924Board.org

johnathan1 · Joined: 08 Oct 2007 Posts: 308 Location: Downey, Ca

I just bought my 924 about a month ago...and it seems like the more I drive it, the more problems I encounter...

First, it's overheating problems...I just replaced the water pump, as it sounded like it had rocks for a bearing, that went smoothly and I took it out for some real driving finally... Generally, the gauge seems to stay around the 1/3-2/3 mark... but tonight a couple of times the gauge went almost to the red while cruising at about 70MPH. Then it will go back down after a while. When coming to a stop or sitting in traffic, or even at idle for a prolonged period of time, it goes close to the red. Fan seems to be blowing, but isn't very loud, and doesn't really seem to be moving much air. Also after I shut down the motor, the gauge will jump all the way into the red. Cooling system has no leaks.

Seems like if I keep RPMs low, and speed around 50-60 and it is cool out, the gauge stays @ 1/3...but seems to heat up when driven harder, or if it is a warm day.

I should also say that the engine doesn't really seem to be abnormally hot when the gauge says it is...there is no coolant bubbling out of the overflow at all. Also, the fan seems to turn on three or four times sporadically after shutting the car down... Stays on for a few minutes each time.

Second problem...well, I'm not sure if it's a problem or not...When I turn the key to the "On" position, I hear the fuel pump whirr for a few seconds and shut off. But if I leave the key in the "On" position for a while, I will hear the fuel pump turn on and off sporadically a few times in a row. It will flash on and off only for a second or two each time...

Any ideas? Also, the pump seems to work fine, as the car never stalls and seems to run smoothly.

Third problem: Now that I have replaced my water pump, and I no longer hear it rumbling away...it has made another noise more apparent...I am now noticing a whining sound that gets higher pitched with increased RPMs, and changes tone when I switch on electrical devices...like the headlights make the biggest change in sound. It seems to be coming from the front of the engine, but I couldn't pinpoint where exactly it was coming from... But the fact that it changes pitch when the headlights are turned on leads me to believe that it may be the alternator? Oh, and my gauges seem to jump around a bit when I switch the headlights on.

Fourth problem: All of the lights on the driver's side of my car seem to have stopped working...(running lights and side markers) indicators still work fine, as does the headlight.

Fifth problem: My windshield wipers aren't working at all...I checked the fuses, and the wiper fuse was melted pretty badly...so I replaced the fuse, and now I hear a relay clicking on and off repeatedly...but the fuse doesn't blow...

Sixth Problem: My heater doesn't seem to work at all...the blower is blowing air, but when I move the temperature control over the warm side, the lever kind of moves back to the center, and the temp of the air doesn't change at all...just feels like fresh air blowing in at all times...

Thanks for your time, and thank you for reading this super long post lol. This seems to be a great Porsche, but it just needs some tender loving care.

Any help is appreciated!

_________________
-1977 924, 4-Spd...Gone
-1987 Toyota Supra Turbo, Pearl White, BPU, 300RWHP @ 10psi.
-1989 Mercedes-Benz 300SEL

WARNING: MAY CONTAIN TRACES OF AUDI OR VW!

Nobbi · Joined: 24 Aug 2006 Posts: 1398 Location: Germany

wow, along one......

some things in youre list are common to most of us...like the unusual sound from the fuel pump.Even the owners in 1977 were alerted, but (the noise) it`s normal.Sometimes its there,sometimes not.My car is doing that since i own the car (18Years).

