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Old 09-04-2014, 08:42 PM   #1
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Default that gear oil smell

So after getting on it I smell gear oil. Only after I get into boost for a few seconds, and after I let off. It was bad at the beginning of my 40 minute commute to work, but as I got within about 5 miles the smell went away after/during boost.

I don't think it is actually gear oil, because the smell wouldn't come into the cabin at speed right? So I'm trying to figure out what else it could be. Any help is appreciated!
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Old 09-04-2014, 08:49 PM   #2
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It could be any of the seals from the transmission or differential allowing oil to sling on the exhaust.
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Old 09-06-2014, 01:27 PM   #3
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So I changed my vacuum routing. I had the wastegate signal coming off the intake manifold. I take it that's a no-no?

Reason I ask, is because the smell is gone. Now it could just be coincidence. Can you over spin the turbo and starve it of oil?
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Old 09-06-2014, 02:03 PM   #4
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Then it wasn't gear oil...
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Old 09-06-2014, 02:48 PM   #5
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If it's gear oil, you'll know for sure. Very deistic smell that smells smelly. Could be shift boots that are torn.
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Old 09-06-2014, 03:49 PM   #6
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You are correct. The wastegate signal does not ever come from the intake manifold. That will make some really bad things happen. I bet your exhaust manifold and turbine housing got pretty damn hot.
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Old 09-06-2014, 04:03 PM   #7
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Hahaha, well it's got good heat protection. I know what gear oil smells like, I just changed the fluids a few weeks ago on both the trans and diff. It smelled just like it, and only after I had made my changes to the routing. Ran it for a week like that, what damage could I have caused? Why don't you take the wastegate signal from the intake manifold? Just like to know reasons behind it. Thanks!

I knew something was different when I heard the turbo was louder than normal. It's back to previous levels though, barely can hear it through the intake.
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Old 09-06-2014, 06:24 PM   #8
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I'm not aware of anything being super wrong with sourcing the signal from the IM.
The ONLY reason people advise against it is because your wg diaphragm is not designed to have constant vacuum applied to it, and you can potentially rupture it after a long period of time.

It will in no way cause anything else from failing or working incorrectly.

...you may get a bit more part throttle boost, but even that wont' be much different from running an mbc
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Old 09-07-2014, 08:19 AM   #9
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It causes the turbo to operate against the surge line of the compressor map, which can cause damage. It causes the compressor to make a huge amount of pressure and heat at part throttle. At part throttle there is a less than full exhaust volume through the turbine but because the compressor is trying to make allofit PSI, there is great resistance to flow through the turbine wheel, ruining fuel mileage and creating a lot of excess heat there also. It is possible that it could be producing 8psi within the intake manifold and the turbo could be introducing 20psi to the inlet tract during part throttle.

TL;DR - Makes big heat in inlet and exhaust and kills MPG with no real upside.
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Old 09-07-2014, 10:17 AM   #10
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Thank you sir. In the back of my mind I was thinking something like that could happen. The turbo overboosting even though you are only seeing 5psi in the intake manifold. That is why I asked if you could over spin the turbo. My turbo is only oil cooled, so I was thinking it was getting too hot and causing the oil to burn off.
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Old 09-07-2014, 03:54 PM   #11
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Quote:
Originally Posted by whinin View Post
My turbo is only oil cooled, so I was thinking it was getting too hot and causing the oil to burn off.
Ouch. Yep, that's a bit savage on an oil only CHRA.
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