2000 996 Porsche mystery coolant disappearing...............

[Johnny-5]

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!

[logray]

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?

[Johnny-5]

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!

[wyovino]

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.

Edited May 26, 2012 by wyovino

[Johnny-5]

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?

[Neb33]

How often should water pump be chnaged? I am at 108k km. on a 2003.

[logray]

Some say appx every 50 k miles. When I replaced mine at ~ 70k miles it was still fine.

[wyovino]

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.

[Johnny-5]

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?

[JFP in PA]

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

[Johnny-5]

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!

[Johnny-5]

anyone?

[Loren]

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

The Porsche OEM thermostat is MSRP $63.03.

[Johnny-5]

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.

[logray]

There is a lot of debate about the low temp thermostat. You can read about it on ln engineering's website.

Basically the concept is either a 160 or 186ish degree tstat will both allow the car to heat up just as much.

However, the 160 degree thermostat does it slower and thus perhaps less of a shock to the aluminum engine, which could perhaps increase longevity and reduce likleyhood of cracks/etc.

[Johnny-5]

There is a lot of debate about the low temp thermostat. You can read about it on ln engineering's website.

Basically the concept is either a 160 or 186ish degree tstat will both allow the car to heat up just as much.

However, the 160 degree thermostat does it slower and thus perhaps less of a shock to the aluminum engine, which could perhaps increase longevity and reduce likleyhood of cracks/etc.

Yea I was doing further research on the thermostat and search the forums and other forums and there is alot (ALOT) of debate over it! I ended up just going with a stock thermostat as alot of people stated for me to save the money and just put in a stock setup so thats what I did.

[JFP in PA]

As much as some would like to debate the utility of the LN lower temp thermostat, it has proven to be a valuable addition to street driven cars. It significantly lowers the operational (steady state) temperatures, and even more importantly also lowers the oil temps. UoA’s have shown that oils stay in grade longer. And while some argue that water and fuel remain in the oil because of the lower coolant temps, again the UoA’s have totally refuted those claims as well.

We have literally dozens of customers running them, both on the street and the track, and all the results have been totally positive…………………

[Interbay]

I had this problem and I noticed it when I looked in the rear view mirror at a stoplight and saw steam coming up through the spoiler. Checking the temp guage showed no change so I moved on. The next light it steamed again and I pulled over and saw water all over the engine. Took it to my favorite Porsche mechanic and it was hot. He said it was the water pump and to leave it overnight to cool down. The next day I went back and he showed me a water hose with more curves and bends than I would have thought possible. There was a plastic nipple that came out of the hose and it had broken at the connection to the hose allowing water to get out. A simple fix but a real problem as the temp sensors are in the front of the car and they failed to detect the loss of water. Good luck.

[Johnny-5]

As much as some would like to debate the utility of the LN lower temp thermostat, it has proven to be a valuable addition to street driven cars. It significantly lowers the operational (steady state) temperatures, and even more importantly also lowers the oil temps. UoA’s have shown that oils stay in grade longer. And while some argue that water and fuel remain in the oil because of the lower coolant temps, again the UoA’s have totally refuted those claims as well.

We have literally dozens of customers running them, both on the street and the track, and all the results have been totally positive…………………

Im sure it has its benefits but I figured with all the debate going on I would just stick with a stock thermostat. Cant really go wrong with OE as its made for the car. If this car was modified or tracked I would have probably gone with a lower thermostat or even better aluminum radiators.

[Johnny-5]

I had this problem and I noticed it when I looked in the rear view mirror at a stoplight and saw steam coming up through the spoiler. Checking the temp guage showed no change so I moved on. The next light it steamed again and I pulled over and saw water all over the engine. Took it to my favorite Porsche mechanic and it was hot. He said it was the water pump and to leave it overnight to cool down. The next day I went back and he showed me a water hose with more curves and bends than I would have thought possible. There was a plastic nipple that came out of the hose and it had broken at the connection to the hose allowing water to get out. A simple fix but a real problem as the temp sensors are in the front of the car and they failed to detect the loss of water. Good luck.

