Puddle o' coolant

Aufgeladen944 · 05-21-2010, 03:50 PM

Alright, so I'm finally getting my finances from school under control, and then bam...it's another hit in the gut.

Anyways, I went out to eat my lunch in the car during my break. I started it up, and turned on the A/C (it was hot today), and everything was fine, err relatively normal anyways. By normal, I mean that the car's temperature went up close to the red, which it always does. It's always done it since I owned it. If I hit the gas, it goes back down again. The actual temperature inside the bay seems very hot, however. Either way, I was told it's not a real problem and I shouldn't worry about because they all do it.

But what IS a problem is what happened afterwards. I turned off the ignition and got out of the car, and then I noticed all this coolant coming out. Not the whole amount, but about half a gallon was missing altogether. The car was not running when this happened. It was piddling out from in between the reservoir and the radiator, dropping onto the plastic tray and then onto the ground. I didn't get under the car to see the exact point of release.

My first thought was that the water pump has died; but that wouldn't seem to be the case because the car was off. My next guess is that either the radiator has a clog in it (I just flushed it last month) or that the thermostat is stuck open (or closed?) I did not replace the thermostat, so I hope it is the latter. I do have one here, finally, so I think I'm going to change it anyways.

The car drove fine on the way home; temp was in the middle (I had left the a/c off the whole way home), and it drove fine. No coolant was coming out when I got home.

My questions are 1) is the thermostat the likely cause, and if not, what? and 2) how would having the A/C on effect the coolant spilling out? Or was that coincidence? Also, is a 180 degree thermostat the right one? Or should I go cooler?

Thanks in...Advance

John_AZ · 05-21-2010, 04:32 PM

Do you think it could be the radiator cap overflow tube?

Maybe the line between the coolant reservoir and the radiator. On the radiator side of the line is a small plastic nipple screw in fitting above the radiator hose. This fitting deterioates and cracks easily. It may not be tight.

When you flushed the radiator did you replace this fitting?

The fan switch on the radiator. Not tight?

Back to the temp guage going to red..........

I am sure you are certain there is no air in the cooling system. Air gets hotter than coolant and is reflected on the guage.

Clean all grounds on the car. Especially the one under the dash above the fuse panel. Thank TechnoDuck:

.

Clean the connections by the engine temp sender.

I know this sounds stupid but clean the oil pressure sender switch contacts. Note-these are hollow and snap off easy--gentle.

Somewhere you are not getting a proper circuit and Porsche designed these in a crazy manner to have a common ground and other circuits can affect and interrupt signals to the guages.

GL
John-ex Checker employee when attending UA

Aufgeladen944 · 05-21-2010, 05:16 PM

But if it was a line, why would it only flood out when the car was turned off? I dunno, the whole thing seems strange.

Then again, the whole car is a little strange

AREA951 · 05-21-2010, 06:59 PM

I would check your turbo thermostat and bleed the system also check the tension on you timing belt which runs your water pump.then do a leak down test.

pontifex4 · 05-21-2010, 07:43 PM

After you parked the car (engine and ignition off) was the cooling fan still running? If you were reading above the half-way point or so on the temperature scale, it should have been. If not, what you were experiencing could have been the normal effect of the coolant expansion tank overflowing because the radiator is bad at cooling without air flow.

Try turning off the car, then turning the ignition back on with the air conditioning and fan switches on and see if it still overflows (the fan for the air conditioning condenser also cools the radiator in this case).

Aufgeladen944 · 05-21-2010, 08:51 PM

Well I never moved the car; I had simply turned it on to feel the glorious a/c since it was hot outside. My fan was on after the temp got up, and it was still on after I turned the car off (that's normal, as far as I know).

Either way, it can't be "normal" that the car simply leaks coolant if it's hot outside. That just ain't right!

I'll be brave and try running the a/c again tomorrow, and see what happens. I'm gonna be home for this one, though...

Techno Duck · Techno Duck's Garage

The temp should never get close to the red, even in the dead of traffic. I have seen mine up at the 3/4 mark once or twice before..this was after turning the car on after it sat for aprox. 10-15 minutes (caused from no circulation of the coolant and heat soak). As soon as the car is turned on it dropped down.

Do yourself a favor and clean all the grounding points and also check the wiring for the temp sensor. Mine were pretty badly beat up with cracked insulation. Hard to tell from the picture, but trust me they were bad. I cut the old leads off and soldered / heat shrinked new spade connectors on.

