V40 Low coolant level warning
Discussion
OK, for those that have followed/contributed to the 2 previous threads on this I express my thanks, I have started another separate thread as there are many differences since further investigations & the original symptoms are no longer relevant.
Sorry it is a long one but there is a lot to say.
OK, as of now if I drive the car for around 45 - 60 min (on the dual section of the A64 York ring road) at 60/70 ish I get a low coolant level warning.
If I then pull over and remove the expansion tank cap the level returns to exactly where it started.
I did find an issue with the rad top to expansion tank line being blocked which caused some previous issues & this is now sorted.
I have changed the stat in case that was causing the previous issues and that is definitely OK.
I have fully flushed the coolant system in all directions & that is definitely OK.
The system holds pressure & shows no signs of external/internal leakage. It will easily still be pressurised 2/3 days after previous run.
The water pump was changed with the cambelt under a year ago.
The radiator and hoses both get up to temperature with the top one (return from stat) being notably hotter than the bottom one (supply to pump) and the engine does not overheat.
After the run today I did a chemical sniff test which was clear of combustion gases & due to paranoia I even used the chemical after the test to sniff the exhaust to make sure the chemical was working.
When I drove it today (ran out of time to do more) it got up to 70 - 86 whilst driving as above (stat is 83) and never waivered from centre on the in-dash gauge.
When warming up the OBD gauge gets to 67 when the in dash gauge gets up to the centre point and remains there until over 104 (running under provocation to get the fan to come on) whilst still reading mid-range.
Due to my finding & fixing the issue with the pipe today, I have currently only filled with water due to time constraints & the car is now in the garage for 2 weeks now anyway.
I am now starting to think that all is left is the hoses expanding increasing the system volume & thus lowering the level, don't know if this is even feasible, but I am at a loss.
Would using just water for the last run make any difference?
TLDR.
Low coolant warning after running, level returns when cap removed.
Don't ask me to do a pressure test as it holds pressure & doesn't lose fluid.
Sniff test done, stat changed, coolant flushed, radiator proven clear, relatively new pump.
Any ideas?
Sorry it is a long one but there is a lot to say.
OK, as of now if I drive the car for around 45 - 60 min (on the dual section of the A64 York ring road) at 60/70 ish I get a low coolant level warning.
If I then pull over and remove the expansion tank cap the level returns to exactly where it started.
I did find an issue with the rad top to expansion tank line being blocked which caused some previous issues & this is now sorted.
I have changed the stat in case that was causing the previous issues and that is definitely OK.
I have fully flushed the coolant system in all directions & that is definitely OK.
The system holds pressure & shows no signs of external/internal leakage. It will easily still be pressurised 2/3 days after previous run.
The water pump was changed with the cambelt under a year ago.
The radiator and hoses both get up to temperature with the top one (return from stat) being notably hotter than the bottom one (supply to pump) and the engine does not overheat.
After the run today I did a chemical sniff test which was clear of combustion gases & due to paranoia I even used the chemical after the test to sniff the exhaust to make sure the chemical was working.
When I drove it today (ran out of time to do more) it got up to 70 - 86 whilst driving as above (stat is 83) and never waivered from centre on the in-dash gauge.
When warming up the OBD gauge gets to 67 when the in dash gauge gets up to the centre point and remains there until over 104 (running under provocation to get the fan to come on) whilst still reading mid-range.
Due to my finding & fixing the issue with the pipe today, I have currently only filled with water due to time constraints & the car is now in the garage for 2 weeks now anyway.
I am now starting to think that all is left is the hoses expanding increasing the system volume & thus lowering the level, don't know if this is even feasible, but I am at a loss.
Would using just water for the last run make any difference?
TLDR.
Low coolant warning after running, level returns when cap removed.
Don't ask me to do a pressure test as it holds pressure & doesn't lose fluid.
Sniff test done, stat changed, coolant flushed, radiator proven clear, relatively new pump.
Any ideas?
It shouldnt hold pressure after 2 days, The pressure is created by the increase in temp of the engine, the pressure should drop down with the temp, can you check how much pressure its making, like with a pressure test kit with a gauge, from cold to hot?