I was checking it out earlier this week and its definitely coming from the tank area. Ill be changing out the thermostat and water pump as well while Im at it. Ill also be double checking the hoses and everything else to make sure they are working or connected as should! Hopefully I dont have any issuess doing this all tomorrow!

Glad to know yours worked out well and was fixed at a low cost!

[Johnny-5]

Ok so I hit out the expansion tank, water pump and thermostat yesterday and it took forever! I think I spent most of my time trying to get the expansion tank and water pump in and out of the car! When people talk about a PITA!!! They were not Kidding! I found a few other things I needed to replace so didnt finish the car yet. Should have coolant and will double check leaks, etc and should be up and running by today.

Oh by the way the water pump gasket comes with the additional gasket attached for the coolant drain unit. Does anyone actually change that out as well or do you just cut it off and just use the water pump gasket? Sort of a stupid design to have both of those attacked! I had a hell of a time cutting off the old one due to the lack of room!

[britdave]

Questions, while we are all talking cooling system here .

#1 How often (time/mileage) should we drain, and replace the coolant. #2 Also , what type ? Prestone makes some coolant ,they claim is compatible with EVERY vehicle made ? Dave.

[logray]

Hello, these are well covered topics here.

The extra portion on the h20 pump gasket is for the coolant guide housing. There is no need to replace that piece unless you drop the motor. You can just cut it off and replace the water pump portion.

As for the coolant, some say "lifetime", however IMO lifetime can be defined as 5 years. That being said, if your coolant is older and still passes PH and hydrometer tests, and looks clean perhaps it can last longer without adverse affects. I found on my car after mixing a little of the compatible prestone after 2 years and 10 years on the car the head gasket sealant material started to separate and float around the cooling system.

For a good read on compatible coolants look here: http://www.pedrosgarage.com/Site_5/Coolant_Antifreeze.html

If you drain ALL 6+ gallons of coolant out of the car, in my opinion you can use whatever coolant you want, but if you mix incompatible coolant types it is a very very bad thing. The coolant can turn to gel and cause major problems.

Edited June 4, 2012 by logray

[Johnny-5]

Hello, these are well covered topics here.

The extra portion on the h20 pump gasket is for the coolant guide housing. There is no need to replace that piece unless you drop the motor. You can just cut it off and replace the water pump portion.

As for the coolant, some say "lifetime", however IMO lifetime can be defined as 5 years. That being said, if your coolant is older and still passes PH and hydrometer tests, and looks clean perhaps it can last longer without adverse affects. I found on my car after mixing a little of the compatible prestone after 2 years and 10 years on the car the head gasket sealant material started to separate and float around the cooling system.

For a good read on compatible coolants look here: http://www.pedrosgarage.com/Site_5/Coolant_Antifreeze.html

If you drain ALL 6+ gallons of coolant out of the car, in my opinion you can use whatever coolant you want, but if you mix incompatible coolant types it is a very very bad thing. The coolant can turn to gel and cause major problems.

I have an issue with coolant! I bought some coolant last weekend as I was planning on tackling this job this weekend. Anyways the coolant that came out is greenish yellow and the porsche coolant I picked up is pink. I got a few drops in it and stopped after I noticed the different colors in coolant. Im assuming I shouldnt use this coolant with the exisiting coolant in the car correct. **** I was really hoping to have this done by today!!!

*update*

I just read online that the new coolant color is pink/red in color and is completely compatible with the older version of coolant. can anyone confirm this?

Edited June 4, 2012 by Johnny-5

[Loren]

*update*

I just read online that the new coolant color is pink/red in color and is completely compatible with the older version of coolant. can anyone confirm this?

That is correct.

Old and new Porsche coolants are compatible.