Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

I have a MY 1999 996 C4 that I had to have towed because of a coolant leak. I saw smoke coming form the engine area so I pulled over, saw the leak and thought it best to get a tow. I initially thought it may be a hose leaking, but found that when I squeezed a hose, it looked like coolant was leaking from the lowermost flywheel (where the serpentine belt goes). Is this possible or could it be leaking from somewhere that I cannot see?

About 1000 miles ago I had a new clutch, IMS and RMS bearings installed. Could any of these repairs be related to the coolant leak? I want to try to fix this myself before having the car towed for repairs if possible.

Thanks in advance for your help!

Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

I checked the coolant tank and hoses and they seem fine. The leak appears to be coming from around the area of the water pump. So, I removed the air cleaning assembly and serpentine belt to try to get a better look. I tried turning the water pump flywheel and it started to turn, then seemed to rub against the engine like it was out of center. Now it will not move at all. Should I replace the pump to fix the problem?


Link to post
Share on other sites
  • Moderators

Replacing the M96 water pump has been written up on multiple sites, with some variations due to model year, etc. It is pretty straightforward. Do a search, you will probably get more data than you really need…………

Link to post
Share on other sites

Thanks. I ordered a new pump and gasket from Sunset Imports. Also, I remembered there's an article in the Aug. 2012 #202 issue of Excellence magazine. Interesting read...

I'll update when I get the part and start repairs.

Link to post
Share on other sites

I have removed the old water pump and installed the new one. I added 1 gal of Porsche coolant followed by 1 gal of distilled water. I thought it would take more than that, but the filler is full (even after pulling up the purge valve on top of the coolant reservoir.

The rear of the car is about 2" higher than the front as I saw recommended online. I went to start the car and everything went haywire. What I mean is the interior lights and dash lights blinked off and on repeatedly and didn't allow me to start. Does anyone know what this means and how I can solve the issue? Could it be that my battery is too low to start or is the car giving me a warning that something is wrong?


Link to post
Share on other sites
  • Admin

Likely a battery issue unless you removed wires and did not re-connect them in the engine compartment.

Best open the bleed valve once you get the engine running as you will need to top up the coolant as the air is bled out.

Link to post
Share on other sites

Yes, it was the battery. The old one tested dead, so I purchased a new one and the car started like a charm. Thanks for your reply Loren.

How long do I need to open the bleed valve? I let the car run for about 5 minutes with the valve open and the heater on high defrost. Turned off the engine, let it cool and topped off with more coolant/water mix. Should I drive around with the valve open for a bit or has what I have done enough?

Link to post
Share on other sites

Thanks for all of the help. I was able to install a new water pump and refill with new coolant thanks to the help on this forum! I got the parts from Sunset Porsche--I still can't figure out why their prices are so great.

The job was fairly easy except for these areas:

-it's fairly difficult to remove one of the bolts on the right side of the pump. I used a combination of different lengths of 10mm sockets and my fingers and it eventually came out.

-the pump is impossible to remove unless the one large coolant line beneath it is temporarily disconnected and the smaller line leading to the pump is dropped (there are 3, 10mm bolts holding its long length in place. Just follow the line down from the end and you will see them).

I have been mainly a regular maintenance, oil-changing type DIY mechanic and since doing this I feel much more confident in my ability to tackle more challenging service tasks. Thanks renntech!

Link to post
Share on other sites
  • 3 weeks later...

Okay, so I think I may have run into a bit of a snafu. I checked the coolant level the other day and it was fine, but the coolant itself looked rather dark, so I took some of it out to get a better look at it in a clear bottle. Next to virgin coolant, the stuff I took out of my coolant resovior is somewhat browner. It's not as bright pink, more of a muted pink color.

Is this something I should be concerned about? The temp seems fine when I drive (doesn't go past the right edge of the 0 on the guage). I'm wondering if oil has somehow found its way into the coolant or if its just old stuff that didn't drain out when I drained to replace the water pump.

Any advice is much appreciated!

Link to post
Share on other sites
  • Moderators

Take a turkey baster and pull out the contents of your surge tank into some sort of glass container; if it is cloudy and looks a lot like hot chocolate, or multiple layers, you have an intermix condition. Regardless of the color, coolant without oil in it will be clear...........

Edited by JFP in PA
Link to post
Share on other sites

Did you examine the color and clarity of the coolant that you drained out of the cooling system?

If it looked like what you are seeing now, you should probably drain the entire cooling system to get all fresh coolant in there.

How much mileage and how many years since the last "lifetime" coolant change?

Regards, Maurice.

Link to post
Share on other sites
  • Moderators

I did that. It looks more like tea than hot chocolate. Any idea where I should look to see what is causing it? Is it unsafe to drive?

Thanks for the help!

Is it clear or murky? Are there any signs of oil drops floating in it?

