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Discussion Starter · #1 ·
Contaminated Oil After Fitting a New Mishimoto Oil Cooler.
Help Please,

I purchased a new oil cooler kit directly from the Mishimoto web site for my dedicated track race car (1000km old professionally built race engine).

I recently installed this oil cooler myself and then obviously changed the Valvoline Formula 50 race oil and filter to complete the job. Engine was then run up to temperature on the car hoist to inspect for any leaks or issues (I'm a Mechanical Engineer by trade).
Upon final checks after only approx. 20 to 30 min running on the hoist to raise the engine and oil to temperature, I noticed a very slight leak from the sump plug so I decided to remove the sump plug to inspect the sealing washer. On removing the plug to drain the new oil, I noticed the (30 minutes old) new oil had turned a dark silver metallic, refer photo below, obviously very unusual and disturbing. Using a magnet confirmed that the contamination wasn't ferrous.
I then inspected the retained old Vavoline Formula 50 oil and filter (600km race old pre-Mishimoto oil cooler) to confirm that the dark silver contamination occurred post fitting of the Mishimoto oil cooler.

Note, after numerous attempts I finally received a reply from [email protected] who state "Thanks for sending those pictures and videos over, that oil is not something that is the cause of our oil cooler. We have years of testing on this product as well as many customers that use our coolers and have never had this issue.

Has anyone seen this issue in the past?
Any suggestions on what the contamination could be?
Help please.


P.S the oil looks worse than the below photo suggests, the video shows it better.

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