Oil Sludge In The Radiator And Hoses (solved)

hendrixgr

Registered
Hi.
for at least 6 months i had a problem with my bike where oil sludge was detected inside the radiator water circuit, not much but enough to cause problems with the stock hoses.
I thought that this might mean another blown head gasket but there where no air bubbles in the overflow tank like when i really did blow the head gasket.
After a good cleanup of the cooling circuit with gasoline, the only solvent that could remove the light brown sludge, the sludge make its reappearance so i knew that something else was causing this.
To make a long story short the culprit was the MOCAL water to oil heat exchanger that allowed a minute oil quantity to enter the water system and this only when hot and the oil pressure was high (tested under pressure).
It almost looks like the Mocal heat exchanger was tired from the alternating heat and cool cycles of the engine and it failed after approximately 2 years without any mishandling or accident.
I must say that i am disappointed that such an expensive piece of a cooler failed so early without being subjected to abnormal operational conditions, here is a photo of it when i was building my bike https://www.hayabusa.org/forum/threads/finally-i-went-turbo.182536/
I decided to fit the stock oil cooler back on to the bike since my turbo unit allow it, the summer is hot here and operating without an oil cooler is not an option for me at least, in fact i will fit a fan also on the oil cooler.
I posted this in case someone might find this information useful.
Chris
 
Last edited:
Back
Top