For your coolant leak, there are 3 common things to check if you are getting a puddle under the expansion tank.

Check the radiator cap gasket and insure the seal is in good shape. No cracks..etc. Usually if this is bad it will cause coolant to come out of the overflow hose on the expansion tank.. and i reckon bad radiator caps have caused many headaches for people..they do go bad.

Check the turbo water pump, the body seal on these goes bad and eventually will piss coolant out all over the place.

Check the plastic end caps on the radiator.. German plastic (we all know how great it is!) subject to 20 years of heat cycling gets very brittle and the plastic nipples do break.

The last thing which you probably dont want to hear is potentially a headgasket on its way out. Route the overflow tube from the expansion tank into a plastic waterbottle. Drive the car around with no boost and check the bottle. If you get overflow you either have air pockets in the cooling system or a bad rad cap. Drive around on boost (give it a few good pulls) and check the bottle.. if it overflows on boost your headgasket more than likely is on its way out and will only get worse. What happens is the cooling system gets pressurized and will push coolant out the overflow tube.

This is one reason i am sick of the 951 and want to pick up a 993..no more coolant leaks.

.

pontifex4 · 05-22-2010, 08:53 PM

Quote:

Originally Posted by Techno Duck

This is one reason i am sick of the 951 and want to pick up a 993..no more coolant leaks.

.

Oil is a coolant, too, Jon!

Techno Duck · Techno Duck's Garage

Quote:

Originally Posted by pontifex4

Oil is a coolant, too, Jon!

True, but if it leaks oil i can just put in a heavier weight

.

HondaDustR · 05-23-2010, 09:25 AM

That didn't help me...

Aufgeladen944 · 05-23-2010, 06:04 PM

Well, I'm putting it up on a lift tomorrow to look at things, and I'm definitely going to change the thermostat and the radiator cap anyways.

But still, what would having the A/C on have to do with coolant coming out? Because I've driven the car for three more days now with no apparent coolant loss. I did not, however, let it idle for any long periods of time.

Gordon Rankin · 08:56 PM

My personal action on something like this is to make sure that you have bled the system properly. You will overheat from the coolant back up caused by an air bubble. You can and will experience that which you described.

BTW, your car should not be running so hot. It is not normal.
Are both of your fans working properly?

Aufgeladen944 · 05-28-2010, 02:54 PM

Both fans are working properly, as far as I can tell. I'm having the shop take a gander on Tuesday. Car still leaks fluid when I idle it with the A/C on and shut it down. It only leaks after I shut it down, but the temperature gauge seems to show relatively normal temperatures.

This is a stupid question: the coolant reservoir cap looks like a radiator cap, but I have a separate part listing for it. When I put in a radiator cap, it seemed to lock into place fine. Is it not just a radiator cap or is it a specialized one?

It's a little weird...

John_AZ · 05-28-2010, 03:30 PM

Early and late cars use a different coolant reservoir tank cap-radiator cap.
Different pressure on each. I use Behr caps.

What is interesting is that early cars use a 110KPA /// 16 lb cap (early cars). The late cars use a 150KPA /// 21.75 lb cap (late cars). KPA stands for Kilopascal

John

Aufgeladen944 · 05-28-2010, 06:48 PM

Right, but is the radiator cap the same as the coolant cap? I mean, if it fits, is there a problem?

Gordon Rankin · 07:02 PM

Same thing.. Just need correct one for your car..And like John said, the proper pressure range. Behr is a very good bet.

pontifex4 · 05-28-2010, 10:14 PM

Quote:

Originally Posted by Aufgeladen944

Car still leaks fluid when I idle it with the A/C on and shut it down. It only leaks after I shut it down, but the temperature gauge seems to show relatively normal temperatures.

Just to be sure, here is what I suggested as a test:

1. Start with car running, and hot
2. Turn car completely off
3. Make sure interior fans are switched on (#'s 1-4 on the fan control) and the A/C is on
4. Turn on iginition, without starting the car
5. Get out, and see if it still overflows

Aufgeladen944 · 06-05-2010, 08:27 PM

Well, I replaced the thermostat today with the help of a local mechanic (great guy), and that seemed to fix the problem. There was also a lot of air in the system, and that didn't help it at all.

The thermostat was not easy to do; the snap rings took forever to do right (he did that part), but hopefully that's all it was.

Next year I'm due for a belt/water pump job, and I'll probably have some other things fixed, too.