Increased oil consumption and coolant loss

Feb 2005 Porsche 997 C2S with 52k miles

Mileage Oil change date
17,242 4,183 19-Nov-09 Mobil 1 0W40
21,752 4,510 07-Jan-11 Mobil 1 0W40
28,230 6,478 31-Jan-12 Mobil 1 0W40
32,914 4,684 05-Jan-13 Mobil 1 0W40
38,193 5,279 27-Dec-13 Mobil 1 0W40
40,353 2,160 10-Jul-14 Millers NT Nanodrive 5W40
45,644 5,291 01-Jul-15 Millers NT Nanodrive 5W40
48,812 3,168 16-Jun-16 Millers EE Nanodrive 5W40

Ok so above is my oil service history since I have owned the car. Oil changed every year, and I do about 3.5 - 5k miles a year.

Whilst the car was below 40k miles I was using Mobil 1 0W40, and oil consumption was below 1.5 litres during the year.

I switched to Millers 5W40 at 40k miles, and straight away noticed a little more oil consumption, however still below 1.5 litres.

Since my last oil change on 16-Jun-16, I have done about 2k miles, used what felt a little more than usual (0.5l) until a couple of months ago and only got round to checking it today.

So today I saw it two bars down (never seen it that low before), and had to top up with 1 Litre. I know a lot of you will say that is normal, however this is a first for my car, and somewhat worrying for me.

In addition to this, I was noticing a little coolant loss, and this is going back to May-13 (at 33k miles). I had the coolant changed, installed a LTT, checked all the Rads for leaks and found nothing. After the coolant change, and a few small top ups straight after, the coolant level stabalized, and was fine for a while. Last couple of years, I have had to do some top ups.

I took it to an indi in Aug-16 to check for leaks, and got told it was all fine (only thing not checked was front rads, as it required front bumper removal), and 0.5L every six months is normal (BS as it is a sealed system - didn't agree at the time, but accepted it). Was also told the water reservoir doesn't leak - which is again BS, so paid an hour's labour and left with little faith in anything else I had been told.

I began keeping a record of coolant top-ups:

22-Dec-15 Coolant topped up 550ml 47,277
26-Jul-16 Coolant topped up 450ml 48,993

So today when I checked coolant level, it was well below min level, and had to top up with a whopping 1.5l. Again a bit of a shock to see it so low.

Engine sounds fine, no blackened tailpipes, no blue smoke, coolant is pink and no froth, as far as I can tell (with no dipstick) there is no mayo in filler cap, and I think oil is ok.

Something is not right, and I plan to take it somewhere more reliable who can do a more thorough check for the coolant loss, and not make me feel like I have wasted my time and money like my recent experience. And also thinking a compression test and boroscope is likely needed.

I am thinking this time I need to get it to Hartech, in the hope they will know what to look for, and resolve it as efficiently as possible!

Any thoughts/advice?

Sorry to hear of your woes. I would get a compression test done too.

Hopefully you will catch the problem before a catastrophe.

Pip

Hmm .. i cant see the car so obviously difficult to diagnose .. but my feeling is a minor coolant leak thats getting worse .. rads would be my best guess .

Some oil usage is normal .. some more than others ..

Get it checked by all means but i wouldn,t loose any sleep over it untill its diagnosed .. and i know thats hard , fact is major problems are not that common .. worrying about one is .

I see many cars .. rare to be a major problem .. it can happen .. but its unusual .

Demort said:

fact is major problems are not that common .. worrying about one is .

Click to expand...

Never a truer word said.. :lol:

probably true, but having read so much about failures over the years, you tend to fear the worst, and taking the car anywhere to have it looked at, you feel like you might be writing a blank cheque.

I'd be happier if it was an obvious rad leak or water pump failure, and there was a pool of water under the car. Right now my worst fear is a cracked cylinder!

Cracked cylinder? Blimey that's paranoia. I would've thought you'd have more severe symptoms if that were the case. Oil in coolant or vice versa, air in coolant or burnt gases in there also.

There's a big cooling system on the 911, it could be anywhere.

