Faulty Needle

[dp_essex]

Hi guys..... I have been visiting this site quite a bit over the last few weeks and i would like to say thanks for all the useful info posted by the members.

 

my problem is this.... i have a 1998 2.3 petrol, automatic Galaxy that seems to overheat when in slow traffic. normally the temp. gauge is in the middle but if i have to crawl for more than a couple of minutes the needle quickly rises into the red, and then the fan decides to come on and the needle drops back to the high end of the scale, and this repeats (sometimes with the red warning light flashing as well) until i get moving again, and then the needle moves back into the middle of 'normal'.

 

I took it to the ford dealer who said they tested the thermostat and it was working properly, and the fan was coming on when it should, but that the needle on the instrument panel was at fault and 'reading high'. They said it would mean a new instrument panel.. about

[bigdaddy]

Could be a faulty needle,,,,,,,mine goes to the O on norm at normal running and goes up to the M when in traffic then the fans come on and it goes back to the O,,,,,,,would not do any harm to change the temp sensor,,,

[MadBaz]

Temp gauge should be available from VW if ford wont supply it, My local VW dealer insist he can get most components unlike ford who prefer to change a whole unit. It is relatively easy to change, no more than an hours work.

 

I'd be suspecting sender/sensor though first.

[Dave-G]

Hi DP, Did this first occur during the recent freezeing temperatures?

[dp_essex]

First off.... thanks MadBaz and Big Daddy for your replies... i will definitely look into changing the sensor unit.

 

Dave G.... in answer to your question, no.... it has been like it for quite some time now. In fact, the problem doesn't really show up in the winter months when the outside temperature is nice and cold... it's about this time of year when it starts to get milder (supposedly) that it happens, and goes through the summer like it. Maybe the dealer is telling the truth about the needle...?

 

 

 

 

Hi DP, Did this first occur during the recent freezeing temperatures?

[mumble_bee]

hi dp,

 

I've had my 2.3 mk1 for over a year now, and only a few months ago noticed this behaviour too,

mine also sits around the O in normal driving and gets up to about the R in traffic, then the fans kick in...

 

after testing everything I finally decided it was the temperature switch that was faulty, and quickly changed that... no difference.....(

[dp_essex]

Thanks for the info Mumble Bee.....

 

it sounds like we have the same type of thing, and like you said, as it's not actually overheating you can live with it but it does get a bit worrying... especially when the scary little red light starts flashing!

 

After reading the replies I have looked around to see how to change the temperature sensor... but I am not sure if there are 3 of them on my model (mk 1, 2.3 petrol) as some of the posts mention this but you can't always tell what model they have. i have read that there is a sensor for 1) the temp. gauge 2) the coolant (both on the thermostat housing) 3) a thermal fan siwtch on the rad itself. If anyone knows what one i should be swapping and where to find it, please let me know. i just need the fan to kick in before it gets to the red.... it would make things a lot more relaxing, I am nearly out of fingernails.

 

Also, am i right in thinking that the stat on my model looks like a T shaped plastic housing with 3 large pipes connected to it?

[mumble_bee]

ayup dp,

 

(the below is speculation on my unmechanicfied part)

 

the temp switch on the rad, I think is to actually engage the fans.. so if your fans are coming on at all, then I think you wont have to change that..(I'm changing this on my 2.8v6 as the fans arent coming on at all.... will let you know tomorrow if you want)

the temp switch behind the stat is the one I changed that my mechanic suggested.. (which made no difference), what that does apparently is "guage" the temperature, and send the kick in request to the fans... dunno about the 3rd.

 

I dont think the stat is at the T, I think its closer to the main engine block where if you're looking at the engine face on.. its in the big fat pipe that comes out to your right and leads down to the T section near the front..

 

pls pls, I'm just mentioning what my mechanic says.. and speculating.. so dont kill me if I've said anything wrong.. well ok kill me then.

[MadBaz]

Thanks for the info Mumble Bee.....

 

it sounds like we have the same type of thing, and like you said, as it's not actually overheating you can live with it but it does get a bit worrying... especially when the scary little red light starts flashing!

