strange coolant problem stupid red light!

[Valsowners]

About 4 or 5 months ago Val (1.6 non turbo diesel - 1982) developed a strange fault. From a cold start upon turning the key the coolant light would flash as it should and then go out. About a mile later the light would start flashing again and the temp gauge would shoot up to maximum, then within 20-30 seconds it would stop flashing and the gauge would return to normal.

I have to admit I just thought Val was posessed. There was no chance that after a mile she was over heating so I just left it as it was.

On the way to Tatton (which was a very hot day) this problem changed now whenever we either stopped or were going slowly (like in the large queue to enter and leave Tatton ) the light was flashing away and the temp gauge was as far right as possible. However once we got moving at speed all was well the light stopped and the gauge returned to normal. This situation repeated itself all the way home, even if we only stopped at lights for a minute or so - the light flashed and gauge climbed, then as soon as we were underway all returned to normal.

I spoke to a few guys at the show (thanks ) who suggested the temp sender, gunk and the thermostat. I just wondered what other people thought? Has anyone else had this problem?

I'm taking Val to my dads now, before I set off I have checked the "gunk" situation. When I looked in the tank with the (blue) darlek cap the coolant is not at the brim - wiki seems to suggest it should be - am I reading that right?

Wiki also talks about the cap and how you shouldnt be able to blow or suck - is that the pipe or the cap?!? I have tried the blue cap and I can suck and blow through it - could this be the problem

I have tried searching previous posts but nothing seems to match this problem, thanks for your help guys and gals

[Aidan]

what's your battery charging like ? Could be bad earth, poor relay contact, low voltage, continuity fault ?

[mirams]

Blue cap sounds like a problem - you shouldn't be able to suck or blow through it (without high pressure opening the valve). Might not be the whole problem but certainly won't be helping!

[R0B]

its knacked if you can suck and blow through it.mirams is not quite right.you should be able to blow.but not suck through it.

I can suck and blow through it - could this be the problem

[andisnewsyncro]

If the dalek is past its best, the system won't be holding pressure. Get a new cap from Mr Baxter and then fill the tank to the brim, replace the cap and check the pressure in the pipes. You might benefit from bleeding the system once you have he new cap on, incase of any air locks in there if it's not been working properly for a while.
It might not be the root of the problem but it's probably the easiest & cheapest bit to change for starters. Then you'll be able to tell if there are any leaks or air getting in anywhere else

[mirams]

Ooops, says the same on the wiki though:

Header tank cap check

just something to check with the cap screwed tight on the bottle when the coolant is cold blow/suck on the take off pipe. you should not be able to blow into the system or suck out. if you can your cap is faulty it needs to seal so the coolant can pressurise and not boil! non sealing will cause fluid loss and so can cause the fault you have with no apparent coolant loss!

[R0B]

that needs changing on the wiki.its incorrect..

[Mocki]

i doubt its bad earth, wrong symptoms....

bad earth only makes the light flash, and it wont stop untill you turn the key off and reset it.
if it is bad earth it will do it when you brake, when you put extra drain on the alternator, like flashing headlights ect.

it coould be a bad temp sender, bad wiring from the temp sender or bad wiring at the dash tho..

but it sounds like it is working correctly and is airlocking...... its not low coolant level warning unless you have to turn the keuy off to re set it iirc

[windysurfer]

Did your rad fan come on when the gauge went to the right?

[Valsowners]

Did your rad fan come on when the gauge went to the right?

As we were driving at the time I'm not sure, but on our previous trip when we arrived home and turned off the engine I could clearly hear the fan going so I think it's working.

it could be a bad temp sender, bad wiring from the temp sender or bad wiring at the dash tho..

I'm going to nip and get some electrical contact cleaner and give everything a blast. After that where do I find the temp sender?? I know the coolant level thingy is in the header tank is it the same thing??

but it sounds like it is working correctly and is airlocking...... its not low coolant level warning unless you have to turn the keuy off to re set it iirc

Just to be a bit girly is airlocking a good or a bad thing??? Just checked again the level in the header tank is about 2 inches below the rim and the expansion tank is about on the minimum

I'm going to order a new dalek from Baxter tonight, we really need to sort this for run to the hills, do you think I should order anything else - cover all bases and all!!

[peasant]

Wouldn't a wonky water pump (i.e. not pumping at slow speeds) also cause these symptoms ?

[R0B]

air locking is not a good thing.and fill the header tank to the brim...

[SplendiferousII]

I seemto be suffering the same problem as you. My light cameon on Monday morning on start upand the needle went to full scale. After a coupe of miesit went out again and the needle dropped. This has happened before when ythe water level is low.problem is with mine I only filled the tank a couple of days prior and it hadnt done a great dea of miles since. I suspected a cracked head but now I am not so sure. I have changed the header tank cap (pressure cap) and that might have fixed it.cant be sure as I have not given it enough of a run yet. Off home to cornwall on Sunday and am towing so that'll highlight any real problems.

Mineis also a diesel n/a but now a 1.9.

Call me on 01452 863239 if you want to ask anything,but dont leave it too long as I have just opened a bottle of wine.

Treve

[R0B]

ah i see the confusion here.the wiki article is saying with the cap on the tank blow and suck down the pipe that connects both tanks.(if the tank is full you wouldnt be able to blow down it anyway)this is no way to test the dalek.it needs to be removed from the tank.and then sucked/blown down.

Ooops, says the same on the wiki though:

[AngeloEvs]

a short circuit across the gauge due to faulty connections at the coolant sender will also cause the LED to flash and the gauge to swing hard over to the right. Suspicious that it did this at start up so I would check the wiring at the sender connection for starters, the module 43 could cause this same problem if faulty.