Various bits n pieces!

[Ben Nichols 1979]

Hi all

Well dad's old car is now on the road and running well. There are however several issues which I could do with some help with. Any help is much appreciated!

Right, here goes!

1. When driving down from up t'north she ran at about 1/2 way up the temp gauge. Then after about 3 hours of driving at about 80-85 mph the temperature gauge started to creep up to the beginning of the red. It then sat there for about 30 minutes then crept up to about 1/3-1/2 into the red. Fortunately I made it home without drama. I am super paranoid about temperature as it was a failed flap that caused cylinder number 4 to overheat and the subsequent rebuild! Any suggestions?

2. The voltmeter is very erratic. I have tested the battery and that's all good, as is the alternator. The red dash light comes on when ever I turn anything on and the gauge drops to circa 10 volts from 12-13 volts. The worst culprits are braking and the indicators. When the indicators are on the voltmeter jumps at the same rate as the flashes. Any idea?

3. The dashboard lights (except the centre console) are very dim. Are these easily changed?

4. The internal fan does not work. There is a centrifugal fan in the engine bay that has one piece of ducting attached to the left side of the engine tin. There is nothing running to the right side of the engine tin. Is this meant to cool the exhausts? That's what I have been told......! The fan vanes are seized, is it an easy item to source?

5. There are quite a few leaks around the door to roof joins. Are seals easily sourced and easy to replace?

6. When the indicators are on both arrows flash on the dash, is that normal? Is there meant to be a cancel on the indicator lever?

7. The screen wash doesn't work. No noise, nothing. Are these easy to replace?

I think that's about it for now, I'm sure I'll think of something else!

Sorry for the length of this but we are new to this!

Thanks

Ben

[Darren C]

Welcome Ben.

Have you got an owners manual or Haynes?
Most of the answers are there, and very useful. I read mine cover to cover before even sitting in my car


1. When driving down from up t'north she ran at about 1/2 way up the temp gauge. Then after about 3 hours of driving at about 80-85 mph the temperature gauge started to creep up to the beginning of the red. It then sat there for about 30 minutes then crept up to about 1/3-1/2 into the red. Fortunately I made it home without drama. I am super paranoid about temperature as it was a failed flap that caused cylinder number 4 to overheat and the subsequent rebuild! Any suggestions?

I'm sure the flaps fail open, have you got a new thermostat, is it working, are the flaps free to move? If you have a bad engine earth then the resistance will increase on the cable from the temperature sender to gauge, causing false high temps on the gauge.

2. The voltmeter is very erratic. I have tested the battery and that's all good, as is the alternator. The red dash light comes on when ever I turn anything on and the gauge drops to circa 10 volts from 12-13 volts. The worst culprits are braking and the indicators. When the indicators are on the voltmeter jumps at the same rate as the flashes. Any idea?

How did you test the alternator?
Possible bad earth?
Is the alternator belt tight, is it charging?
Have you cleaned and checked the earth strap on the top rear of the gearbox?

3. The dashboard lights (except the centre console) are very dim. Are these easily changed?

Turn the light switch, its a variable resistor that dims/brightens the dash lights. Otherwise you've got some blown bulbs. OR its a common bad earth to the dash thats dimming the bulbs and giving you voltmeter issues.

4. The internal fan does not work. There is a centrifugal fan in the engine bay that has one piece of ducting attached to the left side of the engine tin. There is nothing running to the right side of the engine tin. Is this meant to cool the exhausts? That's what I have been told......! The fan vanes are seized, is it an easy item to source?

The fan in the engine bay works from the lever by the gear lever. Widely available new. You've most probably got a failed fan/speed controller in the fan housing under the wipers.

5. There are quite a few leaks around the door to roof joins. Are seals easily sourced and easy to replace?

Seals easy to replace, widely available, quality varies. If you can afford it buy once buy genuine Porsche.

6. When the indicators are on both arrows flash on the dash, is that normal? Is there meant to be a cancel on the indicator lever?

They flash from the a single output C on the flasher relay under the dash. There is a lever cancel ring screwed on the back of the steering wheel. If its not cancelling the rings either broken, screwed on out of place (3 screws) or the two little cams it strikes to cancel on the stalk switch are worn or broken.

7. The screen wash doesn't work. No noise, nothing. Are these easy to replace?

Have you got air pressure in the bottle (there's no pump, works off the spare tyre pressure)

Good luck

[Mr Pharmacist]

The dash gauges cab easily be pulled out of the binnacle to change the bulbs. Do you know that if you rotate the light switch that changes the brightness of the dash gauges. But mine dont get very bright at all.

The fan in the engine bay pushes cold air over the heat exchangers and then into the cabin - it is mixed on the way with child air from the front fan.

The rear fan is operated via the small lever on the tunnel between the seats.

Indicators - iirc newer relays operate both arrows on the dash dial for some reason.

Do you have a screen wash pump or is still operated via the spare wheel air pressure?

[Ben Nichols 1979]

Thanks Darren. I have got a Haynes, must read it!

I have no idea how to tell if the flaps are opening. I bought new ones and had them fitted. How can I tell if they open or not? I am not sure if he fitted a new thermostat. I will ask him.

