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Losing coolant somewhere!

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Vantasy View Drop Down
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    Posted: 18 Jul 10 at 11:31

Hello everyone,

I have recently camper converted a 2009 Transporter T5 T32 Kombi. It has a 2.5 130 5 cyl diesel unmapped engine with just 3,800 mls and we were living the dream. Until now -  noticed mystery coolant loss at approximate rate of 100mls per 100 miles. Have researched forum posts such as cjm-2008 and brownster without remedy so far. Have visited main vw dealer twice, no detectable leaks from system following a repeated extensive pressure tests when hot and left cold overnight - even under UV light I'm told.  No tell-tale signs of emulsified oil/water mix under the oil filler cap or dip-stick and no oil contamination visible in the coolant tank.  There is pressure in the coolant tank when cold - is this a lead? I've tried driving for 100miles with the coolant filler cap not fully clicked, ie. no pressure and coolant still drops. VW technicians say the water pump is ok and they are scratching their heads whilst I am pulling mine out!  Other web searches indicate - as well as common water pump fault, oil cooler fault would show oil trace in the coolant tank and EGR may be faulty and taking coolant through exhaust.  I really don't favour major head surgery on such a new engine - any other views, advice or diagnostic ideas guys? - would be much appreciated,  thanks.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cjm_2008 Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 10 at 13:09
that sort of coolant rate loss would indicate a water pump failure - the oil cooler could also be suspect.

you'd have to be majorly unlucky to have either of those issues @ 3,800 miles though...!

I'd be seeking a second opinion elsewhere.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 10 at 14:17
Thanks for a quick response cjm. 
Would you expect there to be significant release of air pressure in the coolant tank as the cap is unscrewed when the engine is cold ie. the next day? -  enough to see the coolant level rise a bit. 
 
At that rate of loss, which happens only when driven - evaporation could hide any wet evidence perhaps but I cannot see any water marking either, not that I can see everywhere!   My vw dealer has said that the coolant has a tracer that shows up under ultra violet light - I wonder if this still works when it is dried up?  Any other sneeky places that might just be leaking that you know of? 
 
I agree with you, at such low mileage a fault with the water pump is doubtful. These are quite prone to leaking coolant into the engine oil only after the first line drain holes become blocked with rust etc - as I understand (from very light research)
 
I'm not sure what action they'll take next - at present they are seeking guidance from VW on high. I'll ask them to replace the water pump and then the oil cooler before delving deeper I think.    
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Post Options Post Options   Thanks (0) Thanks(0)   Quote T5 TDI Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 10 at 17:58
The pressure in the expansion tank you mention is normal.  I think the fact that it is still there the next day makes it fairly likely that there are no hose/radiator leaks etc.  Even though it's done so few miles and it's an '09 I'd still say water pump.  These rarely leak on a pressure test and only ever leak when the engine is running.  Note that the water that has leaked into the engine from a failing water pump often doesn't mix with the oil and just sits undetected at the bottom of the sump since oil floats on water. 
 
I know any water from a leaking pump should drain out of that chamber which ought to mean if the drain is clear the pump is ok but it doesn't always happen that way.  The easiest way is to drain the oil and look out for this-
 
 
 
This one had been topped up constantly for some time so it's a bit of an extreme case!
 
I haven't seen one personally but I gather the oil cooler problem causes oil in the coolant not coolant loss so I don't think that will be your problem.  If someone briefly takes out the sump plug and no coolant comes out before the oil then it probably isn't the water pump but it's an easy cheap test.   


Edited by T5 TDI - 18 Jul 10 at 18:07

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 10 at 22:04
Thanks for that T5 TDI, especially the graphic photo! - it does make the point and as you say a definitive and easy test.  I have only topped up about 750ml in stages, so far, but if it is getting through it and not just draining out down the tube, it may show in the bottom of the sump..... unless it has just evaporated in the heat of the engine. 
 
I take your view on the coolant tank retaining pressure - a hose or radiator leak would show a drop in level under pressure - so far, even vw techs can't make this happen under pressure when hot or cold...... unless vibration when being driven allows coolant to escape somehow!!? 
 
