Boxster - Water pump failure (twice in less than months) - Page 2 - Boxster/Cayman - PistonHeads UK

A leak in the coolant system? Otherwise, how is the coolant getting onto your floor? I had a rad leak in a BMW once with the same symptoms, although you could see the coolant hissing out through the radiator grille.

To be fair, the waterpump needed replacing at 60k miles which is reasonable. Then the engine was rebuilt, and shortly after the coolant all ended up on the floor. Surely the most likely thing is that in rebuilding and installing the engine into the car something was loose, like a coolant hose has popped off or split? Maybe the coolant headertank has split or cracked? Something cheap and simple? For melodrama and "worse case" maybe the oil in the coolant is the clue, and a head gasket leak has "super pressurised" the coolant system causing a hose to pop off, split, or header tank to crack. But I bet it is something simple following the rebuilt and reinstallation of the engine.

Thanks for the responses. I have been monitoring the car since I received, and parked on different locations to see if there was any leak (but none). The coolant level was also same, there was no indication of a small leak. So I'm also suspicious of sudden coolant hose has popped, the strange thing this just happened when the car was on stationary mode, while waiting the garage door to be opened. (Started to hear water noise in the back and very strong smell, just stopped the car before I leave..)

Has it actually been proven to be waterpump? Are you still on the original expansion tank and cap?

Not sure if it's the water pump again, they will diagnose this week. The water tank and cap has not been changed since. We have bought a new cap but the previous one was still in good condition so the car was still on the previous cap when this thing happened. Do you think the problem with the tank? If so, I thought it would have been already diagnosed as after the engine rebuilt, they have drove around 120 miles, to do both short and long distance tests, and underneath has carefully been checked if there was any trace of leak. edc: By the way, your boxster is a true piece of artwork! congrats, looking amazing just saw now! Edited by ooid on Sunday 28th February 19:41

This could be an airlock, these cars are notorious for this and require properly vacuum bled. The water could be coming from a small pipe on the other side of the filler, in the engine bay, when the system is over pressured the water comes shooting out of this small pipe all over your engine.

If you think maybe the OPC has mis-diagnosed the water pump, and carried out unnecessary work, should you now be taking it to another garage? A good indy maybe? Two reasons: 1/ Get another opinion. 2/ If it's not the water pump, get a written report on what it IS and that the water pump was probably not the issue. Take the latter up with your OPC if you feel aggrieved. Depends if you really trust your OPC. Who did the other, non water pump, work? OPC or one of the other experts you mention?

DJMC said: If you think maybe the OPC has mis-diagnosed the water pump, and carried out unnecessary work, should you now be taking it to another garage? A good indy maybe? Two reasons: 1/ Get another opinion. 2/ If it's not the water pump, get a written report on what it IS and that the water pump was probably not the issue. Take the latter up with your OPC if you feel aggrieved. Depends if you really trust your OPC. Who did the other, non water pump, work? OPC or one of the other experts you mention? Sorry the issue was a bit complex. The water pump was replaced by the official OPC. After their diagnosis and a huge bill (even without a deeper inspection, they were asking more just to check if engine needs replacement) I decided to take it to the indy garage and get the engine rebuilt by their specialists with proper updates like IMS, new clutch, oil cooler and etc.

ooid said: Not sure if it's the water pump again, they will diagnose this week. The water tank and cap has not been changed since. We have bought a new cap but the previous one was still in good condition so the car was still on the previous cap when this thing happened. Do you think the problem with the tank? If so, I thought it would have been already diagnosed as after the engine rebuilt, they have drove around 120 miles, to do both short and long distance tests, and underneath has carefully been checked if there was any trace of leak. edc: By the way, your boxster is a true piece of artwork! congrats, looking amazing just saw now! Edited by ooid on Sunday 28th February 19:41 Thanks for the comments. My car is pretty well sorted mechanically. Cosmetically it's no concours car. It's been modded for driving more than showing. Your mechanic should be able to do a pressure test on the system. That will show where the problem is quick smart. But over time it has been known for the expansion tank to develop hairline cracks or at times crack entirely. If your cap is old check it's the latest revised part with the 04 ending part number.

Hello there, thanks for the advice. I'm yet to learn this week what was actually the real problem though I have a feeling it is the tank. I was not able to remove the whole carpet on the back but I have sensed a bit of coolant+water below before leaving it to the garage. Really hoping this is not another catastrophic issue, it's been almost 5 months now since I could not enjoy the car and did not give me any problem for the last 4 years or so.

If it's wet around the rear boot carpet and you are sure it's not the system burping itself through the cap and overflowing then it's probably the expansion tank.

Looks like an airblock as mentioned before! both tank and cap tested, nothing wrong but we have decided to renew them anyway and there is no leak in the car so far. I will be picking it up this week, and hopefully no more water issue for a while!

Bad news; It started to leak again today! I went to pick up the car today, and both cap and coolant tank replaced with new versions. Tested the car for a while, driving around in the area to keep engine heating.The fan started a few times and later when I went to petrol station I realized the pink water coming again near from the rear right tire. Quickly drove back to the garage, after testing there again we realized It's leaking through the valve? after overheating the car. This time it did not empty the whole tank tomorrow they will test again. (There is a massive condensation on the trunk, where it touches coolant cap) What would be the problem? since engine completely new and both caps and coolant renewed, would it be the bleeding valve? The water pump also tested and checked no leakage over there.

If it's pressure tested and known good then you have to question their procedure to refill and bleed the system.

