Tomit,

I do not think think the timing chain has anything to do with the longevity of the water pump.
Inside the water pump there is a bearing and rubber seals, either the bearing fails or the seal. If the seal fails then coolant leaks, when the engine reaches normal operating temperature there is pressure in the coolant line.
If the bearing fails, then you have the typical noise and eventually a busted water pump.

I think the reason a water pump fails is due to lack of quality of the seal and the bearing.

 

Neucorp, what keeps the chain tensioned? Could it be over tight? Or the chain puts too much pressure on the pump sprocket because of the way it is routed? Just wondering if you had any ideas since you were in there. Thanks.

 

Mega thanks to Neucorp for the PDF! I have a 08 RX350 with 53K miles and the water pump just failed. Without the document I probably would not have tried this on my own. I have replaced many water pumps in the past but none this complicated. It took me about 11 hours. I tried first to take the pump off without raising the engine but quickly realized that the water pump pulley was not coming out nor was the top engine piece that holds the dog bone mount going to clear the engine bay. My only deviation was that I did not drain the engine block of antifreeze. I just placed a pan under the engine to catch the fluid when the pump came off. Only a pint or so spilled out. I replaced the original Aisin pump with a Beck-Arnley since Aisin obviously didn't get it right the first time. Hopefully they have it right now but I wasn't willing to give them a chance. Neucorp send me your PayPal and I'll buy you lunch.

 

No lunch necessary. Just paying it back to the community that has saved me a lot of time and money!

 

Well, you saved me a ton of both. I didn't get a quote from the Lexus dealer but I have seen labor quotes reported online anywhere from $700 to $1100 not including parts. Parts cost me a little under $250 (I replaced the pump, 2 idlers and the belt). Thanks again!

 

Neucorp,

Great write up! Was much easier than I thought.....

 

Thanks Neucorp for the guide! Used it for a 2010 and there were a few minor differences with the newer model but overall the same. It would have been much more difficult without your guide. My dad helped me do it over a weekend in addition to installing new struts at the same time.

 

Nice work. Hope I never have to do this, looks like a huge PITA but do-able. How did you know you had to replace it?

 

The first thing I noticed was a different sound from engine bay one day. Took it to dealer and they said the water pump needed to be replaced for $1,100. Once you remove passenger wheel and some of the fender plastic you can look up and see the water pump and if its leaking there should be pinkish-white crud visible like whats shown here on the bolt closest to the pulley. My car had 95k miles.

 

My wife's 08 RX's pump was replaced in mid 2015 with 97K miles on it. OEM Lexus pump, gasket, coolant and Continental belt was replaced. He charged me $500 for the whole job and no problem ever since (almost 110K miles as of today).

 

That's an incredible deal. OEM parts alone are half that. They didn't make any money on that job.

 

Thanks Neucorp for taking the time. For those who have not seen this, there is also a video. It's not as complete as the PDF Neucorp put together, but it helps with visualization in certain parts of this project:

 

Subbed for just in case.

 

I completed this job this past weekend by following your PDF. Thank you! This is a heck of a job. Took me two days. I have a coolant leak now due to damaging a small hose and I have posted a thread but no response yet. I am going to copy and past my issue below.

So, I just replaced the water pump on my 2008 lexus RX350 with 208k miles. The water pump started making a lot of noise. Knocking noise when the vehicle was put in gear and chirping noise when the AC was on. The water pump replacement was not for the faint of heart. Very limited space made it a very tough job. Noises all gone now but I have a coolant leak.
When I took the coolant bypass hose off, I definitely tore it up some. I knew I should replace the hose but the location of the hose and the difficulty of even getting the clamp on and off lead to me just putting it all back together and praying it didn't leak. Well, it is leaking and now I am trying to find out how to replace this coolant bypass hose. I will probably just start taking off parts until I can hopefully reach the top of the hose and then cut off the damaged section. I haven't been able to find anything on the web or this forum about anyone accessing or replacing this hose. If anyone out there has replaced this hose I would love to know what all you had to take off to get to it.
I have attached a pic and #14 is the hose I am talking about. They call it a water bypass hose. It is behind the thermostat housing and sticking out from under the intake manifold on top passenger side of the engine.Attached Thumbnails

 

For step 13, if RH is the top bolt, where is the FR bolt?