Water Pump (indications of problems)?
 

Hi. First, I have a "97 Boxster with 45K miles. The water pump was last changed in 2010 when it has 28,600 miles. So it has about 17K miles on the pump, but of course 7 years on it too.

Ok....Here's what I observe:
Normal warmup time
Normal max and stable operating temp (~190ºc, straight up needle)
But, I have noticed the low coolant light (red light on the top of the temp gauge) has gone off a couple times in about 4 months. Each time it takes a bit more water to get it to the max line.

I'm going to be a little more scientific going forward, but it took a full 16-oz bottle of water to get level up. I see no leaking signs on the garage floor.

Short of ripping things apart and take a look, is there anything I might do to help my odds of detecting problems before they become a real problem.

Thx!!

Besides the WP, Boxster's have two radiators, lots of radiator hoses a coolant tank and bleeder in the trunk...you get the idea.

Easy things to do is:

1. Look around your rear trunk, under the carpet and near the coolant tank for signs of dampness or leaks.
2. Look around your coolant tank cap. The latest revision of the cap ends in '.04'. If yours is older, invest in a new cap. Look for signs of leaking or dry white residue around the bleeder assembly (Black item next to coolant cap).
3. Remove firewall carpet and firewall behind seats. Start your car and inspect (CAREFULLY!) around your water pump (again, white residue is a sign of a leak).

4. Take your car to good indy and have them pressure test your system to pinpoint your leak.

If your inspections fail to uncover anything

You are not going to get better advise then that :)
My bet goes for the cup.

Sounds good.

But can you guys tell me how often you top off the water reservoir? What's a normal amount and how much do you add at a time?

I just need a benchmark to work with.

Thanks!

Simple benchmark - You should not have to top off.
When all components of my cooling system are working correctly, then I don't need to add any coolant/distilled water.

including the areas dghii suggested, make sure there is no condensation on your trunk lid.

Oh....

Well then...That's helpful information. I have a leak!!

In 14 years and 73,000 miles of ownership from new on my 03 S I have never had to top off my coolant except for the time that the water pump started to fail and was leaking coolant around the bearing.

Yes, under normal circumstances you should not have to top off the coolant. If you are using Porsche coolant it leaves a white residue to help identify the leak. The most common issues are a bad coolant cap or cracked tank. Feel around under the carpet in the trunk, and pry the plastic cover under the cap off and check the bleeder valve. Also, if you have already topped up with 16oz of water you may want to start using a 50/50 mix. However, if you do not know what is in the system do not add a random coolant, mixing different coolants can cause them to congeal.

Ok. I will take another look. Last check, the carpet was good a dry.

I have no idea what type of coolant was used before I added simple water. Maybe the maintenance records will show, but otherwise, no such luck knowing.

You definitely have a leak somewhere and you probably need to find it before it gets critical and trashes your motor. Also, distilled water is recommended instead of regular tap water . The minerals in tap water will cause galvanic corrosion in your cooling system which will become a nasty future problem.

Good luck!

Hi.

I looked again closely at the carpet and trunk. Everything looks really good. But....I did notice that the "cup" section that the water cap and oil cap sit is often just a little wet. Plus the coolant cap is often a little wet too. AND, the cap was replaced way back in 2004 because the owner was complaining about the hot temp coolant light was going on. So, the dealer replaced the cap. My cap ends in 02. So, I'd say that's my first step here right? Change the cap to a newer version ending in 04?

Thoughts?

Change the cap, get a pressure test done, and flush the rads. Then get a proper coolant mix in there and you are good to go.

Condensation is not a leak. I've seen lots of discussions about this issue and some have success solving condensation issues by replacing O-rings in the bleeder unit, or replacing the bleeder itself.

I've done both. Still get condensation.

Thing is, if you look at the trunk and the rubber seal, there's a reason why there's a weather seal around the top of the area of the top of the coolant tank, oil dip stick and fill tube. My guess is to keep the hotter temps and humidity (condensation) out of the rest of the trunk. If there was never condensation, there'd be no reason to isolate that area from the rest of the trunk.

I'd have to disagree a bit. The trunk is common to the passenger compartment by way of the clamshell area (vents just above the trunk light). Therefore I believe it is designed to keep hydrocarbons (oil fill) and coolant vapors from potentially entering the passenger compartment and overcoming the occupants. So with top up, positive ventilation is from cowl intake, passenger compartment/ clamshell, trunk and out the flapper vent at the right rear of the trunk.


Edit: This is also why IMHO it is a bad idea to mount any Turbos, accusumps and the like in the trunk.

I use to think the same thing, a lot of heat there on a cold trunk lid, it was my denial. I replaced my expansion tank (Cracked with trunk filled), new cap still had condensation. I was having to add a 1/2 cup top off every couple of months. Then I started to see a couple drops on the garage floor. The condensation was cooling and draining out.
I sandwiched bagged the purge valve, cap and top of tank and low and behold the purge valve was leaking pressure out of the 'O' rings. Replaced them and now no condensation, no topping off. Condensation is an indication you are losing pressure from something on the top of the expansion tank. BUT it's not going to result in a 1-1/2 gal. leak

I get it! I guess I just live with the condensation and don't worry about it at all.

Any particularly strong opinions of the Porsche coolant cap vs. an after market version? $36.00 after shipping vs. $10.00 after shipping!

Seems like a simple enough part...

Thoughts?

Don't cheap out on cheap parts. Unless you like doing and replacing stuff twice....

So a few years back I replaced with Porsche cap 04. With last year condensation issue, I tried OEM non-Porsche. It seems to hold pressure, it was 'O' rings in purge. The non Porsche will not have the part number on it so no one will be able to tell if it's a 04 version. I taped the part number from the bag onto my expansion tank.

Spend the whopping extra $26 on the real thing

Yeah. I did spend the extra money. It's on order now. Monday.....

So my plan is to check and see if the cap itself stops the leak. That should be any easy check too. If that clears the problem, I think my next step will be to flush the coolant and start anew.

Thanks all!!