Coolant leak / Mystery - help!! SOS!!

[BOOSHAN]

Well that is interesting… I had some coolant loss in September which cleared up by itself and now this week my van has started showing an EML and reporting an issue with glow plugs.

I am assuming the tech bulletin is an flow chart regarding what to check next! £160 for the plug check.

 

[Dellmassive]

Update from me. Decided to replace the egr which will be done next week. I’ll report the outcome of that as it becomes apparent

How are you getting on with this?

 

[DXX]

My T6 150ps went in for coolant loss, around 300ml every 300 miles. Mechy told me to replace belt and pump before running up to temp, (it did need doing). Just driven 1600 miles and the light is back on. Mechy said next port of call, according to tech bulletin, would be looking at glow plugs. Has any one else had there plugs checked (not a euphanism) regarding coolant loss?

The glow plug electrical resistance can be checked in a couple of minutes with a multimeter without removing the plugs.
I think you should ask the mechanic why this the next stage of the diagnostics.

 

[Llama35]

How are you getting on with this?

Had the egr valve replaced. Took it for a long drive a few weeks later (it doesn’t get used that much) and engine management lights came on and it went in to limp mode.
Took it back to the garage and apparently one of the intercoolers ( the mahle one on top of the engine) had gone. Replaced that and went Christmas touring. Happy to report no coolant leak and full power/no lights on the dashboard now.
Total cost around £2k. Nice Christmas present for us!

 

[BOOSHAN]

The glow plug electrical resistance can be checked in a couple of minutes with a multimeter without removing the plugs.
I think you should ask the mechanic why this the next stage of the diagnostics.

He told me they pressure test the system with the glow plugs out. This is the next step to see where the issue is.

 

[Dellmassive]

He told me they pressure test the system with the glow plugs out. This is the next step to see where the issue is.

So that would possibly help locate a cooling system to cylinder leak asuming both valves were closed.

If either valve is open the leak will flow to either inlet or exhaust.

Smoke test could be next.

 

[Loz]

So that would possibly help locate a cooling system to cylinder leak asuming both valves were closed.

If either valve is open the leak will flow to either inlet or exhaust.

Smoke test could be next.

The only thing I can think they meant was to remove the glowplugs, pressurise the reservoir, leave overnight and see which (if any) cylinders fill up with water. You would also remove the front EGR pipe and the air hose from the charge cooler (if you have one) and see if any fill up with water overnight.

 

[Dellmassive]

The only thing I can think they meant was to remove the glowplugs, pressurise the reservoir, leave overnight and see which (if any) cylinders fill up with water. You would also remove the front EGR pipe and the air hose from the charge cooler (if you have one) and see if any fill up with water overnight.

possibly . . . though not so good if the coolant is leaking into the oil, if the rise on the dipstick wasnt noticed?

i dont think VW even use smoke machines for diagnostics.?

i was under the impression that if they done a leak down test . . . and it failed.

they started swapping parts?

+++++++++++


so any garage that tries to diagnose further has my vote. . .

though a smoke machine seems to be the go to tool to locate a mystery leak . . . . its gotta be going somewhere right !


+++++++++++

 

[DXX]

There’s a very good chance that the leak only occurs when the engine is hot so a pressure test on a cold engine with the glow plugs removed will not be 100% conclusive unless it reveals a leak.
To cover both hot and cold a pressure test could be applied on a hot engine if the glow plugs are quickly removed and continued after the engine is cold.

 

[BOOSHAN]

There’s a very good chance that the leak only occurs when the engine is hot so a pressure test on a cold engine with the glow plugs removed will not be 100% conclusive unless it reveals a leak.
To cover both hot and cold a pressure test could be applied on a hot engine if the glow plugs are quickly removed and continued after the engine is cold.

The original test was on a hot engine. I know that as he told me to replace the timing belt as it was fraying and a couple of teeth were degrading. Damn these transporters.
Get a VW Van my mate said.
Bombproof he said

 

[Nik]

Well I’m still no further forward apart from having to continually top up the coolant(and be thoroughly p***** off with the van) There is no trace anywhere. Charge cooler replaced, coolant bottle and cap replaced and we thought that was the issue - neither solved it. We done numerous pressure tests for long periods (hot and cold) and nothing.
My machanic is going to check the DSG oil?? Has anyone had or heard of an issue with the coolant getting into the gearbox?

I’m reluctant to put a new ERG cooler on until it’s confirmed it’s that. When we have taken the pipes off to check it’s been bone dry with no evidence of coolant.

So frustrating…. Reading about doing a smoke test, would that show if fhe EGR was the problem? Getting tired of it now

 

[DXX]

I’ve found coolant in the exhaust gases before with a sheet of clean A4 paper held up to the exhaust tail pipe with the engine revving at 2500RPM.
Somebody with a good nose can smell the trace of coolant on the paper.
Not scientific but it works depending on the rate of leakage and size of hooter.

 

[Loz]

My machanic is going to check the DSG oil?? Has anyone had or heard of an issue with the coolant getting into the gearbox?

A friend of mine had to have the gearbox oil changed because a seal went on gearbox oil cooler.

 

[Fluff34567]

As you appear to have replaced lots of coolant it's either running out onto the road or going out through the engine/exhaust.

The majority of mysterious coolant leaks are resolved with an EGR replacement.

Don't just concentrate on the cooler by disconnecting the inlet and outlet and then pressurising. The egr valve body is also cooled and that can cause leaks when it's in operation but no leak when engine isn't running.

 

[dakin 1985]

My van (150ps) went in for investigation, it was left on pressure test for about 30hrs and dropped a negligible amount. The mechanic said if it’s losing coolant it’s not bad enough to spot easily so keep driving it until it gets worse. 1,200 miles later and it hasn’t lost any, so weird as the coolant dropped from normal max level down to fully empty triggering the coolant light in September so the coolant went somewhere. There must be a pixie in there drinking it occasionally!



My Van is doing the exact same, I've just spent £1300 on it to get head gasket replaced, drove it for 2 weeks and now coolant has dissappear again and smokes out the exhaust

 

[Fluff34567]

Changed the EGR already? The egr is cooled and known to leak

 

[dakin 1985]

Changed the EGR already? The egr is cooled and known to leak

Yes I've change my egr just last year because the engine light came on, had it checked and it said egr was blocked so changed for a new 1

 

[Nik]

Yes I've change my egr just last year because the engine light came on, had it checked and it said egr was blocked so changed for a new 1

And you still have the mysterious coolant leak??

 

[dakin 1985]

And you still have the mysterious coolant leak??

Yea, coolant still disappearing, the van smokes out the exhaust aswel, white smoke, and usually when the heating is on or first thing in the morning

 

[DXX]

Yea, coolant still disappearing, the van smokes out the exhaust aswel, white smoke, and usually when the heating is on or first thing in the morning

I’d get it repaired sooner than later and avoid driving it until it is, producing steam in a diesel engine isn’t going to end well.