Water Pump Replacement????

The V12 water pump is an integral part of the engine, and is an engine out proceedure...However, that being said, usually the part that leaks is the forward-most exposed part of the pump. Raise the car and observe that it is very easy to r/r this. The gaskets are available as a kit for about 50-75USD. Any one of us can accomplish this proceedure in <>an hour or so. If you have the shop manual, the parts and proceedure are perfectly illustrated. I've personaly done this, so I know that any one of us can do this. I hope that this is of some help to you. Thank you. Jacques.

 

Hello Niall
hope you get it sorted, I have had the same thing happen and it could just be the seal gone on the waterpump side try that and check for play.
Ashman kindly helped with a diagram on a post i did will help search for 'oh oh waterpump' by me alastairhouston.
Good luck
Regards
Alastair

 

Do I understand your symptoms correctly; warms to PROPER temp and dumps coolant?
If you aren't overheating but dumping coolant it's time to investigate why the cooling system is overpressurized. Assuming the radiator cap hasn't gone toes up failed headgaskets or cracked castings are usually to blame.
Fingers XXXed for you

 

I would guess it was a stuck thermostat.

 

Niall
I think what some of us are struggling with is what you mean by "dumps the coolant". Does it all push out the overflow?

If yes, head gasket is a possibility but thermostat seems more likely. T-stat is easy to test in the kitchen or you could remove it and see what the car does without it for a short time.
Ken

 

Big N,
Very rare does a water pump fail to pump water. When they go bad they just leak. So in a over heating engine that is rarely the problem.

 

I agree, I would check the thermostat first.

 

Theromostat

 

Head Gaskets most likely cause, check exhaust gases in coolant system with testing kit. I had exactly the same problem with mine.
You can also test by pressurising each cylinder in turn with compressed air, but obviously you need to keep turning the engine so the valves are closed.
When my thermostat failed it stayed open, i'd be surprised if it was the thermostat, but I'm keeping my fingers crossed for you.
If the Radiator is getting hot you know the Themostat is open, (at least a bit) and you have some sort of circulation of the coolant.
Cracked heads are rare indeed, gaskets are much more likely to fail, particulaly if the car has not been well looked after, or used regularly.

 

Thermostat on my 365 went bad around 1999, this sounds like the leading cause. Still no drips from the water pump.

 

Niall
You gave us one more hint. You say the fan comes on. The temperature switch for the fan is at the bottom (cold end) of the radiator. If the thermostat stayed shut the bottom of the radiator would stay cold.

My vote for head gasket, sorry.
Ken

 

While most of the issues have been discussed already, I would like to add a couple of thoughts. Most of you know my wife owns several Subrau Service Centers and its no secret Subaru's have head gasket issues. So with your permission i will add a couple of diagnostic thoughts for basic head gasket failure.

Rather than condem the thermostat, headgaskets, water pump, or cooling fans some simple and easy diagnostics are in order, and are listed as follows. These are some of the Subaru factory reccomended procedures.

Check the coolant level, then start the motor, once the temp gauge has reached its normal place, and the fans turn on, use a thermometer infra red sensor and check all areas of the radiator to make sure you have coolant flow through the core. There should be some varing degree of temperature from top to bottom, usually around 20 degrees differential.

If you have a cold radiator at the bottom of the core, you have a circulation issue, now you have to determine what is causing it. Subaru now reccomends to remove the thermostat and restart the motor. Recheck the radiator core and compare the numbers from the previous test. If the numbers are equal reinstall the thermostat.

We have designed and manufactured a pressure/temp gauge that replaces the radiator cap. This is a direct reading pressure gauge that will give accurate readings of cooling systems pressures and temps. This gauge is a dual action gauge as it also reads direct temperature while running the motor. The normal pressure range is 14 to 17 pounds, and tempuratures at the radiator neck at idle should run 210 degrees, of course these numbers are for Subaru not Ferrari.

Assuming you have the average temps, and pressures you move on to coolant flow. Cooling systems are designed to run 12-17 pounds of internal pressure as an overall average. The water pump is designed to give maximum flow of coolant at those pressures. When a headgasket failure occurs there are 2 possibilities either an internal or compression leaks or an external coolant leaks. If there is an internal compression leak you will loose coolant flow for the follwing reasons. Compression then transfers to the cooling system and increases the cooling sytem pressure not allowing the water pump to move the coolant. We have seen cooling system pressures raise 80-100 pounds with blown headgaskets. So with that kind of internal pressure hoses can split, or push past the hose clamps,or radiator seam splits. Circulation as needed just stops, this causes the temperature gauge to give a false reading. The coolant temp sensor in the motor is designed to measure the temperature of coolant flow not steam. So if you have a over pressureized cooling system there will be no coolant flow past the sensor to give an accurate measurement.

