240 General: New (to me) 1980 Volvo 244

[Laird Scooby]

This is my 760 axle Alan, similar to the 240 but i'm not sure if it's exactly the same. Shows the fill and drain plugs removed :



Hopefully if your 240 is similar enough, it will point you in the right direction. If memory serves, the drain was 13mm and the fill 17mm but being square, open ended spanners were the order of the day.

Not sure if the 240 will have it but the drain plug on mine was magnetic and had a lot of swarf on it, the 30 year old oil was like black water when it came out!

[Othen]

Originally Posted by loki_the_glt

I've just realised where I had seen the Royal Barge's, now-removed, roof goitres before: our tractor units have them fitted to their behind-the-cab side fairings, but they face in the opposite direction to the ones on the car.

Perhaps the PO went everywhere in reverse!

Sounds like I got rid of that just in time!

:-)

[Othen]

Originally Posted by Laird Scooby

This is my 760 axle Alan, similar to the 240 but i'm not sure if it's exactly the same. Shows the fill and drain plugs removed :



Hopefully if your 240 is similar enough, it will point you in the right direction. If memory serves, the drain was 13mm and the fill 17mm but being square, open ended spanners were the order of the day.

Not sure if the 240 will have it but the drain plug on mine was magnetic and had a lot of swarf on it, the 30 year old oil was like black water when it came out!

Yes, that looks quite familiar Dave. I had a look under the back just before dusk: same square head bolts, same sort of access. I think it will be an easy job if I put the back up on a couple of ramps.

I suspect I'll find the same black ditch water inside, but mine will be 40 years old!

Alan

[Othen]

I'm waiting for a new temperature sender to arrive in the mail, so I thought I'd do a little experiment to see if I could re-calibrate the one I have (following Dave's idea of a few days ago).

I took a SWAG at 20Ω being about the right size for a series resistor and made one up that I could clip into the Royal Barge:



I took the car for a spin around the block, it quickly warmed up to just above the middle of the green part of the gauge... and stayed there. Back at the garage I monitored the thermostat housing temperature and could see it was cycling between 83C and 88C, with the cabin gauge reading like this:



... excellent thought I, that proves my theory. Then I was delighted to hear the electric fan kick in, proving that it and the 50050 switch are working well together and with the thermostat. It ran for 8 seconds (1001, 1002...). I left the car ticking over (it had been doing so for some time by now) and sat in the cabin to see if the fan would come on again, and if the tell tale would illuminate. Both happened perhaps 3-4 minutes later, the fan ran for 8 seconds again, and the tell tale came on when prompted.

Whilst this was just an experiment to see if my thesis was correct, it has fortuitously shown the whole system working at the same time. I'm hoping that when the replacement sender arrives I will be able to dispense with the series resistor.

Alan

[Laird Scooby]

Encouraging results there Alan! Hopefully the "calibration" resistor won't be needed after the new sender arrives anyway.

[Othen]

Originally Posted by Laird Scooby

Encouraging results there Alan! Hopefully the "calibration" resistor won't be needed after the new sender arrives anyway.

Hopefully not Dave, but it could be the gauge that is out of calibration rather than the sender (although a bit unlikely I should think). If that is the case then I think a 40Ω resistor would bring the needle to the middle of the gauge at 92c.

I recall you talking of the 50050 being a 92-87 switch, and that sounds exactly right. The thermostat will be operating at 92C, so when driving around with a good air flow through the radiator the right side never gets to 92C, so the switch never operates the fan. When ticking over the fan comes on for about 8 seconds in 5 minutes (ambient temperature about 10C). I see your point about the 50050 switch being set a little cool for a 92C thermostat, I agree but I don't think it is worth changing - I quite like the idea of the fail safe cutting in every now and then on tick over, and it proves the system is working.

The switch should be in the mail tomorrow, so I'll get it fitted, the system drained again and re-filled with the proper coolant. Many thanks for your help, I think this has been a really good enhancement for the Royal Barge and entirely in keeping with the ethos of the car.

