v40 coolant loss

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E-bmw

Original Poster:

9,976 posts

159 months

Friday 4th August 2023
quotequote all
OK, before anyone states the obvious I have yet to have an in-depth look but can't see anything obvious on the surface and I am asking about something I have not worked on before as I am relatively new to diseasels.

Symptoms.

Coolant level at max, after around 100/150 miles I get a coolant low warning & sure enough it will be below min "pressurised". A quick top up of a few 100cc gets it back up to max & the warning goes.

This happens constantly.

Even after a few days there is always pressure in the expansion tank, and there are no visible signs of leaking coolant, so I don't think it is an actual leak.

There is no evidence of fluid cross-contamination (yes, I know there isn't always & will be getting a sniff test done) so I am hoping not HGF.

Am I being pushed towards an EGR cooler issue & if so is there any way to diagnose without dismantling?

Anything else I may have missed?

Desiderata

2,578 posts

61 months

Friday 4th August 2023
quotequote all
What engine? There seems to be a problem with the D2 engines doing this , with all sorts of answers on the various fora from head gaskets to cracks in the block.
Since it's basically the same engine as a Ford 1.6 tdci and a Peugeot Citroen Hdi, which don't have the same issues, I think it's exhaust gases leaking into the water jacket of the egr cooler and the resultant extra pressure forcing water out of the reservoir overflow

Edited by Desiderata on Friday 4th August 23:22

E-bmw

Original Poster:

9,976 posts

159 months

Friday 4th August 2023
quotequote all
Desiderata said:
What engine? There seems to be a problem with the D2 engines doing this , with all sorts of answers on the various fora from head gaskets to cracks in the block.
Since it's basically the same engine as a first 1.6 tdci and a Peugeot Citroen Hdmi, which don't have the same issues, I think it's exhaust gases leaking into the water jacket of the egr cooker and the resultant extra pressure forcing water out of the reservoir overflow
Could be a good call, I will do some digging as it is the D2 engine.

stevieturbo

17,534 posts

254 months

Friday 4th August 2023
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Can you easily remove the EGR circuit for a test ?

E-bmw

Original Poster:

9,976 posts

159 months

Friday 4th August 2023
quotequote all
A quick look says unlikely, but I may be wrong.

As I was always being steered down that way anyway, after a positive sniff test (assumption) I may just remove the full EGR & give it a coat of looking at to see what I think or to see if it can be tested off the car, if that is what you meant,
.

stevieturbo

17,534 posts

254 months

Friday 4th August 2023
quotequote all
Yes. If there is a heater hose running to and from it, just link it out to bypass the cooler.

If it's bolted to stuff and coolant passing through that way, obviously more difficult.

Or try chucking in some Radweld, Bars leaks etc etc

Nothing as extreme as K Seal etc

E-bmw

Original Poster:

9,976 posts

159 months

Saturday 5th August 2023
quotequote all
stevieturbo said:
Yes. If there is a heater hose running to and from it, just link it out to bypass the cooler.

If it's bolted to stuff and coolant passing through that way, obviously more difficult.

Or try chucking in some Radweld, Bars leaks etc etc

Nothing as extreme as K Seal etc
As usual, good points, I will have a closer look at it in the next few days.

E-bmw

Original Poster:

9,976 posts

159 months

Saturday 5th August 2023
quotequote all
E-bmw said:
stevieturbo said:
Yes. If there is a heater hose running to and from it, just link it out to bypass the cooler.

If it's bolted to stuff and coolant passing through that way, obviously more difficult.

Or try chucking in some Radweld, Bars leaks etc etc

Nothing as extreme as K Seal etc
As usual, good points, I will have a closer look at it in the next few days.
OK, in my ignorance (hopefully stoopid question) if I have the EGR cooler bypassed is it not going to damage the EGR without the cooling, as I would need it linked out for a few 100 miles to confirm?

stevieturbo

17,534 posts

254 months

Saturday 5th August 2023
quotequote all
Not in the slightest.

E-bmw

Original Poster:

9,976 posts

159 months

Sunday 6th August 2023
quotequote all
Once again, I thank you.

E-bmw

Original Poster:

9,976 posts

159 months

Saturday 26th August 2023
quotequote all
OK, by way of update, unfortunately time has been my enemy recently.

The day before yesterday I used one of those dooberries that you put in the expansion tank neck with fluid to detect "products of combustion" and literally nothing bubbled through it, which obviously (to me) means there is none getting in.

I even sucked air from the expansion tank to bubble through as nothing naturally bubbled through.

There was obviously no change in colour, I left it running for many minutes & had it sat for minutes at "high idle" for a few period also.

Thus I am convinced it isn't anything major in the engine.

There are no signs of leaks, so I will get some radweld & see if that does anything.

