One big air bubble in the cooling system could explain all the current symptoms. It is very common to have air trapped in the system on these cars.

First thing to do -
Take a deep breath.

Second thing to do -
Take another deep breath.

This will get sorted. I would follow the procedure for burping all the air out of the system before making any rash decisions.

Thanks for that.
The mechanic insists that there's no air in the system, but I'm not convinced yet.

Did he refill the system under vacuum? If not, I would not be surprise that there is air trapped in it. The line you blew off the cooler is the highest point in the system, and is there to vent air trapped in the oil cooler to the tank in the trunk; so I again would not be surprised there is air in the system if vacuum was not used to refill the system.

I honestly don't know.
But he's a very reputable Porsche guy here in Lawndale CA.
He was pretty insistent that there is no air in the system when I asked him earlier today.
I was unable to ask him before he closed for the 3 day weekend if he uses a vacuum or not.
But what doesn't make sense to me is that if there is a circulation problem as he indicates, why wouldn't the temp go up or it overheat?
A second opinion mechanic (a very reputable guy in OC) told me to drive it tomorrow stone cold and not refill the coolant and see what it does.
He also suggested a test for hydrocarbons in the coolant.
Please weigh in, there are some very kind and knowledgeable people here who do not have skin in this game.
Thank you.
Rob

Please help with advice.
Thanks!

DUde. Drive the car!

That half cup of coolant that came out from the overflow means that the air pocket already passed. When air gets in contact with hot in a closed environment the pressure increase by 1000%. That's gone now - you should now see the coolant level 3.24mm lower than it was before and that's all there is to it.

RE vacuum; "all" mechanics (in-the-world) use vacuum to refill. Even the cheapest shop you can find in the middle of china use vacuum refill. How the hell would it work otherwise. Come on guys...

As per advice:

"drive it tomorrow stone cold and not refill the coolant and see what it does"

My advice: "drive it EVERYDAY and have fun" :cheers:

Get someone that knows what they are doing to pull a vacuum on the cooling system to get the air out.

I am beginning to believe that the water pump impeller melted or broke based on the fact that there is a fine black powder in the bottom of the coolant tank now that it's cooled off overnight and is only about 1/3 full.
Do I try bleeding it first?
What do I do?
It's become a money pit and I think that I may have a clogged cooling system as the mechanic suspects from the meltdown.

Any advice?

Junkers will give me about $1500 for the car.
Is it worth putting the kind of $$ into it to see what's going on?
It's a 2002 with 145k that was run while completely overheated. It seems to me that even if I do get the coolant thing sorted out, are there cracked heads or cylinders in my future?

Is this the type of scenario where the temp gauge will not register a problem as going above 190 but if there is no circulation, the temp is actually a lot hotter and then that is causing the overflow to dump coolant once it gets hot?

I'm trying to stay logical and reasoned without losing my mind here.

I know this may sound over simple -- but I had this happen to me coming off of the track one time.

I was double checking everything before I went on track -- even undid the water cap and screwed it back on.

As I came off track -- temperature started to rise -- and it was peeing all over the paddock, right in front of the right rear tire.

I thought my weekend was shot. Water pump for sure. NOPE -- dummy me I had cross threaded the screw on cap.

Found a jug, filled it with water. Opened the pressure vent, and carefully put the cap back on. Went out and ran the next session, took it a little easy -- no issues ever again.

Don't give up on things... Just be diligent and work through some of the kinks...

Mike

There is a possibility the residue in the tank is from the previous water pump. Did you see the removed pump? I don't think your WP saw high enough temps to melt or cause the impeller to fail since they are designed to operate in conditions to 220 deg. Once the system lost pressure steam is only ~212 deg. Yes the cylinders no doubt saw much higher temps but with no coolant transferring that heat, the entire block would have to be heated to the failure point of the impeller. If that had happened I don't think your engine would be running now. The caveat to this is, was there collateral damage to the pump when the alternator failed? Since the car appears to not be overheating while driving then the simplest step is bleed and drive again.
However if this was my car, in order to have any confidence in it, I'd pull the WP and check it's condition. if good, a new gasket and a new thermostat and you can have some confidence that your coolant circulating system is at least functional. If bad then the next steps can be considered to find the parts.

Sorry if this is overly obvious, but has a total system flush been done? I would suggest a flush, drive a while, maybe flush again, and see where you stand. Oh, and yes, get the new cap. I lost coolant about a year ago due to a bad cap (and I would have sworn it was something more serious).

Best wishes.

