Still Overheating! :(

[Richie-Van-GTi 70 2 Cars]

resistor is a cylinder type resistor normally clipped to rad or slam panel. the switch is fitted inside the rad just below the top hose.

If you need a new switch gsf do them cheapoer than pug and you can select it by the temp range. I run same as Anthony, lower temp switch. One thing to watch for is the pin configuration on the switch, theres 2 types, 3 pins in a row and 2 parralel pins with one running above the parallel pins.

[Guest myrichdad]

Thanks. Now found the switch.

 

Took plug off and shorted the connectors in all combinations but nothing happens.

 

This I would guess point to another problem.

 

After the wiring to the switch 3 wires go out from the switch to a brown connector. There is nothing after that connector. It looks from haynes like that should be wired to an earth. is that right and where does the other end of the connector come from??

 

HELP!

 

Thanks

[Anthony 1,000]

There is nothing plugged into that 5 pin connector - ignore it.

 

The earth is next to the passenger headlight - three (I think) green wires going onto a yellow connector. My guess is that this is your problem if shorting the pins on the fan switch connector did nothing.

 

Worth checking that you've a 12v feed from the black positive distribution block as well, as that's where the fan is powered from - there's a fuse for it in there as well.

[Pugnut 9 1 Cars]

its been said earlier in the topic and i'll say it again that the fan , rad switch , resistor etc have nothing to do with over heating at 70+ mph.

 

the problem is mechanical and being caused by the coolant not circulating the system properly. you may end up with a cooling fan that works as it should but the engine will still overheat at speed.

[Rob_the_Sparky 9]

its been said earlier in the topic and i'll say it again that the fan , rad switch , resistor etc have nothing to do with over heating at 70+ mph.

 

the problem is mechanical and being caused by the coolant not circulating the system properly. you may end up with a cooling fan that works as it should but the engine will still overheat at speed.

 

Ah but you assume that no one is hijacking the thread...

[Guest myrichdad]

Ah but you assume that no one is hijacking the thread...

 

Hijack - Guilty - do I get a reduced sentance for admition of guilt?

 

Will check mysterious black box and feed later on. Thanks for your help.

[stux 0]

Im still having some overheating issues. If you travel at a sustained 70 the temp guage climbs up to 3/4... and will increase further if you increase speed. As of yet i havent had the warning lamp come on - dont want to do any damage so stopped.

 

At the first place you should check the gauge and temp. sensor, perhaps the gauge is not calibrated properly (I had this problem after I took my gauges to pieces and then put them together) or the temp. sensor is broken.

1. unscrew your temp. sensor

2. put it into the boiling water and see if temp. gauge shows 100 deg. Celsius

[Pugnut 9 1 Cars]

Ah but you assume that no one is hijacking the thread...

 

i need glasses!!

[axnutty 10]

Thought I would update so far what I've managed to get done.

 

Ive replaced the rad fan switch - if its got nothing to do with it or not is a different matter - but it was faulty so needed doing... luck would have it though the one ive replaced it with must be faulty as now the fan comes on second stage only and wont turn off again for about 30mins after the car has been turned off. I did this with a laser temp guage too, and the rad temp was well below <60degrees with the fan still going strong... so must be a faulty switch. New one arrives Monday so we will see.

 

I also got a new temp sender for the guage. But im a little unsure of which sensor it is.

 

 

I found these down the back of the block below the distributer. Which one feeds the guage? I presume the other is for the ECU? Also whilst looking at these sensors theres a spare twin pin green rectangle type one left unfastened to anything. Just visible under the left hand top sensor. Whats that for?!

 

When I was using the laser temp guage I took some readings of what the car was running at and what the guage was showing. Pretty certain its actually the guage running a high reading now. But again, hopefully this weekend will reveal all.

[axnutty 10]

OK the sensor with orange wire is the coolant warning lamp sensor. Still no idea what the other ones are?

 

So where is the guage sensor exactly then? I presumed it would be one of the above but apparantly not. Ive found another two sensors on the SAD block under the distributer but cant see any more.

 

Also - if matters the cars a 89 1.6 GTi running a "later 309" 1.9 engine IIRC

[davev 1]

if im not mistaken your pic shows your temp warning light sensor, and your temp gauge sensor.

[steve@cornwall 100]

the un-connected sensor would seem to be the ecu temp sensor! As the car shouldn't run with this dis connected, I would assume that there is a collection of different phase parts around this area on your car and the sensor in the ph1 / 1.5 position is also installed and being used.

