coolant leak, but where from?

[Mertian]

Hi all you more experienced than me 996 owners...

My '00 996 C2 Cab has today formed a coolant leak. I've had a look under the engine and it appears to be at the rear of the engine on the left hand side (looking forward). The drips (circled in the photo) appear to be at the bottom of the belt, however I'm not sure where they are actually emanating from. The obscured view from the top doesn't make it any easier to spot. Any thoughts? I'm hoping it is just a clip somewhere or a perished hose.

Thanks in advance

Martin

 

[dij999]

Split in the header tank seam quite likely - if the cap is not the cause.

Dave J

 

[Mertian]

Thanks Dave

Header tank is on far left, the dripping is more left of centre and there is no signs of it running from the header tank to where the drip is.

Any other thoughts?

Cheers

Martin

 

[Callughan]

Its either the cap or tank both of which have had numerous updates. Maybe take to garage to do pressure test?

 

[dij999]

Have had two episodes with header tank leaking in 6 years - on both occasions it was not immediately obvious as the leak was quite small at first even when quite hot and well-pressurised. On each occasion the coolant dripped to the floor in a place that did not make the cause obvious.
On the second occasion I absolutely refused to think it was the cause but again it was proved to be so despite replacement 3 years previously.
It's not to say you may have something different but problems with caps and tanks have been well documented and appear to be the cause of the vast majority of coolant leaks at the rear, but I guess you will check all your hoses and clips especially as they may well all be 10+ years old now.

Dave J

 

[devans]

Agree,
a pin prick can develop and when up to pressure will project spray which at times cannot be seen. This can then run down the engine bay in any number of places,
Split expansion tank is best bet,
good luck.

 

[Richard_Hamilton]

Difficult to tell from that photo. I would second the header tank, but could it be from the thermostat housing, or (worse) water pump seals? A better photo would help.

 

[Mertian]

Thanks all, some useful pointers for me to investigate.

Richard, when you indicate better photo, do you mean better resolution / larger size, or taken from a different angle?

Thanks again, Martin

 

[Richard_Hamilton]

A larger size would be better, with a bit better focus.

 

[Mertian]

Better photo attached. When warm, the water was dripping from the bottom of the belt (circled). There is still a drip there this morning.

Cheers

Martin

 

[Richard_Hamilton]

The water pump is directly behind that pulley, with the inlet pipe at the bottom. If I were you, I would take off the polyrib belt and wiggle the pulley to see if the water pump bearings have gone. If you take off the air filter housing you might also be able to see a bit more from above.

 

[Mertian]

Thanks Richard. You may be onto something with that as there is certainly no visible evidence of the water dripping from higher up the engine.

Cheers, Martin