aTTicism

Interesting that the water pump on my wife's RAV 4 is what caused the timing belt failure. Apparently when I had the timing belt done at 70,000 miles, the water pump was not changed. So, the bearing went out and the toothed wheel broke causing the timing belt failure. Fortunately, that engine is free wheeling, so the valves did not get ruined. Water pump, timing belt, tensioner and all other belts were replaced for about $1,090. The mechanic (who is owner of the independent shop) indicated water pumps should always be replaced when timing belts are replaced because failing water pumps are often the cause of timing belt failures.

I talked to him about the TT problem. He is well acquainted with the 1.8T engine and has had experience where water pumps caused the failure in VW and Audi vehicles. The shop is quite competant. We were a tow-in-drop-off after closing on Thursday last, and my wife's car was back on the road by 3:30 PM Friday.

In any event, the water pump may be the culprit in some timing belt failures, and should always be replaced, even if it is not the direct cause.

fignewton

like replacing a clutch if you have to have the trans out for some reason

TTschwing

But a seized water pump seems to rarely cause a belt problem. Usually it is the plastic Impeller vanes self destructing. This often happens around 60K so replacement of everything is the standard when doing a belt...

TTagz

drive them off the accessory belt like the good old days. There is absolutely no reason you should take a stressed critical engine component and add a lot more stress to it. If they get away from this, timing belt failures will go back to the days of 120k+ miles.

OldSchool AG

i think it's fine... yes, more of a PITA, but a good water pump will outlast the timing belt, so no harm no foul IMHO.

TTagz

I know packaging is a concern, but even with minor design changes, our pumps could be driven from the serpantine belt. It just seems like to me it's an unnecessary risk.

Kareem of Elise

good idea. Most had plastic impellers prone to breaking.

kodeTT

I had mine done end of last year...and the WP plastic impellers were cracked...about half of them! I think it was a matter of time before they actually fell apart...especially when they spin all the time and with the coolant warmed up.

TTschwing

I'll be at about 41K or so...

kodeTT

might be a better idea to change the WP before then.