Coolant leaks from the radiators

I seem to be suffering from coolant leaks from my C4S. It's happened several times in varying severity...the first time I noticed distinct pools of coolant it was from the engine and front, this latest time from the radiators only. Basically, if I use the car every day, it's fine. But because I work offshore, the car sits for 2 weeks at a time...when I return I find two small pools of coolant in front of the front wheels....and the expansion tank just below min. It's been into the OPC for over a week before to have the coolant system pressure tested, clamps tightened up etc...and no fault found. It's back in again on Thursday once I get gack on terra furma. Anyone else experienced this? Glen.

Glen basically the rads are on the way out mate as I had this. firstly it was a small drip then it got worse and worse and then one day I got to work and one of the rads just let go! got it off to porsche for a check up as sometimes they cover this on warranty as long as a stone has not gone through I was lucky enough to be told it had just imploded so a fault from mfr and it was all done under warranty with the centre one done for good measure as you have 3 on the car. can't fauly opc, the pick up service, the loan car and turn around! plus the car was washed and valeted so it earned the service manager as case of wine as he really helped me regarding the warranty claim! hope it all works out and ping me a pm if I can help any further. NW

I do hope it's not the radiators... The damn thing is only 18 months old. I'm confused as to why they haven't found a leaking radiator (s) when they pressure tested the cooling system s few months ago...hmm... I don't think i've got a 3rd radiator either...I'm sure the grille thingy in the centre is a blank. Regardless, I'll specifically mention the radiators on Thursday when I drop it off...and report back and findings. Cheers, Glen.

glen age is irrelevant! basically it is a badly designed system with all the coolant stuff at the front like the AC and rad headers as they take all the impact. if a stone has hit it then OPC might be well tough luck it is wear and tear but they may honour it. argue fit for purpose as well as that it is a bad design and there should be some protection with the later turbo bumpers at least you have some grills on there to protect the header tanks. I am afraid it is that prob as its common on 911s! good luck and keep your eye on the temp gauge. Nw

I agree 100% with Nick... I had all 3 of mine changed within a year of each other.... and paid for them, age deterioration is not covered by OPC Ext. Guarantee. Apparently well documented problem... Sorry.. [&o]

Yet another 996 achilles heel. I replaced both my rads. One problem is the amount of crap that sits at the bottom of the rad housing. The fans act as hoovers cleaning the street as you go. You will find plastic bags, remnants of rabbits, small children etc all mashed up in a gooey mess that knackers the rads and causes microleaks. For those who enjoy this thing I think there is a do-it-yourself rad cleaning article on Pelican parts site. Otherwise, I think OPC's should incorporate it into annual service!

http://www.realtime.net/~rentner/Porsche/Radiator/Radiator.html

Just to note I had something with similar symptoms - after a lot of investigation turned out to be a 3-way valve somewhere in the cooling system (unfortunately my memory of diagnosis doesn't stretch further back than that) - symptoms were that it was fine if car regularly used and pressure test showed no fault, but when left undriven for a few days I would find a pool of coolant stretching from the rads to the engine - the coolant was literally running down the pipes towards the rads, hence it looked like the rads, but the fault was definitely in the engine bay. Was a very difficult thing to diagnose - 3 hours labour to strip and diagnose, then 2 more hours to rebuild - part cost: £2 - not covered by warranty as "small things like valves and seals are not covered"

Thanks for the pointers Gents... Sadly this has done nothing to lift my mood...hopefully the OPC will find a probmem and solve it. Failing that, since it doesn't seem to loose and fluid when used every day...perhaps I should consider a change of career and get a job where I can drive it every day.

why bother dude! you seem to be doing rather ok with an O4 c4s ;-) just one of those things and good point about all the crap that builds up at the bottom of the rads. you might want to look at some fine gauze behind your std vents to give you a bit more protection. the previous owner had changed all 3 rads in early 2005 and then they just 'self implode' a year later! non bon!!