I will see if i can get an auto electrician to have a play for a couple of hours.

I am in Southampton, maybe see you about. Not many down this way from what I have seen!

Ben

[Darren C]

Southampton!

Pop over if you get stuck I'll put the kettle on and take a look at the "faults"

I'd offer to visit you, but I'm not allowed to drive yet following my TIA which is a real pain in the a*se

PS You can see if the flaps are open (when hot) if the lever on the rod (where the thermostat cable attaches) to the left of the oil filler is in the upper position.
Check its position when cold, start car warm through (fully) and look again. It should move upwards when hot under spring tension as the thermostat expands.
The haynes shows you how to check the stat hot & cold. They normally fail expanded open (which fills the housing bracket)
There is a small link rod on one flap (oil cooler side) that unfortunately you cant see without peeking under the tinware. These rarely fail, but can be assembled incorrectly VERY easily if you've not done it before.

[Ben Nichols 1979]

The dash lights are brighter,a. Simple turn of the know. Thanks. Now for a more detailed look at the weekend.

The other thing is the speedo needle bounces around a fair but. Bad earth too?

Cheers

[Mr Pharmacist]

The speedo is mechanically driven so it's not a bad earth. Its a long cable so is probably sticking a bit? Is that long they I'm not sure it would be possible to lubricate it effectively. Worth trying though I suppose?

[Darren C]

As said before, the speedo is mechanical.

For it to jump means its either slipping or there is wear somewhere.

It can slip/jump if either end is not screwed in tight. This is a quick check. If they're are connected ok, then take off the cable end at the gearbox, (check the corners are not worn off the inner spinning part) put it in a drill and spin it on constant speed. If the speedo still jumps its the other end and at worst wear or sticking inside the speedo on the needle shaft (very common if the car has stood a long time & can sometimes rectify itself if used regularly)
If theres no jumping/sticking while being driven by the drill, its wear in your angle drive on the gearbox.

[Ben Nichols 1979]

Hi Darren

I had a fairly good weekend tinkering.

I had a play with the engine flaps manually. They seem to open manually but the spring is very tight and its a struggle to open them. Do you know how far up the temperature gauge they are supposed to open? I got it up to half way and nothing, it took ages to get half way!

I had an engineer friend of mine test the battery (all good) when running and engine off. The alternator was putting out 13.4 volts. I have checked the alternator belt, as far as I can and it seems tight. You can't twist it - think that's how you check the tightness (that's what I was told years ago anyway!) I wouldn't know where the earth is to check!

Dash lights are sorted - very easy thanks!

The engine bay ventilation fan doesn't work - I have opened another thread on that.

I think I know why the indicators don't cancel. Dan changed the steering wheel to a momo prototipo which I guess doesn't have the cancel ring!

Thanks

[914 KEV]

Hi Ben,

The voltmeter doesn’t have its own supply wire from the battery, it is taken off the supply wire to the brake light switch.
All normal when the voltmeter drops when the brakes are pressed and the lights are turned on as there will be a voltage drop on this supply wire when these items are switch on.

The warm up flaps are designed that if the cable snaps or the thermostat fails that they will always be in the hot normal running position.
The thermostat is fully expanded at around 65 degrees. The thermostat and the closing of the air guide flaps is to warm the engine quicker when cold. After a few minutes of running the flaps will be moving to the normal running open position.

To close the flaps the compressed thermostat pulls the cable that pull against the spring loaded flaps closed, the spring pulls them open when the thermostat expands.

The cable connector ridge is horizontal when the flaps are in the normal engine running position, when closed the cable connector ridge will towards the 10 o’clock position.
To check the operation disconnected the cable in the connector and push the connector down and it should spring up when you let go. Check that it isn’t sticking when it is moved very slowly!

Also check that you haven't got something like the engine bay insulation pad, or heater hose restricting the airflow in the impeller.

If this is all working fine you might find that the temperature gauge sending unit has been changed to the wrong one. The original is marked 200 degrees while the aftermarket one used with VDO gauges use a 150 degree sender.
The temperature gauge red mark was changed during the 74 model year from having a red mark starting around the 75% mark to the 95% mark.

[camperco]

"The cable connector ridge is horizontal when the flaps are in the normal engine running position, when closed the cable connector ridge will towards the 10 o’clock position."

Kev I think you mean vertical. If in any doubt disconnect the cable and rotate the part it was connected to towards the rear window. The spring coiled around the rod should be assisting you.

You can run without a thermostat but you cant run with the flaps closed or missing.

[914 KEV]

The cable connector ridge is horizontal when the flaps are in the normal engine running position, when closed the cable connector ridge will towards the 10 o’clock position.

Kev I think you mean vertical.

The ridge on the top of the clamp (the fold over part of the clamp) is horizontal when in the normal hot running position as it holds the cable, see the below photo.

[camperco]

Agreed Kev. Picture shows normal running position.

We've had buses in here with the flaps clamped shut and flaps missing altogether. The Aussies seem to like removing them, no doubt believing they will cool better, but in fact the oil cooler loses out on airflow.