996 C4S Overheating (Europe version)

[declanka]

Hi I have a 2003 996 C4S, Last weekend got an engine warning light, switched off and started again later and goot coolant low warning, so I topped up, was driving again today for a few hours and got coolant warning and Hight temp red light, yet the tem guage seemed ok around 80 in the middle. stopped and saw steam from engine bay, could not locate topped up water which was below min but not by much and was OK got me home. I noticed that heater was not blowing hot as I put it on just in case. Is it possible there is an airlock, or does anyone recognise these symptoms. Any advice welcome Declan

[JFP in PA]

Hi I have a 2003 996 C4S, Last weekend got an engine warning light, switched off and started again later and goot coolant low warning, so I topped up, was driving again today for a few hours and got coolant warning and Hight temp red light, yet the tem guage seemed ok around 80 in the middle. stopped and saw steam from engine bay, could not locate topped up water which was below min but not by much and was OK got me home. I noticed that heater was not blowing hot as I put it on just in case. Is it possible there is an airlock, or does anyone recognise these symptoms. Any advice welcome Declan

 

You most likely created a steam pocket in the cooling system during the first event which is causing the issues you see now due to an air pocket.  The biggest concern is that something is wrong in the cooling system which caused the first event, and the fact that these engines should never be allowed to overheat, as that quickly leads to cracked cylinder heads or worse.

 

I would not be driving the car, or even running it, until the reason for the first event is found.  If you cannot work on it yourself, have it flat bedded to a specialist shop.

[declanka]

Thanks, is there a procedure for removing air pockets, might try that first

[JFP in PA]

Shops remove air pockets using the vacuum filling tool, but it can also be done by "burping" the system by opening the cooling system vent valve located near the surge tank.  The procedure is covered at the every end of this third radiator install DIY: http://www.renntech.org/forums/tutorials/article/69-3rd-radiator-install-instructions/

[declanka]

Thanks this is great, a job for the Christmas holidays :-)

[DaveN996]

Make sure your coolant tank cap is the correct one.  I think the part no should end 04 

I replaced my 996 (1998 c2) cap this year with a dealer part.

 

theres a springy bit of metal on the coolant tank (bleeder valve) that allows you to bleed the system.  If poss get the back of the car up high, set heater to max and run the engine with the cap off slowly filling until it stops taking coolant.  Once it starts getting warm and stops taking coolant put the rad cap on with the bleeder valve up and make sure its ok.

 

good luck

 

thats how I did mine first time, second time (after I replaced a leaking rad) I bought the vacuum tool.

Edited December 18, 2015 by DaveN996

[SabaDabaDoo]

Had something similar, turned out to be a leaky expansion tank's cap, dealer was nice enough to mail me a new one, since I had them install the tank (including the a new cap) a year ago.