Losing Coolant internally 2017 2.0 TDI 150bph exAA van

[DeanCoulson]

Looking for some help / advice / experiences about internal coolant issues with ex AA vans.

I bought an exAA T6 (150bph 2.0 TDI) with 102k miles that has an internal coolant issue. It has been losing coolant.

The ERG cooler has been replaced and the charge cooler has been tested from the place I bought it from.

I have since put it into VW for a diagnostic. They pressure tested the engine which lost 1/2 bar of pressure overnight. Tested both EGR and charge cooler, which were both fine.

They then used a bore scope to look inside the engine. Cylinder 2 was found to have scratched / score marks and found evidence of dampness in cylinders 3-4, but couldn't clarify what that was and so recommended stripping the head to investigate.

Possibly the cylinder head gasket needs replacing, but I'm not sure what the scratches/ score marks mean in cylinder 2. I'm guessing it's possible that if coolant has been leaking into the engine it could have washed oil off the pistons and the metal on metal may have caused it.

My question is, if it is the gasket that needs replacing. Will I be looking at issues down the line from the scratches in cylinder 2? what are the potential problems? or would it be fine? the engine runs fine, well a part from the amber engine management light has just come on, but that is from low ad blue efficiency (the code that popped up)

Has anyone had any experience of this?

 

[Dellmassive]

that sounds interesting.

im assuming they pressurised the cooling system overnight, which lost 1/2 bar.

so that water must have gone somewhere? (exhaust, inlet, cylinder, other)

are they suggesting that the head gasket is letting the water jacket leak to a cylinder then?

++

the cylinder bore and pistons have a max wear limit that's specified somewhere in the workshop guide.

honing and new rings maybe an option. . . . but thats more cash as its a semi rebuild.

++

the head gasket would be the cheaper option. . . . to possibly stop the internal leak?

when they strip it down, they may find the gasket at fault, or possibly a crack or corrosion on the head.

very difficult to tell anything until the head is off.

++

keep us posted.

 

[DeanCoulson]

that sounds interesting.

im assuming they pressurised the cooling system overnight, which lost 1/2 bar.

so that water must have gone somewhere? (exhaust, inlet, cylinder, other)

are they suggesting that the head gasket is letting the water jacket leak to a cylinder then?

++

the cylinder bore and pistons have a max wear limit that's specified somewhere in the workshop guide.

honing and new rings maybe an option. . . . but thats more cash as its a semi rebuild.

++

the head gasket would be the cheaper option. . . . to possibly stop the internal leak?

when they strip it down, they may find the gasket at fault, or possibly a crack or corrosion on the head.

very difficult to tell anything until the head is off.

++

keep us posted.

yes they pressurised the cooling system which lost 1/2 a bar of pressure. There were reported no external leaks so its going somewhere inside. Ironically. Since that time and what VW reported it has stopped losing coolant, I have given it some test runs of at least 200 miles too.

They didn't suggest anything other than they would have to stir the head to investigate further.

Haven't done anything else with it as there is now an oil leak from the top of the engine somewhere. It's very slight and only noticed it as its not dripped onto my driveway. I have contacted VW to see whether they may have inadvertently done it when using the borescope to look inside the engine.

 

[DeanCoulson]

One thing I should also mention (but I was a bit thrown by the VW diagnostic report) is that after the EGR cooler was changed and the coolant dropped about an inch in the expansion tank, it hasn't lost any more coolant at all and yet VW said they pressure tested it and it lost 1/2 bar of pressure overnight.


So now I am wondering whether it still has a coolant leak?

 

[Broadside]

I’m interested what you find with this. My 150 also loses coolant occasionally. Over summer it got quite bad losing a reservoir of coolant in about 200 miles but when pressure tested it lost virtually nothing after 24 hours. I got the EGR cooler changed as it’s a culprit in lots of coolant loss stories and it’s got much better losing about a reservoir of fluid after 2-3000 miles. I’m not totally sure if this is really coolant loss or if it’s still trapped air working its way through the system - mine is a Shuttle so has lots more coolant pipe work going to the rear heating system.

 

[Broadside]

My van’s been in for investigation today about the ongoing coolant loss. A different garage has stuck a camera in the new EGR and found it contains water. There is apparently a service bulletin that requires some new modified bits when fitting an EGR or it risks over heating the EGR and splitting it internally. There is a small pipe that should be routinely replaced with an EGR swap. My newly replaced EGR is now scrap apparently. Has anyone heard of this before?

There is apparently another pump which feeds the coolant flow to the EGR which can fail without throwing a fault code where the motor works but the impeller doesn’t spin, again leading to an overheating EGR which will then fail.

This photo from the camera shows some droplets of coolant making their way to the EGR outlet of mine

 

[Raul a/3]

I had a egr cooler leak, my problem was the gasket to the egr body, I used high temp gasket maker silicone type, and it’s been fine ever since, 3 years and counting. Daua 2.0L 140hp.

 

[Broadside]

I spoke to the garage that replaced the EGR, the say VW need to look in to a warranty claim. I’ve booked it in to VW who have warned if it’s due to a fitting error they will charge me £138/hr labour. A trusted (different) independent garage has said he has seen this happen before and VW will blame the garage that did the work. That leaves me stuck in the middle with a 6 hour labour bill to claim for a £500 part while VW look in to it, and then the original garage will argue with me.

Pretty fed up so will get the local specialist independent to do the lot. I’ll be £1100 down on the original EGR work but I feel like I’m being led in to a trap so need to get out of it as neatly as possible without a load of pointless arguments that will ultimately lead to nothing. Lesson has been learned to use an independent specialist rather than a local garage who are happy to hide behind the VW warranty process rather than do the honourable thing and sort it out.

 

[deny_mx]

I had a egr cooler leak, my problem was the gasket to the egr body, I used high temp gasket maker silicone type, and it’s been fine ever since, 3 years and counting. Daua 2.0L 140hp.

did you use just gasket maker or used in combination with old gasket?

 

[deny_mx]

This EGR cooler has a major design flaw. The cooler is made of aluminum, while the EGR valve is cast iron, with an unknown metal gasket between them. These materials have different thermal expansion rates, and the six bolts only require 12.5 Nm of torque. I question whether this is enough to create a proper seal between the cooler and the valve.
Using gasket maker seems like reasonable approach. but only around the coolant passway.