I had coolant loss a couple of years ago which my specialist found and the front of the engine somewhere. So he put some k-seal in and I've not lost any coolant since.

Give k-seal a go and see how it goes. It's the cheapest option first and go from there.

Oil doesn't seem to be using too much but then again, I'd try changing to a thicker grade, 10w50 millers nanodrive is the way to go.

:thumb:

Not sure about your oil use.
But the coolant sounds like what happened to me.
Topped up a very small amount in over 4 years daily use.
Then max to min in a week and about 200 miles.
Then max to min in 10 miles.
Went to garage and found coolant leaks.
Basically the joints on all the coolant pipes were corroded.
A design flaw I am afraid.
Engine out and all pipes replaced.
Wallet/credit card empty
1000 miles not a drop used and the car runs like a dream.

I had a very small leak last year, barely any coolant being lost then became progressively worse. It was a leak at the front where the pipes go in-board, just noticeable from within the wheel arch area. Common fault and not too expensive to fix.

My 996 was losing coolant when I first got it which was a bit of a worry as no leaks visible anywhere but it turned out it was just the header tank cap - a new one cured it completely thankfully.

*
*
Del.

As mentioned before I did take it to an indi to check for leaks in August 16, and was given the all clear, and told 500ml use every six months is normal, and that the reservoir does not leak!

So relieved of £72, and got nothing but BS in return. Won't go back there again.

Anyway, having to check everything daily now, and so far, levels are all normal.

Going to have to take it somewhere else to have it looked at thoroughly, as it is just too cold to spend a day trying to locate a leak.

Yeah .. erm .. not really the best advise you were given there ..

Tanks do leak normally around the valve , more so on a 996 though .

Its a sealed system so you shouldn,t have any leaks and certainly not half a litre .

You do sometimes get very small leaks from the coolant cap , youll notice a white residue on the cap but it will loose very little coolant from that.

If they did a reasonable look over then crossover pipes etc should be ok as a coolant leak even when not currently leaking will leave a residue ( often pink ) to indicate a slow leak.

Try running the car upto operateing temp then whilst the fans are running smell the air being blown out .. if any kind of sweetish smell to it then the rads have a small leak .

I dont feel the oil usuage and coolant leak are related ... if they were then i think you would have some more obvious running faults .

Demort said:

I dont feel the oil usuage and coolant leak are related ... if they were then i think you would have some more obvious running faults .

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Good to hear - thanks for the advice. Perhaps the Miller's EE Nanodrive 5W40 is not up to the task, I switched to it from NT, to try and save some money! Think I will switch back to NT next time.

I will try the sniff test on the rads..

Demort said:

Yeah .. erm .. not really the best advise you were given there ..

Tanks do leak normally around the valve , more so on a 996 though .

Its a sealed system so you shouldn,t have any leaks and certainly not half a litre .

You do sometimes get very small leaks from the coolant cap , youll notice a white residue on the cap but it will loose very little coolant from that.

If they did a reasonable look over then crossover pipes etc should be ok as a coolant leak even when not currently leaking will leave a residue ( often pink ) to indicate a slow leak.

Try running the car upto operateing temp then whilst the fans are running smell the air being blown out .. if any kind of sweetish smell to it then the rads have a small leak .

I dont feel the oil usuage and coolant leak are related ... if they were then i think you would have some more obvious running faults .

Click to expand...

Ok so I have finally found roughly where the coolant is leaking. I found the drip just at the back of the passenger side tail pipe, could see it dripping from there today (a few minutes after I had used the car and parked it) and was pink, and coolant level lower.

Any idea where the leak might actually be? Is the water pump on the same side?

Thanks

You need a new expansion tank. Over time they go brittle and crack. When cold the crack is closed, but the hotter it gets, and the greater the pressure, the crack opens up and you get a leak. Mine went last summer on my 996 C4S, same symptoms as yours. I had a new tank, cap, did the water pump whilst it was in. No problems since.

Thankyou for the advice. It has taken me forever to spot this leak.

You have told me the opposite of what the indie I paid to look at it in the summer last year, who said the expansion tank doesn't leak!