Not well phrased so this may be helpful here

 

http://forum.205gtidrivers.com/index.php?s...sender&st=0

 

No idea if this would give any issues at all.

 

My overheating 1.6 is about to be removed. I'm betting that there will be a blow in the h/g between cyls 1+2 with gas escaping into the waterways at high load. Should be interesting, as the symptoms are identical.

[Richie-Van-GTi 70 2 Cars]

that one that isnt connected is the ECU temp sesnor, check down around the SAD for another similar looking one connected (not the black one on the SAD). If there isnt one connected anywhere the car will be running rich.

[axnutty 10]

OK some further tinkering has shown the following. There is another sensor on the SAD housing facing towards the bulkhead... as shown (not best pic but you can see the HT leads for reference). This must be the ECU one as engine wont start unless its plugged in as stated.

 

 

I know the engine is from a later car so wouldnt be surprised to learn its a mix of pieces.

 

Now I removed the orange wire and ground this out - results in the warning lamp coming on. But the purple wire seems to do nothing! If I disconnect it it has no effect on the gauge... if I earth it -no effect again! So what is that doing? I presumed it would feed the gauge!

 

Is there any other place you could have a temp sensor?

[Duroc 2 1 Cars]

presumed it would feed the gauge!

 

Yes, it should.

 

If I disconnect it it has no effect on the gauge... if I earth it -no effect again

 

The sender works by increasing resistance to the earth it gives, the hotter the water gets. So when the water is cold, the earth is 'perfect' and the reading is zero. As the water temperature increases so does the resistance in the sender, and moves the needle up the scale. If you unplug it, then the circuit is broken and there will be no reading. I had problems with my gauge recently. To test the gauge I connected the wire to a spare low speed fan resistor, and earthed it from that, to check that the gauge worked. It did the trick.

 

I hope that makes sense!

[mark rushton 0]

dont mean to but in here,

heres what happened to me on friday , have just put my 1.6 gti back on the road after 2 years because of other cars and its been running hot especially when im doing high revs fan runs all the time, and i had to keep the heater on aswell, so took it to work for a run before pugfest next week . on the way home friday it was raining but really hot so i turned the heater to cold and a mile down the road the temp gauge went right up and the engine stop light came on so pulled over into a layby got out and the fan was on high speed . and when i tried to open the cap off the tank it blew hot water everywhere thought headgasket or worse so phoned the breakdown and took it home, was absolutely gutted, only a week to go and engines knackered so came on here saturday morning and read this thread , and saw that it could be the radiator, went out side and took one off my other gti as its only a year old , filled it up and went out not expecting to come home.

well just wanted to say cheers you lot you really know your gtis , as its now fixed doesnt get hot ,fan only comes on in traffic then goes off again, went to oulton park on sunday round trip of 120 miles , and did it with ease, well worth a try, really made my day thanks again lads.

[axnutty 10]

UPDATE - I got hold of a another new (this time working) fan switch and a new temp sender and fitted them. Now the guage still reads very hot, almost on the red itself if your pushing it, but the fan cuts in and out as it should. Later tests showed the fan was cutting in at the correct temperatures and that the engine itself wasnt overheating. (Done using 2 separate temp guages (one laser/one probe))

 

In short the dials themselves are reading too high.

 

Just a little unnerving though driving a long with the needle that high! Replacament set of dials on the way though - hopefully this will be the end of it.

[pug_ham 240 3 Cars]

In short the dials themselves are reading too high.

 

Just a little unnerving though driving a long with the needle that high! Replacament set of dials on the way though - hopefully this will be the end of it.

Charlie, the clocks haven't ha d a replacement set of white dials or similar fitted have they? If they have I woulldn't be surprise if the needles had been fitted in the wrong place.

 

Where do they sit in you current (old) clocks with the ignition switched off?

 

Graham.

[steve@cornwall 100]

Well, stripped the head off the CTI with same symptoms today......

As said, it's been run with neat water since the problem started - hence the colouring. Check out the pitting on the head around the waterway.

Remember, this ran fine if kept below 70mph

 

 

 

 

 

[lagonda 41]

Thought this had been hijacked, but seems back on track, almost!

Anyway, AXnutty .... as stated before, I've been experiencing same trouble as you, temperature increasing with speed. Well not any more! It's not the radiator, it's the thermostat. Took mine out and now I'm running too cold at speed, which is a really pleasant problem to have. To be honest I was worried my new head gasket had failed so I'm well chuffed.

Hope this helps.