Coolant Woes...

[LukeyP]

Hi All,

 

MK1 Octavia 1.9 TDI ASV (110)

 

OK, so since having my timing belt replaced (really wish I had not bothered) I have had a few issues with the car. I'd really like peoples thoughts around this if possible...

1. Fuel pump was slightly out but this was fixed.
2. Coolant issues
3. Turbo pipe came off

Items 1 and 3 are now fixed, can't fault that.

On Saturday morning, after leaving the car stood for a couple of days - I checked coolant to find it had dropped again (2nd time in 3 weeks). Started it up and the coolant light started flashing, which I expected.

Now I am trying to narrow down what the issue could be and I'm thinking it could be air in the system, although the header tank is the highest point of the system. So I did the following;

1. Started it up, with coolant cap off.
2. Let the car get upto temperature, with the air vents/heating on full and varied the revs.
3. After 25 minutes, the car was at 90 degrees and coolant had risen.
4. The heater inside was FLAT COLD though, no heat coming through.
5. I started to squeeze the pipes into the car - flow and return and the pipe did start to get warmer.
6. Topped up the coolant and left the engine running

The car then was getting nice and toasty again, left it for a good 10 minutes and remained warm throughout. Yesterday, I took it for a run and left the car running whilst i nipped into B&Q (wife was in the car!) and the heaters remained warm - usually when stopping, they went cold.

Have I fixed the issue? Was it just an airlock that causing me to loose coolant?

I am not a mechanic, nor technically minded but I am trying my best to teach myself and learn it as I go along. One person on a Skoda group said it sounds like early signs of a head gasket, but not sure I am fully on-board with that given these issues have only started since the belt was changed.

Any advice appreciated. I will obviously keep eye on the coolant in the meantime, garage are aware but given my not so great experience - I'd rather fix it myself first.

Cheers

Edited 10 February, 2020 by LukeyP

[J.R.]

I think that you have done exactly the right thing and with luck will have sorted the problem, worth keeping an eye on the level in future.

 

I replaced my own cam belt on my MK1 & the fuel pump timing needed a slight tweek, done by using a drill bit to align 2 holes IIRC, the turbo pipe also dislodged due to the oil within getting to the mating surfaces when dismantled, I did not change my water pump but would have expected the same sort of air lock as you had.

 

The first 2 are par for the course and the second very likely unless they keep your car a few days and drive it around and do what you had to do before returning it.

[LukeyP]

29 minutes ago, J.R. said:

I think that you have done exactly the right thing and with luck will have sorted the problem, worth keeping an eye on the level in future.

 

I replaced my own cam belt on my MK1 & the fuel pump timing needed a slight tweek, done by using a drill bit to align 2 holes IIRC, the turbo pipe also dislodged due to the oil within getting to the mating surfaces when dismantled, I did not change my water pump but would have expected the same sort of air lock as you had.

 

The first 2 are par for the course and the second very likely unless they keep your car a few days and drive it around and do what you had to do before returning it.

 

Thanks JR.

 

The fuel pump was sorted by the garage, luckily and that's fine now. I have just been out in the car and it was getting nice and warm, it tailed off slightly when I got on the drive but a little rev and warm air pushed back through so it seems like everything is working I think, but maybe still some air within the system.

 

As I'm not mechanically minded, if there is air - how would coolant escape (or is it not?)

[KenONeill]

2 hours ago, LukeyP said:

if there is air - how would coolant escape (or is it not?

Well, at least some air would get in when you changed the water pump.

 

Air is definitely a compressible fluid, and water is more or less in-compressible.

[LukeyP]

Well following on from this, the coolant light re-appeared this morning.

 

I have now booked it back in the with garage who did the belt to sort it as it didn’t do it before.

 

Now the turbo is dying a lot more often, I am hoping it’s just the boost sensor.

[LukeyP]

Quick update. 

Dropped car into garage to mainly check if I had a water pump issue from the recent belt change but all reported back okay. Mechanic said he couldn’t find a trace of any leaks whatsoever, but ever since I had the belt changed I had been loosing coolant every 10 days and mixture of rubbish heating going cold occasionally. 

He couldn’t find any obvious leaks but did change the thermostat which seems to have resolved my heating problem now. He flushed e matrix out and did see deposits of some Radweld stuff so it’s quite possible the change of coolant as upset the radiator maybe and this is where I have a leak, but going to monitor for the next week or so. 

The head gasket has been tested and that’s all okay too. He did feel the radiator and it was flat cold, so that’s been bled and a lot of air did come out of it apparently. Took the car for a good 30 mile run yesterday, got to 90 quicker and maintained there, with heating staying nice and hot throughout - if anything too warm ha ha. I also really worked the turbo as been cutting out a lot and over the 30 miles, it didn’t cut out once. I did read the vanes stick more when the engine is cold and I’m wondering if the thermostat was meaning the engine was cold, so it was cutting out more but yesterday pulled much better and maintained boost - who knows. 

£20 for replacement thermostat so for now, I’ll hopefully be able to enjoy it for a good few months again. 

[Vijay2018]

Ring do a dye for the coolant system that shows up any leaks under a UV light. I suggested it to a mate who was loosing coolant and couldn't find any leaks - showed up straight away!

[LukeyP]

Thanks 🙂 can’t remember if garage did that or not. I’m gonna run car for a week or so to monitor how it goes. 

[MikeTheThinker]

1 hour ago, Vijay2018 said:

Ring do a dye for the coolant system that shows up any leaks under a UV light.

 

Just what I need, too. Thanks!

 

https://www.amazon.co.uk/Torch-Detection-Cooling-Antifreeze-System/dp/B00TU8VCB4