sankysvr6 0 Posted May 14, 2015 (edited) I've got a very slight coolant leak, coming from near the PAS pump. I'm guessing and hopping its just the thermostat housing that's leaking as the pump itself looks quite new. So I'm getting my shopping list together but I'm not sure which is the correct thermostat for my car. According to the Parts Base catalogue I've got a choice of 2. 044121113 coolant regulator; 87C-102C 056121113D coolant regulator; 87C-102C According to VW Heritage 044121113 Is 87C 056121113D Is 71C So which one should I be ordering, as I just want the correct part that would have been fitted from the factory. Unless there is any benefit from fitting something else. Edited May 17, 2015 by sankysvr6 Quote Share this post Link to post Share on other sites
sankysvr6 0 Posted May 15, 2015 Well according to the dealers it's the 044 121 113. But VW heritage reckon it 056 121 113D. I've gone with what the dealers have said for now. The problem is now after taking the bits of to access the housing, I'm not convinced the leak is coming from there. As it's only dripping, when the engine is hot. And i can't see dried coolant on the housing or around the pump. Might have to wait for it to get more serious, or strip it down again when it's hot. Quote Share this post Link to post Share on other sites
Gti_Jamo 10 Posted May 16, 2015 The plastic housing is likely warped with age and heat. Thermal expansion could be causing it to leak once warm. It could be the pump itself that leaking or where it is sealed to the block. Not really anywhere else it could leak from down that side of the engine other than a headgasget seepage but they are more likely to leak when cold. Quote Share this post Link to post Share on other sites
sankysvr6 0 Posted May 17, 2015 I think the leak I think is coming from the pulley end, which I've read on here can happen if the car has not been used for awhile. Causing the seals to harden up which in turn starts to leak when you start using the car again. I've stripped it all down, and will get a new pump ordered this week to to replace it with and new thermostat at the same time. Is there anything I can do prevent the seals going, in the future. When the car is usually off the road during the winter months. Maybe a different coolant mix or something? Quote Share this post Link to post Share on other sites
sankysvr6 0 Posted May 24, 2015 Just to update, this leak was from the pump, most likely the pulley seal. Must have dried out, with the lack of use of the car. Quote Share this post Link to post Share on other sites