SleepR1

I was having a vacuum problem, and traced the leak to vacuum chamber completely filled with oil. How does that happen? I replaced the old vacuum chamber with a brand new one.

Yes I've installed new check valves (vacuum, double throttle control, pressure chamber), turbo control solenoid, turbo control actuator, wastegate/precontrol solenoid, charge relief valve, and air bypass valve.

Can you tell I was having trouble with my second turbo coming online @ the switchover rpm (4500)??

New vacuum chamber and new 2nd turbo-control-related parts, now have the secondary turbo coming online properly--yee hah!

I just hope the new vacuum chamber doesn't fill up with oil again.

I'm told by Greg Staff of Staff's Auto that the oil injectors could be bad, but my motor is only 6000 miles old. I'm presuming the Malloy Reman (torn down and rebuilt by KDR) came with new oil injectors??

Thoughts? Opinions? Comments?

CrispyRX7

iTrader: (139)

Go to my webpage Manny and look at the oil catch can mod and it will answer your question ;-)
Regards,
Crispy

SleepR1

Chris,

Yeah, but my vacuum chamber is now an oil catch can, er at least it was until I replaced it with a new one??

SleepR1

Where's the link to your homepage, Chris??

DamonB

Crispy, for those of us who are not mind readers, where might your webpage be?

SleepR1

I found it...

http://reganrotaryracing.tripod.com/catch.htm

Still doesn't explain how the vacuum chamber can fill up with oil??

CrispyRX7

iTrader: (139)

Oil sucked into the intake from the oil filler neck WILL end up in low points in the vacuum "system," the vacuum reservior being one of them.
The puddles of oil seen in the TB's and IC's, in the intake piping connectors, its' all coming from
somewhere eh? Seeing as there are half dozen
vacuum taps on the bottom of the UIM it just seems natural that oil will "drain" to the lowest point in the system. I'd bet good money that it's oil that kills a good many of the solenoids leading to wacky the turbo behavior we see all too often.
My take on things,
FWIW
Crispy
PS sorry for not posting the webpage.

DamonB

I think Crispy's theory is perfectly true. In hard right turns the oil climbs the filler neck and then gets sucked into the intake manifold. Even so I would expect the check valve at the manifold to no allow enough oil in to fill the chamber; that's a lot! I would expect the valve failed first. I know when I rebuilt my 100,000 miles motor my vac chamber was most definately empty.

One mod I still have not done was posted by I believe jimlab long ago. If you remove the oil fill tube and look inside you can see that if oil is climbing the sides when it gets to the openings in the tube where the vac hoses connect it will easily get sucked in. If you were to slip some brass tubing through the hose nipples from the outside you could in effect make the ends of the nipples end in "air" inside the tube rather than at the tube walls. Now the oil cannot easily enter the vac hoses when it climbs the walls, it would have to actually slosh into the end of hose which is mush less likely.

SleepR1

Yes, I suspected the 1-way vacuum chamber check valve may have failed in May. This is when I noticed the strange secondary turbo behavior.

BTW, I managed to drain the oil out of the old vacuum chamber with a siphon. There was probably over a quart of oil in that chamber! Upon inspection of the old camber, the only thing I noticed was that it was slightly concave (collapsed). The seams were still in good shape though.

I guess I'll get a Mity vac and suck out the oil from the new vacuum chamber periodically, when I start noticing that strange second turbo behavior again.

BTW, the vacuum chamber replacement was a bee-atch...had to tear into the intake, elbow, throttle body, and removed the oil filler neck and alternator.

SleepR1

Or did you mean a bad 1-way check valve ala PCV??

SleepR1

Actually, a bad PCV valve would not close under boost pressure, thus bleeding oil blowby into the manifold plennum (when it's supposed to go to the primary turbo) as well as the primary turbocharger. That would explain the oil blowby possibly seeping through the vacuum lines and collecting into the vacuum chamber. I just ordered a new PCV valve, and will install it tomorrow. That job will be a cake-walk compared with swapping the vacuum chamber LOL

http://www.autosportracetech.com/RX-...tm#CheckValves

DamonB

I bet. The only time mine was out was when I swapped motors, the chamber is buried behind several brackets. But you still impress me with your new found mechanical ability

SleepR1

Well, I had a little help from a local Rx7 Club member in Ben Langhammer...but I did quite a bit of the work myself. Ben was my technical knowledge resource

DamonB

No. Since the manifold is boosted a failed pcv would flow from the manifold to the filler neck, not the other way around.

Oil anywhere in the intake tract comes from one of two places: the seals in the turbos or somehow sucked from the filler tube. If it came from the filler tube and all the check valves are functioning, the oiling is limited to downstream of the UIM (poor man's oil metering if you will ). If it's anywhere else in the system it's coming from the turbos. If the pcv were not closing under boost pressure (and I find that highly unlikely) you would be pressurizing the sump which may exagerate the oil slosh problem in the filler tube.

Tim Benton

iTrader: (1)

Not to mention, we all know Manny tracks his car often. Although if KD did the engine removal and install, I would like to think Dave would recognize the fact that a 2 oz piece of plastic was now weighing near a pound or two if it was being filled prior to the engine replacement. How many track events since the replacement?

