The Dispatch | Expert | Scudo Hub

sam_loves_hdi

Member

Registered: 2026-05-09

Posts: 2

Coolant loss from cap, maybe somwhere else? 2.0HDi

Hi!

I have a Jumpy 1 with the intercooled 2.0HDi form 2006. Bough with 230 000 km from an old tyre firm. Seems to have had issues with loosing coolant for quite a while, notised residue from coolant under expansion tank, sender for coolant level disconnected, tap water instead of coolant in the system (fucking hacks...).

Anyways, girlfriend and I made a van conversion of it and we like it, but it looses coolant. Over 500km it empties the expansion tank. I seems to seap out near the cap. I recently replaced with an OEM calorstat one but it persists. I sure hope it´s not the head gasket...

The can doesn´t smoke, temperature shows 90 when driving. Got a little hot once when there was ice in one of the hoses (due to the previous moron of an owner running tap water). thermostat seems fine, it doesn´t seem to build excessive pressure in the cooling system. If i open the cap after letting it cool down for 10 minutes it makes a faint "pssht" sound like a coke bottle but no gushing out of liquid or anything like that.

What would you do to diagnose further? Try a new expansion tank? The one on the car seems a bit shit. Any good aftermarket options or should I go oem?

Also if anyone wants to add keyless entry for less than 25€, here´s a guide I made:
https://www.youtube.com/watch?v=KH3vvnSjV-0

RegW

Member

From: Bristol

Registered: 2024-04-21

Posts: 356

Re: Coolant loss from cap, maybe somwhere else? 2.0HDi

Hi Sam,
I have the same year Expert HDI with similar mileage 255k vs your 230k
Assuming/Hoping it isn't the head gasket....
So, it's Losing coolant over  500km/300miles.
Do you know how much it has lost in this period ?
How much do you need to add to get the level back to normal?

I can only make Guesses:
Expansion tank plastic structure or cap degrading and venting water vapour
slow leak on radiator/hoses or bleed screw at top of rad
slow leak around thermostat housing
I know from my own work there is a pipe behind the engine that goes from the engine block to the heater core
and this returns to the header tank
so any slight leaks here may not be easy to spot.

Sometimes if a head gasket is failing you'll get a somewhat sweet smell at the exhaust
from the antifreeze
I have experienced this on motor bikes which are obviously petrol engines so not so sure
if this is as noticeable on a diesel.

Thanks for your Youtube link, I have bookmarked it to be studied later
I have remote central locking which works via key but the Remote doesn't
the fob puts out RF but the van doesn't respond so have a cheap EBay keyfob remote system
I want to hack in after I get the MOT work done.

Last edited by RegW (2026-05-09 12:24:57)

---

When all else fails, RTFM  - 2006 Expert 2.0 HDI/110

sam_loves_hdi

Member

Registered: 2026-05-09

Posts: 2

Re: Coolant loss from cap, maybe somwhere else? 2.0HDi

thanks for the response RegW.

Today after driving and cooling down for 2 hours I checked the coolant level, and it showed empty. Then I opened the cap and loads of air/gas came out and the expansion tank filled again. What is this about?? Air bubble somwhere messing with me? How to bleed the system again.

It looses aproximately 1.5L over 500km, which is quite a lot in my opinion but no smoke...

RegW

Member

From: Bristol

Registered: 2024-04-21

Posts: 356

Re: Coolant loss from cap, maybe somwhere else? 2.0HDi

It is a lot to lose so where we wonder, is it going?
Cracked cylinder wall or head or head gasket has to be considered
Also the egr and oil coolers could be an issue.

How is the heater? I had to fit a new core to mine as the old one was full of crap
so easy to get trapped air in there
Bleeding the system at the thermostat housing and top of the radiator took a few tries to get
the air out  too.

Goodluck with it, let us know how you get on

---

When all else fails, RTFM  - 2006 Expert 2.0 HDI/110