Bring back air cooled motors I say! Has anyone retrofitted a proper Porsche engine into one of these thangs? Just think, no RMS worries, no water leaks, no slipping liners, no porous blocks. A well fettled late 993 motor would not give too much away in the horsepower stakes!

but then you look like sth out of miami vice and everyone going...it's an old one! plus you get the boiled sweets for dials and that older feel to it!! everything has its time and place and believe it or not things do move on!! ;-)

Was using mine daily and the water level light would come on about every 3 months or so......I'd top it up again with a fair amount. Took the bumper off a couple of weeks ago to clean and inspect to find the rads looking damp. Rigged it up to a pressure tester and found no problem although there was deffo a leak. Left it pressured over night and the rads started seaping all over the place....they'd turned porous. Replaced all rads and seals......cost £900 plus vodka for the bits.

Hey Daz, I don't mind movin' on but I draw the line at jumpin' over a cliff of reliability! My '84 Carrera 3.2 was no trouble at all. So why don't I get another one? I'd love to but that car was not popular with my better half!

Yes they called it the GT3 [ ]

Problem diagnosed, Gentlemen... Arrived at Aberdeen OPC first thing this morning and delivered the car... I was chatting to the Service Manager and started to say "It seems there are people who have suffered with porus radiators on 996s...." When he said "You've been on those internet forums again haven't you?" A few moments later the Tech then pops his head through to the showroom and says "New radiators required" Excellent. Job done. Car left behind...radiators ordered VOR, Cayenne courtesy car handed over...happy me! Should have it back tomorrow PM assuming Porsche GB have 996 rads in stock. I had my customary crawl about under the car whilst it was on the ramp...to be given the news that both rear Michelins are in need of replacement and my rear discs are in need of some work. They are suffering with the usual rusty inners..a skim may buy me a bit of time on those. It seems that the usual experience of having my wallet lightened by £500, or upwards in multiples of £500 continues with visits to my OPC! No matter... Thanks to those who gave me the pointer...an internet beer heading your way! ...and I'm liking the Cayenne! Despite be being a self confessed hater of SUVs...it's a nice car.

good news dude and those service managers must hate the forums as it gives power and knowledge back to the people! but why not as it helps us from being ripped off all the time! I would get a 2nd opinion on the tyres as OPC always tell me I need new brakes after like 6 miles.! surely you make brakes lasting longer than that porsche with your focus on quality engineering and race performance!! they told me my tyres needing doing. my local garage just laughed n said there is at least 2.5 mm on there! few more 1000 miles in those plus OPC charge way over the odds for tyres! I take it thisis all being picked up by weissach on the warranty?? job well done.

Pilot Sports are difficult to guage. My OPC said they were in need of replacement but consultation with Michelin showed that the outer grooves are not considered part of the tread pattern. Michelin's reply (with my emphasis) UK regulation, regarding tyre tread depth, states that that the central 75% of the tread width, in a continuous band around the circumference of the tyre, must have at least 1.6mm depth. The remaining tread area can have zero depth in the UK, although law in Continental Europe requires visible tread depth. The tread pattern width considered, is that having the principle tread grooves, not the sipe/fine-cut design, being in contact with the road. The nominal sizing (295mm) is not the dimension used as the reference width.

The tyres are 2mm on the inside, 3mm in the middle and nearly 4mm on the outers...pretty well worn out. I'll get another 1000 miles or so... They suggested skimming the discs, but also said they'd rust again...so unless the brakes are bad (they aren't) they suggested waiting 'till just before the MOT and having them skimmed then. Sounds fair enough to me. The quote I got for tyres was only about £20 more than any tyre fitting place locally...and for that, I think I'd rather have the peace of mind that they'll make good with no squabble, if the wheels get marked. Yup..a pair of coolant radiators, a LHS air con condensor and the associated re-gas and coolant re-fil...all warranty. Which is good...but shouldn't have happened at all realy, should it? Alls well now though...gave them their Cayenne back at 5pm and got mine back...washed and unmarked. Good, good...

That's interesting... Mine are more worn on the insides...maybe a feature of the X73 suspension? With the amount of rain we get up here in the frozen north...anything below about 3mm gets noticably worse to drive on...I can tell they let go more readily now.