Hi All

 

The wife noticed coolant lying where the car was parked. The coolant has dropped on the expansion bottle and we are keeping an eye on the level.

 

Is there a common issue I should be investigating with the expansion bottle or coolant hoses etc?? It's a 2010 VRS CR.

 

Cheers

 

Dave

 

Common one tend to be the water pump

I suffered total coolant loss the day after having the cambelt and water pump changed. It was put down to a faulty water pump. 

Got the water pump changed at 60,000 miles with the timing belt. It's only coming up for 85,000 miles now.

 

Will have a check. Am I looking for any tell tale signs??

Is it a faulty cap if lying on the bottle ?  Has it had the last click to secure the lid?

The bottles tend to have a release end usually covered that expells excess fluid under pressure. Is that the only side you see Coolant  residue?

Worth carefully checking the outside of the expansion bottle for staining. Others have reported on here that a crack has developed on the bottle, which opens up when under pressure to release a small amount of coolant.

Check the lid for leaks and the bottle for cracks dry the bottle make it all clean then go drive it and keep checking it see if you can spot any trails of coolant 

Cheers folks. I have had a wee look but can't see any coolant / residue. I did top it up a couple of days later and it's been fine since.

The wife took it a blast up the motorway to clear a regen today and it's still fine. Will keep an eye on it.

When I had my mk2 it was leaking from the bottle. Might be worth while looking there as well.

Will have another check at the bottle.

Hi All

 

The problem has appeared again. The coolant level has been spot on for weeks but we haven't checked it much over the last couple of weeks.

 

I took it out for a good steady run in 5th gear to clear a regen last week but didn't check the coolant after it.

 

The wife went out in it today to come home from work and there was lights on the dash and a loud high pitched alarm sound. The coolant bottle was empty and she put about 750ml of water in to get her home.

 

The engine oil has no visible water contamination and there is no oil residue in the bottle. The bottle is very clean with pink clean coolant in it.

 

I read about reving the engine a bit and watching for bubbles in the top of the expansion bottle but when I tried that, there was no fluid going into the bottle. Should there be or does that only happen at full temp??

 

I can see no leaks or dry coolant residue anywhere.

 

Any ideas guys?

 

 

 

Anyone know the part numbers for the correct (2010 VRS CR170 CEGA engine) expansion tank and cap ?

Ordered a new expansion bottle and cap. £23 odd Inc vat for the bottle and £12 odd Inc vat for the cap from local dealer.

 

Will change these to eliminate them and see how it goes from there.

 

Should there be coolant flowing into the top of the bottle all the time or only when up to temp or something else??

 

Just an update - the leak seemed to be the radiator. It had coolant along the bottom of it and I couldn't find any coolant anywhere else. Replaced it and filled with new coolant.

 

Coolant level has dropped in the expansion bottle (new bottle and cap) twice. I have topped it up again and will monitor to see if it drops more.

 

I am hoping that it's just the air working through the system as it's only done a few miles. Again there is no evidence of a leak anywhere. Oil had no trace of emulsion in it (just changed it too) and no oiliness in the new coolant. Old coolant was very clean.

 

Here is the radiator. Identical to what came out. Less than half the cost from ECP.

 

https://www.ebay.co.uk/itm/8MK-376-774-044-HELLA-Radiator-engine-cooling/302356818664?epid=749884395&hash=item4665deeae8:g:HQQAAOSwAO9ZSmIL

 

 

Hi 

Did the new radiator fix your issue??

Hello again,

 

Now in the proper post to ask the question how you solved your coolant loss, if you did?

 

I have had coolant loss for many months and its bizarre. I can drive fifty miles without any problem and then when coasting to a stop, suddenly I nearly jump out of my seat as the coolant alarm goes off. I rush round to see what the problem is and there's no coolant (at all!). So I have been topping up with distilled water for a long time now as coolant would be bankrupting me. But there's something very mysterious about this. One person suggested I remove the expansion tank and fill the coolant system with a hosepipe which would allow water to be forced into the block and enable me to ensure there is no air. That person said its extremely difficult to get air out of these engines once the factory coolant has run out or the coolant has been lost for some reason, no matter what instructions are followed. He means normal instructions of course, rather than removing the expansion tank to get the coolant forced through. I would prefer to get the coolant in another way. I also noticed on various forums of members with cars of similar age to ours remarking that a common failure is the gasket on the Coolant Flange on the battery side of the engine. It looks easy enough to get to so I ordered a Coolant Flange and intend to fit it as a matter of course. Before I get into it, I thought I would seek your final experience on your coolant loss and how you solved it. Was anything I mentioned similar in your case?

 

My car is actually an Octavia mk2 VRS 2.0 TDI with CEGA engine.  I believe that is extremely similar to one of yours.

 

Thanks for your many contributions here.

Edited 22 October, 20205 yr by OctaviaVRS2
errata

Faulty water pump- Replaced water pump and got timing belt changed at same time as same expense - fixed problem - you never said if you can see leaking coolant under engine or on engine tray ? water pump failing is a common issue with these apparently. 

 

If you have been topping up with water I recommend getting a coolant flush done  at same time also.

 

Hope this helps.