You say normal for coolant tank pressure when cold? I can understand this when hot as the tank is also for expansion and there is a warning symbol on the cap for this purpose - but why should it stay pressurised when it all cools back down - a feature of the water pump action or something else?
 
Thanks for your view on the water pump possibility - now looking like the most probable cause of the problem. I suppose this fault only shows as 'mayonnaise' on the underside of the oil filler cap in extreme cases when the oil and a lot of coolant get whizzed in the engine block. Changing the water pump does seem the next logical step in searching for the cause so I'll ask them to start with the sump plug and I'll let you know.  
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Post Options Post Options   Thanks (0) Thanks(0)   Quote T5 TDI Quote  Post ReplyReply Direct Link To This Post Posted: 18 Jul 10 at 23:39

I took that picture with my phone because it was so bizzare!  Never seen anything like it!   I know some won't agree but it's a shame this gear driven engine wasn't made to work properly before they replaced it.  Because it's really clever.  If it had worked like the designer intended it would have been bomb proof for 500k.

Back to your leak.  I think coolant pressure retained when cold can only be a good thing.  As far as I've seen the evaporation theory only works on radiators.  Don't forget although your leak isn't huge you have lost the equivalent of a whole bottle of wine somewhere (not that I'd know that that is exactly 750ml of course) LOL  Not sure about the EGR.  As far as I know if yours is a manual transmission it doesn't have any connection to the cooling system.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote gregozedobe Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 10 at 03:47
I have heard of porous alu in heads or engine blocks allowing coolant to get where it shouldn't be (and being quite difficult to diagnose and locate).  If the engine oil level isn't increasing then the coolant obviously isn't getting into the sump side of things.  Maybe it is getting into/on the exhaust system somehow and being evaporated by the heat ? 
 
Have you tried flexing the radiator hoses while the engine is hot ? ( be very careful you don't burn yourself).  Sometimes the leak may only happen when the engine moves a bit.  If it was coming out as steam in a hidden/obscured location it may not be very obvious.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cjm_2008 Quote  Post ReplyReply Direct Link To This Post Posted: 19 Jul 10 at 08:17
at less than 2 years old, i'd be asking mr warren tee for a replacement engine...!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jul 10 at 08:25
Having the water pump replaced tomorrow in a bid to discover the mystery cause of coolant loss. Should I also insist on anything else in that same procedure other than changing the oil and presumably, the oil filter too?
 
I don't know yet if there is any coolant residing under the oil at the bottom of the sump - I'll certainly suggest they look into this as undoing the sump plug will be part of the job.
 
I will also ask to see the 'old' water pump ( it's a 59 plate T5 ) and hear the 'auto'psy report.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Happy Yellow Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jul 10 at 10:29
When my water-pump failed, I experienced similar coolant loss, that got worse over a 2000 mile journey.  When home, I removed the plastic belly-pan and the felt jacket around the sump and found the coolant weep pipe (which lets out any coolant that passes the coolant seal of the water-pump).  Coolant dripped from the pipe very slowly when the engine was running, and not at all when not running.
 
The coolant that was expelled from the pipe while driving soaked into the felt jacket and evaporated - that's why I could not see evidence of the cooling system leaking!  Fine work VW! Angry
 
 
  


Edited by Happy Yellow - 20 Jul 10 at 10:30
2005 Sari Yellow Caravelle 174/AXE 200k miles
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jul 10 at 13:54
Another fine photo for my mystery coolant loss collection, thanks.
 
Could be worth trying this trick too, especially since the engine is virtually new and the water pump drain cannot be choked with rust.......surely?
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 30 Jul 10 at 23:44

I promised to update you all on the mystery coolant loss. As of this morning, it ain't no mystery - at least as far as I'm concerned and has been quite a saga that's not finished yet!

Before investigating the water pump - surgically, it was decided to give a replacement coolant tank cap a go - even though the original one seemed to hold pressure, while stationary at least. Apparently, when pressure testing for hose leaks etc. the pressurising gadget fits on top of the tank and so the cap can't be tested.
 
