Temperature guage - late 96 440, and lumpy engine

[volvo4me]

Hello,
Can anybody provide advice?
The temperature guage on my 440 does not work. Should I just replace it, if that job is simple to do, or could there be another reason?
Also my engine has a lumpy idle speed. Taking advice from another thread I have changed the plugs, HT leads, distributor cap, rotor arm and thoroughly cleaned everything under the bonnet, and the checked connections.
As a pensioner I have to watch the pennies.
Thank you.

[B20F]

Most of the times the cause for a non functioning temp. guage is corroded contacts at the back of it. Simply remove it, clean the contacts with contactspray and re-attach them with a bit of vaseline to prevent them corroding in the future. Another cause could be a bad sensor in the block.
As for the lumpy idle we need to know of which engine we're talking about.

[volvo4me]

Originally Posted by B20F

Most of the times the cause for a non functioning temp. guage is corroded contacts at the back of it. Simply remove it, clean the contacts with contactspray and re-attach them with a bit of vaseline to prevent them corroding in the future. Another cause could be a bad sensor in the block.
As for the lumpy idle we need to know of which engine we're talking about.

Thank you for your advice regarding the temperature guage, is it easy to access?
The engine is a 1.8 fuel injection, manual.
Thanks again.

[Paul240480]

Okay, (B20f will correct me if I'm wrong!). Mine is B18ft. Idle probs are notorious & I THINK the same for you.

First port of call is Idle Control Valve - Take a peek at this brill 'how to':

http://volvo480.dragons.org.uk/forum...ic.php?t=15569

If yours has a throttle position sensor, clean it up with contact cleaner & Vaseline, then refit.

You may have an engine temp sensor & an engine COOLANT temp sensor (mine does). The latter if dead can cause rough idle as it tells the ecu that the coolant is still cold (continously) so "give me more fule please" causing rich running etc..............

Good Luck

[B20F]

If it's not the B18U (monopoint)engine, then Paul480240 is right. If it's the B18U the setup of the idle controller is more complex. The idling in the B18U is controlled in a completely different way than that of the multipoint engines. The B18U doesn't have an external idle control valve, the idle control is integrated in the throttle body. I've got no experience on the B18U setup so can't give you advice on that one, sorry.

[volvo4me]

Originally Posted by Paul240480

Okay, (B20f will correct me if I'm wrong!). Mine is B18ft. Idle probs are notorious & I THINK the same for you.

First port of call is Idle Control Valve - Take a peek at this brill 'how to':

http://volvo480.dragons.org.uk/forum...ic.php?t=15569

If yours has a throttle position sensor, clean it up with contact cleaner & Vaseline, then refit.

You may have an engine temp sensor & an engine COOLANT temp sensor (mine does). The latter if dead can cause rough idle as it tells the ecu that the coolant is still cold (continously) so "give me more fule please" causing rich running etc..............

Good Luck

Thank you for the input Paul.

[bvs]

Just in case it is helpful for anybody with fuel/temp gauge problems...I did this job a few months ago('96 440), luckily had the help of an electrician at work who knew roughly how to do it.

Remove the instrument panel surround as described in chap 12.16 in the haynes comic but note you do not have to remove steering wheel (I put it at its lowest setting !).
The actual instrument unit is only held in by 2 screws on RHS of unit (pic2) and then carefully prised out towards you and to the right (the LHS is just 'slotted in').
Next you remove the 8x No10 torx screws and lift off the perspex cover,being very careful not to damage odometer zeroing shaft.
The fuel/temp gauge is held in place by 4 x 7mm nuts (the blurry ones in pic3 ),remove the 4 nuts and carefully pull/push gauges out(pic4)...caution do not lose the 4 brass spacers(you can see one in pic4) as these are the electrical connection to the printed circuit board !
You will now see the PCB...missing on my photos but you can see the connector holes for the six pins (just above the 2 top gauge mounting holes),the PCB just 'pulls out' from the six pin holes.
My PCB was very corroded so I changed that and the gauges as well(as a unit,i did not try breaking it down further)
Obviously the gauge/brass spacer/PCB connection has to be very clean for everything to work ok.

cheers baz

[veegard]

Thank you for your thread. I've been suspecting the temp gauge sender itself, but this seems like a much more logical step (although a more difficult one).
Not keen on changing any more components, except if it looks really **** back there. Was the pcb expensive?

[bvs]

Originally Posted by veegard

Thank you for your thread. I've been suspecting the temp gauge sender itself, but this seems like a much more logical step (although a more difficult one).
Not keen on changing any more components, except if it looks really **** back there. Was the pcb expensive?

Hi V
I was lucky to find an inst panel from a pristine 19,000 mile 440 (dont ask me why it was in the scrappy ) for £10.So i just took the relevant components from that,if I had a petrol car I would have been able to just bolt in the new one,but I believe that the rev counter is different on the diesel.
Of course you can never discount a sender/wiring fault.
good luck

cheers baz

[veegard]

Took off instrument panel, checked behind it. Looked very nice, just like new. Except the very thin cheap pcb film looked a bit crispy. But all my lights are working, and circuits seemed fine.
Ohmed both meters to 50 ohm, and since the gas tank meter works fine I suppose it's a good chanse the gauge is working.

Swapped thermostat, radiator cooling fan switch, engine block temp sender yesterday.
Went for a drive, it looked like it was working better than usual.. But can't really know until I've done several trips. It tend to not work after a couple of trips in a row, for some reason. But hopefully, once I fix the leak in the aeration screw in the T-section behind the engine, and a little leak i accidentally made in the radiator airing, I'm good to go!