Coolant system over pressurizing

**qalaray** · 05-12-2012,01:40 PM

Hi
I have issues with coolant wanter loss.
ICar is Passat tdi sports 130bhp 2001, bought a month ago. Its losing hell amount oif cooling water. There was a leak in radiator so radiator replaced. The day radiator was replaced, next morning coolant was low again even the car was standing all the night. However it was topped up and afterwards it loses 1 liter water even in samll journeys and when you open the header tank cap, too much pressure released even when engine is cold.
I have observed few things;
No water dripping on floor, no signs of engine over heating, no loss of power, heater blowing nicely.
Sometimes smell of coolant inside car, condensation inside wind screen when its really cold outside.
Temperature guage is always at 90, in the centre even when engine is in 6th gear and warm, however when coolant is low the needle moves right to the red zone but comes back as you deaccelerate.
Hydrocarbon chemical test was done and change of color to blue indicated the presence of hydrocarbons in coolant water, mechanic suspected head gasket leakage. He said it normally turns to yellow when its blown but seems you have got slight leakage. I am not sure how valid is this test as it detects carbon monoxide.
I am not sure if it can be linked to diesel cooler somehow.
I am puzzled as if i follow HG repair, it costs a lot and problem may persist if it was not HG. Is there any other way checking HG leak without taking head off.

I would appreciate if someone can come up with knowlegable technical help.
Thanks

**martin1810** · 05-12-2012,08:20 PM

Sounds like you've had all the answers you need. Pressure in water from blowing head gasket. Block test fluid changing colour showing engine gases in coolant. You need a new head gasket.

**qalaray** · 05-12-2012,09:17 PM

Thanks
Do you have any idea of using sealing liquids in coolant. Do they work? or cause harm to engine or cooling circuit. HG replace is quite an expensive option so I was thinking to try this but not sure if its a good idea. Do you know any cheaper good garage.

**OddBallBoy** · 05-12-2012,10:18 PM

Sealing liquids in coolant are, as far as I understand, only aimed at sealing minor leaks in the cooling system itself, eg slightly perforated radiator etc. Can't imagine them being any use what so ever with head gasket problems I'm afraid.

**qalaray** · 05-12-2012,10:38 PM

Thanks, the quote i got for repair is around £600 or do u know anyone who can professionally do it for cheaper. I knw the gaskit and bolts cost £75 but the rest is labour cost.

**zollaf** · 05-12-2012,10:52 PM

thats far too cheap. i presume that gasket is unbranded whici is asking for trouble. you want a genuine or payen head gasket and head set and bolts. then you need injector seals and all the bolts that hold the injectors and cam in place, and these together are about £150 from vag. then you want a head pressure test and a skim, then on top of that, because the timing belt has to come off you want a new one including the kit, water pump and new coolant. this is to do a proper job that will last. anything less may be a short term fix but may cause more grief in the long run. basically, if the head is ok then you need to spend circa £1200.

**OddBallBoy** · 05-12-2012,11:16 PM

Originally Posted by zollaf

basically, if the head is ok then you need to spend circa £1200.

Ouch! 😱

**zollaf** · 05-12-2012,11:17 PM

thats for a proper job.

**Toonmania** · 05-12-2012,11:26 PM

Originally Posted by qalaray

Thanks
Do you have any idea of using sealing liquids in coolant. Do they work? or cause harm to engine or cooling circuit. HG replace is quite an expensive option so I was thinking to try this but not sure if its a good idea. Do you know any cheaper good garage.

K-seal is the only one i would recommend and it works very very well it's about £15 for a bottle I would try it and see if it helps your engine first at worst you've lost £15 but if it does work it should last long enough for you to save up and get a proper repair done.
K-Seal Car Leak Repair: Coolant, Head Gasket & Radiator Sealant

**qalaray** · 06-12-2012,10:44 AM

Thanks all, I am new in the car problem zone as never had any major engine problems before. Not a technically knowledgeable person so your suggessions are worth considering. I heard of the leak repair fluids on internet but no proper independent review found on this issue so I would not consider this as I am afraid messing up engine.
Actually the block test to sniff the CO does show that un-burnt gases are present in coolant and mechanic said its slight leak as it turned blue (if turns yellow then its blown). I was wondering if any possibility of these gases coming from diesel cooler- any idea what else can cause problem.