Have done coolant flush and the water is now clear and stays clear. Changed Timing belt, ancilliary belt, all the rollers and tensioner plus water pump. Nothing appears on the undertray. The most curious thing is I can be staring in the engine bay after just stopping the engine and see the coolant disappear from the bottle as if it has been simiply 'opened'. Its really fast. I filmed it one time and it was about a minute for it to drop 2cm. Other times I have parked up, everything fine, visited someone for a few minutes, come back and the coolant is gone, despite actually seeing it was all there before I stopped the engine. I've been making those sort of OCD checks in an effort to nail the symptom and when it occurs in the hope I could trap the culprit. I can drive round town and locally and apparently have the same level of coolant on my return as I did when I started. I make sure I am doing my checks so I can compare like for like. In other words start with a level of coolant I can mark precisely when the engine is warm, drive and then check again before stopping the engine and so often all is fine. Someone said a bad thermostat can cause this.  I bought one of those too as they cheap enouhg, although at about £150 to fit it, the labour cost is not something I want to waste. There's so much stuff in the way, I havent yet found a site that shows a relatively easy way to get the thermostat out! It looks like the EGR and throttle body has to come off in any event, even if one can work round the alternator.

 

For some time I thought this was associated with DPF regen as I was getting quite a few regens until I went on a longer journey. That has put regens to sleep for time being. So I now know its not regens. Another person says the water must be going in the exhaust although I have never seen any evidence of a whole bottle of coolant in the exhaust, either by steam or shooting out when revving the engine.

4 hours ago, OctaviaVRS2 said:

The most curious thing is I can be staring in the engine bay after just stopping the engine and see the coolant disappear from the bottle as if it has been simply 'opened'. Its really fast. I filmed it one time and it was about a minute for it to drop 2cm. Other times I have parked up, everything fine, visited someone for a few minutes, come back and the coolant is gone, despite actually seeing it was all there before I stopped the engine.

 

Sounds like you have a head gasket leak. What happens after a short burst of full power is that the engine gasses are forced through the head gasket leak into the coolant system. The excess pressure in the coolant system causes coolant to be automatically vented out by the pressure release cap (filler cap). When the engine and coolant starts to cool down, the coolant in the expansion bottle get drawn back into the engine coolant passages.

The variability you noticed is common as it depends on temperatures and amount of gasses leaked to get enough pressure to open the pressure relief valve in the cap. When it does happen it can be fast.

Looks like it is a not a major leak so may be difficult to confirm with a coolant pressure test or a coolant chemical test. 

 

Thanks pikpilot. I'll try a high tech sealer - one of those without particulate matter in. There are a couple that are said to be good for minor head gasket problems. Any opinion on the best of these?

Edited 27 October, 20205 yr by OctaviaVRS2
additional information

K-Seal is widely recognised as one of the best, if it doesn't work they also do a Heavy Duty version.

 

£8.99 delivered on the bay.

Edited 27 October, 20205 yr by MicMac

20 hours ago, MicMac said:

K-Seal is widely recognised as one of the best, if it doesn't work they also do a Heavy Duty version.

 

£8.99 delivered on the bay.

 

I have considered K-Seal, but concerns over the particulate matter in it and the possibility for the very small channels in my engine to block up is the reason I haven't done so. The stuff usually has a tell tale sign of use by its colour and blocks the heater core matrix if not reducing the effectiveness of the radiator. Ideally the solution would be transparent and not coat everything in a kind of 'paint'

22 hours ago, OctaviaVRS2 said:

Thanks pikpilot. I'll try a high tech sealer - one of those without particulate matter in. There are a couple that are said to be good for minor head gasket problems. Any opinion on the best of these?

 

I looked into my coolant loss a bit more pikpilot, and the puzzle is not clear pikpilot. No contamination of oil, no steam from exhaust, coolant system appears to have pressure even after cooling so no pressure losses, coolant cap appears to work, No lack of performance or rough running, no coolant on the ground (remember everyone, if your car is leaking coolant onto the ground where animals can lick it, you need to prevent that from happening as it kills them quickly and in great pain). My plan now is to replace the thermostat as much as that was £100 of labour I had hoped to avoid and replace the coolant flange, widely reported to be a cause of coolant loss. I'm pursuing the cheaper options first given that the parts themselves are not expensive. I hope its not the EGR cooler as I understand that is a difficult replacement. One member here kindly suggested his experience with K-Seal, but I'm avoiding it. Not that I'm avoiding all sealants but I am avoiding those that contain solids, that work by 'cooking', rather than a chemical reaction. All view are welcome. I notice many people with the VAG 2.0 TDI have referenced inexplicable water loss that has defied expensive intervention or testing at main dealer. £150 for keeping car overnight to see if coolant dropped is not really my idea of money well spent. I can do it myself by opening the bonnet and looking!

 

Finally, what are members views about opening the coolant bottle. Is it something that is without consequence or should it be minimised. The 2.0 TDI coolant bottle markings are not the easiest to see on my car the way the markings are placed. I try to shine a torch behind the bottle to see the level but sometimes I do open it and of course when doing so I am relieving pressure that might be a needed stabiliation of the system. clearly the bottle is meant to be viewed without opening the cap or there would be no need to make it translucent!

16 minutes ago, OctaviaVRS2 said:

coolant system appears to have pressure even after cooling 

That's a sign that exhaust gases are getting into the cooling system. 

If you top up the coolant to the right level when stone cold, then put the cap on, there will be no pressure in the system.  When the coolant heats up during engine running, the system pressure increases due to (contained) thermal expansion. If it then all cools down to the same stone cold temperature, the thermal expansion reverses completely and there should once again be no pressure in the system and expansion tank.

31 minutes ago, OctaviaVRS2 said:

the very small channels in my engine to block up

The heater matrix has much smaller channels than anything in the engine, to the best of my knowledge.

Edited 28 October, 20205 yr by Wino

On 27/09/2020 at 09:45, BillDub said:

Hi 

Did the new radiator fix your issue??

Hi, sorry only just saw this. Yes the replacement radiator fixed the issue. No issues since, just over 95,000 miles on it now.