There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
richhead said:
It shouldnt hold pressure after 2 days, The pressure is created by the increase in temp of the engine, the pressure should drop down with the temp, can you check how much pressure its making, like with a pressure test kit with a gauge, from cold to hot?
There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
I get what you say about the pressure, and that has led me a merry dance recently.There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
When hot if I open the cap, I get a good chuff and see the level rise, after a day or two there is much less of a chuff, but it is still there.
When the reservoir is cold the level is at max, when I have been driving & the warning comes in the level is about 5/6mm below min & as I release the pressure from the cap, the level goes back up to max.
Good point about quantifying the pressure, I am away now for 2 weeks, but will try that when I get back and report back.
E-bmw said:
richhead said:
It shouldnt hold pressure after 2 days, The pressure is created by the increase in temp of the engine, the pressure should drop down with the temp, can you check how much pressure its making, like with a pressure test kit with a gauge, from cold to hot?
There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
I get what you say about the pressure, and that has led me a merry dance recently.There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
When hot if I open the cap, I get a good chuff and see the level rise, after a day or two there is much less of a chuff, but it is still there.
When the reservoir is cold the level is at max, when I have been driving & the warning comes in the level is about 5/6mm below min & as I release the pressure from the cap, the level goes back up to max.
Good point about quantifying the pressure, I am away now for 2 weeks, but will try that when I get back and report back.
richhead said:
E-bmw said:
richhead said:
It shouldnt hold pressure after 2 days, The pressure is created by the increase in temp of the engine, the pressure should drop down with the temp, can you check how much pressure its making, like with a pressure test kit with a gauge, from cold to hot?
There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
I get what you say about the pressure, and that has led me a merry dance recently.There should be room in the expansion bottle to acount for the pressure, you say that the level returns to normal when the cap is opened, can you test the level sensor also? you may not really have a fault?
When hot if I open the cap, I get a good chuff and see the level rise, after a day or two there is much less of a chuff, but it is still there.
When the reservoir is cold the level is at max, when I have been driving & the warning comes in the level is about 5/6mm below min & as I release the pressure from the cap, the level goes back up to max.
Good point about quantifying the pressure, I am away now for 2 weeks, but will try that when I get back and report back.
The level starts at max & the warning comes in about 5/6mm below min.
I don't have a pressure test kit as such, but can kind of manage to do most functions with work stuff that I have access to, it is a valid point to test it, I shall give it a go.
The cap is new, but obviously that doesn't mean it is good.
Back from work now, so time for an update after an extended test drive this morning & again this afternoon.
I did 4 laps of the dual section of the A64 from North of York to the A1M and the car worked faultlessly.
No low coolant warnings, no overheating, no residue in coolant (didn't bother to check for combustion gas in the coolant as I wanted to preserve any pressure after testing to see what happens to it overnight) and the temperature (once up to temperature) never waivered from 79 to 87.
'Stat is 83 but the difference between 83 & 87 could just be a slight inaccuracy, so not seeing an issue there.
The actual level went form exactly on MAX when bled to around 5mm over when I pulled onto the drive, so not seeing any issues there either.
I will see if there is any residual pressure in the coolant in the morning but am not expecting any as, as stated above the symptoms have changed slightly for the better.
Conclusion thus far:
The major issue was likely the radiator having a huge airlock due to the blocked balance pipe to the expansion tank..
I suspect there may have been another smaller airlock which was causing the level change when up to temperature as not having bled again the level never dropped.
For the moment it is fingers crossed time as I suspect I may well have been very close to killing the head/block due to the radiator airlock/blockage.
Hopefully that is the end of it.
I did 4 laps of the dual section of the A64 from North of York to the A1M and the car worked faultlessly.
No low coolant warnings, no overheating, no residue in coolant (didn't bother to check for combustion gas in the coolant as I wanted to preserve any pressure after testing to see what happens to it overnight) and the temperature (once up to temperature) never waivered from 79 to 87.
'Stat is 83 but the difference between 83 & 87 could just be a slight inaccuracy, so not seeing an issue there.
