Hello, fellow Skoda drivers!

 

I am very alarmed by the rapid consumption of coolant in my 2006 Octavia II, the engine is 1.9 PD TDI 105HP, code BKC.

 

The symptoms so far are:

Coolant level in expansion tank dropping from MAX to MIN about every 180 miles

Moderate amount of white smoke in tailpipe when engine is cold started

No visible traces of coolant leak on clear ground and on the plastic engine cover.

 

The car reaches the operating temperature of about 90C, but stays there, doesn't overheat, i checked the coolant hoses carefully and they are not steaming or leaking.

I don't think that it's related, but i flushed and changed the coolant in September 2017.

 

I'm at a loss here, really want some feedback, maybe someone has experienced this gremlin.

would seem to be head gasket /oil cooler/ or do you have a water cooled egr setup ?  if so my bet would be in reverse order   I think a pressure test is in order before any damage is done

Yes, i think my car does have an egr cooler, how do i check if it is bad? For the pressure test, do you mean the one with glow plug holes?

What's the mileage?

have you checked around the edges of the radiator for white/pink residue if you put proper g12/13 coolant in?

Also if it is indeed pressure from head gasket, any pressure when opening expansion bottle is released, does this still apply I wonder?

How about beneath expansion bottle same white pink residue from expelled coolant from bottle?

Does it only happen when used for fast driving but ok around town ?

Had a rad go on my 2005 BKC but it was gushing out.  

Had a head gasket go on a 1997 Golf

So above all my personal experience, hope it helps. 

Edited 2 February, 20188 yr by gav_is_con
Typos

Also have a look by the water pump. Might have a leak there.

it needs a cooling system pressure test  any decent garage should be capable

On 2/2/2018 at 20:24, gav_is_con said:

What's the mileage?

have you checked around the edges of the radiator for white/pink residue if you put proper g12/13 coolant in?

Also if it is indeed pressure from head gasket, any pressure when opening expansion bottle is released, does this still apply I wonder?

How about beneath expansion bottle same white pink residue from expelled coolant from bottle?

Does it only happen when used for fast driving but ok around town ?

Had a rad go on my 2005 BKC but it was gushing out.  

Had a head gasket go on a 1997 Golf

So above all my personal experience, hope it helps. 

the odo reads 206k miles

i checked in all of the engine bay and no sign of those residue spots anywhere

the coolant loss is the same either driving around town or in motorway, it depends on the distance driven mainly

On 2/3/2018 at 16:07, Stuart-h said:

Also have a look by the water pump. Might have a leak there.

checked underneath the car, with engine cover removed, but the pump seems fine, no residue of coolant

Mine had a similar issue. Nothing noticable on the ground or any other sign of leakage.

 

Finally I was able to find it.. didn't need a presuretest for it. Mine was leaking on a gasket between the engine block and some cooling lines. (BKD engine). 

If you remove the airfilter housing you could easily spot it. With the air filter still installed and a bright light it was also slightly visible: A small amount of coolant could be found just below the battery housing.

Actual flange is on the right side of the engine, just below the vacuum pump.

 

In my case it was a small leakage. Of course it wasn't leaking when the engine was off (so no leakage on the ground), and with the engine running.. it mostly got evaporated so it was barely visible.

I finally found some pink traces.

 

In this case it was an easy fix, fixed by replacing the flange (approx 10GBP or so).

