CLightning

Hello my fellow DIY'ers. I'm going to replace the water pump on the 8AR-FTS motor. Can anyone please provide me the torque specs of:

Water Pump
Tensioner
Idler Pulley

Thanks!

d2k2vic

How about 2 out of 3? Don't know about the tensioner, but the water pump bolts are 15 lbs-ft, and the idler pulley is 32 lbs-ft.

CLightning

You sir are a gentleman and a scholar!

chuyrobles

Water pump went out? How many miles? I maintain my sister’s 2015 NX200 and it coming up to 110K.

CLightning

85K miles on a 2016 Lexus RC with the same exact engine (8AR-FTS) as the NX. I also own a 2018 NX300 with 30K miles on the odo with zero problems so far.

chuyrobles

Thanks for the pic, was the leak from the weep hole or the form-in-place gasket failure, or something else? Did you replace the whole tensioner or just the pulley/bearing? At 150K, when I do the second coolant flush, I plan to replace the thermostat, hoses, and the idler/tensioner pulley bearings. Will do the water pump if I see more WP failures. Anything special to know about replacing the WP?

CLightning

The leak was from the housing gasket of the wp (the gasket between the wp and the engine block). With the wp out of the car, the pulley spun smooth, quiet, with no play and there was a collection of debris in the weep hole collection compartment but that's normal.


The idler pulley and the tensioner were still good so I did not replace them. Because the engine is mounted longitudinally on the RC (as opposed to transversely like the NX) there was lots of room to work which made this wp replacement a piece of cake. Nothing special about the water pump install. It's just 5 bolts @15 ft*lbs using a 12mm socket (thanks to the responses here as well as I verified via TIS). Make sure the mating surfaces are free of debris and you are good to go. If you're an avid DIY'er, you could probably do the job without removing the tensioner and idler pulley. If I were you, I would replace the wp and serpentine belt on the next scheduled cooling system flush @ 150K miles being cheap insurance (Aisin water pump from Amazon at $83 and a Continental belt at about $20.)