Temperature issues, please help 2.016v

[renson 0]

After searching i have found plenty of info but not all that i need.

 

Car started getting a lot hotter than usual after this recent cold snap, It started when i left the car running to demist the windows. The water temp light started flashing. (this has only happened once before a few summers back when i had a wiring issue with the fan). I assumed that the thermostat had failed as the top hose was hot and the bottom wasn't once it was up to temp.

 

After replacing the thermostat, the same thing was happening unless i took the car for a spin then both hoses were hot.

 

I also noticed that the fan was only coming on at the last stage (110?) so i changed the radiator fan switch also.

 

Now the fan comes on at both speeds around where you would expect looking at the dash but it is still running hot.

 

Driving the car at a normal 60 its hovering around 100 water and 120 oil but if i sit and wait it climbs to around 110/130 with the fan going at full chat. (This also happened tonight and its only about 2 degrees outside)

 

The heaters are working, i am losing no coolant and there are no signs of the head gasket failing. I haven't 'overheated' and broken down with steam billowing out but i'm worried i will.

 

I am assuming that the water pump has packed in and it is not circulating properly unless it is revving high (could this explain why the thermostat is only opening when driving?).

 

How hard is changing the water pump? Is it slam panel and everything off? Or quickly whip off the alternator and power steering pump for access job?

 

Any ideas would be great, pictures even better if there is a guide to changing the water pump.

 

Thanks in advance,

 

Darren

[davidwort 0]

Water pump isn't too bad, only pas pump and alt has to come off nothing else, the only issue can be the mounting bolts of the alternator bracket that go through the pump into the block, be careful none snap I have seen that happen on one, and fit a new stat and do it with the new pump off the car a lot easier.

the pas bolts aren't always immediately obvious, I did have a thread/guide to this somewhere

[renson 0]

thanks for that :) i changed the stat a few days ago, removing the pas pump wasn't too bad and the after buying 3 faulty alternators from a national motor factor i've become a dab hand a changing them. i@m going to bleed the system again in a bit in the hope that it cures itself............. if not then its pump and probable radiator change this weekend or next :(

 

out of interest, i've had my car for 6 years and its always had the black cap on the coolant tank, whats with the blue ones people change to?

 

---------- Post added at 4:31 PM ---------- Previous post was at 3:08 PM ----------

 

Right, so i have been outside for 40mins with the car from running from cold. Put the heating on full and started it up.

 

Removed the radiator cap and got it up to temperature. its sitting round 90 water and 110-112 oil. The radiator is nice and hot and both pipes are warm too. I couldn't get it hot enough for the first stage fan to even cut in.

 

I am assuming then, with the failure of the fan switch and thermostat that whilst changing i must have caused an air lock somewhere that has now cleared.

 

does this seem like it could be the culprit?

 

I shall monitor the temps for a while and see what happens

[robrado974 1]

I would think about changing the temp senders first , having said that do valvers have three temp senders ,the same as vr's ?. just a thought .

[renson 0]

Temp Sender? For the dash reading?

[davidwort 0]

16v's have sensors on the side of the head for the dash, ecu, idle control, 2 or 3 are the same, may vary from 1.8 to 2.0.

putting the heating on full in the car makes no difference :) it's just a flap in the dashboard.

Can get blockages in rads, not always air, but it can be hard to get air locks out sometimes, you need to fill slowly from header tank and check the volume you put in.

blue tank cap is just a revised part, black ones can in theory not release pressure correctly but I've never com across a problem one, plenty of original black news in use :)

[renson 0]

http://www.vwspares.co.uk/product_info.php?products_id=735

 

is this the correct part for the gauge reading?

 

---------- Post added at 10:07 PM ---------- Previous post was at 10:03 PM ----------

 

Or these??

 

http://www.gsfcarparts.com/parts/cooling-heating/cooling-system/coolant-temperature-sensor

[davidwort 0]

Yeah, the small sensor, black top, original ones have a flat spade connector, those ones look more like the little oil temp sensor on the back of the head but it does say coolant on the gsf site. The 1.8 has 3 identical ones around the water outlet on the head, think the 2l has two the same and one with the rectangular 2pin connector.

[Grim1 1]

We had a problem with ours whereby it kept getting up to and running at 112 degrees. Turned out to be the radiator fan temperature sensor. Fitted a new one, now runs nicely between 105-108 degrees (and that's a tuned 2.0 16v).

The sensor isn't expensive, and is simple to fit.

[davidwort 0]

just to clarify, the 1pin black sensors on the side of the head are for the idle stabiliser and coolant gauge and are 049 919 501 (0-125 deg C)

[robrado974 1]

A little but important tip . Dont forget to check when you remove the old sensers that the rubber 'o' ring comes out as well . Its an easy mistake to make . I know someone thats an ex vw mechanic and he has seen it done at work . I left one in ,all was well till it got up to temp and the pressure blew it straight out of the housing , coolant everywhere and stranded till someone came out with water and new coolant !. Rob