Oil pressure at turbo

Not sure if this helps...

Oil pump

Discharge pressure:

600 RPM: 14 psi

5,000 RPM: 43 psi

Did the old turbo put metal into the engine ?

The oil cooler has been known to hold metal chips and repease them back into the system.

By all over the place...

Oil pressure raises and lowers as the RPM's change. It's not a constent.

warning noob advice from me... those fluctuations *may* be normal if u are measuring pressure at that location due to the ocv advancing/retarding the cam timing. however, i would be concerned if the pressure reads low for more than a couple seconds.

does your ecu have any error codes? an ocv stuck open can drain the pressure on that line shared by the turbo and cause it to fail.

try measuring the pressure at or immediately after the filter. from the sump, the oil is pumped directly to the filter before being circulated throughout the engine. if theres any debris that blocks the pickup screen in the sump, oil pressure will fluctuate constantly. it should remain steady as long as the load on the engine doesnt change. i forget where i read it, but i saw a blurb on a superseded pickup tube due to clogging.. (verification please) but if memory serves, thats a good place to start looking.

based on general knowledge: the oil pressure sensor uses a 5v reference signal and the ecu calculates oil pressure based on the voltage value from that sensor. you can backprobe the sensor (stick a thin wire into the back of the connector, usually its a two pin connector, and use a voltmeter) and watch the voltage fluctuations. if the sensor registers the same pattern in fluctuation as your pressure gauge, then the source of your problem is before the sensor. that leaves only a few components: pump, pickup tube/screen, filter, or a clog in any of those components. if the sensor registers a constant reading and has no pattern like the gauge, then the problem is after the sensor.

good luck!

for peace of mind, having a turbo has nothing to do with this issue, any car could have an oil pressure problem. biggest disadvantage is the turbos are expensive to replace... =(

Could be a cracked pickup tube. It can cause all kinds of oil pressure fluctiations under similar conditions.

http://photos.killerbmotorsport.com/i.ashx?gallery=244340&mid=16978710&mt=Photo&standardsize=640x480

If you want to see more pics like this, look HERE.

Oh you mean like this...

http://photos.killerbmotorsport.com/i.ashx?gallery=244438&mid=8602825&mt=Photo&standardsize=640x480

I was thinking of saying the pick up tube may be cracked the other day. But I'm not sure if your issue would be caused by that.

I would think the air leak would be constant and not opening and closing giving you the readings your getting.

Oh you mean like this...

 

Exactly. Though I was thinking something more like this: http://www.killerbmotorsport.com/index_files/OilPickupStory.htm

Or maybe this: http://www.killerbmotorsport.com/index_files/UltimateOiPickup.htm

I'd be curious to find out if it is indeed the oil pick up tube that's causing this. Cause I would think a cracked tube would damage parts in the short block first. But maybe if it is indeed damaged, the crack may be extremely small.

Interesting suggestion gt06unlimited. I would definitely try what you say.

I was thinking of saying the pick up tube may be cracked the other day. But I'm not sure if your issue would be caused by that.

 

I would think the air leak would be constant and not opening and closing giving you the readings your getting.

It is typically highly irregular and not consistent at all until the crack becomes significant (or complete failure occurs). A typical syptom is pressure wandering under constant conditions (cruise, idle, etc.). If the low pressure becomes constant, failure is VERY close. Although, something to keep in mind, we see a lot more immediate failures of the pickups (with zero warning) than cracks that give sypmtoms. If you have syptoms, replace your pickup and go buy yourself a lottery ticket because luck is on your side

Exactly. Though I was thinking something more like this: http://www.killerbmotorsport.com/index_files/OilPickupStory.htm

Or maybe this: www.killerbmotorsport.com/index_files/UltimateOiPickup.htm

Oh I see what you did there

try measuring the pressure at or immediately after the filter. from the sump, the oil is pumped directly to the filter before being circulated throughout the engine. if theres any debris that blocks the pickup screen in the sump, oil pressure will fluctuate constantly. it should remain steady as long as the load on the engine doesnt change. i forget where i read it, but i saw a blurb on a superseded pickup tube due to clogging.. (verification please) but if memory serves, thats a good place to start looking.

 

based on general knowledge: the oil pressure sensor uses a 5v reference signal and the ecu calculates oil pressure based on the voltage value from that sensor. you can backprobe the sensor (stick a thin wire into the back of the connector, usually its a two pin connector, and use a voltmeter) and watch the voltage fluctuations. if the sensor registers the same pattern in fluctuation as your pressure gauge, then the source of your problem is before the sensor. that leaves only a few components: pump, pickup tube/screen, filter, or a clog in any of those components. if the sensor registers a constant reading and has no pattern like the gauge, then the problem is after the sensor.

good luck!

