So, my Caravelle back with the dealer who sold it me (12 month warranty) and their garage can't find any fault. It literally hasn't lost a drop of coolant now since I topped it up before taking back to Hertford from Bristol. The garage has pressure tested hot, cold, overnight, no loss of pressure. Used it as their daily hack for 5 days and still nothing. I've had several conversations with them and they seem to know what they are doing - any suggestions of diagnosing this when it's clearly an intermittent issue?
Engine coolant bottle empty [Resolved]
- Thread starter MarekS.
- Start date
baggiero
OBDII User - London
@Duncc26 - I'll be v. interested to hear if there ends up with a diagnosis. Our 67 T6 is in with VW now, thankfully under a year since purchase (and subsequent camper conversion) - and seemingly has no visible leak but does fail a pressure test. Now it's "just" a matter of them figuring out where it's going! Are the dealership checking what it sounds like your other garage did - for coolant/oil/exhaust mixing?
yep - multiple block tests - no sign of gases every time. What I don't get is how it can be intermittent. Is there some control/bypass valve in the cooling system that only directs coolant via a particular passage way under certain conditions?
At least you have a failed pressure test baggiero so they are looking into it further. I'm in limbo at the moment.
At least you have a failed pressure test baggiero so they are looking into it further. I'm in limbo at the moment.
Sorry to ask, the advanced search does not allow to query for posts. Could you please indicate the time frame of that one?
Kind regards
Could this happen with a new EGR cooler (less than 6 months old)?
Well, finally got it sorted. It was the EGR cooler. Very unusual fault in that it was intermittent and didn't fail pressure test even when left overnight. The fault was likely only activated when doing a DPF regen when the EGR etc gets very hot - enough to open a hairline crack.
Very glad that we didn't just go ahead with original garage advice and change the head gasket - would have £1K down the drain. Will not be going to that particular VW specialist again!
I think I posted before that the EGR valve / cooler unit is mounted securely at both ends. This prevents the unit from freely expanding and contracting with temperature change. Hardly surprising that they fail.
Normally an industrial heat exchanger either has one end sliding or the more likely the tube bundle is mounted in flexible packing.
VW, cheap design, expensive sale and works on the day you drive out of the showroom.
Normally an industrial heat exchanger either has one end sliding or the more likely the tube bundle is mounted in flexible packing.
VW, cheap design, expensive sale and works on the day you drive out of the showroom.
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