997 overheated

[leswh]

can anyone help ?
my 911 997 battery was slow so i left the car running to charge and totally forgot about it, the rad fans did`nt kick in and it overheated, when i went to the car the inside glass was totally steamed up, the warning read engine to hot, so turned it off, stupidly i opened the cap on the expansion tank to let steam out, i left it until the next day, it took a lot of water to refill but don`t know how much is due to me taking cap off.

I started the car and sounded sweet, i lifted the bleed plug next to the expansion tank and took it for a steady drive, it seemed to run smooth i`d driven about a mile when i turned the heater on, then warning lights appeared with a message take to workshop, drove it home slowly, started this morning ran to about 40 degrees the engine is running unevenly, has anyone had this or knows what it could possibly be ?
thanks in advance

[996TT02]

Not really, but if we are into guesswork your heater matrix or a hose leading to it may be leaking. Maybe.

[leswh]

hi thanks for the reply, could that make it misfire ?

[996TT02]

Not directly no. Perhaps the overheating particularly due to the fact that the car was started up and stationary for a long time, damaged one of the coil packs. Perhaps completely coincidental. Perhaps not a coil pack. All guesswork, your problem will not be definitively diagnosed off a forum, that is the only thing that is not guesswork.

[Filibuster]

Can't add much to your problem and I don't mean to be rude, but what made you think it's a good idea loading a battery with an idling engine??
You get only about 13.8 Volts from the alternator while idling. You need 2.5k -3k revs for the full 14.2V.
You'd be better off with 1/2h drive or by buying at battery conditioner.

Also why didn't the fan kick in? It should make no difference whether you are stationary or moving to do so.
And for how long did you have it running??

[jonno_]

I'd get it recovered to your local trusted Indy to check:
Battery and alternator output
Cooling system, thermostats, fan operation and coolant level and concentration
Codes read

That way it's no guesswork, safe and least aggro for you.
Sure we can recommend somewhere - where is the car?

[Demort]

Once you removed the coolant cap the coolant would have boiled .. the coolant would have been over 100 degrees C which when under pressure wouldn,t boil but removing the cap would lose the pressure and it would boil .. not recommended to do this.

You will now have airlocks in the system and from the sounds of it the heater matrix .. this can be bled .. leave it overnight and top up.

My concern is possible damage .. you said it ran fine but then asked about a misfire .. if the car does have a misfire after this then i would suspect a possible head gasket failure .. if it doesn't misfire then you might have got away without any damage.

Both fans not cutting in though is unusual .. I would try a screwdriver through the arch liners to move the fans .. its possible both are jammed due to debris.

[996TT02]

Demort said:

Both fans not cutting in though is unusual .. I would try a screwdriver through the arch liners to move the fans .. its possible both are jammed due to debris.

Would happen if the temp sensor for the fans has failed. To check that the fans are actually operational all you need to do is turn on a/c, they should come on immediately.

[leswh]

Hi thanks for everyones response, ive booked it in to the local Porsche specialist in Telford to run diagnostics, he seems to think it could be the start of a liner crack, due to the fact it misfired when i turned the heater fan on, transfering water,, and running it may have evaporated the water from the cylinder, and an airlock stopping any more getting in to the cylinder

yesteray i let some oil out yesterday and it was as it should be with no signs of water in it and also no signs of oil in the water,
no strange smoke or steam from the exhaust

[leswh]

Just managed to put hand up though bumper on nearside and fan moves freely , but when turned on i cant hear it running

[leswh]

hi, following on from an older post i placed last weekend about my car overheating and a misfire that cleared itself.

i took the car to a local garage and he put a diagnostic on the car which showed misfire cylinder on, he cleared the fault on the dash and the car has run fine all week until today, I started the car and it was missing again and again the message came on the dash (take to workshop)

I`ve heard all kinds of horror stories about cylinder crack and £12,000 to rebuild engine, does anyone have any thoughts, could it be a coil pack? and if so how can i test it ??

[speedyman]

Just swap the coil pack around to another cylinder if the fault moves it's the pack if it stay with the same cylinder swap or replace the spark plug.

[Bullet-Proof_Biscuit]

Fan relays and fan motors die, if do some research into how to diagnose which it's quote a straight forward procedure,.

If the heater matrix/system was empty then turning the heater on will have taken several litres of coolant to fill, causing the header tank level to drop causing the 'low coolant' or engine warning light to come on. Surely you turned the heating to full when refilling the coolant system anyway? This is basic knowledge.

Also opening the coolant cap on a hot, pressurised engine is the worst thing you could possibly do - The coolant is pressurised to raise it's boiling point, by depressurising it you've allowed the hottest part of the engine, the cylinder heads, to boil the water in their coolant jackets, this causes head castings to crack. The logic behind your decision 'to let the steam out' lol.

I would recommend a compression test to identify a heat/block/gasket failure, and/or a coolant system pressure test, as said above steamed up cabin means a leak on the heating system probably,

[Chamon_Lee]

Don't take this the wrong way but I would seriously stop doing your own diagnosis on the car.
I see you have taken it to the specialist, I would leave it with them and let them sort it because so far you've made a bit of a pigs dinner of everything.
Even filling up the coolant tank with tap water (which I have assumed from what you have said) is also a big no no besides the other points brought up already.

Leave it with the techs and let them get it 100%.