The actual level went form exactly on MAX when bled to around 5mm over when I pulled onto the drive, so not seeing any issues there either.
I will see if there is any residual pressure in the coolant in the morning but am not expecting any as, as stated above the symptoms have changed slightly for the better.
Conclusion thus far:
The major issue was likely the radiator having a huge airlock due to the blocked balance pipe to the expansion tank..
I suspect there may have been another smaller airlock which was causing the level change when up to temperature as not having bled again the level never dropped.
For the moment it is fingers crossed time as I suspect I may well have been very close to killing the head/block due to the radiator airlock/blockage.
Hopefully that is the end of it.
Final (hopefully) update.
No residual pressure this morning, so I am 100% convinced that this was basically caused by the blocked pipe causing a huge airlock (gradually increasing) in the radiator & the (inevitable) resultant high temperature warnings.
Unfortunately this morning, that meant that I needed to get a stronger anti-freeze mix into the coolant, so have had to partially drain/refill.
I hope that I have managed to keep any more air out by doing so by draining from the lower rad hose with a 2 litre bottle of concentrated coolant up-ended in the expansion tank to back-fill as it drains out.
Even if not, as I found a few weeks ago, a couple of bleeds got there in the end.
No residual pressure this morning, so I am 100% convinced that this was basically caused by the blocked pipe causing a huge airlock (gradually increasing) in the radiator & the (inevitable) resultant high temperature warnings.
Unfortunately this morning, that meant that I needed to get a stronger anti-freeze mix into the coolant, so have had to partially drain/refill.
I hope that I have managed to keep any more air out by doing so by draining from the lower rad hose with a 2 litre bottle of concentrated coolant up-ended in the expansion tank to back-fill as it drains out.
Even if not, as I found a few weeks ago, a couple of bleeds got there in the end.
With cars that are a b
h to bleed/achieve full circulation after draining and refilling (and there are lots with badly designed plumbing nowadays), I have resorted to initially filling with just water for the purpose, so bleed screws can be left open to spit and puff and any spillage is only plain water.
Once satisfied that all is well (all pipes piping, rad hot all over, fan cycling), I then syphon the reservoir empty, which usually removes enough (1.5 to 2l.) to simply replace with neat antifreeze to gain the correct strength.
No need to bleed again as the level has not dropped below the critical point where air can be trapped, just run it for another fan cut-in/cut-out cycle and it's road-test time.
h to bleed/achieve full circulation after draining and refilling (and there are lots with badly designed plumbing nowadays), I have resorted to initially filling with just water for the purpose, so bleed screws can be left open to spit and puff and any spillage is only plain water. Once satisfied that all is well (all pipes piping, rad hot all over, fan cycling), I then syphon the reservoir empty, which usually removes enough (1.5 to 2l.) to simply replace with neat antifreeze to gain the correct strength.
No need to bleed again as the level has not dropped below the critical point where air can be trapped, just run it for another fan cut-in/cut-out cycle and it's road-test time.
OK, I was hoping that any additional update would be to confirm that my "fingers crossed" driving & bleeding had now resulted in me driving with full confidence.........
Sadly, no, all was going well until 3 days ago, with around 7/8 hours driving under it's belt and then it overheated in exactly the same way. Leaving the top half of the radiator full of "air", which resulted in loss of coolant flow when the level reached the bottom hose.
I then spent a few hours the next day coming up with a rather protracted way of being able to check for exhaust gasses in the coolant again, as all normal attempts going into the expansion tank proved nothing.
So today I went out for an extended test drive to try to replicate the issue.
1 hour of motorway speed driving in, no problem.
1.5 hours, no problem, 5 min later, it happened again, so I pulled over at the next junction, kept the engine running & connected my chemical exhaust gas detector pipette via the rig I had made up & after about 30 seconds the colour changed, so I have finally 100% proved the issue to be the engine block/head, so now need to swap the engine!
It has been a bit of a mare & many would have just swapped the engine as it seemed to be the likely cause, but I have always preferred to diagnose rather than just swap parts.
So far it has cost me a stat & some coolant, also had I just changed the engine I might not have found the sticky stat (only found this yesterday as I decided to test the one I changed again) which was a bit intermittent or the blocked bleed hose from the top of the radiator and so could have caused more problems further down the line on the replacement engine.