 

After reading the replies I have looked around to see how to change the temperature sensor... but I am not sure if there are 3 of them on my model (mk 1, 2.3 petrol) as some of the posts mention this but you can't always tell what model they have. i have read that there is a sensor for 1) the temp. gauge 2) the coolant (both on the thermostat housing) 3) a thermal fan siwtch on the rad itself. If anyone knows what one i should be swapping and where to find it, please let me know. i just need the fan to kick in before it gets to the red.... it would make things a lot more relaxing, I am nearly out of fingernails.

 

Also, am i right in thinking that the stat on my model looks like a T shaped plastic housing with 3 large pipes connected to it?

 

Had a look in haynes comic and tis, both a bit vague but here goes:

Temp gauge sender on all petrol models should be on the underside of the thermostat/coolant outlet housing on the n/s of the cylinder block, where two sensors are fittedthe lower one is the temp sender, the upper is for the ECM don't connect anything to this one, ie multimeter, the ecm controls the fans on the 2.3.

According to tis it should have a white/red wire connected to it, doesn't show it on haynes wiring diags but don't take this as gospel.

 

the sender decreases its resistance to electric current as the temp rises.

When coolant temp cold, sender sends small current, Temp gauge = low/cold

when coolant temp is hot, sender sends more current, Temp gauge rises

 

Hope this helps, clear as mud to me B)

Edited March 20, 2007 by MADBAZ

[dp_essex]

Madbaz and Mumblebee..... thanks for your help, you've certainly made things a lot clearer and i will get out there and have a go.... as soon as it warms up a bit! I'll let you know how i get on.....

 

Cheers

[dp_essex]

ok.... i went out and tried to find the coolant temp. sensor today but i am not sure if i have got the right bit. I am looking where Madbaz said and i think i can see it but would like to confirm it. i have taken a photo but i can't find out how to post it to this site.... can anyone tell me how to do this? there a couple of posts with pictures that show the temp sensor but they are for the Tdi.... nothing for the 2.3

 

what's confusing me is that i have a print out from a friend that says to change the temp sensor you must raise the vehicle and remove the engine undershield... but the bit i am looking at is easily accessible from the top of the engine bay...? If i could post the photo maybe someone could shed some light on it...

[MadBaz]

Message from dp

 

what do you reckon.... is it the nut type thing with the gray connector, and if it is, do you know how it comes off 'cos i tried and i couldn't budge it!

dp.bmp

 

Dp that looks like the one , it should undo using appropiate spanner, but it will be a tough nut to crack (sorry, couldn't resist) the coolant will drain out of hole so be prepared for spillage and topping up when replaced.

[Guest T120]

Greetings

If you have access to a Vag Com go on the instrument check it will check the needle on the temp gauge it zeros, spans and checks the mid point of the gauge, if this is ok its the sender if not its the gauge.

Speak to you soon.

T120

[dp_essex]

First off, thanks Madbaz for posting that photo for me, and you reckon it's the right bit? I'll get down to the dealers and order one then.... i'll probably have to wait a week for it as they never sem to have any galaxy spares in - always a 'special order'.

when i said about how do you get it off, i actually meant the grey connector on top....i think it's been welded on! Thanks once again for all the help.

 

T120.... thanks for the info about vag com... i am afraid i don't know anyone who's got it but i'll change the temp. sensor and see how it goes (shouldn't be too expensive...?)

 

ps... mumble bee, if you are reading this, how did you get on with changing the temp switch on your rad..... any luck?

[MadBaz]

Duh, sorry dp_essex, Thats defo the sender, don't know how to get connector off though, last one I changed was on a series landrover and that had a capillery tube, not one of these new fangled leccy thingamibobs.

 

just a word of warning though it might not be the sender causing probs

 

Let us know how you get on mate.

[dp_essex]

will do mate.... and if i can't get it off i will take a leaf out of your book and get a bigger hammer.

[MadBaz]

will do mate.... and if i can't get it off i will take a leaf out of your book and get a bigger hammer.

 

 

Just don't go too far or you'll be doing last line of my sig :lol: