Isn't that a 997 problem/fix?
Low Temperature Thermostat
- Thread starter Rodney Naghar
- Start date
Hi,
booking the 996 (2003) in for a coolant change in a couple of weeks and wondered if anyone has experience of the above?
Reccomended by Hartech to help maintain cylinder lubrication.
The car won't be going on track but maybe low revs / high torque is the most testing time anyway.
Any opinions welcome!
Tim
booking the 996 (2003) in for a coolant change in a couple of weeks and wondered if anyone has experience of the above?
Reccomended by Hartech to help maintain cylinder lubrication.
The car won't be going on track but maybe low revs / high torque is the most testing time anyway.
Any opinions welcome!
Tim
Yes I'm sure it's for all M96 and M97 motors. Seriously considering doing that mod to my 997S. OPC quoted £200 for fluid and labour, I supply new thermostat. I don't have Porsche warranty so no issues with non original parts.
Having re-read Bazs posts, I think it is directed at the 997/987 block 'a piston siezure on bank 4-6 seizing one side of the piston - due to the cylinder running too hot' He does mention that high mileage 996s suffer from cracked liners - but of all the posts I've read over the years the only terminal problem I keep reading about on 996s seems to be the IMS. With the 997 it seems to be the overheating problem leading to piston seizure on bank 4-5-6. The thermostat is cheap, so maybe worth getting anyway but it may affect your warranty.
Warranty runs out in four months so that's not an issue. I was thinking that if the problem is mainly down to high temperature thus lack of lubrication strength this could indicate a need for a slightly thicker oil. Maybe will also change up to a 5W-50, i'm a bit uneasy about the Magnatec 10W-40 as it's unsupported and the car takes a while to warm up. I'm hoping 2003 cars are after the IMS problem? Tim
Baz explains it that the engine is getting too hot and as a result the oil is becoming too thin for purpose. Once you fit the new stat the oil should be fine:- 'The biggest problem I can see occurs when the engine is driven spiritedly. At that moment the cylinders will imediately get hotter and conduct that heat to the cylinder block and the coolant in it - but in that block the amount of coolant is small (compared to the amount passing through the cylinder head) and the cylinder head is no where near as quick to conduct the heat outwards and to the coolant (which is flowing through it in large volumes). So the small amount of hotter cylinder block coolant mixes back with the larger amount of cylinder head coolant (which is still cool) and passes at little increased temperature to the radiators - which therefore have a marginal affect on the temperature drop (being a function of the temperature differece which has been diluted by the mixing ratio). It then passes back to the engine thermostat which hardly notices the difference and in any case is designed to react slowly - and back round the engine again. While all this is going on the temperature between the cylinder wall and the piston has increased significantly and with it the oil seperating the two gets thinner and does not provide the support it should (while the coating on the pistons may get too hot). Eventually it all settles down to a constant temperature again until the driving style changes. If you compare this with more tradditional engine design, all the coolant frst goes into the block and cools it quickly first - then it passes through the head (so even if the cylinder block temperature has increased - the head raises that temp little more than before for a period of time) and the result then hits the thermostat (which sees the higher temperature and opens more) and then it almost imediately goes into the radiator. If you then fit a higher temperature thermostat (to help run the engine with reduced emissions) and cheat the dashboard reading (to avoid upsetting owners) - you get the scenario in full. Without re-machining inside the engine - unless the thermostat is changed to reduce the temperature it opens at - there is nothing any other changes will do to influence the cooling rate of change inside the clinders - because that thermostat controls the flow rate and the balance of coolant flow inside the engine is unchanged'
The IMS was still an issue until 2005 until they introduced the new design in MY'06
chriscoates81
New member
So is this a big job then i thought the thermostat is quite wasy to get to?
Replacing the thermostat is easy. Its at the bottom on the engine near the water pump (on the nearside). You'll see a inch and a half diameter hose exiting from the housing. You will need to drain the coolant first then disconnect the hoses and remove the housing cover. Porsche specify a special tool to wind the thermostat to remove it but on other forums, people have done it with long nose pliers. After that its just a matter of replacing the thermostat with the new one, use a new gasket for the housing cover, re connect the hoses and then fill the engine with coolant slowly and then bleed it using the Porsche stated technique.
The thermostat itself only costs around £60+VAT.
Could you advise from where? The LN Engineering item is $160, which includes the complete housing with stat installed.
That's the price http://www.hartech.org/ are selling them for.
Thanks, Looked at website but can't see any reference to it. So I have emailed them for info.
You're right it's not on their site. I got the info from a thread where Baz mentioned his price.
I agree. He's one of the most helpful and knowledgeable Porsche people out there - I've never heard anything but the highest of praises for him and his business. Him and Chris Franklin should set up together as the ultimate one stop Porsche service centre.
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