D24 - Can't solve temperature problem

[Maciek4530]

Originally Posted by ngoma

I don't know if the diesel versions of the temperature sensor and gauge are different from the gasser versions but there was some extra circuitry involved in the model years of your samples that tampered with the "true" readings that artificially kept the needle in the middle.

This is why I wanted you to take readings with an IR thermometer, so you could easily verify actual temperatures. Can you borrow one? You could read the temperature of the temperature sensor itself and compare it to the gauge.

"1986-1993 240 models are equipped with circuitry that is designed to keep the coolant temp gauge needle positioned in the normal zone (9:00 position) even if the engine is running a bit hot. The idea is to prevent minor variations in coolant temp from causing worry for the driver. As these cars age a common problem is the failure of the circuit board and connectors resulting in erratic readings or no reading at all. We have put together a simple bypass harness that reverts the function back to the earlier trouble-free design."

From
https://www.ipdusa.com/products/5670...-Volvo-1363117

More info:
https://cleanflametrap.com/tempFaker.html

https://www.youtube.com/watch?v=0AL4hphLMnE

Yep, but that is about US versions

In Europe we don't have system like this (and we happy abut that ) - we know exacly about all small changes in water temperature basis on gauge.

I try to borrowe IR thermometer

[Maciek4530]

Everything was ok 3 days... Now my radiator got a hole next to upper hose....

It could be problem since start of cooling problem?

[ngoma]

So, what fixed the temperature problem for those three days?

[Maciek4530]

Originally Posted by ngoma

So, what fixed the temperature problem for those three days?

Other temp gauge... I though...

Now i don't know sh*t.

My friend borrowed me early D24 radiator, i test it and find out if it was luck that everything seems normal but when coolant leak appears temp gauge get up to 3/4 of the scale (i stopped after going uphill as always).

Today i change steering joint (to make car maybe a little easy to control - old one was so loose...)

And i put radiator from my friend. I let car idle and make it to operation temp. But ther was no heat in vents. After few mins on "normal" temp i drive 50m at my driveway front and backward forward and heat starts to going through vents (I register car 2 days ago and change license plate - need to buy new frames to mount them and test drive car tommorow).

After that i stoped on parking stop and temp goes to 3/4 of scale and then set on "normal" agine. After that i hold accelerator pedal for 1 or 2 mins at high revs. Temp gauge just move 1-2 mm and shake a little - nothing that normal person would observe.

Tommorow i mount new plates and try to drive it on the road. I'm scared that something really bad happening...

It's middle of fall, my red B230F 240 should be in storage and i should drive this winter beater since 3 weeks...

I need to ask how much will be cost to replace core in my old radiator or i need to weld that hole... But next one can appeard after 32 years of this radiator existance...

[Maciek4530]

Now i think about sensors agine - I change both my sensors to "old" ones - but front one, to gauge is "no name" with 111 stamp. Maybe it's him? I experience weird temp readings in my brother B200F 240 when i put new EPS sensor it shows that rebuild car overheat. Then i find out that: old owner put heater valve upside down (that's why there was no heat in car) and new sensor was wrong. Can somone give me correct VW/Audi coolant sensor number for display?

Maybe both: my new and "old" - no name sensors aren't correct fitted? Only rear sensor in car s VW/Audi old orginal temp sensor.