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Boxster Coolant Leak

½cwt

Well-known member
Joined
1 Sep 2018
Messages
223
My 2000 Boxster S has now revealed why it has needed a top up to the coolant header a couple of times.

I've found evidence of coolant leaking from the front left of the car but it appears to have a source further back than the two rubber hoses that connect from the metal Y pieces to the rad. Whilst they have very rusty retaining clips (thankfully not the 987 type connectors, those look awful once they get old) the hoses are nice and flexible and spring back into shape when squeezed. No evidence of weeping at either end. I can see a hint of moisture on the higher Y piece pipework about 50mm/2in inboard of where the pipe turns toward the centre of the car but further back from there is a goods smear of coolant on the under tray and under the body. It drips after running sometimes but not others...

Could is be a hose feeding the heater core/matrix? If so where does this tap off the cooling system and has anyone got any pictures of what the plumbing is like in this area so I can work out a plan of attack.
 
Somebody on Boxa.net may have an answer for you :thumbs:
 
OK so I've subscribed to Boxa.net also now and posted the same query; but are you suggesting there is a specific answer searches haven't shown up that you know of on Boxa.net?
 
No, just a lot of Boxster folk on there that have likely encountered your issues before. Great forum, I was active on there for many years and met some good friends via it.
 
I've just ordered a UV coolant leak detection kit (£12 for fluid and a UV torch) so I'll report back the findings.
 
Sometimes the alloy pipe corrodes under where the rubber coolant hoses fit, it can be just the corrosion build up swelling the hose under the hose clip and causing a gap for coolant to escape, to cure this you need to remove the rubber pipe and clean up the corrosion.

I have done this several times on my 996 over the years and I did one last week that was weeping a little, once cleaned up its cured and all it has cost is your time and maybe a bit of spilt coolant.
 
It has taken some time as the water loss have been very small but I eventually tracke the leak to the end of the return hose for the left hand rad on to the alloy return pipe has started to perish.
Question now is if I'm going to drain the coolant how mush other work do I do on the system whilst it is 'dry'. I guess a full hose inspection and change as necessary is a given, but what about header tank, water pump, fit low temp thermostat as precautions? Also what coolant brand/type to use when refilling?
 
The coolant system is quite robust on these cars. I've rarely had to change much, the odd hose maybe. You can go as crazy as you like of course, changing the header tank and all pipes etc. Other than the rads which are the biggest source of coolant leaks, the ally ends of some of the hoses can corrode and let fluid past.

I was speaking to my indy a while ago about header tank leaks. He's done loads on 911's but only one or two on boosters for some reason.

Coolant? I use Comma. I usually buy it from Halfords. I can't remember which specific type (they stock two types) but its clearly labelled on the tub.
 
Good to know your experience with the cooling system, header tank was one of my concerns, but seems like I might just have a good check over and only replace obvious faults rather than PM. 21 litres is a lot of coolant but I guess it doesn't hurt to change it every couple to three years as leaks develop and get fixed periodically.

I did the air con condensers as one of my first jobs back in September and the rads were in fair condition and I gave them a damn good cleaning. Fan mounting brackets were rather rusty in places, need a strip and paint when the rad(s) do eventually leak and need changing.

Comma was the lines I was thinking along. 10% discount to AA members at Halfords to end of May at least as well. :)
 

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