Red9zero

7,913 posts

64 months

Saturday 26th August 2023
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I can't offer any advice, but I found the V40 Facebook group very helpful when I had mine.

stevieturbo

17,534 posts

254 months

Saturday 26th August 2023
quotequote all
E-bmw said:
OK, by way of update, unfortunately time has been my enemy recently.

The day before yesterday I used one of those dooberries that you put in the expansion tank neck with fluid to detect "products of combustion" and literally nothing bubbled through it, which obviously (to me) means there is none getting in.

I even sucked air from the expansion tank to bubble through as nothing naturally bubbled through.

There was obviously no change in colour, I left it running for many minutes & had it sat for minutes at "high idle" for a few period also.

Thus I am convinced it isn't anything major in the engine.

There are no signs of leaks, so I will get some radweld & see if that does anything.
I think those kits largely only work for cylinder to cooling system leaks.

Not sure there would be enough exhaust gas entering the system from an EGR, to change colour, as most of the pressure is from the cooling system, going into the exhaust, rather than visa versa

Have you tried pressurising the system and leaving it for a few hours ? In theory it should hold easily with no drop.

Although it just proves you have a leak, which you seem to already know.

I've small stuff like Bars Leaks, Radweld, Wurth etc before. I've never used any of the "big" stuff like K Seal...it sounds like desperation when it's at that stage.

Although if you could clamp hoses ether side of the EGR, or remove it entirely and do the same pressure test drop, it would help prove or eliminate that.



stevieturbo

17,534 posts

254 months

Saturday 26th August 2023
quotequote all
eg, likes of this would be very easy to either bypass or clamp off.

https://www.proxyparts.com/car-parts-stock/informa...

E-bmw

Original Poster:

9,976 posts

159 months

Wednesday 30th August 2023
quotequote all
stevieturbo said:
E-bmw said:
OK, by way of update, unfortunately time has been my enemy recently.

The day before yesterday I used one of those dooberries that you put in the expansion tank neck with fluid to detect "products of combustion" and literally nothing bubbled through it, which obviously (to me) means there is none getting in.

I even sucked air from the expansion tank to bubble through as nothing naturally bubbled through.

There was obviously no change in colour, I left it running for many minutes & had it sat for minutes at "high idle" for a few period also.

Thus I am convinced it isn't anything major in the engine.

There are no signs of leaks, so I will get some radweld & see if that does anything.
I think those kits largely only work for cylinder to cooling system leaks.

Not sure there would be enough exhaust gas entering the system from an EGR, to change colour, as most of the pressure is from the cooling system, going into the exhaust, rather than visa versa

Have you tried pressurising the system and leaving it for a few hours ? In theory it should hold easily with no drop.

Although it just proves you have a leak, which you seem to already know.

I've small stuff like Bars Leaks, Radweld, Wurth etc before. I've never used any of the "big" stuff like K Seal...it sounds like desperation when it's at that stage.

Although if you could clamp hoses ether side of the EGR, or remove it entirely and do the same pressure test drop, it would help prove or eliminate that.
I realised what you said about detecting coolant/cylinder leaks & that is what I was ruling out with the test to ensure I didn't have a bigger problem.

Weirdly as I said in the OP the expansion tank will hold pressure for several days with no noticeable loss.

Unfortunately my EGR isn't as easy to bypass, so I will see what happens with Radweld.

https://www.ebay.co.uk/itm/373731386795?fits=Car+M...

The inlet/outlet are the flange & the pipe stub.

E-bmw

Original Poster:

9,976 posts

159 months

Thursday 7th September 2023
quotequote all
Latest update.

I got hold of some radweld before my latest journey from York to Norwich (which normally results in a low level warning on the way) and aside of the warning seemingly occurring later in the journey it still happened so it looks like my next course of action could well be a new EGR cooler.

bearman68

4,795 posts

139 months

Thursday 7th September 2023
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Why do you think it's the EGR cooler? Plenty of other possibilities.

Pressure check it, and see where the water's coming out. My bet is a thermostat housing. They fail frequently on the Pugs and Fords.
Or maybe something has damaged the rad?

Lots of scope for leaks.

stevieturbo

17,534 posts

254 months

Thursday 7th September 2023
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I'd give it a while for the rad weld....or another bottle. Well shaken

stevemcs

8,990 posts

100 months

Thursday 7th September 2023
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Are you sure it’s not the coolant tank ? We had one in the other day with one, also if it’s in anyway related to the psa lump check above the gearbox, the coolant housing, module or whatever you wish to call it leaks

E-bmw

Original Poster:

9,976 posts

159 months

Friday 8th September 2023
quotequote all
Thank you all for your contributions.

As per one of the early replies it seems there may be a common issue at play, hence the thought of EGR.

All the rest are good points alas there are no external or internal signs of leakage.