Well that was a waste of a test drive - but had to be ruled out I suppose.  The water pump was next and even though no sign of any residue was seen at the drain pipe, it too had to jump through it's hoop and was replaced. They took it off for a test drive, but for only 15 miles and with the rate of loss being a steady 100ml in 100miles who could spot a 15ml drop in coolant level taking expansion into account! The upshot was they declared it cured would you believe.  What about the sump plug test I said - not enough coolant in the oil to show they said and 'you haven't got any sign of coolant in the oil anyway' (no mayo' under the filler cap) BUT...... we (vw techs) did notice an over filled oil level.... so we sucked some out so now it's all ok!!... goodbye.
 
That was yesterday - today we have custard under the oil filler cap - virtually no oil showing on the dip stick - down to the last star up from minimum level - and once again, the coolant tank level dropped to near the minimum level too........  Well what would you do?
 
I phoned VW Customer Services - and trying hard to be polite, I asked them what the next step might be. They phoned my main vw dealer and shortly afterwards I had a phone call back " your dealer suggests you seek a second opinion at another van centre ....oh and by the way we advise you not to drive the vehicle but contact vw road-side assistance and get the vehicle transported to a garage".   I can't write the next part but you can use your vivid imagination!
 
It must surely be a leaking head gasket, cracked or porous head casting, or block, in a vitually new 2.5 engine that's only done 4000 miles - many of those test driven! (no oil in the coolant, by the way) Now we face enduring all that diagnostic stuff and nonsense all over again since the new dealer is in a different group who will insist on making there own judgement following a repeat of the dedicated fault finding schedule.    This must be so rare? in a new engine?.... and if found to be a manufacturing defect in the cylinder head - what kind of damage could have been done to other parts of the engine in the meanwhile?
 
Sure, I've got plenty of warranty left, but this is a now a T5 converted camper, and as a leisure vehicle, not likely to clock up enough miles in the warranty period to take care of the legancy of any harm caused by running from new with contaminated oil.  If I'm going to make a warranty claim for a whole engine replacement, do you think I have a sound case and on what technical grounds would you say?  I really need to know what parts of the engine, specifically, would have been harmed by coolant entering the engine block over a six month period since new.... or as I'm sure they'll try it on me..... a repaired/ replacement head is all I'll get. 
 
Sorry it's a saga - and it's not over yet - but I know you'll be on my side so please help me out with some hard hiting info..Thanks
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gregozedobe Quote  Post ReplyReply Direct Link To This Post Posted: 04 Aug 10 at 16:53
It sounds like the start of a run-around to me :(
 
If coolant has been circulated to bearings (instead of oil) then you could get wear/scoring on the main bearings, conrods(bottom and top), and cams and followers. 
 
It might be worth taking several oil samples and sending one off to be tested for evidence of excessive wear (metal particles in the oil) and keeping the other samples for ammunition in any further arguments with VW/dealers.  IIRC testing an oil sample can also detect coolant in the oil.
 
If there was a lot of wear in the bearings then the oil pressure (with the engine running at idle and at higher speeds) may be lower than usual.
 
Good Luck.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 05 Aug 10 at 09:20
Thanks for that helpful info greg' though I'm not sure what 'IIRC testing' means yet. From the appearance of the underside of the oil filler cap I think there is no doubt that coolant has entered the engine. I now know that something of this emulsified effect can also occur with condensation in the filler pipe due to short running, but this is worse.
 
It is now at another VAG Van Centre, having been recovered by VW Roadside Assistance and a full report is expected soon.
 
Incidently, I've been told that water pumps for this engine were recently modified with a larger and more reliable drain pipe - a feature that has commonly caused coolant to enter the engine when this becomes blocked and the seal on the coolant side fails. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GBMUD Quote  Post ReplyReply Direct Link To This Post Posted: 11 Aug 10 at 09:40
Originally posted by Vantasy Vantasy wrote:

TI'm not sure what 'IIRC testing' means yet.

