Porsche 996 maintenance schedule

I have the 1999 Mk1 996 coupe with 87k. I know that the IMS was replaced with the LN dual row at 86k. The AOS was changed as well as the coolant tank and cap. The car underwent a PPI that revealed no serious issues. Since I bought it in December of 2014, I have put on about 1800 miles of exhilarating driving. The 3.4 pulls very strong - passing through 4000 rpm in second gear is simply awesome. Car is tight, hard and rattle free. I am very happy. I want desperately to STAY that way and I am learning as much as I can about the DIY maintenance. Now that I have some reassurance that the intermediate shaft is safe, my mind turns to the cylinder heads and how to assure that they don't overheat, resulting in oil / coolant intermixing from cracking. With 87k on the engine with no issues (including the original IMS bearing which, when removed, proved to be perfectly ok) I imagine if something catastrophic were to happen to the heads and their lokasil treatment, it would have already. This then leads to my question about how often you all are changing out your water pumps. I have no WP bearing noise and no leaks. I have no idea how long the current one was in there and whether or not it has a metal impeller. If I replace it as a security measure, would you go OEM Porsche which has a plastic impeller, or some other less expensive pump from Pelican? As always, I am thankful for your comments, Bob

Your car is beautiful, I love the color. I also have an early one, mine is a 2000 and Jakes shop did the bearing and some other stuff. I had the water pump replaced with a stock Porsche one as thats what Jake uses. I'm like you and want the car to stay as it is as long as possible. I use a fuel additive that claims to coat the cylinders with something that keeps the temps better. Maybe it works maybe it doesn't but it cant hurt and it raises the octane which is important as Porsche originally wanted 93 octane minimum for these engines and 91 is all you can get anymore out here in western states. If you are interested in the upper cylinder lubricant the website is www.bndautomotive.com I know drag racers that use this stuff, its called ACES gasoline formula. I'm happy to hear you like your car so much as we both feel the same. Good luck with it and have fun.

The recommendation to replace the water pump is every 30k. At the same time, remove the fenders to replace the radiators [every 30k recommended on these, too] and scoop the leaves out from behind the radiators. Replace the water pump with plastic impellers because the metal blades will gouge the housing metal when the ball bearings start to fail and make the shaft wobble. These recommendations come from the PCA technical guys....

Replace radiators every 30k miles? Seriously? Paging Imo000..

I assume he meant clean the radiators.

Quotes source post: 12043030

yet ANOTHER double race bearing removed IN TACT from a 99 job. I have yet to hear of a 99 double race bearing catastrophic failure. My water pump played up at approx 70000 miles which I replaced with the OEM Porsche. You could put in a low temp thermo when you change the water pump. Cleaning between the Rads and the Condensors would help on keeping temps down. Then add home made grills to the front air intakes. . Follow my postings to find the best way for next to nothing dollars. That way you need only check your rads for crap every 5 years or more. If EVER again.

I'd add spark plugs and coils to the laundry list of items. That's a real humdinger of a treat to change out, easiest if you remove the rear bumper and rear mufflers. Also flush the brake fluid every 24 months regardless of mileage, the Motive Power Bleeder works great for single man operation.

Here are a few for you in the 80k+ mile club: 1. An often overlooked item(according to the experts) is changing the oil in the manual gearbox every 15k. 2. And the nemesis of my engine - the DMF- idiot mechanic of the P.O. 'misunderstood' the specs for free-play. 3. He also replaced a water pump without retrieving the broken bits of impeller. I found them in time. Most were in the oil/coolant heat exchanger. I bet it was driven with a leaking/squealing pump for a while toooo long.Replace promptly is the take home... 4. Lifters - often gone soft or 'hammered' tappet. 5. Exhaust manifold studs corroded- replace with s/s 6. Second gear pops out & driven too long for the 'detent' fix YEMV

30,000 miles seems like a short maintenance interval for the waterpump, especially if it is a daily driver. That can mean changing a waterpump every couple of years. Here's a thread referencing an Excellence article that says every 40,000 miles. http://www.renntech.org/forums/topic...pump-2002-c4s/ Another referencing apparently a different Excellence article quoting every 4 years or 50,000 miles. https://rennlist.com/forums/997-foru...xcellence.html Jake's website recommends just changing the waterpump no matter what - I assume a blanket recommendation to the recent purchaser of a 996. I would assume he has a service interval for subsequent water pump changes, but I didn't comb through his website to look for it. http://www.flat6innovations.com/inde...ure-directives : "Things to do: Upgrade the IMS bearing within the engine. . . Replace the water pump, water pumps can fail silently and lead to cracked heads! Replace the water pump no matter how many miles are on your car, as time in service kills the plastic impeller blades of the pump, not miles!! Water pumps are cheap insurance, if a water pump creates a cracked head and intermixed coolant and oil exist the costs can be over 15,000.00 for repair"

All you can do regarding keeping the cylinder heads intact is to ensure the cooling system is leak free. If the system has a leak it can't hold pressure and the loss of pressure allows hot coolant to flash to steam which can block coolant flow and lead to localized overheating which can lead to a head cracking. However, I'm not sure this explains all the head cracking (not that there is that much to begin with). Could be just a stress fracture. In this case carry a rabbit's foot. With keeping the cooling system in good working order and the rabbit's foot, you have all bases covered. You will get all kinds of advice regarding how often to change the water pump. You can change it as often as you want, can afford, I guess. My advice is to change it only when it needs changing. With reasonable coolant changes -- every 4 years or so -- the water pump can last a long time. The one in my Boxster lasted 172K miles. The one in my Turbo lasted around 120K miles. In the case of the Boxster the pump started making noise and I id'd the pump as the source and had the car flat bedded to a dealer and had the water pump replaced. In the case of the Turbo I caught a whiff of anti-freeze odor from near the rear of the car and suspecting a leak I had the car checked out at the nearby dealer and the tech spotted signs of a water pump leak. For which water pump to use I would use the genuine Porsche water pump. There have been too many reports of OEM pumps not being up to spec. Seems for every person who gets a superior after market water pump another owner gets a crummy one. The replacement water pump in my Boxster has over 110K miles on it and appears to be just fine. The replacement water pump in the Turbo has just 12K miles or so on it but I expect it to last at least another 110K miles and more. Way more. Be sure to keep the radiator ducts clean of trash. Be sure to keep the body drains free of trash. Check vital fluid levels every so often and if a fluid level is dropping get this looked into promptly. If you hear a strange/new noise get the source of the noise id'd pronto. Where owners run into trouble is they keep driving the car and the water pump then fails catastrophically often with dire consequences. 'course this just fans the paranoia and leads some to believe the water pump needs to be changed much more frequently. Drive carefully. As a car ages and accumulates miles it is more at risk of being involved in an accident. You can lose a good car to an accident just as quickly as you can to a wholesale engine failure. In fact I dare say the accident risk is greater than the risk of the engine blowing sky high, so to speak.

I agree with Macster about the risk of accident being greater than risk of engine failure, especially if you live in Los Angeles, Las Vegas, or any other big city. Here in Vegas a huge percentage of folks are driving after leaving casinos where the drinks are free if you gamble.