How to tell if it's a VCG leak or both VCG and Oil Pan Gasket?

n55jb4 · 01-07-2017, 12:38 AM

Obviously leak from VCG drops and flows down due to gravity and wind during driving, so I need to somehow differentiate between them. What's the best way to pinpoint, power wash engine and then observe engine on idle for 30 min to see if something will start to leak from oil pan gasket?

How common is oil pan gasket leak compared to VCG?

dstrickland · 01-07-2017, 07:52 AM

Quote:

Originally Posted by n55jb4

Obviously leak from VCG drops and flows down due to gravity and wind during driving, so I need to somehow differentiate between them. What's the best way to pinpoint, power wash engine and then observe engine on idle for 30 min to see if something will start to leak from oil pan gasket?

How common is oil pan gasket leak compared to VCG?

If it's above the oil pan & below the valve cover then your valve cover is leaking. Wind may be able to make it blow upwards slightly, but not that far.

If it is below the valve cover, replace the gasket, clean the engine, drive the car 10miles then reinspect to see if the oil pan is leaking as well.

iahawkeye · 01-07-2017, 03:37 PM

Often the vcg leaks will roll onto the exhaust and smoke when the car is idling... This happened to me. The oil pan obviously wouldn't do that

n55jb4 · 01-07-2017, 06:41 PM

Thanks'all I'll try to replace VCG and then wash it and hope that oil pan is not leaking. I can do work on my car, but my back issues limit it to something like VCG. Replacing oil pan is a PITA as I've heard it requires a subframe drop and this is something I won't be able to do myself with my back. In worst case scenario will look into some indy shop hoping that they won't charge me more than $500-600

matteblue3er · 01-09-2017, 01:41 PM

Clean up the motor and look for where leaks originate.

You could also add UV dye to the oil and use a blacklight to see where oil is coming from. Not really necessary though

Efthreeoh · 01-09-2017, 02:32 PM

It's easy. If the valve cover has oil residue on it around the mating line with the cylinderhead, then it's the VCG. If there is oil on the right side of the engine near the mating line between the engine block and pan, near the back of the engine, then it's the pan gasket.

01-07-2017, 12:38 AM	#1
n55jb4 Lieutenant 131 Rep 535 Posts Drives: 328xi 2007 Auto Join Date: Jan 2017 Location: AZ iTrader: (0)	How to tell if it's a VCG leak or both VCG and Oil Pan Gasket? Obviously leak from VCG drops and flows down due to gravity and wind during driving, so I need to somehow differentiate between them. What's the best way to pinpoint, power wash engine and then observe engine on idle for 30 min to see if something will start to leak from oil pan gasket? How common is oil pan gasket leak compared to VCG?
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01-07-2017, 03:37 PM	#3
iahawkeye Private 20 Rep 77 Posts Drives: '07 328i e92 Join Date: May 2013 Location: Chicagoland iTrader: (0)	Often the vcg leaks will roll onto the exhaust and smoke when the car is idling... This happened to me. The oil pan obviously wouldn't do that
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01-07-2017, 06:41 PM	#4
n55jb4 Lieutenant 131 Rep 535 Posts Drives: 328xi 2007 Auto Join Date: Jan 2017 Location: AZ iTrader: (0)	Thanks'all I'll try to replace VCG and then wash it and hope that oil pan is not leaking. I can do work on my car, but my back issues limit it to something like VCG. Replacing oil pan is a PITA as I've heard it requires a subframe drop and this is something I won't be able to do myself with my back. In worst case scenario will look into some indy shop hoping that they won't charge me more than $500-600
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01-09-2017, 01:41 PM	#5
matteblue3er Captain 238 Rep 947 Posts Drives: Racecar Join Date: Jul 2015 Location: Philly iTrader: (0)	Clean up the motor and look for where leaks originate. You could also add UV dye to the oil and use a blacklight to see where oil is coming from. Not really necessary though
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01-09-2017, 02:32 PM	#6
Efthreeoh General 17416 Rep 18,797 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	It's easy. If the valve cover has oil residue on it around the mating line with the cylinderhead, then it's the VCG. If there is oil on the right side of the engine near the mating line between the engine block and pan, near the back of the engine, then it's the pan gasket.
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