If the headgasket is an external leak when driving the car and the cooling system is fully pressurized coolant will push past the gasket and cause a low coolant level and an overheating result. This is usually spotted by adding dye to the coolant, putting the car on a lift and using a black light watching for the dye to excape.

There are several ways to check for an internal head gasket failure, these all do the same basic thing measure the hydrocarbons excaping into the cooling system. There is a chemical process that actually sucks the coolant up into the chamber and turns colors if there is exhaust gas(hydrocarbons) in the coolant. The other is to use ph paper avaible at most parts stores, the paper turns colors when dipped into the hot coolant. The 3rd and most accurate is to measure the hydro carbons with a 4 gas analizer. We actually take the analizer probe and put it into the radiator while the motor is running at operating temeratures. This will measure how many ppm's, parts per million in the coolant. This is the most accurate measure of headgasket failure. The last check would be a visual inspection of the cooling sytem with the cap removed on the overflow bottle, if there is an oily resudue inside the tank and a oily scum on the coolant, you probly have an internal leak.

Our service writers would have a number of questions before condeming any part of your car. They would want to know how long has the fluid been pushing out of the cooling system. Did it start after a long trip, was it after a long time in storage. was there a recent coolant change?(possible air bubble) Was there a new reserve tank cap installed before the issue?(wrong pressure) Has any service been performed recently?( possible timming issue) Has anyone modified or instaaled any computer modifacation just prior to this issue. As a general rule of thumb, these issues just don't appear they are more usually something that happens over time.

Sorry to have been so wordy,

Howard and candy Musolf
1981 308gtsi
1982 400i Cabriolet
Maserati Spider
1987 Lotus Turbo Esprit
2 many brass era cars.

 

Howard
If a Subaru has a 12 to 17 psig radiator cap and the head gasket causes the pressure in the cooling system to increase to 80-100 psig, it will "dump" all the coolant out of the system, just like Niall is seeing. The added pressure will not stop the pump from pumping because the pressure will be on both sides of the pump. The pump will stop pumping if it is pumping vapor rather than liquid.

I have one SVX and sold another, both with over 230,000 miles. One blew its head gasket and I tried lots of solutions before giving in to the head gasket renewal. Pulling the thermostat on the Subaru means draining and refilling all of the coolant since it is at the bottom of the system....one task easier on a Ferrari than a Subaru.
Ken

 

No, it is not an engine out effort. I've rebuilt the water pump in my 1984 400iA. It's not easy but it can be done. I might suggest removing the front sway bar to anyone who wants to attempt this. I didn't and it's pretty tight working down there at the front of the engine. I don't remember the specifics but I got a kit from T. Rutlands for $30 or so.

If you have a friend with a couple of extra joints between their wrist and elbow they could be of great help doing this rebuild. *<|)

Al

 

Original radiator cores are IRON material, weigh a TON, and will clog, and are not really worth the risk of "boiling it out".

I reccommend a re-core, utilizing what is knowm as: an "L" core, quite expensive($800-1000) for a C/4 and or Daytona...it will drop operating temps in California environment 20-30 degrees IMMEDIATELY.

It takes, now, 20 minutes of driving before oil the t-stat opens...
the thermal exchange efficiency is is so vastly improved.
It is so efficient, in point of factual functionality that: when the fans kick, you can WATCH the guage drop by 10-15 degreesin a matter of SECONDS(30-90, lets be serious here...)!

Go with this first-along with a new t-stat, and I am willing to bet that your problems are solved...blowing head gaskets are a possibility, but so expnsive, and labor intensive, I STRONGLY suggest eliminating all the simple and frankly more likely solutions before suggesting open motor surgery, head gaskets on a c/4, when you are all in and done, will end up over 10K...in MY experience, I am certain, and I've done more of these than ANY poster in all likely hood...

 

I'm glad it was the thermostat and not something more serious.

 

Not that I've heard, check with Rutlands as well, I think I saw a stack the last time I was there.

 

Also check Superformance and Marannelo in the UK or Italparts in Holland. I am sure you'll find one there

cheers

F.