I was thinking of the ATF as I drove around this afternoon. The box is changing well, but the stuff that came out was pretty manky. I was thinking I might try to put a few hundred miles on the car in the next week or so and then change it again. That would be a 75% change, which might be a good idea in the circumstances what do you think?

Alan

[Laird Scooby]

Originally Posted by Othen

Hopefully not Dave, but it could be the gauge that is out of calibration rather than the sender (although a bit unlikely I should think). If that is the case then I think a 40Ω resistor would bring the needle to the middle of the gauge at 92c.

I recall you talking of the 50050 being a 92-87 switch, and that sounds exactly right. The thermostat will be operating at 92C, so when driving around with a good air flow through the radiator the right side never gets to 92C, so the switch never operates the fan. When ticking over the fan comes on for about 8 seconds in 5 minutes (ambient temperature about 10C). I see your point about the 50050 switch being set a little cool for a 92C thermostat, I agree but I don't think it is worth changing - I quite like the idea of the fail safe cutting in every now and then on tick over, and it proves the system is working.

The switch should be in the mail tomorrow, so I'll get it fitted, the system drained again and re-filled with the proper coolant. Many thanks for your help, I think this has been a really good enhancement for the Royal Barge and entirely in keeping with the ethos of the car.

I was thinking of the ATF as I drove around this afternoon. The box is changing well, but the stuff that came out was pretty manky. I was thinking I might try to put a few hundred miles on the car in the next week or so and then change it again. That would be a 75% change, which might be a good idea in the circumstances what do you think?

Alan

I'd try a 47 Ohm resistor at first Alan if you find it necessary after the new sender if it doesn't make any difference. If that's too low on the gauge, change it for a 39 Ohm.

I take your point about the 50050 switch, it seems to be working well for you so i'd leave it be as it is.

As for the ATF, yes, if you do a few hundred miles next week, very good idea to do another part-change after. THen do it every few hundred miles, i'd worked on you just doing about 150-200 miles a week in it when i said monthly so if you're doing more, adjust as necessary.

[Othen]

Originally Posted by Laird Scooby

I'd try a 47 Ohm resistor at first Alan if you find it necessary after the new sender if it doesn't make any difference. If that's too low on the gauge, change it for a 39 Ohm.

I take your point about the 50050 switch, it seems to be working well for you so i'd leave it be as it is.

As for the ATF, yes, if you do a few hundred miles next week, very good idea to do another part-change after. THen do it every few hundred miles, i'd worked on you just doing about 150-200 miles a week in it when i said monthly so if you're doing more, adjust as necessary.

You mentioned a voltage regulator in the instruments previously Dave. If it turns out not to be the sender would it be worth looking at that?

[Laird Scooby]

Originally Posted by Othen

You mentioned a voltage regulator in the instruments previously Dave. If it turns out not to be the sender would it be worth looking at that?

It could be if the fuel gauge is also over-reading Alan. That's difficult to ascertain unless you run it out of petrol, add a gallon, zero the trip meter then drive to a filling station, add half a tank less a gallon and see where the gauge settles after a couple of minutes. If it shows more like 3/4 than half, that would suggest (but not confirm) a dodgy voltage reg on the instrument cluster.

Can't remember the last time (or even if although i'm sure at some point) i saw a 240 instrument cluster - if you have a photo of the back of it i could probably point you in the direction of it though.

[Othen]

Originally Posted by Laird Scooby

It could be if the fuel gauge is also over-reading Alan. That's difficult to ascertain unless you run it out of petrol, add a gallon, zero the trip meter then drive to a filling station, add half a tank less a gallon and see where the gauge settles after a couple of minutes. If it shows more like 3/4 than half, that would suggest (but not confirm) a dodgy voltage reg on the instrument cluster.

Can't remember the last time (or even if although i'm sure at some point) i saw a 240 instrument cluster - if you have a photo of the back of it i could probably point you in the direction of it though.

Thank you Dave.

Hopefully the new sender will just fix the problem, and that would be the simplest route. I'm not sure how the gauge is reading yet.

Here is a photo of the back of the instruments, it would be handy if you would point out the item just in case.



Alan