Tim

CrispyRX7

iTrader: (139)

Glad to hear you guys agreeing with my theory
But I must add contrary to what you said DamonB, oil will be found ANYWHERE in the intake system because remember that second line from the oil filler neck goes to a vacuum "source" upstream of the primary turbo. So when the intake is underpressure and you get some oil slosh up the filler neck when blasting out of that low right hander at WOTwhere is the oil going? Well with PCV valve close it's going to the upstream end of the primary turbo and oiling down your entire intake system.
I'd submit that this is also the cause for many a mis-diasgnosed blown turbo oil seals. As for how to stop the oil from creeping up the oil filler neck, I have an inverted funnel down in the filler neck and a nipple on the inside of the oil cap running to the catch can (not pictured on my webpage) to help stop the oil from finding it;s way out of the oil pan. As for hard data I ran a track two weeks ago which was run in the counterclockwise direction and had no long high G right handers. The result...not a drop in the catch can. now run a track like VIR (clockwise direction with a wicked Turn 3) and I'll fill the catch can every other session.
As for Manny's err problem, the check valve is a good start but there's still the issue of that oil intake, or as someone put it the poor mans premix method
Regards,
Crispy

artowar

iTrader: (1)

Manny, you should have kept that catch can mounted-- you might have kept it to 1/2 quart in the chamber!!

SleepR1

Good point Damon. Well the PCV valve is on the way from Mazdaspeed, so I might as well swap it out.

What's a poor man's oil metering?

BTW, what do you all think of Greg Staff's hypothesis of leaky oil injectors being responsible for a vacuum chamber full of oil?

SleepR1

Rx7 Store did the engine swap. Not sure if Zavier Neeley noticed that the vacuum chamber was filled. I suspect that the oiling of the vacuum chamber is new phenomenon cuz I didn't have trouble with my secondary turbo coming online before. I've had four open track weekend sessions since the motor swap in January.

SleepR1

It appears the old vacuum chamber was the new oil catch can LOL

SleepR1

I replaced the vacuum chamber, double throttle control, and pressure chamber check valves. A new PCV valve is coming and will be installed tomorrow night. I have evening track session Friday @ Putnam Park, so I'll find out if the vacuum chamber fills up with oil again (when I start to lose the second turbo @ the 4500 rpm switchover)...

DamonB

Oops, forgot that one. And since it's on the intake side with no check valves or filters it's pulling vac 100% of the time.

Anything that puts oil down the intake and into the motor

I guess it's possible but highly unlikely. I have not cut an OMP injector open yet, but from looking at them here's how I believe they work: The oil comes up the OMP lines and into the sides of the injector where the engine sucks it in since the injectors are on the intake side. The injectors really don't "inject", they just allow the oil to pass through. The vac line that connects to the back of the injector is opposite a rubber diaphram that blocks off the injector, like putting your finger over a straw. The vac lines on the injectors see vac 100% of the time while the engine is running. So imagine the OMP lines full of oil from the pump to the injector. When you shut the pump off (kill the engine) the oil would siphon back into the pump so that the next time you started up oil would have to climb all the way through the tubes again; starving the engine of OMP oil for a time. That rubber diaphram is the finger over the straw. With vac present (engine running) is stays open and oil passes. With no vac present is stays shut so the oil doesn't siphon back down the lines.

If the diaphram were to compltely rupture I guess you could now suck oil, but I feel that is highly unlikely.

If the vac lines on the OMP injectors were to leak, you would not get oil into the motor as the diaphrams would not stay open to allow oil to pass.

SleepR1

Hmm...yeah, I think I agree. Crispy's theory is probably more likely...but who knows...I'll have a Mityvac ready to suck oil of the vacuum chamber as soon as I have secondary turbo problems again LOL

SleepR1

This didn't take long. My vacuum chamber is full again. I'm pumping out the oil from the vacuum chamber now with 2-mm OD nylon tubing stuck down in the vacuum chamber (through the chamber nipple), with the other end hooked up of the nylon tubing hooked up to a vacuum pump holding 26 inches Hg vacuum. It's a slow process because of how small the ID of the 2-mm OD tubing is!

I'm having Crispy make me one of his special oil filler necks to hook up to my old catch can (which I will be installing again!)...

SleepR1

Catch can re-installed, Crispy cap installed, and as Crispy advertises, the catch bottle does not fill easily, and when it does, it's filled with condensate (water). I still have the problem of the vacuum chamber filling with oil (but not completely this time).

I disassambled my intake and UIM to replace a broken pressure hose attached to the TCS (turbo control solenoid). Upon disassembly, I've noticed that the intake piping is dry from the Efini crossover pipe to the IC core, but the intake piping is slightly oily from the IC core to the GReddy intake elbow. I also noticed some oil in the TB (throttle body).

I suppose the GReddy Type 24 V-spec FMIC core is rather large, and probably has residual oil in the end tanks (before the oil catch bottle was re-installed), and the oil in the FMIC end tanks is what's filling the vacuum chamber now?

Thus far, I've been pumping oil out of the vacuum chamber consistently about once per week for about 3 weeks. Volume range is between 80 to 340 mL depending on how often I'm in the boost.

I just got back from a Mid Ohio TracQuest event over the Labor Day weekend. I started with an empty vacuum chamber before I left for Lexington OH Sunday evening (August 31). I pumped out 340 mL oil from the vacuum chamber, yesterday (September 3). This was after 500 miles round trip of travel, and 220 miles of Mid Ohio laps. Theoretically the catch bottle and Crispy Cap should have eliminated the oiling of the intake tract, but I pumped out 340 mL of oil from the vacuum chamber?

I have to hope that with enough on-boost driving, I'm, going to force the residual oil out of the FMIC end tanks eventually...it's either that, or removing the FMIC core and draining the oil out that way, which will be a BEE-ATCH...

Stay tuned...

BTW, DamonB, do you think it's worth replacing the oil metering nozzles (oil injectors), as a possible cause that could explain the oil filling the vacuum chamber? Or is my residual oil in the FMIC end tanks a more plausible theory?