When water pumps attack!

New series, starting this weekend.... 9am central Anyway. The coolant leak is not a hose its the water pump. Its a slow leak but its getting worse. This may sound like a silly question but the reason I ask is becasue on a 928 if you drive with a bad water pump the impeller can dig into the block and ruin the block. I ordered a new pump today and of course the weather is great this week. When water pumps attack on the 996 can the destroy anything when they do? Or do they simply just leak more and more? Basically is it safe to drive while I wait on my new pump to arrive?

My guess is it's the shaft seal that's leaking... I don't think driving it will hurt anything. (but, fwiw, I've never had one apart.)

I had mine replaced last year after I blew a seal (I know that doesn't sound right) during a DE. Filled it up with water and drove home. It did not appear to leak while driving but only after the car sat for 15 minutes. I think you are fine as long you check the levels.

+1 for shaft seal and I dont think you will hurt anything.... probably failed because it has been running below its designed tempature

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There's a risk that since the water pump is leaking the seal obviously compromised allows coolant into the water pump bearing. Coolant is not a good lubricant and the bearing could fail, come part, and the shaft could snap or the water pump suffer a severe mechanical failure that could damage the block. Or experience a sudden loss of water pump pumping and the engine could overheat if one is moving along at a good speed when this occurs. Instantly the coolant is no longer being pumped through the engine and localized overheating can occur which may result in a head gasket leak. Sure the odds are slim, but not zero. My feeling is why risk it? Many older yet still servicable cars are lost due to cooling system failures that result in the engine overheating and causing a problem that costs a considerable fraction of the car's current value to put right. Sometimes this arises from a "small" leak that on a hot day turns into a big leak that causes overheating. On drive to South Lake Tahoe last July -- and to be clear it was a rather hot day -- going east on 50 up the mountains towards the summit I passed way too many cars parked on the shoulder with the classic signs of an overheated engine in evidence. And I'm not talking about clunkers either. Surprisingly (or maybe not if one knows a bit about them) many were rather newish BMWs. Anyhow, my opinion is to drive the car as little as possible, best none at all -- arrange to get a cheap rental car (available from rental car agencies/offices located near dealerships) -- and fix your Porsche's water pump pronto. Sincerely, Macster.

You are going to have fun with the WP nuts. I replaced my WP (and other parts) when I had the engine out, and decided it was easier to remove the 4 bolts holding the engine brace than wrestle with the 10mm nuts that were impossible to get to. Once you have full access, it is a 5 min process to remove WP.

not sure how hard it is to remove the rear engine bracket at home, but once that huge thing is off the waterpump is easy access, at the shop its easy to pop it off (well relatively easy) with the car in the air....

ivangene: "..probably failed because it has been running below its designed tempature" Looks like the 997s were designed to run cooler then our HOT rod 996s.

its that "new water" it is stronger hell even my soap for washing cloths works on cold now what will they think of next..... AIR COOLING?

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remove drain plug and drain antifreeze, remove bumper (~8 screws), remove side heat guards (3 nuts?), remove exhaust cross pipes (2 nuts), suspend engine, remove engine mount nuts (2), remove 4 bolts for cross member, should have great access to WP.

you are right, I forgot about the cross pipes - little more work but you sure gaiin the space

It depends on if you have an aftermarket warranty.

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It�s a no-brainer with the engine out, but I think it would be a time saver and most definitely a knuckle saver with the engine in. The process is much easier than it sounds. Sure glad I pulled the engine and replaced so many things all at once.

Water pumps are evil. You can start with a little drop here and there. Then the noise starts. Then you have less than 24Hrs to replace it. make sure you order the OEM METAL gasket.

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I've noticed that the water temp in my 997 hits the 175 mark and then the needle never moves from there. The water temp on my 996 would move up and down depending on whether or not I was in traffic, etc. The oil temp on the 997 will flucuate, but the water temp doesn't move. Andy

Maybe it's really 'air-cooled'. You know they have infiltrated the 996 forum...