If I Remember Correctly, testing....

Chris
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 11 Aug 10 at 23:18
Clear as MUD! .... now transparent.
 
Latest pressure test is the EGR......now six weeks since first visit to first VW van centre with coolant loss problem. I'm told that if it turns out to be the headgasket the engine will be stripped down bearing by bearing and examined for damage by contamination with coolant.  Wouldn't running for a thousand miles or maybe even 4000 from new with coolant in the oil make bearing damage a forgone conclusion?  Why don't they just replace the whole engine, saving time and money and get my camper back on the road while there is still some summer left!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gregozedobe Quote  Post ReplyReply Direct Link To This Post Posted: 12 Aug 10 at 11:59
Originally posted by Vantasy Vantasy wrote:

Clear as MUD! .... now transparent.
 
Latest pressure test is the EGR......now six weeks since first visit to first VW van centre with coolant loss problem. I'm told that if it turns out to be the headgasket the engine will be stripped down bearing by bearing and examined for damage by contamination with coolant.  Wouldn't running for a thousand miles or maybe even 4000 from new with coolant in the oil make bearing damage a forgone conclusion?  Why don't they just replace the whole engine, saving time and money and get my camper back on the road while there is still some summer left!
 
Next time you can't figure out what an ACRONYM means, try this site:  "IAD" the Internet Acronyms Dictionary Wink
 
As far as what gets done for warranty work unfortunately VW has their (sometimes very bureaucratic) strict procedures which dealers MUST follow if they want to be paid for their work.  So if the procedures specify that your engine gets stripped down and checked then that is exactly what the dealer has to do.
 
I had my oil cooler replaced after it failed, then some months later they did the official oil cooler "recall" and replaced the good new oil cooler with one that was EXACTLY the same.  I tried to persuade them that there was no need (and because I was worried they might stuff something up doing it again), but no dice, if I wanted to be covered by warranty I had to let them do it again.
 
Crazy, but that's how the VW procedures seem to work ie absolutely no flexibility or common sense.  I suppose it could be to protect VW from customers and dealers colluding to VW's detriment.


Edited by gregozedobe - 12 Aug 10 at 12:01
ELVIS: "apply accuracy/brevity/clarity rule before you put ones fingers near the keyboard."

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Post Options Post Options   Thanks (0) Thanks(0)   Quote kawolsky Quote  Post ReplyReply Direct Link To This Post Posted: 12 Aug 10 at 20:12
out of interest... which VW centres has it been to?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Vantasy Quote  Post ReplyReply Direct Link To This Post Posted: 19 Aug 10 at 12:34

Pressure test on the EGR cooler showed no visible signs of coolant leaking and no drop in level either. A lengthy road test of 135 miles with the EGR bypassed with a pipe resulted in NO FURTHER  COOLANT LOSS so, although I've not noticed any 'steamy' exhaust emissions usually associated with a leaking EGR cooler, this is now diagnosed as the problem.  The earlier VW Van Centre noticed that the oil level was high, took some out but didn't inspect it! The current VW VC haven't found any water in the sump oil and the oil looks ok at the dipstick. However, I'm still concerned about the visible signs of yellow emulsified oil/coolant mix on the underside of the oil filler cap (could show a photo but don't know how to upload it?) - especially since the camper has not done ANY short runs which might produce condensation and the same effect. Can a faulty EGR cooler leak coolant into the engine or does it ALL go out of the exhaust without causing any damage what so ever?

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Post Options Post Options   Thanks (0) Thanks(0)   Quote T5 TDI Quote  Post ReplyReply Direct Link To This Post Posted: 19 Aug 10 at 14:01

There isn't any direct connection to engine oil.  However if it has been running on moisture laden air it could enter the crank case by creeping past the pistons which is normal and part of the of the breathing system (especially since it's not fully run in) and condense on the coolest part of the engine which is the top.

Given your small mileage I doubt if it's done much harm.  But I'd make sure they change the oil if it hasn't been done very recently which would also allow a proper chance to look at the oil and then monitor oil and water carefully.    

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