Thanks guys!
I am encouraged.
I just bled the system and then drove it up and down a very steep canyon road.
It's sitting in the garage now and only let out a few drops! from the overflow.
I'm going to let it cool down for a few hours and then drive it again.
Temp gauge stayed right around 190 which was good.
I need to change the oil from the meltdown tonight, which I have not done yet.
I also will also change out the water pump and thermostat as soon as I can swing it.
I will also need to flush the whole system.
I like the idea of multiple flushes, but not $120 in coolant again (still cheap insurance)
And yes, I did see the old pump when it was removed and all of the vanes were intact.
But so far, so good!
This is a new cap as of yesterday. I read on here to drive for a few days with the bleeder valve open. Is that a good idea? One guy said that's what they do when they race Boxsters. I'm just a daily driver guy, though.
This board is a lifesaver and I'm beginning to think that my mechanic is a "Worst case scenario" thinker. He's right in the fact that he doesn't cut corners and does lay out all possibilities though.
I LOVE my Boxster and need to listen to the warnings from now on.

Good news! BUT get that oil out of there before you drive again!!! That oil has done a marvelous job but should be changed out ASAP since I'm sure it's suffered from Thermal Breakdown and if any engine deserves it I think this one qualifies. And yes leave the bleeder open and the cover off and see if you can identify where the coolant is leaking from. Congratulations on maintaining sanity/

Thanks Monty!
We know for sure that the coolant was coming from the overflow. The mechanic had it on the lift yesterday and showed me. I just looked again (OCD) and there are only a few drops on the garage floor.
One other question, there's nowhere to get a German oil filter (Hengst is what I like to use on this Sat of a 3 day weeked. I found this at Autozone: STP Oil Filter S8278 - Read Reviews on STP #S8278

I guess it's going to have to do as it's all I can find within a short distance to go pick it up. I think it will hold me over until I change the oil again which will be in way less than 5k just to play it safe.

Yes I have no doubt it's coming from the overflow. The coolant cap and the purge valve are in the overflow formed into the top of the expansion tank. With the cover off you should be able to open the trunk and see the coolant leaking. Just don't attempt to tighten when leaking!
Do you have a NAPA nearby? I think they carry the Hengst filter but I'd put a WIX/NAPA gold in if they have it.

Napa is not answering their phone and they close soon.
Oreilly has this Wix: https://www.oreillyauto.com/detail/wix-5291/filters-16470/oil-filter-16731/oil-filter-12090/oil-filter/57211/4836299/2002/porsche/boxster?q=oil

would this be a better choice than the STP one?

Yes. WIX is the one of the best.

I'm going to get it and the oil now.
Should I let the oil drain overnight?
Does that really make a difference?
You have been most kind.
Thank you!

You're welcome! Just let the oil drain for 30 min to an hour.

Ok thanks!

Update:
I just took the car out to get new oil, a filter, and run a few more errands.
Along the way each time I stopped I sat down next to the ground near the passenger rear tire to listen for hissing or dumping coolant. I did not see or hear anything.

I live at the top of a steep canyon and as I was driving up the canyon the temp gauge rose a bit higher than it's (formerly?) normal temp of around 180. This time it was more like 190. It is a very hot and humid day here in Socal so that may account for some of it.

Anyhow, as soon as I pulled into the garage, guess what? Hissing and coolant started dumping out of the overflow. I had the wire in the up position the entire trip and I could hear air escaping from that valve. The coolant level in the tank is now is down to a bit more than 1/3 (from dead in between max and min) but certainly lower than it was when I started. At one point, while I was doing my errands I saw that the entire coolant bottle looked like it was full. It was almost all the way up to the black plastic.

I'm new to this car and new to all this. I'm learning what "normal" is from this forum.

Please let me know what's going on and if this is all part of the bleeding process or if I do in fact have some sort of coolant or circulation issue going on.

The oil is draining and looks pretty black to me. This is probably from the meltdown last weekend and it had been changed less than 1k miles ago.

Thanks in advance. This ought to be called Porsche University Online. I'm really learning a lot here!

It would not hurt to pull the bumper at some point and check the radiators for debris. Some cars are driven in the rain and over several years parts of the radiators get clogged with dirt, which will cake up on the radiator which stops air flow. Not to mention leaves, grass clippings, etc When I cleaned mine, I found cigarette butts, a chewing gum wrapper, a small piece of paper, plus many leaves, and some pine needles. No dirt, but I did find a small amout of sand in the lower corners of the radiators. It's just good maintenance! When I drive my car the temperture guage needle sits the with of the needle past 180. Never any higher even when the A/C is running. I might add, the temperture guage is watched more than any other on my car.