"WE" have but we miss you guys (wait I didnt mean you were doing the crying HAHAHAHAH )

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It's worse than "Attack of the Pod People". They see anyone with water and you best not fall asleep.

^^^^^^ hahaha!

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I just replaced a water pump on a friends boxster.(same part as a 996) and she had a small coolant leak but ignored it.I found this out after picking her brains on the events leading up to her almost "Catastrophic Failure" The seal failed causing the bearing to follow. This caused the belt to de-rail and shred to pieces.When I removed the pump The impeller was broken clean off the shaft. Lucky for her the Impeller was made of plastic or it would of torn up the water pump housing.I'm guessing the block? The replacement pump had a metal impeller(not oem) so I 'm not sure this was the way to go but she went for the $150 pump instead of the dealer asking $325 oem unit.Don't know if oem replacement is metal or plastic.From what I've seen if the impeller was metal in this case, she would've torn the *** out of her block or w/p housing.If your water pump is leaking I would strongly advise you not to drive the car until you replace the pump.

sbpsu354: "I've noticed that the water temp in my 997 hits the 175 mark and then the needle never moves from there." If you look closely at the gauge you will see a small pin at the 175 mark. If you overheat a 997 you could bend the needle as it tries to pass that pin. Wonder if Jake and 1999porsche911 know about this? I wonder how they keep the temp below the 180 thermostat? Porsche surly would not believe that a lower temp T- stat could help lower the operating temp? The 997 fans must run on high speed all of the time.

http://www.youtube.com/watch?v=h0L0klF8lVo Good video!! Id use better coolant and less silicone...but overall gives you a good idea where everything is located!!

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With the M96 when the plastic impellers begin to age and chip, those chips find their way into the tiny capillaries within the coolant passages of the cylinder heads.. This blocks coolant flow and creates hot spots and ultimately leads to a cracked cylinder head. I have two cars down stairs right now that have suffered from this mode of failure, neither was caught early enough in the intermix cycle to salvage the engine. Its not miles that causes this to occur, its the age of the plastic impellers... This is another one of those instances where a simple primary failure can lead to a much more serious secondary failure. Neither of the engines that are down stairs failed right now had high coolant temps, that one hot spot led to the issue. We've had a rash of cracked heads for the past year, in EVERY one of those instances the water pump impeller had chips missing from it. In several of those situations the chips of plastic were found inside the cylinder head's coolant passages when the crack was milled away for our crack repair to be carried out. This is how we determined that the pump impellers were the actual primary failure leading to this mysterious cracking issue stemming from engines that had never "overheated". The chipped impeller pieces are another reason why the engine cracks a head before it blows a head gasket. This is because only a very small (and weak) portion of the head contains these capillaries and when that one spot gets hot enough the crack forms.. The cracked heads are occurring on pre-02 996 and pre-03 Boxster engines primariily. When the cylinder heads were changed for vane cell vario cam (and VC+ in the 996) the cylinder head casting was completely changed and no longer includes these small capillaries. The ultimate solution is a billet water pump impeller. Here is a 18,000.00 crack.

Jake,was there any warning to the owners of the 2 cracked heads, such as noise/sound before the impellers fragmented in their water pumps, which then caused blockage of coolant? Curious because you are suggesting mileage has no bearing(no pun initially intended). Thanks

plastic... again with the plastic parts! have any of you (other than Jake) seen the "button" on the IMS chain tensioner arm This is one more case where you have to change these parts based on age not miles. (that said my 86' just broke a plastic gear on the odometer, but it isnt a big $$$$ repair, just another case where plastic ages and oils degrade the plastic to the point of being very unpredictable when they will fail)

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This is crazy. What else is plastic? I know that the bearings inside our transmission also has plastic

