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Monday, 6 June 2016

07 Toyota rav4 water pump problem

Toyota  rav4 water pump problem

what would cause the water pump on a '07 rav4 V6 with 72000 miles to fail. seen others with same problem & we received recall notice for internal oil hose replacement. is this related to water pump problem? and yes, i've had regular maintenance on vehicle. i've driven toyotas since 1979, including 2 rav4's, and most with 175 - 200k before selling/trading and never had a water pump replaced in any of them. does the '07 rav4 V6 have a problem?

The oil line replacement is part of the 90K recall, and has nothing to do with the water pump. They've found that a number of the oil line hoses were failing very prematurely, and making a HUGE oily mess. It is a piece of hose with about a 45 degree bend that is less than 6 inches long.
The water pump unfortunately is not considered powertrain. The engine, transmission, etc are your drive train. The waterpump is considered an accessory, much like a power steering pump, A/C compressor, or an alternator. I've seen a lot of them fail and start leaking, but is much, much more common in the 4 cylinder rav's and camry's. Most of those seem to go out between 80k and 100k miles. You may have not known about it before because most of the older vehicles had timing belts, and if you'd replace the timing belt usually you will replace the water pump at the same time (and if you put 180-200k miles, that's a couple timing belts right there).

MSRP on the part is $171 and labor to install it shouldn't be much. Like I said, Most guys can do them in an hour and a half or so. Honestly, there IS a TSB for an engine ticking noise and/or a BUNCH of CEL Codes where you replace the vvti actuators, 2 cams (the other 2 are reused) the cradle for cams, you have to remove the timing cover, which to get you you much remove the oil pan and secondary oil pan, along with PS Pump, alternator, intake, water pump, etc etc etc. You're basically stripping the engine down to the heads (only the bottom 1/3 part is left in the car) and block, replacing a few parts and resassembling. That entire job under warranty pays 16 hours, plus a couple extra hours for different combinations you can add in, but you're lucky if you can get 18 hours labor to strip the entire engine down to next to nothing and rebuild it. A water pump for 10-14 hours, you can't be serious. I'd be taking it to somewhere else, or raising holy hell at the dealership you've been servicing it at, ESPECIALLY if it is covered.

Water Pump Operation:
A device, usually located on the front of the engine and driven by one of the accessory drive belts, that circulates the coolant by causing it to move from the lower radiator-outlet section into the engine by centrifugal action of a finned impeller on the pump shaft.

The majority of water pump failures are attributed to leaks of some sort. When the pump seal fails, coolant will begin to seep out of the weep hole in the casting.
Signs of leakage from the water pump vent means the pump's seal is bad. Courtesy of Federal-Mogul Corporation.
This is an early indicator of trouble. The seals may simply wear out due to abrasives in the cooling system, or some types of seals crack due to thermal shock such as adding cold water to an overheated engine. This could also cause other internal parts to fail.
Other failures can be attributed to bearing and shaft problems and an occasional cracked casting. Water pump bearing or seal failure can be caused by surprisingly small out-of-balance conditions that are difficult to spot. Look for the following:
  • A bent fan. A single bent blade will cause problems.
  • A piece of fan missing.
  • A cracked fan blade. Even a small crack will prevent proper flexing.
  • Fan mounting surfaces that are not clean or flush.
  • A worn fan clutch.

To check a water pump, start the engine and listen for a bad bearing, using a mechanic's stethoscope or rubber tubing.
  • Place the stethoscope or hose on the bearing or pump shaft.
  • If a louder than normal noise is heard, the bearing is defective.
Whenever working near a running engine, keep your hands and clothing away from the moving fan, pulleys, and belts. Do not allow the stethoscope or rubber tubing to be caught by the moving parts.
There is another test that can be performed on vehicles with an engine-driven fan.
  • With the engine off and the fan belt and shroud removed, grasp the fan and attempt to move it in and out and up and down.
  • More than 1/16 inch (1.58 mm) of movement indicates worn bearings that require water pump replacement.
  • To determine whether the water pump is allowing for good circulation, warm up the engine and run it at idle speed.
  • Squeeze the upper hose connection with one hand and accelerate the engine with the other hand.
  • If a surge on the hose is felt, the pump is working.
  • Any air being sucked into the cooling system is certain to have a detrimental effect.
  • It cuts down pumping efficiency and causes both rusting and wear at a rate approximately three times above normal.
  • To test for aeration, have the engine fully warmed up, all hose connections tight, and the coolant level up to normal.
  • Attach one end of a small hose to the radiator overflow pipe and put the other end into a jar of water.
  • Run the engine at a fast idle. If a steady stream of bubbles appears in the jar of water, air is getting into the cooling system.
  • Check first for a cylinder gasket leak by running a compression test.
  • If two adjacent cylinders test low, the gasket is bad. Otherwise, there is an air leak somewhere else in the cooling system.

  • When replacing a water pump, it is necessary to drain the cooling system.
  • Any components--belts, fan, fan shroud, shaft spacers, or viscous drive clutch--should be removed to make the pump accessible. Some pumps are attached to the cylinder block as shown below.
Installing a water pump. Courtesy of Dana Corporation.
  • Loosen and remove the bolts in a crisscross pattern from the center outward.
  • Insert a rag into the block opening and scrape off any remains of the old gasket.
When working on the coolant system (for example, replacing the water pump or thermostat), a certain amount of coolant will spill on the floor. The antifreeze in the coolant causes it to be very slippery. Always immediately wipe up any coolant that spills to reduce or eliminate the chance of injury.
  • When replacing a water pump, always follow the procedures recommended by the manufacturer.
  • Most often a coating of good waterproof sealer should be applied to a new gasket before it is placed into position on the water pump.
  • Coat the other side of the gasket with sealer, and position the pump against the engine block until it is properly seated.
  • Install the mounting bolts and tighten them evenly in a staggered sequence to the torque specifications with a torque wrench. Careless tightening could cause the pump housing to crack. Check the pump to make sure it rotates freely.
  • The water pumps on many late-model OHC engines are driven by the engine's timing belt. When replacing the water pump on these engines, always replace the timing belt.
  • Make sure all pulleys and gears are aligned according to specifications when installing the belt.

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