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Q: On the radiator cap there is light brown pudding/paste deposit.

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In Nissan model year 2005-2010 Pathfinder, Xterra and Frontier SUVs have defective radiators. There was settlement about a defect that permits cross-contamination of engine coolant and transmission fluid, ultimately causing the radiator and transmission to need substantial repairs or fail entirely.

I bought my 2006 Nissan Pathfinder on 3/15. Within one month it needed a new transmission and new radiator. I rarely check the coolant but one month ago I notice the reservoir was low and I checked the radiator cap. The cap has a light brown soft paste on it. Should I get a engine coolant flush? Do coolant flush now a days flush the engine block, the heater core and the radiator?

Thanks Daniel

My car has 68880 miles.
My car has an automatic transmission.

Hello Daniel, thank you for writing in. While these issues are frustrating, it may be as simple as needing to flush the system. Yes when you flush the entire system, you should be able to flush the water pockets as well. This all depends on how clogged the system is and how well the system is flushed. You will also want to make sure you are using a quality coolant when you replace it after flushing it. Keep an eye on the engine for any signs that the head gasket is damaged. If you suspect the sludge is oil contamination, then this is where it would be coming from. For any further diagnostic help, contact our service department to schedule an appointment.

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Hi there. I would recommend first contacting the Nissan dealership to see if your vehicle falls under the warranty or recall claim. If it doesn’t then I highly recommend having a professional mechanic complete a coolant system flush as it’s possible the sludge is oil that has contaminated the coolant system. It’s also possible that the sludge is caused by different types of coolant used, carbon build-up or something entirely different. Regardless, contact the dealership to ask them about the recall issue.

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