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Nope. Absolutely silent, when plastic breaks it doesn't make much noise. The thing you need to understand is the ONLY symptoms the two engines I have downstairs now exhibited was intermix.. The engine NEVER overheated its coolant because one small portion of the head was cracked. Had we not seen so many of these issues and found plastic impeller pieces inside cylinder head coolant passages we never would have figured out why the cracks magically appear when the engine never overheated. I'd like to start keeping a tally of how many water pumps that are replaced have a small chip of an impeller blade missing.. That small chip floats around until it finds a capillary that it can't pass through, then its game over. Not all M96 engines have that.. The early Boxster and '99, 996 engines had a metal wear button. The new billet IMS tensioner paddle that we use is also equipped with the metal wear button, I will not risk the life of an engine on a piece of plastic. Here are some pictures of that plastic part compared to the updated billet part. Here is also a picture of what happens when the plastic part fails, the tensioner slips and jams the tensioner paddle resulting in a catastrophic failure.

would anyone suggest replacement as preventative maintenance on a 10 yo car w/ 90K miles?

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Ha. reminds me of a joke.... Penquin comes into the garage and says "fix my car I am going across the street" He comes back an hour later and asks "what was the problem" The wrench says "oh you blew a seal" The penquin wipes his lips and says "oh no, thats just ice cream" Funny guy.... Yeah my other aircooled friend already reminded me she doesnt have a water pump As usual the very imformative and helpful knowledge of one of my favorites on this board. I agree.. It sat at home today and the pump is to be here tomorrow. Yeah watched it today already. Im going to tear down tonight. 18K in crack... whats the street value... Thank you Jake. I have paid attention to your hot spots.. Now what if some of my propeller is missing when I get the pump off?" From what I can tell this is the original, I'm 11 years old and 112,000 miles

It'll be interesting to see if your impellers are missing any material..

+1 for the '99's! So does this mean that you should replace the WP with a metal impeller one? Who sells the billet impellers?

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OK, No my propeller was fine. The job was done. it took a little more than 8 min like the video shows. But the video is perfect. BUT I think I know why plastic impeller. I may get flamed for this but I called it as I saw it... I put the pump on and the impeller was rubbing very slightly against the block.. Ever so slight. I could turn it by hand no problem.. and it even spun a bit when I turned it fast.. Like I said ever so slight... So silly me I pull it back out... Then when I got to looking at the old vs new, I could see where the old pump had rubbed also at one point. So I think this is the way it is designed. I figured a new pump was to rub a little and it would set into place after a min or two of running... and it did. I ran the car for about 2 min. shut it down and took the belt back off and turned the pump and it was fine.... No rub at all.. took the car for 40 mile drive and it was perfect. So I know I have a really tight tollerance in there to get the best pump action possible... Am I crazy or correct. The job took about 3 hours.. But I did it twice..... I think I could do another in less than 1.5 hrs

Was your original impeller plastic or metal? Sounds like the new one was plastic?? I wonder if the Boxster metal replacement mentioned earlier was tight enough to scuff the block?

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Both are plastic.. I am not saying what I did was correct. But it did all seem to make sense after I got looking at things.

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when you do the IMS upgrade you cane to remove the tensioner. The button is hard to see (you have to look directly into the hole with light) but I think LNE offers a replacement that can be done without removing the entire arm (which requires motor teardown) Jake can answer that best - BUT for me, the plan was to look in there (since its open while doing the retrofit) and see if there was anything I could tell, then decide to replace if available. You can just set the motor to TCD and pull the tensioner and have a look too....if you saw the 2 parts (LNE's and OEM) on a bench side by side you would be shocked and in wonderment as to why the OEM part is in your car. (sorry guys, just the truth) I hope that Q was about the arm and not the WP.... if for the waterpump, I would not replace as a preventative item, Jake may have a differant opinion and maybe after hearing his I could be pursuaded to re-think my opinion) - I am easily swayed these days

ivangene, I posted pics of the two different tensioner buttons on the previous page of the thread..

got it Jake, but my Q is..... can just the button be replaced thru the tensioner hole.

