[NutterKam]

I've been chasing a phantom coolant leak over the past week due to smelling something very much like antifreeze inside thw cabin once the engine is up to temp. However, it seems like the smell is actually emanating from the rear feed and/or return pipes to the rear heater. Has anyone expwrienced this before??

 

[Spanners]

I would check your rear heat exchangerT:

 

[NutterKam]

I have bene monitoring coolant level and not seen any visible loss. However, I realise that this isn't exactly an exact method. I have also ran the rear heater at various speed on hot and venting to different ducts and have not detected the offending smell coming from the air that has passed through the matrix. I have even stuck my nose into the blower vent with it on and off and not detected the smell coming from the within the heater itself. However, when I whiff the pipes seven semi close up they really do pong! I can see no weeps from the pipes themselves and there are no traces of fluid in the area surrounding them but they, honestly, do give off an offending smell that is either very similar to hot coolant or actually hot coolant. I am a loss. Given that the heater unit has air con as well, I do not know what to try next as I don't want (or even know how) to dismantle/remove the rear blower unit. Any suggestions on how else to check the matrix in the rear unit while in situ?

 

[jayc]

I have the same smell from my rear heater, only really noticed it when i removed the plastic panel. Took it in to vw as its still under warranty and they couldnt smell it. Quite an uncomfotable smell when hot, I work as a tech so I know only to well what hot coolant smells like. Can only think its the slight crustation of coolant on the hose joints to heater.
When conversion on this van complete im hoping i will not notice the smell.
Let me know if you sus anything

Jay:ILU:

 

[NutterKam]

Don't take it the wrong way but you have no idea how glad I am that somebody else has the same problem! I was starting to think that I was barking up the wrong tree and/or going mad!

Even with the panel on I get a whiff of the offending smell but only when I've been running the van for quite a long time - maybe an hour.

I'm pretty sure it's not the joints to the heater. If you try to stick your head right into that panel void you can see the joints. Mine are clean and dry (pre, during and post running at temperature). Have you actually tried to sniff the pipes (LoL)? I've found that it's actually the pipes that give off the pong!

Mine's also under warranty (one of the merits of buying an approved used VW!) so I'm going to see if they will try replacing the pipes. Worst case is do it myself, although it looks a right pain in the butt to remove the pipes from the heater itself! I reckon the replacement part number is 7H0819886D at an approximate cost of £60. TBH if it costs less than a ton to get rid of the smell then I'd be happy! My dealer is 80 miles away and if they want to keep the van then it costs me more than that to be off the road for a day since it's a working vehicle.

 

[NutterKam]

Does anybody actually know the internal diameter of these feed and return pipes/hoses for the rear heater? I'm considering doing a cheap test before replacing them by inserting a tube to bypass of the rear heater matrix.

 

[jayc]

Hi, did you ever get to the bottom of your coolant smell?
Jay

 

[NutterKam]

Hi, did you ever get to the bottom of your coolant smell?
Jay

I actually took it in today for a warranty fix and I've not heard anything yet but hope to within a day or so. Will post update as soon as I find out.

 

[NutterKam]

Just received a call from VW Sittingbourne. Turns out the pipes were perishing from the inside! Can't tell you how relieved I am that 1. I've been vindicated on my findings and haven't been going mad, and 2. can finally be free from gassing myself after two months A:

Top marks to JCB Sittingbourne for an efficient service! Only neg is having to endure the worst section of the M25 twice more!

 

[NutterKam]

Got me van back and after a long drive home I can confirm that I have no more smelly pipes! They changed the pipes and a rear flap actuator (smell unrelated). So hope this helps anybody else with similar symptoms.