a3dcadman

iTrader: (1)

During the last month or so, I have been fixing a number of things on the 7 - rebuilt the tranny, put in a hi-flow cat and fixed the oil pan leak which included replacing the driver side motor mount. It was relatively easy to do the oil pan fix with the tranny out allowing me to raise the engine higher for more clearance.

Today I finished putting everything back together. The car runs fine, the oil pan leak it fixed, the tranny shifts as it should, but now there is a new problem. As the car warms up it starts smoking, smells like oil burning. I thoroughly cleaned the engine fefore starting the project, so tracing the oil leak was easy, or so I thought.

Where the effini y-pipe sections join together there is a constant dripping which goes directly onto the downpipe resulting in a lot of smoke. I looked all over that side of the engine trying to find out the source of the oil leak. Nothing. I searched the forum for answers and from what I could derive from a multitude of postings, the source is probably my rear turbo.

At this point, Im thinking there wasnt a problem before I started all this work and now there is? The only thing that I did relative to the turbos was to r&r the downpipe and the piping to the intercooler.

I figured I would put the scenario up and see what the forum could yield for ideas before taking all the components on that side of the engine apart.

Any info would be greatly appreciated!

thanks, Chuck

scotty305

iTrader: (2)

Hi, Chuck!

I have a theory, not sure if it holds water or not.

I'm guessing you drained the oil pan to fix the oil pan leak, and then refilled the oil. I don't remember where I read this, but someone once mentioned it's a good idea to use a funnel when refilling the oil... without a funnel there is a chance you may pour oil into the crankcase ventilation line that runs between the oil filler neck and primary turbocharger inlet.

At low RPM when only the primary turbo is running, the Charge Control Valve is shut which may allow pressure from the primary turbo to push oil out past the o-ring at the Y-pipe joint. Most y-pipes I've seen look as if they've had lots of oil seep past that o-ring... I wonder if this is a significant boost leak also? Might be interesting to add a flange to the assembly, or some additional sealant to the joint.

a3dcadman

iTrader: (1)

Hi Scott, havent heard from you in a long time.

I usually use a funnel (short neck) to put oil in. Im wondering if there is a higher potential for oil to migrate into the crankcase ventilation line when the crossover pipe to the intercooler is not present. The question now is how much oil would be present in that line and will a road test which engages the second turbo clear out any residual oil that may be left.

I havent road tested the car yet, ran it on the jack stands. I think that while its on the stands, Im going to pull the crossover pipe and take a look in the y-pipe to see how much oil is there.

Thanks for the input.

Scott, good to hear from you! Im still up in Washington working on the 787 and the RX7. hmmm.... Send me a note and let me know what youve been up to.

chuck

ThaiTea

iTrader: (14)

Hello Motto,

I was having similar issue in the turbo area. I was leaking oil out near the primary turbo and was struggling to find the source of the leak.
Here are the few posts I made. There were very usualy answer regarding oil in intercooler piping.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/leaking-oil-but-where-909636/
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/oil-intercooler-piping-909411/

In the end, I attacked the suspect that stood out, which was the gasket between primary turbo and y-pipe. Luckily it was where the leak was coming from.
But Also check your BOV. When I run my car in hard corner I do get some residue on the outlet of my BOV which ends up dripping a few drops down.

Hope this helps.
TNT

PS I'm in Bellevue/Redmond Area

a3dcadman

iTrader: (1)

Last night I pulled CEL codes and came up with #20 METERING OIL PUMP POSITION SENSOR and #26 METERING OIL PUMP STEPPING MOTOR both of which could be open or short circuit. Could these items cause a buildup of oil in the Y-PIPE and a subsequent drip out of the join?
-chuck

Juan

iTrader: (28)

Have you checked the o-ring that seals both halves of the y-pipe? My y-pipe was dripping a tiny bit of oil onto the downpipe from that joint. I took it apart and the o-ring was very hard and brittle. I replaced it and havent had that issue anymore.

Sgtblue

iTrader: (16)

^That was my first suspect. That 'O' ring getting old and brittle...maybe combined with slightly overfilling with oil will also contribute. Could have made it appear "suddenly".

RE: The CEL codes involving OMP, I don't see that as contributing to your issue. They should have put you into limp mode though.

a3dcadman

iTrader: (1)

Problem resolved! The harness close to the alternator for the OMP had come disconnected either when I raised the engine for the oil pan fix or when I removed the tranny. Seems that when there is no connection the OMP runs constantly or perhaps with more pressure? The CEL codes did make the engine run in limp mode; could not get it to go over 3000 rpm or so.

Thanks everybody for your input, much appreciated!

-chuck