Preventative maintenance whilst coolant is out?

Thought my car caught fire today but on (rapid) closer inspection it was just a lot of steam due to a failed coolant connector pipe spraying water all over the engine bay. Pretty sure I discovered it early enough that the engine is ok. Obviously the connector needs replacing but what else should I do whilst the coolant is out? So far I'm thinking water pump, low temp thermostat, aux belt and pulley. I might do the hoses around the pump/thermostat as well regardless if they're not expensive. Are there any hoses or similar that commonly fail that I should do at the same time? (Yes, I know it's a quarter of a century old, so anything could fail at any time!) Also I was thinking to fit the larger oil cooler from the 997, but if this is a faff I might not bother. Thanks in advance for any tips. Funnily enough it's only the second time I've needed a tow, the previous time was also due to a coolant issue in 911, albeit that was a then nearly new 991 Turbo S that I was ferrying between sites for work. (Not the cars fault, the coolant had been drained but on refilling the workshop hadn't got all the air out!)

With you on the LTT. Worth doing if you drop the coolant When topping back up, you will need to add a bit more coolant each time after the next two or three hot cold cycles before you reach the final level.

Coolant expansion tank itself if it's original, they are known to crack. Same goes for the water pump if it's still original. Low temp thermostat, sure cheap enough.

Your engine will only run cooler with an LTT if conditions allow , that being low revs at 50-60 mph on a cool day. As soon as you enter an urban environment the temp will rise to the usual and eventually the fans kick in if your stuck in a jam

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This makes no sense to me. There's no "usual" to rise to with a lower temp thermostat, are you getting confused with the fact the upper half of the gauge is, for lack of a better word, fake in 996.2 models, so the needle will eventually climb to the middle (in conditions when actual temps are higher anyway)?

What he means is that the LTT is no more useful than the regular temperature thermostat when the car is stuck in traffic - which is true. However, if you modify your car to activate the high-speed fans earlier, or at your request, then the extra airflow through the radiators at slow speeds will help cool your car down better and you’ll reap the benefits of the LTT.

I mean if you’re driving in cool air or with a strong head wind at cruising speeds your temp will be below 80 on the gauge but as soon as you come into say a town with traffic lights, stop start traffic the temp will rise just as it does with a normal thermostat. So a LTT thermostat is a good option if you drive for long periods at say 50mph in 5th gear in cool air. Apart from that it makes no difference. It just opens earlier but does not increase the efficiency of the cooling system , to do that you’d need to remove the aircon condensers or add a 3rd radiator, or both. Or like Radish says above , have a manual switch for the fans but that could be bad if you forget and it overheats I hope that makes it clearer.

I know nothing of 996`s though would imagine that fitting a manual switch would configured as an over ride to the normal water temp sensors operation, thus wired in parallel to the sensor...? Thus the sensor would control the fans as normal, and if for any reason you wished to have the fans running you flick the switch.... Also very handy if the sensor fails, when again you can just flick the switch... Perhaps could also be handy in fault finding processes relative to engine temps...? Just thinking in type...

Totally agree Luddite , a parallel system would be a really good option especially if you're in that urban environment quite often. My 98 C2 has a LTT and yesterday I did a long cross country trip to Berwick U Tweed avoiding nearly all towns apart from Kelso and the temp sat well below 80 but even the short section to the train station it rose and went past the vertical. I'm considering removing the Aircon system in that car (less the pipes) as it needs looking at for leaks and I'd never use it, better cooling and weight loss mostly the compressor.

I agree that it doesn't make the cooling system more efficient, so if your coolant is running at 100% flow the temperature will be the same. However, £40 or so (if he's doing the water pump there's no added labour cost) to have a higher temperature delta and reportedly lower temp deviation between banks is a no-brainer.

Some great LTT comments above. It's true that normal running, say at 50 to 70 will now read 79 on the gauge as opposed to the normal 83. In stop and go traffic, with the AC off you will get up towards 90 before the low fan speed kicks in. With AC on the low speed fan is always on. In the stop and go scenario, as also said, both LTT and normal stat will be fully open. Tony Hart of Hartech has suggested that the LTT can give you headroom when going from a good thrash to idle for a short period (such as traffic lights for example), then getting straight on it again. This scenario, he theorises, is likely a potential bore scoring scenario. The idea of the LTT is to arrive at the lights a bit cooler and with the stat fully open to minimise heat soak before you resume driving at or near peak performance.

