Johnny-5

As stated previously try to crank the motor manually. If it doesnt move than its most likely hydrolocked. How deep was the puddle? Its sort of weird that it could have sucked in water as our intakes isnt really that low from what I see???

For a street car it is debatable whether it would help that much.

The Porsche OEM thermostat is MSRP $63.03.

Thanks Loren!

If anyone on here is able to throw in some insight on the low thermostat and its benefits on a street car that would be great! If its that much better to put it into the car since Ill be in that area Im fine with picking it up.

anyone?

If I remember right the 99-00 Expansion Tanks are smaller than the 01-05 which are longer in size. Im not sure if the newer ones will fit for our years. Sort of weird how the older tanks cost more than the newer ones!?!

The LN 160 stat is fine for the street, we have a lot of customers using them with no issues.

One more question for you. Do our n/a cars run that hot that we really need this low of a thermostat? Or will the stock thermostat be efficient enough? I could understand if the car was modified or tracked or driven extremely hard than it would be beneficial. But if these cars tend to run hot in general and will help prolong the life of the car than Im all for it! Also is there another brand or company that sells lower thermostats for our cars or is LN pretty much the only company? $100 for just the thermostat is pretty high!

If you're going to do the thermostat, I'd replace it with the low-temperature version, especially on a MY2000 car (like mine) which may be a bit more susceptible to cracked heads.

That was my next question I was going to ask! LN Engineering sells a 160F Low Temperature Thermostat. Wouldnt this be to low for street use? If it is than what temp thermostat should I go?

I did a pretty good job wearing them in last night and have to say they are really quiet and the big deal to me is the dust is way down. The feel of the pedal is great, the brakes grab way better than they did, my rear pads and rotors were tired.

I made the mistake with going with OE Porsche Rotors and Pads on the fronts which I probably wont go anymore. The rear I ended up going with a set of Sebro rotors and PBR front pads. Was going to go with Balo but they didnt have it in stock.

I did the same, Sebro rotors and Lexar pads, I had all the set front and rear included handbrakes shoes and sensors for 600€

I learned from my mistake thats for sure. I paid over $600us for just the front setup alone.

There are many people who agree about changing the water pump preemptively because of the damage that can be done by broken impellers. Others say wait until there are symptoms of failure. Personally, I would do it if money isn't an issue.

Since I already have it on hand I figured I do it. Is there anything else I should do while Im there? Thermostat? Are those common to go bad as well or should I be ok?

I did a pretty good job wearing them in last night and have to say they are really quiet and the big deal to me is the dust is way down. The feel of the pedal is great, the brakes grab way better than they did, my rear pads and rotors were tired.

I made the mistake with going with OE Porsche Rotors and Pads on the fronts which I probably wont go anymore. The rear I ended up going with a set of Sebro rotors and PBR front pads. Was going to go with Balo but they didnt have it in stock.

Ok I went and picked up the replacement tank and cap as well as a bunch of other parts so I can start working on it this weekend and the shop kept pressuring me to pick up the water pump as well. He stated it should be replaced every 50k miles? Is that accurate and should I replace it while Im in there? I believe my pump is fine but I figured I ask the pro's here. Im thinking he did it for the sales!

http://www.renntech....-for-a-bad-aos/

You rock! Thanks for the link!

This is the support topic for the DIY Tutorial An inexpensive way to test for a bad AOS. Please post here if you have any questions or feedback.

You rock thanks for link. Ill probably build one later on this weekend and see test the vacuum in the system.

I really would not be driving a car with a coolant leak around; if it totally fails, you are stranded, and you could do some irreparable harm to the engine if it overheats (alloy engines do not like being overheated). Park it until it is fixed.

You got a point! Better to be safe than sorry!

The AOS (when new and correctly functioning) should show a vacuum of about 5 inches of water at the oil cap with the engine running (temp is pretty much irrelevant). When the AOS craps out, the vacuum level at the cap sky rockets to several times the correct level, making it nearly impossible to remove without a substantial degree of effort.

It is also not uncommon for the engine to stumble or have the idle speed change with the cap is removed (remember, you just vented an engine vacuum source).