Link to post
Share on other sites

If it is any consolation, I recently changed my water pump. Prior to replacement, I had the green colored mix anti-freeze in the expansion tank. The new Porsche anti-freeze is pink, and that is what I refilled the system with. Result - Pink+Green=light brown color. I'm not worried about the way it looks. Temperature stays at 180 and everything else is fine. One day I'll flush the whole system and replace with the new pink colored coolant. But for now, daily driving and love this car!

Link to post
Share on other sites

Thanks for all of the responses. I really appreciate the help. The coolant I removed is more orange, not as dark as I initially thought. However, it's not the bright pink that the factory fresh stuff is and that's what worries me. To me, the color is consistent with adding a bit of contrasting color, green, to the pink. Just as DBJoe996 suggests. It looks clear and I do not see and drops of oil in it. I've attached a picture for further consideration.


Link to post
Share on other sites

If there are no drops of oil floating in it, you are okay. The coolant in the bottle in the photo looks clear and not murky, so that looks good too.

Take a few ounces of the coolant you drained out and mix it in a bottle with a few ounces of the fresh coolant you added to your reservoir and see it you get the same resulting color as what is now in your cooling system. That should put the issue to rest.

Regards, Maurice.

Link to post
Share on other sites

Unfortunately I already took the old fluid I dumped to the recycling. My local Porsche dealer is having a free inspection event this weekend so I will have them take a look. I'm sure they'll find something. :)


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Content

    • By FlashingBlade
      2002 C2 manual:
      Problem: when parked outside in freezing temperatures, oil leaks from the lower oil pump connector, item 7 in diagram below. When parked in a warm environment, it remains dry.
      Anyone had that problem? Should I replace the gasket #8?
      M96.01/02/03 Oil Pump M96.04
    • By royp4
      I have a 2003 996 carrera cabrio. Recently it has developed a rattle or possibly a warning buzzer at exactly 60 mph. Could this be related to the limiter setting? Any help would be greatly appreciated. Thank you in advance
      Roy Parnell.
    • By deane.barker
      My 1999 911 Carrera started smoking at a streetlight. Very smelly blue smoke was coming from under the engine cover. I pulled over and popped the cover. Blue smoke was coming from somewhere under the engine (not the exhaust). The engine stopped very suddenly.
      We don't have a local Porsche dealer, but the Subaru dealer owns a bunch of 911s and he has a couple Porsche mechanics. I had it towed there.
      The C1 fuse ("Engine Electronics") was blown. They replaced it, but as soon as they turned the key, the "cam adjuster wiring harness" (I do not know what this is) began to smoke, and the fuse blew again.
      They disconnected the cam adjuster wiring harness (I don't know what this means, and neither did the service advisor), and the fuse stayed intact, and they got the car started. They were able to drive it out to the parking lot with no problems.
      They said I need a new cam adjuster wiring harness (again, no idea what this is), and this would require an engine out repair, which they could not do. They estimated this work at $5,000 to $6,000.

      Additionally, they did not know how drivable the car was with a disconnected cam adjuster wiring harness.
      So ... how bad is this?  (Service report image attached.)

    • By radial
      To all 996 owners with PSE, especially those with a 4S. 
      I think my 996 C4S exhaust behaves oddly. I think it's a fault but you might tell me it's normal behaviour. The problem is that I've always had this 'fault' on my car so I don't know if it's a fault or intentional behaviour. If you have the same car, perhaps you can shed some light on this.
      When I start it, it's noisy and sounds great. It quiets down as it runs for the first 5 mins. 
      I have the PSE system and when I press the button you can audibly hear the exhaust note change - quieter when on and louder when off. Default is off so loud.
      Here's the rub. Up to around 1500rpm it's got a good noise then it fades out to the point where it's so quiet it's like driving my partners Yaris. If I keep accelerating, when I get to around 3500rpm the exhaust suddenly gets loud again. I mean it's immediate - like someones flipping a switched marked loud. It sounds great. 
      It happens in 2nd and 3rd gears most noticeably and the PSE is in the 'off' position. If I have the PSE button on, then it's just quiet all the time and that works fine.
      So why the silent spot?

      I did read somewhere that German market cars might have had a system that turns on and off the PSE at certain speeds to prevent people driving round residential streets with a loud exhaust but information is thin and I don't think I was ever on UK cars. 
      I have also had a small go at checking vacuum pressure at idle on both sides of the Y piece in the engine bay but both hold good pressure. One side has only a microscopic leak but not enough to cause this kind of issue. 
    • By Dlowe
      Hi everyone, I just got a set of gauges for a 2005 996. I'm building a simulator for PC and would like to wire the gauges to work with racing games. I am in need of the wiring diagrams for the cluster. If anyone has a picture or manual that can help me out it would be great! Looking for inputs, power, signal.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.