
'05 CBR 600RR
Driving around the block can put you into boost, which is different than letting the car idle to check the oil pressure with the line disconnected. But I still defer to someone with the experience to give the idea a thumbs up or thumbs down.
Driving around the block can put you into boost, which is different than letting the car idle to check the oil pressure with the line disconnected. But I still defer to someone with the experience to give the idea a thumbs up or thumbs down.
C:\>
That's true. But I wouldn't want to risk it. MAYBE if you left the wastegate open so that hopefully the shaft wouldn't spin...
lol!