Were you able to positively identify the purge valve leaking? You said air but should be steam? When it is actively leaking you should be able to see from where. The purge valve is not supposed to leak externally. If it does it will need to be replaced. That's why I've suggested this for the 3rd time. You have replaced the cap so it can be ASSUMED the cap is not leaking. I don't like to replace parts needlessly. Is there a white crust around the purge valve. Throw me a bone here.
At this point I believe your leaking is due to heat soak. After your drive when the engine is shutdown Coolant circulation ceases and temp increases from the residual heat in the cylinders. This is normal. However if the system does not maintain pressure such as the purge valve leaking, the coolant will boil, turn to steam and leak. The purge valve can be replaced, but it is more cost and labor effective if it can be identified as the source of the leaking.

On reflection perhaps you aren't aware the overflow hose that you see leaking is the drain hose from the basin cast into the top of the expansion tank, that the coolant cap, dipstick and purge valve are located in. When they leak, liquid is collected and drains out that hose. Yes?

I'm sorry maybe I misunderstood. Are the purge valve and the bleeder valve the same thing?
It's definitely dumping liquid coolant and not steam and it is coming out from what the mechanic told me was the overflow that dumps above the passenger rear tire.

As it has cooled over the last hour or so, no new liquid drained out, but the tank is now well below the minimum mark and less than 1/3 full again.

No, there is no white crust around the valve or in the oil/coolant fill area. When it's dumping liquid, I don't see anything going on (steam or liquid) in that filling area.
It's all coming out from under the car above the passenger rear wheel.
Which is what the mechanic told me was the overflow while it was on the lift yesterday.
I'm also wondering now if that valve is bad. When I pull up on the wire it doesn't move very far and then when I put the wire back down it doesn't move too far either.
Should it be flush with the top of the valve in the closed position? Because it's not. But you also mentioned that this should release steam and not liquid.
I did hear it gurgling air while the coolant was dumping out, though.
The other part that I'm not clear on is if the valve is defective, should I be seeing the liquid and steam collecting in the basin and then running out through the hose or only as it runs out the hose?

I'm not doing something right, as I'm getting the same results.

I'm obviously not understanding something correctly here, Lew.

But I am learning and I think we are getting closer to where I understand what's going on.

Ahh Good. Yes the purge and bleeder valve are the same thing, it has the wire bail on it. It's purpose is to purge or bleed the air from the top of the radiators and oil cooler so the system is completely fluid packed.
Now the two sources for coolant draining out the drain/overflow hose are the coolant cap and the purge valve. The drain hose attaches to a nipple on the tank which drains this area. The hole is just forward of the purge valve, hard to see but it's there. If the fluid is coming out of the drain hose then one of those two points must be leaking. Do not install the plastic cover over the purge valve. This way next time you hear the hissing open the trunk and see if you can tell which one is leaking. Again if the cap is leaking do not attempt to tighten until the car cools off. Better?

If the cap or purge valve are not leaking then perhaps the hose from the oil cooler you replaced the fitting on is leaking???

add some distilled water . and keep driving. I had exactly the same thing and as I said
first off and then all the experts said get it on an incline. I backed it up on some ramps and opened the valve and ran it and finally after months of seeing a coolant level up and down it stopped.Good Luck

Best advice was the jfp in pa expert says get someone who knows what they are doing and pull a vacuume....done

Ok. Thanks. I'm really beginning to understand. Yes, the hose BEHIND the firewall on the coolant tank is where the liquid is leaking from.
So, I am going to keep an eye on that bleeder valve as well.
I'm not sure if it's defective or not.
On the Pelican page the following reviews describe my valve pretty well:
Pelican Parts - European Automotive Parts and Accessories - Porsche • BMW • Mercedes • Volkswagen • Audi • Saab • Volvo • MINI

I did buy "The German" bottle and not The Porsche. Lesson learned. No more cheaping out on parts.

If that valve is indeed leaking during the cool down or heat soak, would I see liquid or steam coming out of it?
I do not see steam, condensation, or liquid near the new cap or the bleeder valve, yet the liquid spews by the rear tire.
This morning I did not get the engine as hot, which is probably why it didn't leak as much. This afternoon's leak was about the same as yesterday's.

I'm not sure that rushing out and buying The Porsche valve is a good idea just yet.
I'm also going to keep a close eye on the hose from the top of the oil cooler, as I don't know if that's the culprit.

Besides, Pelican is closed until Tuesday.

I found a thread with a lot of good info dealing with this with pics and everything! Enjoy

http://986forum.com/forums/boxster-general-discussions/56959-ugh-i-need-some-help-identifying-coolant-leak.html

Thank you!

Rob - if you have air in the system it can cause your car to spew coolant via the relief valve in the coolant cap. The coolant will flow down a tube and be dumped in front of your right rear tire.