My worry , if this is not just a air-bubble in the system but something different that not letting the coolant overflow in the system and bleeding instead?? Not to mention the car is in London and currently weather is pretty cold, so it should not cause this issue. I have used this car on quite hot days in the summer, in traffic and never had a coolant lost issue like this before.

a few more info maybe - no change in the oil level. Always stayed between 3-4, checked the dipstick twice last week there was nothing dodgy. - I can't see any weird puff or weird smoke coming out of the car. Its pretty usual. - The engine is very responsive since the rebuild, no stalling or anything. - Fans seem to be working after a while (especially on a idle) and this basically happened again where I had to stop the engine and the fan stopped as I was at the petrol station. (The guy in front of me probably was doing his grocery shopping! had to wait in my car like 5 minutes for him to move on so that I can put some petrol) - The garage told me they did a pressure test before, I will ask them to do this again. For a note again, it did not leave the whole water+coolant out, it was probably 1 litre in total this time? not sure if this has anything to do radiator or something else? Quite annoyed as it's been in the garage for a while now. Ps: The car has a full-porsche service history. Half from me, half from previous owners. Ex- MOT checks does not show any major issue, except small oil leak where they could not find the source. Since the leak was not major, we delayed the major inspection and fix until the clutch change but ofcourse last october with the water pump failure, rebuilt needed. I'm pretty disappointed actually, previously used a 2000 model GOLF (4 motion) V5, 2.0 engine. I know its not for compare but, done about 150.000 miles, never had any engine issue. Currently that car is still in the family being used. I know this is my used choice but I hear also from my friends owns Porsche having similar issues even with a brand new one? Edited by ooid on Saturday 12th March 11:48

Put the car on a downward slope and open the bleed valve and bleed the system. It's just sounds like a minor air lock or overfill.

Since the pump is belt driven, anything that causes the belt to run in a way that puts side pressure on the pump pulley could cause unplanned for stress on the bearing. Check everything that the belt rides on especially the tension pulleys.

Got the car back today. Drove around 20 miles so far in 3 hours, very busy traffic. Stopped the car probably 2-3 times in 10-15 mins intervals, for grocery shopping and etc.. No leaking or overheating, actually even the fans did not start today? The weather has been pretty cold today and the heat level was up to maximum 85 or 90 but never went got close enough for fans I guess? I've checked the trunk, no sign of condensation. Fingers crossed, Hope to make a very long journey soon, so will keep updated!

Not sure if a similar thing discussed but I do own a 2000 boxster, 2.7 manual (around 60.000 miles) just for weekend fun. I'm the second owner of the car, and always kept in official porsche service and etc for the last 4 years. About 5 months ago, after coming back from a supermarket visit, I realized the fan did not stop and the heating level was going up. After parking the car, the whole water coolant and antifreeze was on the floor, in a few minutes or so. We sent to official porsche center and after first check they advised for a water pump change. After replacing the pump, they have found some oil in the coolant and advised me for a further check. I have decided to rebuild the engine and update with necessary IMS and whatever necessary, which took about 3-4 months recently after a serious diagnosis from different experts. (The car is very clean and low mile, no damage on chasis and never gave me any other expense or headache so decided for this expensive route to keep the car going!) A few days ago I have received the car, after a few miles drive (15-20) today I have realized that again the whole coolant and antifreeze was on the ground!. So next week will be towed away to the garage, there is a warranty on the new engine rebuild but It's quite suspicious to have same issue after a major rebuilt and several tests on the car? Any ideas or suggestions would be much appreciated! Edited by ooid on Friday 8th April 16:07

I have just managed to take a video last week, just before the coolant dumped on the ground. I took these videos literally just a few minutes before the whole coolant was on the ground, if you hear or see anything strange would be great to point out, since the engine is rebuilt recently. https://www.youtube.com/watch?v=HyucNKxXC3E (The garage is semi-underground so there is a bit of echo in the space) Also made me realize when I was browsing the original boxster manufacturer guide, on page 47 it says "Do not allow the engine to warm up when stationary. Drive off immediately..." - Both incidents just happened when the car was stationary, I had never this issue on driving. Edited by ooid on Monday 14th March 00:30 Edited by ooid on Friday 8th April 16:08

Cooling Problems. In my very long experience (I'm a Senior Citizen now!) any engine that needs vacuum bleeding or has loads of little bleed screws in its coolant hoses, is a crock-of-s t that needs to go to the crusher ASAP. Basically with such a cooling system one will be on a hiding to nothing no matter how much the car cost or how new it is. The problem is that metals and gaskets are usually micro-porous. In addition Aluminium expands about three times faster than Steel so alloy heads on iron blocks will fret when the temperature changes (MLS gaskets help) When the engine is running there will be peak pressures of several hundred pounds per square inch in the cylinders and the hot gases will do their utmost to escape. Imagine an engine that is somehow micro-porous and vents-off one cc of gas per hour into the cooling system. If the cooling system is badly designed, air locks will eventually occur. On the other hand a properly designed cooling system will purge the gas/air into the header tank from where it can be vented-off. SIMPLE! The water pump should be low down in the engine, NOT high up (remember those early single-overhead-cam engines that were really just a conversion of a push-rod motor?) With these the distributor was relocated to one end of the cylinder head where it was directly driven by the camshaft. So far so good! The thing that ruined the design however was when some absolute dope decided that the place where the distributor used to be on the push-rod engine would be a good place to put the water pump. This location was too high up so it was a total disaster. Surprisingly another car maker bought the bad engine design and cured the problem by moving the water pump down to near the sump. With the cooling sorted they then fitted a low pressure turbo giving 7 psi of boost. The engine that used to be junk now gave a reliable 150 BHP when needed which was a vast improvement over the original. Believe me, high mounted water-pumps are a waste of time and money. There are probably still naive young designers out there who believe that metals and gaskets make 100% perfect hermetic seals but it ain't necessarily so!