 

for peace of mind, having a turbo has nothing to do with this issue, any car could have an oil pressure problem. biggest disadvantage is the turbos are expensive to replace... =(

The pickup screens on these cars are very big. Can they clog, yes, but from the many I've see they clog AFTER catastrophic failure

I think what you may be thinking of is the TSB that was going around about the oil feed lines being clogged. This is a porous metal filter that fits inside the banjo bolt to the turbo oil feed. They are well documented as a problem, because they can clog, causing premature turbo failure. IIRC the TSB recommended the filter be removed completely.

On the switch, the OEM pressure switch is a simple on/off. It's triggered when pressure drops below 2.1psi . The sensor is located right above the pump, under the alternator. Like gt06 said, it's the best place to measure oil pressure. When we install pressure gauges we relocate the OEM sensor to the rear gallery (to maintain functionality), and put the gauge's sensor in the OEM location.

As far as a cracked pickup causing turbo 'issues', it's completely possible. A crack can compromise flow/pressure rates without triggering the oil pressure light. The turbo uses a restrictor as a means to step down pressure and maintain a specific flow rate. If the system's output pressure/flow drops, the very flow/pressure sensitive 100,000+RPM turbo sees it too. Not only that the turbo is last in line on the lubrication circuit only making matters worse if there is a problem.

I'd be curious to find out if it is indeed the oil pick up tube that's causing this. Cause I would think a cracked tube would damage parts in the short block first. But maybe if it is indeed damaged, the crack may be extremely small.

 

Interesting suggestion gt06unlimited. I would definitely try what you say.

You'd think, but these engines/oil pump flow a sheet load. A little bleeder is going to hav more of an effect on a component that is highly sensitive to flow/pressure vs one that is supplied with an abundance.

Here are a couple pics we've had customers send us of cracks caught VERY early.

http://photos.killerbmotorsport.com/i.ashx?&mid=11125299&mt=Photo&standardsize=640x480

http://photos.killerbmotorsport.com/i.ashx?gallery=244340&mid=11125295&mt=Photo&standardsize=640x480

If you're brave enough to inspect your OEM pickup and put it back in (NOT recommended!) look for the surface conditions...

http://photos.killerbmotorsport.com/i.ashx?gallery=244340&mid=63513478&mt=Photo&standardsize=1600x1200

Thanks for the detailed explaination.

Great post.

BTW, I have both banjo filters removed on my 05.

I did find just yesterday that the 09's still have the banjo filters installed. It's on page 1029 in the 09 service manual, item #30 for 2 each.

Have a killerB oil pick up sitting on the shelf and this thread made me think about the actual install--didn't realize it was quite so involved, but oh well. If my garage is cleaned up by the time I do my next oil change I might give it a go...

 

Can you really jack the whole engine up just from the headers? Never would have imagined that...

Thanks for using our product!!

The install is pretty involved, but the steps themselves are not difficult. I tell anyone that's never done it before to read it over a few times, make sure you have the right tools and just take your time.

Here is the install for those intersted in seeing it.

I would not jack the engine up from headers. If the factory manifold is in place, then that would be no problem. I've seen it done that way a few times. Personally I prefer to jack up up by the oil pan or by the tranny.

EDIT: just noticed the trick there about throwing the nuts back on to let the engine mounts keep the engine up a bit--guess I could jack up from the pan, set that little bit of wizardry up, then drop it back in place for pan removal / install.

Yep. Scraps of wood, chunk of metal, and anything that would make a good spacer will work.

One thing that isn't in that procedure that we recently came across was loosening the pitch stop. I don't know why it happened on this particular car recently, but when we jacked the engine (from either pan, manifold or tranny) it would lift and tip making the motor mount bolts not line up for droping back down. This was frustrating to say the least, and required a few people pushing, pulling and lowering to get the engine to drop back down. Once the pitch stop bolts were loosened, it went up/down perfectly straight Just a tip in case you should run into that scenario.

I was thinking of saying the pick up tube may be cracked the other day. But I'm not sure if your issue would be caused by that.

 

I would think the air leak would be constant and not opening and closing giving you the readings your getting.

I would tend to agree, but if the crack is close to the level of the oil in the pan, any sloshing of the oil may temporarily expose the crack and allow it to briefly suck in air