Thanks for the additional info. Ill probably get it checked sometime next week to make sure everything is up to par

My AOS catastrophically failed not too long ago so I can tell you my telltale symptoms that I ignored right before it failed. The idle was rough. That idle problem got progressively worse until sometime at a red light the engine would just die. There was also white smoke on most mornings after start up. RIght before it failed the check engine light came on. Then within 1 day, driving down the highway white smoke started pouring out of the exhaust. After the AOS replacement the idle is quite controlled and I hardly see any white smoke when I start her up.

Im not seeing any sort of smoke, rough idle or stalling so I think I should be ok for now at least!

I had the front rotors and pads replaced at Porsche 2 years ago for a wopping $1150.00, never make that mistake again.

Yesterday one of the techs at the Cadillac Dealership I work at repaced the front pads with ceramic enhanced semi-metallic with Kevlar Pads. The front pads I took off were really still 90% there after 2 years and 20K miles. I saved them and we just put in new pads.

I bought Balo Coated rear rotors that I picked up at Pelican Parts for $117 for the pair including shipping, amazing. I used the ceramic enhanced semi-metallic with Kevlar also on the rear. I spent $190 for everything and gave the tech $100 for the install.

After one day of use, really quiet and dust is down by 75%. I have black wheels on the 996 and the dust from the factory pads was really bad. I had to clean the wheels every day.

Here is a link to eBay where I got the pads: http://www.ebay.com/itm/Rear-Brake-P...91560661388863

Here is a link to the pads: http://www.ntadi.com/galaxypads.htm

Write to the seller and tell him you want both front and rear pads. I paid an unbelievable $73.88 for pads for all 4 corners with free shipping.

**** I just pulled the trigger and bought a rear set of rotors and pads. Ill keep those links and order those next time Im needing to do my fronts again. How do you like the semi-metallic? I was going to go with a set for the rear but ended up going with a PBR set. Being told its either equal if not better than OE.

Ok I had a chance to go out and start the car up today and double checked the coolant tank, cap was on tight and was going to take it for a spin and decided to look down near the exhaust and Im currently seeing a little bit of coolant already. Im thinking the coolant tank is my issue as its not coming from the cap. So Im assuming its most likely my tank that is the issue.

Since its a gradual leak do you think it will be ok to drive the car to the parts shop to pick up the tank and back home? Its going to be probably about less than a hour each way for me? Currently my commuter car is currently down due to brakes which the parts wont be here till tomorrow.

In a previous thread somone mentioned something about my AOS so I did some research on it as well as talking to a few shops and would like to confirm a few things. I just went out to the car and started it up and Im not smelling or seeing any type of smoke coming from it. Ive also removed the oil filler cap pretty easy and noticed that there is some vacuum to it. Im being told this is normal. Car wasnt fully warmed up or anything so should the car be fully warmed up?

If the AOS is bad there would be smoke on startup and when removing the oil cap would be extremely hard or impossible to do depending on how bad it is? Also if the oil filler cap was removed it would drop idle or something die on you?

Can someone confirm this?

Unless you are changing pads freqeuently or just don't have that many miles on them, if the pads are worn down enough to need replacing, chances are the rotors are going to be beyond the wear limit as well.

If you are in doubt (or always), use a micrometer on them or remove the rotors and take them to your nearest machine shop to be measured (and then turned if they are still within spec). Machine shops (and auto parts stores who turn rotors) will measure your rotors for free if you do not have a micro meter.

You do have a point! Ill probably check out the specs on them this weekend and see how worn down they are. If anything after I figure out the coolant issue Ill probably take these off than and see about getting them resurfaced if they are within its limits. Thanks for the clarifications. Or I may just say hell with it and pick up a new set as I did the fronts.

The older caps are known to leak, the -00 part numbers especially. I encountered one of these on a Boxster at an autocross just this last weekend in fact.

You can normally see tell tale evidence of coolant that has leaked out near the cap and has been leaking through the overflow tube and burning off on top of the coolant tank.

It could also be due to improper threading (cross threading) or undertightening of the cap.