If you can't find someone that can do a vacuum fill (best solution - as JFP suggested), the next best way to get rid of that air in your system is to get the back of the car up in the air and open the bleeder valve on top of the overflow tank. Park it on a steep downhill or get the back end up in the air using ramps. If you can get the back end up it will burp out the air and it will stop spewing coolant.

You should also make sure that your coolant cap is one that ends in a 4. Heck, they are cheap enough - change it anyway.

Just my 2 cents...

Bill

This just in.....

I changed the oil and filter and the car does run well.

But (there's always a catch here) I think the mechanic is right in that there is a circulation problem. I jacked the rear of the car and got under it while it's running.
There is a steady stream of drips of coolant constantly coming out. When the car is moving they vaporize so quickly that I don't see them. When I get the car hot enough or when the heat soak occurs, it really starts dumping coolant.

From what I can gather it seems like it's more than just an air bubble. Tonight after the oil change when I took it out for a very brief drive (I am getting wiser here) the temp gauge almost immediately went up to 180 before I even got out of the driveway. (It's never done that before it used to take a while to get up to temp)

So now my questions are centered around why there is a constant dumping of fluid.
The mechanic told me that the cap is designed to vent at 15 psi or thereabouts. So what is causing this to happen?

So far my hypotheses as to why this is happening after the meltdown are:

1. The impeller blades melted or broke off and are clogging the radiator, the thermostat or worst of all a coolant channel in the engine.

2. The thermostat was destroyed in the melt down and is permanently closed and not allowing coolant to circulate.

3. The water pump is bad and/or the impeller does not create enough coolant flow.

4. The radiator(s) are damaged or clogged from the melt down.

5. The bleeder valve is permanently open and is allowing air into the system. Should the little part that rises when you lift the wire go back down to being flush with the top of the valve when it's closed? The rubber in it is of really poor quality and the wire keeps coming out of the holes and is ripping the side of the piece that it lifts up and down. If this were the case, would the coolant or steam be coming out from under the valve where I wouldn't see anything?

6. It's still possible that there's air in the system, but would it constantly be leaking coolant (which it is as I have now confirmed) if this were the case or would it just dump occasionally as I had thought it was doing?

7. A pressure test was suggested, but I know that the coolant overflow hose is where the leak is coming from. If it's the thermostat or internal problems in the engine that's not going to help diagnose anything, is it?

8. The coolant tank has gone bad. I kind of doubt this one, as it's even dumping coolant on start up from stone cold and it's bone dry in the trunk. The ONLY place where it leaks is the overflow hose.

9. I can't think of anything else!

The strange thing is that tonight, as soon as I started the engine, there were drips of coolant coming out of the tube. From a stone cold start and it only started to flow more as the engine heated up. I had not noticed that happen before in the last few days since the mechanic fixed the pulley and belt.

This is very frustrating, but also kind of a fun (albeit expensive) challenge and a good learning experience. I plan on owning a Boxster of some sort until they pry it out of my old feeble hands many years down the road. So this knowledge is invaluable.

The question is where is the most logical and cheapest place to start given these symptoms? The temp gauge does not go into the red or even above 190 which is higher than it used to be prior to the meltdown. This is as it's spewing fluid out of the overflow.

I realize that I still may have an engine that's going to have a cracked head or cylinder looming in the future as a result of my idiotic decision to keep driving during the melt down last weekend. This line of thinking leads to me not putting too much more money into what's going on and walking away after inspecting the water pump and replacing the thermostat and/or the bleeder valve if they are indeed bad.

But, I also have faith that once I can figure out why it's leaking coolant I may have a chance to have many more miles of "Happy Boxstering" ahead. The challenge is to get to that point without going broke first!

Please keep up the flow of good advice. I feel like we are zeroing in on where the culprit may be.

I love this car and want to keep it alive if at all possible.

Thank you!:D

Looks like its time to bring the car to a mechanic/shop. These folks learn all about car diagnostic and carry most if not all the checks that you've described in this thread. Kind of a second nature to them mate... all it needs is a pressure test kit, which they 'all' have anyway.

Any reason you don't want to give the car to a mechanic? If you want to keep it that's what I'd recommend you to do

No question that my indy can do it. He's $140 an hour though.

I'd also like to see and do as much as I possibly can before I take it to him as well.

It's a 3 day weekend here and he's not in until Tues anyway.

I also think that the more information I can give him, the better.

And hey, I may just stumble on to the solution and save some $$

When he gave me the new cap on Friday and I called him to tell him i was still leaking his reply was, "This is where it gets complicated"

I survived cancer, I'll survive this.

