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Thermoplunger fault

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12K views 2 replies 3 participants last post by  Dancingdad  
#1 ·
Hello all. I appreciate any help with the following issue.
After an engine change, my laguna diesel is now very slow to heat up the car interior - it was previously very quick to do so.
The temperature gauge goes up normally as before and thermostat has been replaced. It now just takes ages to warm up.
I have read about thermoplungers but I can not find much info about them i.e.
- is there a fuse for them
- how are they wired etc
- would they stop working after engine swap

Any help will be appreciated
 
#2 ·
On the Clio they are mounted on the top of the gearbox
in a unit with wires and water pipes going to it, maybe the wiring as been disconnected or the plugs damaged in some way during the change, they only come on at low temp 3 or 5c rings a bell. there is likely a fuse in the under bonnet fuse box and it will be a big one maybe 50 amp.
 
#3 · (Edited)
Surely a thermoplunger is only there to heat coolant at lower temps/before engine warms up ?
Actually rethinking that statement, uhm, could be:eek:

Personally I'd have the stat back out and check in a saucepan. Not all thermostats are created equal and many open early or late.

You can get an idea of stat operation by starting from cold and feeling hose from stat. If it's getting warm much before engine is up to or close to temp it indicates an early opener. Getting warm with the engine indicates a stuck open stat.