Thread: Coolant loss worry

Originally Posted by Morry948

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Have been on a few expeditions locally so prob have put about 1.5K since I bough it, not using oil, not running hot, nothing unusual considering its age

It starts and runs sweat :-)

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define "not running hot"

Is this via the gauge on the dash, or via an external gauge?

if via the dash gauge .. it means nothing!
As already inferred, by the time you see it's running hot via that gauge, it's probably too late!

if you have an external gauge, what temps do you see.

on mine with an external gauge:
At about 55°C the dash gauge has hit the low mark.
At about 65°C the dash gauge hits the mid range.
At it's normal operating range between 82-85(maybe 86) it's still at this mid spot, maybe a millimeter below.
I've seen the external gauge at 105°C and the dash gauge is still in this same middle spot(just a tad below).

As everyone else will comment, that dash gauge is pretty much close to useless!

I bought one of those engine data scan gizmo's from 4WDsupercentre Primarily as a temp gauge and a volt gauge and it works a treat, Much better that the factory gauge and cheap as chips as well

Having a bit better look and found this at the back of the head. Internal heater has been bypasses and there is a decent kink in the hose

Shall be replaced forthwith

2017-10-01 16.45.44.jpg


Also, there appears to be 2 sensors on the thermo housing, so which is which ?

2017-10-01 16.47.17.jpg

I am guessing here But the second sensor may be a Low Coolant alarm .

Not sure...cant see any low coolant light or indication....and I dont want to drive around to find if it is or isnt

I was talking to Shane at Whyatt's the other day about these low coolant alarms and if I have any cash left over from the head gasket job I will definitely be fitting one of these.
There is No gauge with the unit but an audible alarm goes off which gives you time to stop the engine Before any damage can be done.
From memory I think they cost a bit less than a couple of hundred, Which is far Far cheaper than replacing the head gaskets again

Originally Posted by Morry948

Having a bit better look and found this at the back of the head. Internal heater has been bypasses and there is a decent kink in the hose

Shall be replaced forthwith

2017-10-01 16.45.44.jpg


Also, there appears to be 2 sensors on the thermo housing, so which is which ?

2017-10-01 16.47.17.jpg

yours is 200tdi so i could be wrong but they appear to be factory so it won't be low coolant alarm. my guess is that they are the same as the sensors which are on the bottom of thermostat housing u pipe on 300tdi. they are for AC purposes. one switches off AC when the engine temp gets too high and the other i can't remember, but it's basically for AC operation. assuming you have AC. it's possible that even if you don't have AC the wiring is still there from factory or they serve another (but similar purpose) to do with engine overheating. The UK 300tdi vehicles with no AC didn't have the sensors on the pipe at thermo housing. just a blank flat section where you could basically tap that sensor into place. apparently you can't buy the housing with the sensor anymore and only the blank one. luckily for me they are in two sections and the u pipe which is where the sensors are can be unbolted from the housing. my housing was too corroded to use again but the pipe with sensors was still good, so i bolted it to a new housing.

that kink is not ideal. if you look at my head thread i have pictures of how i bypassed the heater matrix. basically had a 90 degree brass piece and just cut a small section at the end of the heater hoses so that it gives you a nice even flow without any sharp angles. there is a picture of it i posted. the brass fitting is basically fairly close to the barbs which come out from firewall and into the dash. not behind the head like yours.

i would say your heater matrix is leaking which is why they did this. i believe on a 200tdi to put new matrix in is a dash out job. on the later 300tdi models you can slide the old matrix out with a bit of fiddling.

Originally Posted by trout1105

I was talking to Shane at Whyatt's the other day about these low coolant alarms and if I have any cash left over from the head gasket job I will definitely be fitting one of these.
There is No gauge with the unit but an audible alarm goes off which gives you time to stop the engine Before any damage can be done.
From memory I think they cost a bit less than a couple of hundred, Which is far Far cheaper than replacing the head gaskets again

i wouldn't go anywhere without a low coolant alarm. mine cost 150 and it's probably the number 1 investment on a d1. if you are replacing the head gasket i would not even drive it until i had a low coolant alarm fitted. you don't want to do the job all over again. it's such a small simple piece of equipment but worth more than anything else you can do to the car.