Similarly, you can normally see if the tank is leaking, when you shine a good flashlight on it you should be able to see the evidence of coolant leaking out and burning off (you'll see a crusty yellow or brownish fluid from where the fluid is eminating).

Ill probably replace the cap this weekend since its cheap anyways and probably drive the car locally. Than Ill come back home and feel around under the tank and see if I can feel anything leaking around the reservoir.

Ive also posted something else above.

AOS is the air oil seperator (search).

If the water pump is bad generally it will leak, but it is also possible for the blades to disintegrate, typically either situation will come with other symptoms including leaks, unusual noises, or overheating. None of which are good things.

Be sure to buy the latest cap with the -04 part number.

The cracking tanks is an issue primarily with older cars, the plastic has either worn and is brittle or could be due to a defect.

I did a search on AOS and I believe I understand the concept of it. What I cant find is how do you know if one is bad? Ive read at start up if you have a good amount of smoke coming from the exhaust than its a good indication that its bad or going out. Other than that is there any other way?

Sorry, no advice on the brake rotors but did benefit from others responses but being in the East Bay area myself and a longtime 996 owner, I have always had terrific experiences with Sunset Porsche in Oregon and/or Pelican Parts as they have a NorCal warehouse and can get parts out to you quickly.

I use Pelican Parts alot for my BMW as well. Ill check out sunset though.

I did quite a bit of research before buying my pads, but I ended up just buying pads from OEM manufacturers. I believe Textar is the main manufacturers, and even the Bosche or Brembo pads have the name Textar stamped into the actual pad. My conclusion was that buying a set from Porsche would likely result in the identical pad but at twice the price.

Also there are options to get better breaking performance on the track, but you have to compromise on cold performance and noise (and possibly dust). I was about to try a set of "EBC Red Stuff" since they claim to generate less break dust, but the reviews weren't stellar. I'm happy with the Textars so far although they didn't quite stand up to the heat when I had them out for a track day.

I dont do any sort of tracking on the car so Ill probably stick with OE pads. Thanks for the info.

Maybe it's just me, but typically I use my pads to the point where either the rotors are shot OR they need to be resurfaced (and then replaced if they cannot be turned).

I tried replacing pads once on a differnent car without turning the rotors and it worked fine, but unscientically I don't think the pads lasted quite as long as with new or turned rotors.

If you have a couple sets of pads and swap often, (example track, autocross, etc) perhaps a different story...

If you experience any shimmy or unusual braking then certainly rotors are going to be suspect.

No issues with the brakes just the rear are getting low so thats why I was asking. I still have some life on them but I like to replace them before I start hitting metal to metal like I did on my commuter car just recently. I wasnt keeping up with the maintenance on that car unfortunately!

Almost no modern sports cars have enough rotor left after one pad change to last a second set of pads - let alone a turning them.

I afraid that is just the way it is now. Thiner - lighter materials make cars lighter and less sprung weight but suffer shorter life.

This was in a previous post:

According to "Porsche 996 The Essential Companion" by Adrian Streather, the allowable wear is 2mm per rotor (ie 1.0mm per side). For the regular 996 the new rotor thickness is 28mm front and 24mm rear.

even if it falls under the allowable wear of 2mm? The car is not tracked nor driven hard?

AOS is the air oil seperator (search).

If the water pump is bad generally it will leak, but it is also possible for the blades to disintegrate, typically either situation will come with other symptoms including leaks, unusual noises, or overheating. None of which are good things.

Be sure to buy the latest cap with the -04 part number.

The cracking tanks is an issue primarily with older cars, the plastic has either worn and is brittle or could be due to a defect.

Car runs fine and dont see much fluctuating in temp so I believe the pump is still in good working order. Ill probably look around still for a place that can do a pressure test on the coolant and try to hit everything out this weekend. Im sure its the tank but figured it would be good to see what else it could be. Hopefully I get lucky and its just the cap. Which I doubt!

Johnny - talk to Eduardo who owns a shop in Fremont called Foreign Auto. He did my IMS and clutch last winter and was very reasonably priced. The guy owns a Porsche himself so he understands our emotions.