If you're unlucky, the leakage might be caused by spilling oil/diesel from your vacuumpump. (causing the rubber gasket to get f*cked up). When replacing check your vacuum pump for leakage. If that one is leaking, symptoms vary from having oil in your diesel filter to coolant in your oil  ('never need to fill oil.... but not highly recommended)

 

by the way

If I remember correctly, a leaking vacuumpump can cause white smoke as well, and no visible trace of coolant leaking. But having oil in your diesel/fuel filter was also one of the symptons. You should google for that if it's not your flange. (Flange is plastic, so can cause leaking on its own)

If I remember correctly a bad tandempump had symptons like

- Oil in fuel filter

- Coolant mixing with the oil (causing oil levels to even rise above max.. due to addition of coolant)

- Lack of vacuum, not always noticable, but can be tested when you just press the clutch and repeatedly brake - causing the pedal to get more stiff  (don't know if thats proper english)

- Leaking oil or diesel can affect o-rings (rubber) so they can start leaking (eg the coolant flange below the vacuumpump)

 

Vacuum/tandempump is easily 250GBP ex labor so I hope that's not your issue

 

See eg http://forums.tdiclub.com/showthread.php?t=336418

On 2018-02-08 at 00:01, DJSmiley said:

Mine had a similar issue. Nothing noticable on the ground or any other sign of leakage.

 

Finally I was able to find it.. didn't need a presuretest for it. Mine was leaking on a gasket between the engine block and some cooling lines. (BKD engine). 

If you remove the airfilter housing you could easily spot it. With the air filter still installed and a bright light it was also slightly visible: A small amount of coolant could be found just below the battery housing.

Actual flange is on the right side of the engine, just below the vacuum pump.

 

In my case it was a small leakage. Of course it wasn't leaking when the engine was off (so no leakage on the ground), and with the engine running.. it mostly got evaporated so it was barely visible.

I finally found some pink traces.

 

In this case it was an easy fix, fixed by replacing the flange (approx 10GBP or so).

If you're unlucky, the leakage might be caused by spilling oil/diesel from your vacuumpump. (causing the rubber gasket to get f*cked up). When replacing check your vacuum pump for leakage. If that one is leaking, symptoms vary from having oil in your diesel filter to coolant in your oil  ('never need to fill oil.... but not highly recommended)

 

Thanks for reply, i checked the place you mentioned and nope, no noticeable leaks. But i actually spotted a considerable wet area on the metal right below and around the expansion tank, i checked it to be sure and its 100% antifreeze. It probably means that it leaks out somehow through the expansion cap? But i always check that place when the engine is hot and spot no leaks...

33 minutes ago, domistrg said:

Thanks for reply, I checked the place you mentioned and nope, no noticeable leaks. But i actually spotted a considerable wet area on the metal right below and around the expansion tank, i checked it to be sure and its 100% antifreeze. It probably means that it leaks out somehow through the expansion cap? But i always check that place when the engine is hot and spot no leaks...

 

Check the tank for cracks. The coolant is only expelled through the crack when under pressure so cracks are hard to find but should leave a coloured trace. There a couple of past threads describing this problem.

 

 

 

Edited 10 February, 20188 yr by pikpilot
Also take a look at this https://www.briskoda.net/forums/topic/432440-coolant-bottle-crumbling/

Update: did check the tank for cracks and found nothing. But i did a CO2 sniff test a few hours ago and sadly it came back positive, despite the fact that coolant loss has almost completely stopped in the last few days :( So most likely head gasket or block crack?

Did you check your fuel filter for traces of oil? And how is your oil usage? Still normal or less?

 

If coolant gets mixed with oil your oil consumption might drop. Oil levels even might rise above MAX. Also, oil in the fuel filter can occur. Both are symptons of a defective tandem pump. If coolant gets into the oil you can't spot that.

But this might be caused by a head gasket as well.

 

Is your coolant still as pink as when you replaced it last time?

 

Edited 16 February, 20188 yr by DJSmiley

Big update:

Decided to take the car to a mechanic to fix it up. He lifted the head and said that there was a very slight bump in the block and gasket and that was the most probable cause of gasses and leak of coolant. Changed the headgasket and grinded the block. Also the EGR cooler was bypassed from before (bought a used car, didn't know) so he reconnected the hoses to it. I hope it is the end of car problems for a while for me

Edited 21 February, 20188 yr by domistrg
missing info