Coolant loss and intake runner stuck open/closed

[sams-vans]

I know these issues are well documented. However, I wanted to consolidate information as I progress through the diagnostics and fixes of the issues in my van - hoping it will help someone else in the future.

The Van
2018 T6 150ps CXHA - at 95000 miles. I have owned since 91000 miles.

History
69k miles - EGR replaced (coolant loss)
83k miles - Intake manifold replaced (assume intake runner stuck, but not documented)
93k miles - Intake manifold replaced (intake runner stuck)

Symptoms
Coolant loss. Pressure test fail. No smoke or visible sign of leaks when pressure tested. Suspect EGR again and this follows the circa 30k mile lifespan of most EGRs.

Next steps
Isolate coolant leak - bypass EGR coolant circuit and pressure test
Test intake runner solenoid - vacuum and electric (if possible)

My hope is the root cause is the faulty EGR leaking coolant into the intake system that is fouling the runners. In which case I'll replace the EGR and do a chemical clean of the intake manifold. With fingers crossed that will be that.

 

[Binned_it]

I looked inside my EGR cooler via the front manifold pipe. It was visibly wet looking inside.

B

Post in thread 'EGR cooler wet inside (pics) - is it leaking coolant, or is some wetness normal?'

3 May 2025

To conclude this post/issue...

I bit the bullet and bought the genuine VW cooler, bolts and gaskets (just the heat exchanger, not the EGR valve unit) £310 delivered.

Removed the old unit, separated the cooler and rigged up a bench test: it failed: it was leaking somewhere inside.

Rebuilt the EGR with the new cooler and refitted: seems fine now.

If anyone else suspects their EGR cooler failed: looking inside with a cheap endoscope is an easy way to diagnose - it shouldn't look wet.

If you are thinking of replacing it yourself: it's do-able, on the driveway, but a b*****d of a job! Took...

• Binned_it

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