It is likely those are stress cracks. Yes these coolers do fail. I would replace it. As for the gasket hardening that is a sign that the engine oil is overheating. You may want to monitor oil temperature. That engine in its original application didn’t run at 4,000 rpm for continuous periods. Re-gearing and or additional oil cooling could be benificail. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Neil N
Sent: Tuesday, December 22, 2015 12:03 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Oil Cooler Marks

Hi all.

This is regarding the oil cooler on a Jetta 2.0 engine in my Vanagon.
I know the 2.1 WBX uses a similar or same part so....

Are these gouge-like marks on the oil cooler normal? Did they hasten the gaskets demise? Or, are they providing a path for oil to leak out?
oil cooler image: http://tinyurl.com/z4rc27v close up shot: http://tinyurl.com/puaj2a5

I don't know how many miles are on my Jetta engine but its been running for at least 6 years now. I replaced the oil cooler gasket at time of swap.
Over time, an oil leak developed at the oil cooler.

I know that this rubber gasket can fail over time and suspect that's what's happened here; the gasket feels quite stiff. i.e. heat took its' toll.

Thanks,

Neil.

--
Neil n

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