So now it is time to order a replacement engine/belt kit/gaskets etc, which I have all lined up ready to order, and replace it next month.
Wish me luck, the last engine I changed was a 1.3/1.6 Capri conversion.
Sadly, no, all was going well until 3 days ago, with around 7/8 hours driving under it's belt and then it overheated in exactly the same way. Leaving the top half of the radiator full of "air", which resulted in loss of coolant flow when the level reached the bottom hose.
I then spent a few hours the next day coming up with a rather protracted way of being able to check for exhaust gasses in the coolant again, as all normal attempts going into the expansion tank proved nothing.
So today I went out for an extended test drive to try to replicate the issue.
1 hour of motorway speed driving in, no problem.
1.5 hours, no problem, 5 min later, it happened again, so I pulled over at the next junction, kept the engine running & connected my chemical exhaust gas detector pipette via the rig I had made up & after about 30 seconds the colour changed, so I have finally 100% proved the issue to be the engine block/head, so now need to swap the engine!
It has been a bit of a mare & many would have just swapped the engine as it seemed to be the likely cause, but I have always preferred to diagnose rather than just swap parts.
So far it has cost me a stat & some coolant, also had I just changed the engine I might not have found the sticky stat (only found this yesterday as I decided to test the one I changed again) which was a bit intermittent or the blocked bleed hose from the top of the radiator and so could have caused more problems further down the line on the replacement engine.
So now it is time to order a replacement engine/belt kit/gaskets etc, which I have all lined up ready to order, and replace it next month.
Wish me luck, the last engine I changed was a 1.3/1.6 Capri conversion.
OK, so I have sourced a replacement engine with 3/4 of my mileage & with a reasonable length warranty from a Volvo specialist breaker & have been doing some prep work on it in readiness for the swap in a couple of weeks.
Made a stand out of 4 x 2 to allow me to work on it.
Cleaned out injector holes as they had already been removed.
Cambelt kit done.
Clutch & flywheel done.
Removed the usual cut hoses & wiring left when they removed it from the donor car.
I am likely to use my own EGR & turbo as they are good, but decided to remove & clean the EGR & piping!!!!! Feck me it was full of crap! I have cleaned it out anyway but, I will still likely do mine & fit it.
Unfortunately it gives me a bit of a dilemma.
The intake manifold is part of the head & although I have reached in with a rag, I have removed what I can & it isn't as bad as the EGR pipework, but my question is, should this carbon remaining in the intake worry me?
I ask because I didn't really want to pull the full head.
Made a stand out of 4 x 2 to allow me to work on it.
Cleaned out injector holes as they had already been removed.
Cambelt kit done.
Clutch & flywheel done.
Removed the usual cut hoses & wiring left when they removed it from the donor car.
I am likely to use my own EGR & turbo as they are good, but decided to remove & clean the EGR & piping!!!!! Feck me it was full of crap! I have cleaned it out anyway but, I will still likely do mine & fit it.
Unfortunately it gives me a bit of a dilemma.
The intake manifold is part of the head & although I have reached in with a rag, I have removed what I can & it isn't as bad as the EGR pipework, but my question is, should this carbon remaining in the intake worry me?
I ask because I didn't really want to pull the full head.
The carbon will have been there for many miles, and would for many more. So is it a worry ? Probably not.
Would it be worth finding somewhere local to walnut blast it ? Maybe
Certainly a lot easier to do out of the car, than in.
Can you pressure test the EGR cooler before you use it ? In case it has been the source of the problem all along ?
Would it be worth finding somewhere local to walnut blast it ? Maybe
Certainly a lot easier to do out of the car, than in.
Can you pressure test the EGR cooler before you use it ? In case it has been the source of the problem all along ?
stevieturbo said:
The carbon will have been there for many miles, and would for many more. So is it a worry ? Probably not.
Would it be worth finding somewhere local to walnut blast it ? Maybe
Certainly a lot easier to do out of the car, than in.
Can you pressure test the EGR cooler before you use it ? In case it has been the source of the problem all along ?
