VW LOSING COOLANT ONLY WHEN TOWING!

[stevew1]

Hi can anyone help me I have a 57 vw jetta 2.0 tdi runs and tows lovely , my only concern is that every time I tow my caravan for a long period of time or up a lot of hills my coolant levels drop off and require topping up. The coolant levels remain constant whilst not towing and there is no evidence of any leaks under the bonnet. I had a passat before the jetta and had the same problem with that .Is this a common vw fault??

 

[weejock]

Steve I had this problem on a Ford Galaxay which was fitted with the VW 1.9 tdi 150 engine. The issue slowly got worse with there never being any sign of a leak. Also the usual checking of the engine oil filler cap for sludge never showed any signs that the head gasket was leaking.
I adopted the usual method of caution with these things and sold the car

 

[otherclive]

Sometimes you can have a very slow leak via the EGR internal cooling pipes. Difficult to identify without removal and bench test/inspection.

 

[Ivorwetwun]

Do you have a temp. Gauge fitted?
Is it running hotter when towing?
If so I would have the thermostat checked.

 

[JohnGriffiths]

I'm a little bit rusty on these things, but the usual cause of this problem is surely that the coolant is being pressurised and forcing its way past the spring valve in the filler cap. This can be either the coolant is boiling, which could mean the radiator is blocked, sludged up, thermostat stuck or the fan isn't working. Or possibly there is a small leak between the cylinder and water coolant in the cylinder head although this usually produces white sludge/oil visible in the coolant.

 

[Maric]

Sometimes you can have a very slow leak via the EGR internal cooling pipes. Difficult to identify without removal and bench test/inspection.

Good call, I had exactly the same on my 2003 Audi A3 2.0 DSG. It took the dealer several attempts to identify the fault. What was most confusing was the absence of any fluid on the drive or anywhere else, I'd just get the low coolant alarm every now and then.
The coolant was leaking into the exhaust and disappearing out the back as steam.

 

[seth1]

Empty post (likely not intentional - probably an Internet Explorer issue!)

 

[Sproket]

Seth
Are you lost for words

This will sort it !

Internet Explorer 9 users

 

[seth1]

Try using Firefox or Google Chrome Seth, IE 9 doesn't work very well on this forum
Parksy (Moderator)

 

[seth1]

Hello,i wonder whether im working now?

 

[Sproket]

Welcome back !!
I can see your post on Google Chrome & IE8

 

[seth1]

That took some doing,ive only been trying for two weeks!Getting back to the VW problem,i had a friend with a Passat 2litre TDI with the exactly the same fault and it seems common on the early PD version of the engine.It returned to VW a few times before they lifted the cylinder head but couldnt find anything wrong.He lived with it until the day he got rid of it.Since then we,ve repaired a few Caddy vans fitted with 2litre TDI,s and with water problems.Up till now the problem for us has always been the front mounted water to oil heat exchanger(oil cooler).That might not be the case for you though.The best thing to do might be get the engine as hot as possible and then pressure test the coolant system to show anything up with the engine hot.

 

[DevonshireDave]

Hi Steve
I found this while researching the Golf/Jetta/Octavia/Leon family as we have been considering a new car for my wife. Most relevant is the paragraph on coolant down by the bottom Jetta photo.
http://www.honestjohn.co.uk/carbycar/volkswagen/jetta-2006/?section=bad

Dave.