Originally Posted by glennsz

I purchased a Stillen 25 row oil cooled kit back in June of 2012 along with Gen3 CAI and Exhaust. Z ran great with no more "Limp" mode at the track. I high speed autocross at Blackhawk Farms Racetrack turning 1:29 times and run my Z hard. Last year I saw a few drops of oil under my Z and found the top of the oil cooler was leaning back about 3-4 degrees and the center row had split open just enough to start dripping. I called Stillen thinking there was no way anything could have hit it being behind the front stock grill. Stillen had not heard of any issues and I ordered a replacement core for $129.00 and put it in. I thought I had 4 years out of it so lets just get it fixed and back on the road. Last night, less then 1 1/2 years after the replacement and maybe 3000 street and track miles I see smoke in my mirror and not 15 seconds later my engine oil light comes on. I pull into a gas station 2 miles from my house, shut down the Z and see oil all over my front end. After a short tow back home I see the oil cooler has once again split open around the middle row but this time I could see the 1/4" slit the oil was coming out of. Before I call Stillen I wanted to see if anyone has experienced this before. One time is enough but twice and this time driving at speed (45mph) makes me afraid to just replace it once again. My towing bill would have been much higher if it happened at the track I was just at 2 weeks ago!