If you're still looking for parts like the coolant cap, call Parts Heaven in Hayward. They are the Porsche Gods in East Bay.

Thank you Ill give them all call later today and see what they can do for me. Thank you for giving me the info on the parts place locally. That should help me out with alot of the parts Im needing to order.

I have never believed in the recommendation to automatically resurface the rotors before putting on new pads. If they are damaged at all (including grooves, pitting, uneven wear etc) than resurfacing may be able to restore them. I have heard the theory that resurfacing them helps the brake pads 'mate' with the rotor but I'm sure that a good break-in will do the same thing. In my opinion mechanics usually recommend resurfacing since the cost isn't that high and it reduces the chance of the customer coming back complaining of vibration in the steering wheel or other problems.

But it does reduce the thickness of the rotors.

My advice is to check the rotors visually and with an inexpensive micrometer paying particular attention to any cracks starting from the holes in the rotor. If they are fine, than get a good set of pads and seat them properly. There are some good posts on this site on how to break-in new pads.

I will be off Friday so ill go in and double check the thickness, cracks, etc. If it all falls into category Ill just throw in new ones than. Saves me the hassle of resurfacing or buying new. Any recommendations on pads? Or shall I stick with OE?

Does sounds like a leaking coolant tank and/or cap. Yea, these tanks tend to crack in time and the cap is also known to leak. The cap has been redesigned for a few times.

Definitely go with OE parts. You could get good deals from Sunset or Suncoast Porsche.

Its just odd that Im reading even with cars with low miles are having reservoirs crack and leak. Design flaw? Im pushing more towards the reserviour and figured I replace the cap while at it or do it in steps. Yea Ill most definitely go with OE parts.

Start with the simplest, (and cheapest) route- replace your cap to the newest available. It is only about $16 and the earlier ones do fail- mine did. Then move on to pressure testing the system. The water pump replacement isn't hard to do- I had to replace one with my broken wrist in a cast! There are excellent DIYs here and over on Rennlist. The AOS can also leak a lot of coolant and often drips down near where you are describing. The reservoir can fail and is another possibility. I have 120k on my car and the reservoir is still fine. I am planning on replacing it at some point this summer just to be sure I don't have an issue.

Yea Ill probably go with a new cap first and test it. Im still not able to find a shop locally that can do a pressure test on the system so ill probably call around later today. Worst case scenario if its still leaking Ill probably just say hell with it and replace it.

Glad to know that the water pump isnt that hard to do. How would I know if its gone bad? Or is it something I should replace while Im at it?

Also what is a AOS sorry for the newbie questions!

These are not necessarily the correct specs for your 996, but they will give you an idea of the wear values from new to replace.

From the Bentley manual for a 986 Boxster:

The brake rotor machining limit is 22mm for the fronts and 18mm for the rears.

New rotors are 24mm thick for the fronts and 20 mm thick for the rears.

The brake rotor wear limit (before machining) is 22.6mm for the fronts and 18.6mm for the rears.

Since your rotors are OEM (they are "good" quality), you should be able to see the minimum values stamped on the side of the outside circumference of the rotor.

Sunset and Suncoast are for online purchases (unless you find yourself in Florida or Colorado, IIRC).

Regards, Maurice.

Got it! Thanks for the clarifications. Ill look them up and see how good they are as Im needing to buy some things soon.

According to "Porsche 996 The Essential Companion" by Adrian Streather, the allowable wear is 2mm per rotor (ie 1.0mm per side). For the regular 996 the new rotor thickness is 28mm front and 24mm rear. For the 4S and turbo it is 34mm front and 28mm rear.

When I just did my pads at ~70K Km I checked the rotors and all 4 had worn roughly 1mm measured at multiple points on each rotors. There were no cracks around the vent holes in the rotor. If I remember the spec was for any cracks to be less than 3mm from the hole but I'd have to check that. Since they were only 1/2 warn I left them on my car and will replace next time.

Isnt it recommend to resurface them before putting on new brake pads? Im assuming you just replaced the pads and called it a day?