# [SOLVED] Nasty oil leak...



## GZ (Jan 31, 2010)

My Audi sprung an oil leak... I am pretty certain it is coming from the oil cooler seal but I figure I would run it by and see if there may be something I am missing.



I am losing about a quart every 100 miles or so.
The leak is definitely coming from the front of the motor. 
Increasing RPM (and oil pressure) causes the leak to increase in volume.
Initial thought, front crank seal.
Timing belt is dry. (the entire upper end of the timing system is dry)
Drive belt is dry.
Oil is originating on the driver side of the motor... splatter would be to the passenger side (judging by rotation of crank).


The only things in that area that could potentially lose that much oil in that way are the crank seal, oil pressure switch and the oil cooler... AFAIK.


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## Scottg1 (Jul 30, 2011)

Sounds like it's coming out the front crank seal. If so, I would check for a gummed up crankcase breather tube. Pretty common on Audis


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## GZ (Jan 31, 2010)

*Re: Nasty oil leak...*



Scottg1 said:


> Sounds like it's coming out the front crank seal. If so, I would check for a gummed up crankcase breather tube. Pretty common on Audis


Didn't get around to checking the PCV system today (had to work). I am going to try idling without the oil cap in place for a bit to see if the pressure release slows the leak.

Strike one... replaced the easiest to replace seal out of the three... The oil cooler seal. Thought I had it licked but, lo-and-behold... fresh oil started dripping from the front of the motor after about 10 minutes of idling. 

I guess I will be running to the dealer tomorrow to pick up a crank seal. I am tearing apart the front of the car on Saturday to replace the drive belt tensioner pulley and drive belt. It won't take much longer to pop a new seal in. 

Leak is getting exponentially larger. Drove from Phillipsburg to Flemington to get the car inspected and lost about 3 quarts of oil on the trip. I am almost certain it is the crank seal at this point as I don't see how the oil pressure sending unit could piss out that much oil.


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## SABL (Jul 4, 2008)

*Re: Nasty oil leak...*

I wouldn't guess......clean the area around the seal and the sending unit and fire it up enough to get pressure and shut it down. Look to see exactly where it's coming from. Where's the oil filter located?? I've seen bad installs on filters.....


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## GZ (Jan 31, 2010)

*Re: Nasty oil leak...*

@ SABL - With this motor, you can't get at the seal or the oil pressure switch easily.

My angst was premature last night. After driving to Flemington and losing so much oil on the trip I needed to do something about it.

I hadn't discounted the crank seal or pressure sending unit yet, but the most likely cause was the oil cooler seal. It is sandwitched between the block and the oil cooler and held on by a flat nut on the oil filter tube.

When I posted last night I had let the car run for about 15 minutes and saw fresh oil dripping on the cardboard I had placed under the car and thought it was a fail.

Drove all the way out to Lehigh street to the Audi dealer to pick up a crank seal today. Got out of the car and didn't see the tell-tale trail of oil and the puddle forming under the car... My first thought was that the oil idiot light didn't work and I drained the engine...

Checked the oil level... lo-and-behold, it was full... not a drop missing. Ran the car through a car wash with an undercarriage wash and I have only seen some spotting since. 

I am still tearing the front of the motor down this weekend to replace the drive belt tensioner and to perform a full inspection so I will clean up any residual oil at that point.

Thanks for your input guys!


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## Scottg1 (Jul 30, 2011)

Good luck, hope it's a cheaper fix


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## GZ (Jan 31, 2010)

<$5 & 20 min... 

I am still going to replace the front seal. I have to tear the front of the motor halfway down to get at the accessory drive belt tensioner, so I might as well pop the timing belt and replace the crank seal as well.


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## mikeber (Jan 10, 2007)

gavinzach said:


> <$5 & 20 min...
> 
> I am still going to replace the front seal. I have to tear the front of the motor halfway down to get at the accessory drive belt tensioner, so I might as well pop the timing belt and replace the crank seal as well.


Wow, sounds like a heck of a $5 overhaul! 
Do you do all this work by yourself?


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## GZ (Jan 31, 2010)

Yep. I do all of the work myself. The only thing I take my car to the garage for are tires and oil-changes (in the winter).

The $5 was for the oil cooler seal. The crank seal was $15 and the belt tensioner pully and belt were about $60 together. I am just waiting for them to come in.


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## Troy_Jollimore (Dec 31, 2007)

The oil cooler is definitely a weak point on a few of the VW/Audi engines. Which model Audi and which engine do you have? An A4 with the 1.8t is most likely...


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## GZ (Jan 31, 2010)

A4 Quattro 2.8L


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## Troy_Jollimore (Dec 31, 2007)

Good catch on the oil cooler, the V6 is always a treat to work on. I opted for the 1.8t in my Passat just to save myself some pain...


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## GZ (Jan 31, 2010)

Well. I was still dripping oil at a much slower rate and today I tore apart the front end of the car to inspect everything and replace the drive belt tensioner. While I was at it I pulled the crank pulley and checked the seals. They were all dry. For giggles I pulled the oil pressure sender... There was no gasket washer. 

Let her run for about an hour and it seems all leaks are resolved now.


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## Troy_Jollimore (Dec 31, 2007)

> Let her run for about an hour and it seems all leaks are resolved *for now*.


Fixed it for you.  Two constants with these cars are slow oil leaks (automatic anti-rust undercoating) and 'Check Engine' lights...


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