What is the proper way to flush the coolant on a 1998 Q45

DULISSI

MEMBER
1998 INFINITI Q45
90,150 MILES

The owners manual states capacity is 12qts and that there are two plugs
on the block. I flushed it today by removing the rad drain plug and got
a gallon of dirty fluid. Refilled with garden hose ran motor until motor got hot and fan was running & drained again. Refilled with distilled water
and ran again until hot and drained. Last time ran motor with rad plug out and ran distilled water through until clean. Replaced plug and filled with fresh coolant and distilled water.

Why am I only seeing a gallon of fluid if the system is 12qts?

3 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Open the radiator drain plug drain the coolant completely out get the water hose fill it and start the engine and run it while you put water on the radiator constantly till the water is no longer diluted and becomes clear-now shut it down secure the drain plug fill it with the correct amount of coolant to use on 12qts-Your done

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Tuesday, September 6th, 2011 AT 4:17 AM

DULISSI

MEMBER
2 POSTS

Thanks but I am only getting a Gallon out with this method. Surely if I used the drain plugs on either side of the block I would be OK. Don't think they are easy to reach though! I have always flushed my coolant on all the American cars I have owned and never had this problem. I believe the cool water going in just recloses the thermistat. Also I think this car has small heater hoses so a Prestone flush kit won't work. I could try dropping the heater hoses and or lower rad hose?

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Tuesday, September 6th, 2011 AT 6:07 PM

RASMATAZ