I am going mad BTW, when I posted that my mind thought inlet as it is on the opposite side of the engine to the exhaust/cat/dpf downpipe, but of course that is because that is where the turbo is situated.Would it be worth finding somewhere local to walnut blast it ? Maybe
Certainly a lot easier to do out of the car, than in.
Can you pressure test the EGR cooler before you use it ? In case it has been the source of the problem all along ?
I quite simply wasn't thinking at all.
The soot is in the exhaust manifold.
I am going to look into options for cleaning prior to fitting the engine & as you suggest will try to get the cooler tested but I don't think it will be the issue due to the pressure with which the exhaust gases were coming out.
I find it hard to believe that such pressure would be generated in the exhaust to overcome coolant pressure.
E-bmw said:
I find it hard to believe that such pressure would be generated in the exhaust to overcome coolant pressure.
It's a turbodiesel, on boost you would hope boost is higher than coolant pressure unless it's a really low powered diesel, and in turn pre-turbine pressure will be even higher than boost pressure.The carbon build up is weird.
When I did my van years ago, the intake, pipe from EGR to intake etc etc were all absolutely clogged up. You'd have thought it a miracle the thing ran.
I spent ages cleaning it, that s
t gets caked on something shocking. And when all done, whilst I felt better for doing it.......didn't make one bit of difference to how it drove.
stevieturbo said:
E-bmw said:
I find it hard to believe that such pressure would be generated in the exhaust to overcome coolant pressure.
It's a turbodiesel, on boost you would hope boost is higher than coolant pressure unless it's a really low powered diesel, and in turn pre-turbine pressure will be even higher than boost pressure.The carbon build up is weird.
When I did my van years ago, the intake, pipe from EGR to intake etc etc were all absolutely clogged up. You'd have thought it a miracle the thing ran.
I spent ages cleaning it, that s
t gets caked on something shocking. And when all done, whilst I felt better for doing it.......didn't make one bit of difference to how it drove.
I had the same thought when I saw it on the replacement engine. I am going to remove it but as you say, not sure I will see any difference.
OK, further update.
Took the car out today & all seemed well until I got the the A64 & booted it down the slip road.
"Reduced engine performance" warning came up on the instruments!!!!!!!
When I plugged in my reader it told me there was a MAF issue, can't remember the code number.
As per usual that can be caused by pretty much any inlet issue, so I got to work looking it over.
After a lot of looking round I noticed that there seemed to be a displaced seal on one end of the EGR pipework.
What a f00ker of a job to get to!
I think it was number 2 on the production line for the engine build & so everything else was in its way or the engine was coming back out!
I have now managed to 90% get it done & back together before running out of light.
Will finish it off tomorrow & try another test drive.
Fingers crossed.
Took the car out today & all seemed well until I got the the A64 & booted it down the slip road.
"Reduced engine performance" warning came up on the instruments!!!!!!!
When I plugged in my reader it told me there was a MAF issue, can't remember the code number.
As per usual that can be caused by pretty much any inlet issue, so I got to work looking it over.
After a lot of looking round I noticed that there seemed to be a displaced seal on one end of the EGR pipework.
What a f00ker of a job to get to!
I think it was number 2 on the production line for the engine build & so everything else was in its way or the engine was coming back out!
I have now managed to 90% get it done & back together before running out of light.
Will finish it off tomorrow & try another test drive.
Fingers crossed.
Hopefully a final update!
Managed to get the EGR/inlet etc off with a few grazed knuckles & expletives!
Replaced the seal and TBH, it was good that I did have to do it because there was actually a small leak from the EGR cooler pipework, which I sorted also.
Test drove again today & all seems good again, job done & although it was a mare of a job the engine change has been well worth it & another skill set to add to my repertoire.
Managed to get the EGR/inlet etc off with a few grazed knuckles & expletives!
Replaced the seal and TBH, it was good that I did have to do it because there was actually a small leak from the EGR cooler pipework, which I sorted also.
Test drove again today & all seems good again, job done & although it was a mare of a job the engine change has been well worth it & another skill set to add to my repertoire.
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