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Actually, I think I have noticed the fans running more on the 997 than on my 996. This has been with or without the AC running.

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I've never tried it.. I am sure it could be done, but would not be fun or easy. Accessibility isn't the greatest.

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To remove the rear engine brace would have taken removing the exhaust. Just and FYI

yea, but you gain HUGE........... TRACKS OF LAND !

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The exhaust on the 996 is the easiest exhaust to remove that I've ever seen. You won't believe it til the first time you do it.

good thing they made it easy to remove the mufflers... as you need to remove them 5 times per year...

if you drove it more you wouldnt have to remove them for cob-web removal

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After I installed the pump I spun it by hand and it was indeed hitting about every 180 degrees, so twice per revolution.I moved the pulley back and forth over the contact points to "mark up" the offending impeller blades. I then removed the pump to have a look-see and sure enough I could see where two of the blades were making contact.I gently filed down a little meat on each one and reinstalled, Perfect! With that being said I am going to replace the w/p on my 996 because of age and mileage 99' w/90k It looks to be the original pump.My thinking is to go w/ the oem plastic impeller pump and if there is any interference I can file those blades as well.It's a fine line.Plastic impeller= blocked cooling capillaries or Metal impeller= Your own mini milling machine (If the the bearing fails) I choose Plastic!!

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After reading your post I looked at a high res pic of my 02 Boxster's water pump that was replaced at 172K miles. No shaft fracture failure just noisy and a bit of a leak. Upon looking at the tops of the impeller vanes I see signs the tops were touching the metal of the cavity into which the pump impellter fits. I had the pump replaced at the dealer so I didn't have a chance to look at the engine area where the impeller fit to see if I could spot any signs of the vanes hitting rubbing. Chances are though since it happened so long ago and we're talking plastic vanes now not diamonds any marking has long been removed by the corrosion that erodes the surface of the engine's coolant passages. Still it is kind of interesting that the vanes would make contact. Should make for a very efficient pumping action to have such a close fit between the vanes and the opposite wall of the pump cavity. Sincerely, Macster.

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I think this is why they are plastic. I have learned something with doing my own work on the 928 and now the 911. I have learned Porsche does almost everything for a reason. No matter how idiot it looks to us their is usually a reason behind it. I found this to also usually be a performance reason. And I am sorry. The 911 is all about the "GO", So its like a good woman.. You want one thats going to stay faithful.. get a homely one.. You want one that is gonig t run with the super models.. Be ready to pay the price. BUT my plastic impeller out lasted the pump seal. So whats the big deal? Are the plastic impellers failing becasue people are not running the correct coolent? And the american cheap stuff is breaking down the plastic? Some thoughts to ponder.

so what is a good coolant to use ? ... aside of the oem porsche coolant ? is the color enough ?

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Don't be suckered in by a mere image of a 997 instrument cluster. The 997 engines run hotter than the gauge reports. They are dumbed down water temperature gauges. The coolant gauge reports water temps at 175�F well into the the higher temperatures until it finally moves to the max. There is little warning provided.

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What's wrong with OEM coolant? Why go to the trouble to seek out something as good as OEM? Had coolant changed once around 2006 after I busted a radiator and coolant leaked out. Then had it changed again when water pump done year or more back. Wait: car has 232K miles now so 60K miles ago... make that 2 years or so back. Then had some added when coolant tank replaced a few weeks ago. (Not all coolant lost. Tech just had to top up.) I mean most people aren't going to change the stuff more than once and risking saving a few bucks on some unknown coolant just seems senseless. Anyhow, I believe the manual calls for phosphate free anti-freeze mixed 50:50 with distilled water. No additives. Sincerely, Macster.

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I went OEM. Like Macster said, why try to save a couple of bucks on something so critical. It's lifetime coolant. My dealer told me they only make the pink coolant now. I topped off my green coolant with some pink when the cap had a leak, maybe 5 oz., and no problems 5k miles later.

Im running pantosin red

What you guys think of 'Water Wetter' from Redline?