U.M. Using no more than logic, failed or otherwise, it seems that Porsche design their engines cooling systems to run within a particular temp range regardless if driving in either hot or freezing climates, or anywhere in between... I guess even a new Porsche can pick up any variable amount of detritus partially blocking the rads, thinking driving along a broad leaf forest road when the trees are at the peak of shedding their leaf's. On the other hand older Porsches water galleries in either their rads engines or associated pipework, can perhaps begin to "fur up" to some extent, thus becoming a tad more restrictive to water flow...? For sure the water temp sensor is only interested in water temps regardless of the possible variation of outside influences, and will bring the fans on relative to that temp, though again, logic suggests that the fans will perhaps come on earlier on a journey and run longer perhaps suggesting to the driver that detritus may have blocked up the rads and all that is required is to clean out some leaves or brush away the remnants of flies etc.etc, but if caused by general ageing of the system, than perhaps more invasive attention could be required...? Extended running of fans struggling to keep an engine cool, also puts more strain and potential wear into the electrical system, the fans themselves will have more running time, and the alternator working a tad harder longer, as well as some degree of fuel efficiency drop off..? I have never carried out any cooling system maintenance or repairs on any water cooled Porsche other than clearing out leaves etc from the front of the rads, and... I have no idea whatsoever if any of the following might be useful or potentially damaging to any Porsche, and would be grateful to be educated by anyone who has any real world Porsche experience in this area.. Also perhaps modern coolants that Porsche recommend to be used in their engines greatly reduce the opportunity for waterways to become restricted in varying degrees relative to time..? I have been known to flush out the cooling systems on old sports cars I have on occasion using a garden hose. I would remove the coolant thermostat and replace the cover to maintain the circuit integrity, attach the hose to the vehicles pipework and leave the other end of break I created in the system open to allow the flow from the garden hose to escape to ground... I guess much depends upon how much pressure is available on one`s hose as to quite how effective the process might be at clearing out "fur"....The colour of the water would change to eventually run clear, at which stage I would reverse the connection of the garden hose to the end of the cooling circuit that was formerly opened to drain to ground, thus reversing the direction of flow. With that done and the pressure again applied via the hose, the colour of the water would no longer be clear, indicating that reversing the flow had freed off more "fur." By repeating this process a few times the water would eventually run clear immediately after reversal of flow direction suggesting the process had achiever all it could. I have used a similar process of on suspected heater rads by connecting to their pipework at convenient points where they pick up and return their hot water supply from the engine, of course the heater valve requires to be opened to allow flow... The heater matrix could be the highest point in the "cooling" system, and thus susceptible to air locks, and could also be the first sign of a problem on a cold day when the heater output turns cold..

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That's where the LTT is a good option , it buys you a minute (at most) when stopped at traffic lights/jam etc. Having said that on a baking hot day I don't think the LTT will lower the cruising temp at all.

I think it’s possible if you have a third radiator. For example: It’s 90*F today, and I’ve been driving my C2 equipped with 2 rads and a LTT. I activated my high-speed fans to run continuously today. My average speed is about 50mph with the occasional stoplight every 5 minutes. My coolant temperature generally held around 92 Celsius. I remember back into the days before I had a LTT, but did modify my fans to run at high speeds, and on a 40*F day the lowest coolant temperature I could record was 93 Celsius. On a 90*F day with the same setup, my coolant temperature was typically around 98 Celsius. The 40*F day example shows that despite the cool ambient temperatures, the regular thermostat will restrict flow and a lower coolant temperature cannot be obtained. And with the LTT, your cooling ability is now limited by a combination of radiator size, air flow, and ambient temperature. I apologize for the mix of Fahrenheit and Celsius units. I find it easier to recall my ambient and coolant temperatures like this.

Thanks for the advice, adding expansion tank to the list. Also being a C4, the tank inhibits changing the fuel filter, so I'll do that too.