General Thermostat Question - 1.9JTD

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General Thermostat Question - 1.9JTD

NeilT

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Dec 31, 2014
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Hi,

I recently purchased a 2003 Doblo 1.9JTD 5seater.

It seems obvious that the thermostat must be stuck open since it takes
several miles before any warm air enters the car and the temp guage reads
normal. Reading the manual and looking at the prices, it seems that what
used to be a simple quick and cheap job has been turned into a dismantle
half the car style nightmare, with a whole housing costing over £60
instead of a waxtat costing about £3 and a gasket.

My question is, in principle, could I insert an inline thermostat in the
top hose such as this one on Ebay:

eBay item number:
221704091892



designed to do a similar bypass on another make and model, and restore a
quicker warm up that way without mucking things up with the temperature
sensor which informs the fuel injection control unit, or any other
issues? The doblo thermostat is rated at 88 degres +- 2, and this
potential alternative at 89, so no real issues there. I have already
blanked the EGR at the exhaust end of things, and the thing took off with
wheelspin after I did that - whoa boy!

If anyone understands the plumbing on these things well enough to know if
there might be any issues I'm unaware of, it would be much appreciated.

Thanks, Neil
 
Hi Neil I have just bought something very similar for my Dobby. Its coming from USA and is a two part housing that takes the old type wax thermostat you spoke of. There is a YouTube video of someone fitting one like you are looking at. Looks a little bit awkward but nowhere near as bad as changing the original.
 
Hi,

I recently purchased a 2003 Doblo 1.9JTD 5seater.

It seems obvious that the thermostat must be stuck open since it takes
several miles before any warm air enters the car and the temp guage reads
normal.

Several miles to reach normal would be about right. If the thermostat is stuck open if you are stationary and idling from start up after a couple of minutes of running and well before the engine has got to temperature the top and bottom radiator hoses will feel more or less the same warm temperature. If the thermostat is working properly the bottom hose will be very much colder.
 
Hi, I've had 2 Doblos since 2001 - a 1.9 normally aspirated diesel and currently a 1.9 120bhp TD. Both cars have always taken up to 10 minutes to get engine fully warm (depending on weather and driving conditions). Once up and running the temperature is rock steady. I believe this is normal for Doblos. My Vectra, however, takes no more 2 minutes before there is warm air entering the cabin.

I don't think the Doblo has a bypass hose, like many other cars, that runs directly to the heater matrix so getting the cabin warm in winter takes a long time - and its quite a big space to warm up.
 
What a brilliant idea/tip. I never knew such things existed and yes a darn sight cheaper than replacing the buried thermostat. Just make sure its as close to the block as possible and/or theres a tiny bleed hole just so the hot water can get to it before it opens.
 
Last edited:
Hi
I had the same problem in Ireland and cost over 200 euro to do but worth every penny takes mins to warm up now. not sure bout your idea never like to chance these things
 
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