Can a charge cooler leak cause hydrolock and engine destruction?

[c_paul]

My t6 204 is slowly losing coolant (separate thread).

One of the symptoms is that about half a dozen times the starter motor has struggled to turn the engine over.

It turns over for a bit then freezes as if there isn’t enough power to turn the engine over.
But battery and starter are strong.

Given the coolant loss issue, could it be coolant lost in the charge cooler going into a cylinder causing a slight hydrolock?

My concern is that it causes major engine damage.

The current advice from vw specialist is watchful waiting.

Pressure test all came back normal.

Coolant loss is sporadic. Wont lose any for a while then loses 200ml.

Total loss has been about 1.5l in 6 months so not very much.

No oil contamination, water contamination or mayo.

No visible leaks.

No steam in the exhaust.

I am worried that waiting could cause catastrophic engine damage.

What does everyone think?

 

[TimT6]

Egr valve coolant leak can cause loss without any signs.
If it's hard turning, it may be head issues but that's really going down the omg I'm going to lose my marbles route and is unlikely before other omg it's dead now things happen...

Yes, water in the engine can damage it.
If your that concerned, the only way to test if your getting water into the cylinder is by removing an injector/glow plug and seeing if the bore is wet with water/coolant after re creating the scenario in which you then suffer a hard start.

There's four common coolant loss failure points.
I reckon identify which of those four it is (I can't remember but there is somewhere on here that mentions it, one of them is the egr valve, or some part there of... Ask me how I know...) And you are probably going to be ok.

In my case I was loosing a litre every 250 miles! Pretty ruddy bad! Only used two litres of diluted and it sat the dealers from this point for two months as I was where you were... Rather not risk it.

To be fair though, the two issues may not be related and a hard start can be caused by a plethora of issues, so much so, that if you have a porblem that you think may cause the said problem, use a method to find this out (hence one of the above paragraphs)

 

[Hamster67]

My t6 204 is slowly losing coolant (separate thread).

One of the symptoms is that about half a dozen times the starter motor has struggled to turn the engine over.

It turns over for a bit then freezes as if there isn’t enough power to turn the engine over.
But battery and starter are strong.

Given the coolant loss issue, could it be coolant lost in the charge cooler going into a cylinder causing a slight hydrolock?

My concern is that it causes major engine damage.

The current advice from vw specialist is watchful waiting.

Pressure test all came back normal.

Coolant loss is sporadic. Wont lose any for a while then loses 200ml.

Total loss has been about 1.5l in 6 months so not very much.

No oil contamination, water contamination or mayo.

No visible leaks.

No steam in the exhaust.

I am worried that waiting could cause catastrophic engine damage.

What does everyone think?

Where you able to resolve this?

 

[c_paul]

Where you able to resolve this?

Sadly not. Yet.

Am currently looking for a specialist.

I have work out:
After a reasonable journey the coolant system is under excess pressure that remains after the system has cooled.

If I don’t release this pressure it will cause a hard start / hydrolock situation.

Oil is clean. Economy has fallen through the floor. Engine running okay ish. Bit rough. Regen every 150 miles ish.

My current hypothesis is cracked head which has caused bent conrod.

I vw specialist wants £1600 to change egr as first port of call. I think i want to take it to an engine specialist to check internal condition first.

 

[Hamster67]

VW 2.0 TDI Engine Problems: Common Issues & Solutions

I am experiencing a similar issue.

The long wait, as the garage work their way through each potential fault, leads to reading articles like the above.

Like yourself @c_paul, I always think the worst. Hope it's not as bad as you suspect.

 

[c_paul]

Update on this. Economy fell through the floor then a fault code came up on the EGR.

Main dealer did full diagnosis and said EGR had failed. Replaced at £1600. they tried getting good will from VW but it was declined. I am suspicious. I think the dealer knows something they are not saying.

Had to top up the coolant today so issue is clearly not fixed. However, economy is back to normal.

 

[DXX]

If there is no detection of combustion gases in the coolant system it could be a very small crack in the charge air cooler that seals when the induction system returns to atmospheric pressure when the engine is stopped.

 

[Deaky]

Update on this. Economy fell through the floor then a fault code came up on the EGR.

Main dealer did full diagnosis and said EGR had failed. Replaced at £1600. they tried getting good will from VW but it was declined. I am suspicious. I think the dealer knows something they are not saying.

Had to top up the coolant today so issue is clearly not fixed. However, economy is back to normal.

Could have been an airlock in the cooling system. Had this on mine after an egr cooler swap. It’s been fine since I topped it up

 

[WinFreak]

Had to top up the coolant today so issue is clearly not fixed. However, economy is back to normal.

Having to top up the coolant after the egr swap isn't uncommon though, they've had it all apart. I had to top mine up twice after fitting the new EGR and then it seemed to stay stable.

 

[Fluff34567]

I changed my 204 egr and you need to drain the coolant, there are so many pipes you should expect a drop in coolant level afterwards even with vacuum filling.

Top it up and recheck every few days. You shouldn't have to refill too much. Take note of how much you put in. If it's more than a litre then either it's leaking somewhere or they didn't fill it properly.