Thanks for the solid advice nine8Six

Totally feel you. That is the main reason I've purchased a VW Lavida 1.4TSI under warranty. I just can't afford to drive a Porsche everyday man, even less afford to buy a new one under warranty. One day I will tough :D One day lollll

Try to see if you can get a (cheap) pressure test kit with a Porsche adapter for less than $40~50. If this exist?... Harbor freight? Autozone....

WP is fine imo... the car would overheat instantly if you'd have failed impeller(s). Certainly would run much hotter that what you are describing anyway.

The reality of my situation is that I am a recent cancer survivor.
I was laid off during my treatments and had been doing delivery work that involved using the vehicle while I looked for a real job.
I was able to afford the necessary maintenance until the meltdown.
I'm at the crossroads now of just how much more I can put into this car to hopefully keep it for a few years while I save up some cash.
Or to cut my losses and get out of it if it's a money pit.

I'd like to keep the trips to the $140/hour guy to a minimum right now while I evaluate what my next move is going to be.

If there are things I can do, I want to try those first.

My experience so far with The Boxster has been good medicine while I recover.

It brings joy into my life and that **************** eating grin that anyone who drives one knows.

That is worth fighting for.

If you are getting coolant running from the tank overflow pipe it can only come from two sources , the cap or the bleeder valve .You can see both of these if you remove the cover plate below the coolant cap / oil filler cap , neither should leak .As JFP says the only sure fire way to bleed this system is to apply vacuum .If you have a compressor an Airlift vacuum bleeder is about $100 , if you don't I have used a Harbour Freight vacuum brake bleeder $10 and a rubber bung ,a bit slower but it worked ok. Utube the operation detail .I think you still have air in the system , the heater circuit can be the problem as the pipes are at the top of the core
Peter

Great hope for those who are fighting, thanks for sharing.

Survivor myself. Survived suicide tendencies only one week ago (also Porsche/part/price related lollll). First time it even happen to me and hope it doesn't again. Porsche cars looks so much better when they work. Hope you'll (our indy, I suspect) get it fixed

Someone on Rennlist suggested that I check the coolant hoses that flow both in and out of the radiators to see if the water pump/thermostat are working.
This makes sense to me and not something I had considered.
He suggested that it be done on a lift, though.
Can I get the front end up high enough to get under it and run it until it's hot enough to get under it and squeeze the hoses that go in and out of the radiators to check them?

This is a good proactive action that I think I want to try.
I still have 2 more days of a long weekend with a car that's really only useful to take to the grocery store at the moment.

Any other tests, ideas, or things that I can check in the next few days would be greatly appreciated. I'm tempted to try and take out the thermostat and even the water pump to see what's going on.

This car is my daily driver and I'm willing to try as much as I can first before going back to the mechanic on Tuesday. Not out of shame or ego, but I'm running out of $ to throw at the problem. There's enough left for one last repair at the moment.
If we can get this leaking problem licked, I am able to keep earning in the mean time to make my next move.

The other issue is that if it is the water pump and missing impeller blades are clogging water channels somewhere in the engine, am I correct in my thinking that it's really then just a matter of time until the thing grenades on me? If so, then I cannot sink much more $$ into the car.

Agonizing to say the least.

I'm not spilling my guts here for :ah:

I'm just being as honest as I can possible be so I can formulate a plan working with what I have for the best possible outcome.

There are people here with decades of accumulated knowledge about these cars that are willing to share it freely and I'm grateful for their help.

Well since it's been too damn hot for golf or driving the Box (115 deg yesterday) I guess I'm your Huckelberry, if you're interested.
While your temperature sender apparently needs to be changed I think we still need to verify the leak issue. I have attached a few pics since they're far better than words. So to be clear, your leakage looks exactly like the last pic in the thread I attached yesterday? From the same hose? Maybe this is simple but long range troubleshooting and assumptions don't work. You can verify by having someone pour water into this area while you observe it draining out the hose from below.

In this image I am pointing to the drain. As you can see the only sources (normally) are the cap and the purge/bleed valve.
http://986forum.com/forums/uploads02...1504458451.jpg

In this image you can see the tank is two pieces bonded together. The forward nipple is the nipple for the drain to the manifold where it passes thru the trunk. If you look closely you can see that this nipple has very little clearance between it and the tank. There is a possibility this seam has failed here from the overpressure and is leaking coolant. If you can with engine running,and coolant leaking, look down into that hole and see if coolant is coming between the seam. As long as the cap and purge assembly are not leaking, then this really is the only point coolant can drain to that hose.

http://986forum.com/forums/uploads02...1504458973.jpg