Hi,

i am new to the 350z world. Recently purchased 2004z. noticed Brown creamy sludge on radiator cap and in the reservoir. car doesnt heat up. Coolant levels dont drop. Temperature guage slightly moves up till almost half in traffic and drop back down while moving all fans works needs advice !!!!! no water mixed in engine oil.
seeking advice

 

Oil contamination in cooling system (one way) likely due to a leaking head gasket. Check compression, leakdown, flush cooling system, replace with WATER (for now) until problem is identified and resolved. Reflush cooling sys and refill with coolant.

 

Hi Thanks will check but no other symptoms of leaking head gasket - No radiator not bubbling, No white smoke, No loss of coolant... I am confused :S

 

A high pressure one way oil seepage into a cooling jacket can produce the coffee milkshake effect in the cooling system with no contamination of the engine oiling system.