coolant level dropped

[DAVEEVO]

hi guys ,i got the red warning on dash and checked coolant to find it had dropped below low level but not empty , my missus drives it now and a couple of days ago she reported a noise which sounded like a washing machine pump , im guessing its the electric coolant (B) pump . ive not had a chance to look under it yet to check for leaks etc . anybody else had a similar issue and do you think they might be connected ? 

 

the coolant droped about an inch in the expansion bottle and once topped up the light went out and it drives normally .. 

 

1.6 tdi 105hp 

 

thanks 

 

dave 

[mrgf]

Hard to say what the noise is so keep an ear open for it. Coolant can just get low but if when topped up, it keeps doing it and you need to add coolant often, its a leak. They can leak from many places and some models have a plastic flange on one side of the engine, which may also house the coolant temp switch along with a few hoses. The seals can perish and the flanges can crack/split so look closely for anything like that, along with leaking from hoses, etc. Also, check there is no water escaping into the oil... Check the inside of the oil filler cap for stuff that looks a bit like mayonnaise. I doubt it will be this but when that happens to a regularly run car, it can point to a blown head gasket. (Bubbling/pressure coming up in the coolant bottle can, too but don't mistake that with the coolant being hot or its natural circulation). 

[DAVEEVO]

21 minutes ago, mrgf said:

Hard to say what the noise is so keep an ear open for it. Coolant can just get low but if when topped up, it keeps doing it and you need to add coolant often, its a leak. They can leak from many places and some models have a plastic flange on one side of the engine, which may also house the coolant temp switch along with a few hoses. The seals can perish and the flanges can crack/split so look closely for anything like that, along with leaking from hoses, etc. Also, check there is no water escaping into the oil... Check the inside of the oil filler cap for stuff that looks a bit like mayonnaise. I doubt it will be this but when that happens to a regularly run car, it can point to a blown head gasket. (Bubbling/pressure coming up in the coolant bottle can, too but don't mistake that with the coolant being hot or its natural circulation). 

thanks for replying , im now monitoring the level and checking when cold in the mornings to get a true reading every time . when cars coolant drops and there is no leaks where does it go ???

[mrgf]

It could be going in to the engine or exhaust system and being blown out via the tailpipe. I doubt this is the case though but possible. Be  aware, if you are only topping up with water, the boiling point is much lower then coolant and so will evaporate quicker and need topping up more! It will also allow all sorts of muck, rust etc to form and will not protect the engine from freezing. 

[J.R.]

I dont call 6°c much cooler (water 100°C 50/50 glycol 106°C)  in the pressurised system water alone would not vaporise until 128°c well beyond the normal operating temperature, the pressurised expansion vessel is there to prevent any loss of coolant or vapour up to 128°c minimum.

 

If there is no leak from the system, no overheating or no pressurisation from a leaking head gasket there will be no evaporation and no topping, if as in this case there is a leak the difference in volume leaked if the system had previously been topped up with water instead of a coolant mix would be de minimis.

[J.R.]

19 hours ago, DAVEEVO said:

 when cars coolant drops and there is no leaks where does it go ???

Ejected from the overflow tank, - easy to detect with a tissue.

 

Leaked into the combustion chamber on inlet stroke, - white smoke visible

 

Leaked into the EGR gases from the EGR cooler, - very difficult to detect as its a small percentage of the intake charge and only under certain engine conditions, I doubt that you would see it in the rear view mirror. A pressure test would reveal the presence of a leak, close examination required to prove it is in the EGR cooler.

[DAVEEVO]

thanks guys i will monitor it and if it drops again its time to get under it and have a look firstly ...

[mrgf]

I dont call 6°c much cooler 

 

You would if it was your core body temperature!  Well, you wouldn't but your family might as they stand around you in intensive care! (Tongue firmly in cheek here).

[MijIsTired]

On 10/12/2021 at 17:34, J.R. said:

Ejected from the overflow tank, - easy to detect with a tissue.

 

Leaked into the combustion chamber on inlet stroke, - white smoke visible

 

Leaked into the EGR gases from the EGR cooler, - very difficult to detect as its a small percentage of the intake charge and only under certain engine conditions, I doubt that you would see it in the rear view mirror. A pressure test would reveal the presence of a leak, close examination required to prove it is in the EGR cooler.

 

Resurrecting this thread, as I've have a 'red light ding ding' situation, twice in the last couple of months, having never had it in 12 years. Both times coolant dipped below minimum in expansion tank. Both times topping up = warning light off, everything running normally. 

Time to get out Haynes to find the [checks @J.R.'s reply...] overflow tank. 

However, as we're also getting the occasional EM warning light come on, but because it also shows up when the earth in the boot loom is flapping about (fixed once, needs re-doing having Learnt Lessons) I wasn't paying much attention to it. 
 

But mention of potential for a leak into EGR gases, that's worrying me. 

Edited 10 June, 2023 by MijIsTired

[Ootohere]

@MijIsTiredRunning normally but with a leak that you need to find.

 

Are you posting about a 1.2 TSI from 2011 rather than a 1.6TDI or is it a 1.6 TDI you have?

 

OT. & in the past. & front loom.

There was / is a TPI (Service Campaign) on 1.2 TSI looms from over a decade ago.

Maybe your car had the loom replaced and maybe not.

http://briskoda.net/forums/topic/297028-my-monte-has-been-recalled

 

Edited 11 June, 2023 by toot

[MijIsTired]

@tootoh d’oh, sorry, you’re right yes I still have a 1.2TSI 2011. 
 

I wasn’t paying attention to enough specifics in this thread, while I was stress-scrolling through search results 🙄 

 

Thanks for the link. I had the car from 4yrs old, had service history, didn’t see seem to be anything as interesting as that. 
 

Off to re-search for threads about coolant issues for TSIs, slightly sheepishly…