200tdi conversion, temperature gauge reading too hot

[larna86]

I have looked on previous posts but all the suggestions dont seem to work. Situation is as follows:

S2 with S3 gauges (temp and fuel) with a Disco 200tdi. I changed the temperature sender for a series 2.25 with adaptor (Steve Parker) as recommmended. The wiring is brand new and connections good. the wiring runs a fused supply to voltage stabiliser (metal thing behind the dash) and then on to the gauges.

Fuel gauge is working fine but the temp gauges when running sits just under the red area and doesnt move. The radiator has the Disco themostate (changed for genuine) and is correct at 88 degrees. Themostat works fine as checked with hot water and thermometer.

Question is how do i get the temp gauge to read level and normal at 88 degrees and could the volatge stabilizer be the problem? If so where do i get a reputable one (or aftermarket) and not made by "Br**part"

Any help much apreciated as its beginning to do my head in.

Thanks

Ed

[Phil Hancock]

The temp gauge would read normal with the old engine which would have a 74* or 82* stat so with the disco stat which is 88* it will read higher.

[larna86]

I thought that this might be the case, is there any harm (or potential damage) to be done by using the 74 or 82 degree thermostat in the Disco engine?

Thoughts please - positive and negative!

Thanks

Ed

[Phil Hancock]

It would need to have the 'valve' washer set up on the bottom like your 88* disco stat has otherwise the bypass will be wide open all the time and that will cause overheating.

[ejparrott]

I have a 200 disco engine, and I have my Series 3 gauge, I didn't buy any expensive adaptors, I connected the disco sender to the Series gauge, and fitted an independant gauge at the back of the head. when my independant gauge says 90degrees C, my Series gauge is sitting just below the 'N' on the series gauge.

[Gazzar]

On my tdi200 (-T) I re-cut the threads on the head to take my series sender, using an old sender with half the threads cut away vertically. I'm using a 2.5 petrol thermostat and housing and the temperature gauge NEVER reaches the normal section.

When I was running the petrol engine, with the same sender, the gauge would read just under "hot".

I wish it was hotter, as the heater doesn't work anymore. A radiator muff may be on the Christmas List!

G.

[Snagger]

I use a SIII gauge and sender with the standard Tdi thermostat. The temperature sits right in the middle of my gauge and the heather works very well. I was careful to use a genuine sender unit as pattern senders are notoriously unreliable.

[larna86]

Thanks all. I thought I had a genuine sender but will check the bag it came in. Please can someone confirm the correct part number I should be using. Thanks Ed

[Ratty43]

For what it's worth I ran the 200tdi in my S111 diesel with the original 200tdi sender running to the S111 gauge and it sat square in the middle of the range when warm. Given all the different results could they stem from the gauges wearing differently (don't know if that's possible)?

[Jon White]

Mines always read hot too. At normal temperature it sits just under the red. I just ignore it knowing that if it ever goes any higher then its a problem.....

Jon

[larna86]

Thank you everyone for your help on this matter. I seem to have solved the situation by retaining the Disco 200TDI 88 degree thermostat and using the green temperature sensor (PRC9917).

I also replaced the stabilizer behind the gauges and made sure the gauges and the stabilizer are properly earthed. This seems to have done the trick and the temperature now reads dead in the middle (i.e on the N mark)

FYI - replacing the 88 degree themostat with an 88 degree thermostat brought he temp reading to just over the "white area" and so was discountede as being "too cool"

Ed