The heating problem is unusal.After a long ride on a hot day the fan is turning on 2 times (when parked) for a minute or so.Thats it.My temp.gauge is never going over 50% because thats the point were the fan is kicking in.(Never reached during normal driving).
I wouldt check the spark-plugs,how do they look? If they are a kind of grey and the contact is burned down i wouldt say your ignition is to early and the engine in general is running hot.Check ignition timing, vacuum hose of, 10 before TDC. How is the engine idling?
Another thing could be your cooling system,did you bleed the air out of the system( open that red marked bleeder screw thing) That could also help a lot.!?
The heater switch on your car isnt working,cable bend or broken.You can open that valve close to the fire wall with your hands before starting the car, this is recommended when bleeding the air ou of the cooling system.

so, thats what i thing for the moment.Good luck and dont worry to much...
Nobbi

steeny · Posted: Fri Oct 26, 2007 8:28 pm Post subject:

check all the electrical ground points and clean them. rewire the alternator/starter circuit back to the three prong plug up above the brake booster and wrap it all in heat resistant tape. pull the windscreen wiper motor and see if its seized. make sure the battery tray is not rusted and allowing water to drip on the fusebox.

in general, most of the electrical gremlins will go away with that treatment. the rewiring of the starter/alternator is not absolutely necessary, but they are both in a bad spot, so it cant hurt.

as for the overheating, i'm stuck on that one. perhaps its electrical problems too.
_________________
1978 924 N/A
she's gone.....

Smoothie · Posted: Fri Oct 26, 2007 11:52 pm Post subject:

Your third problem is with the alternator belt and/or alt mount bushings. It's not tensioned enough. And often the bushings are overdue for replacement on the 924NA, which leaves the alternator crooked and the belt out of alignment.
Your belt should be a "9.5mm x 888 LA without teeth" according to the specs. '81-up uses the same size, but "with teeth"(, but I can't imagine the with/without teeth issue being too important).
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

You may have a clogged radiator. . .if you pop it out a radiator shop can flow test it, and may be able to flush/clean it for you.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Ozzie · Posted: Sat Oct 27, 2007 12:09 am Post subject:

IIRC the later models had a smaller pulley on the alt which increased its volts at idle. hence the need for a different belt.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

!tom · Posted: Sat Oct 27, 2007 2:11 am Post subject:

Overheating could be caused by a number of issues.

Obvious ones are low coolant (due to not completely bleeding the system after filling up -- it necessitates removal of that red plug as mentioned above).

Could be a bad thermostat.

However, the fact that your fan turns on means the coolant in the radiator is getting up to temperature, and the level is above the temperature switch. So, maybe the problem is something else.

This leaves generating too much heat in the first place (Nobbi's idea), or maybe poor cooling of the radiator.

This could be caused by the fan, but the fan only really helps to cool the radiator in stop and go traffic or when not moving at all. The forward motion of your car provides the majority of the cooling, and when you're cruising around 70 MPH, you should have loads of cooling. So, the fan as a culprit is unlikely.

This suggests instead there may be a blockage of air flow through the radiator. Perhaps your A/C condensor is restricting air flow through your radiator.

Lots of possibilities.
_________________
78 924 NA
5-lug

!tom · Posted: Sat Oct 27, 2007 2:14 am Post subject:

Smoothie · Posted: Sat Oct 27, 2007 4:32 am Post subject:

johnathan1 · Joined: 08 Oct 2007 Posts: 308 Location: Downey, Ca

WOW! Thanks for all of the help guys!!

Steeny: Where are all of the major chassis ground points? I don't have a wiring diagram for this car.

Smoothie:

Right, that makes sense, since it just started making this noise after removing the belt to change the water pump...it has a toothed belt on it, but it wasn't making any noise before with that belt...how exactly do I tension it? Does the whining mean it's too tight, or too loose? When I changed the water pump, I just unbolted the V-shaped bracket that connects the alt. to the water pump.

Rasta: Thanks for the reply...I think I am going to take it to my local radiator guy and have him check the radiator, possibly clean it out...I noticed some sediment floating around in my brand new expansion tank.

Ozzie: I am guessing since my car is an earlier model, it doesn't have the alternator you are referring to? So that would mean a toothed belt will work okay?

!tom: How can I check for a bad thermostat? I read in another thread that if you get heat through the heater vents, that means that the thermostat has opened?

And I pulled the bleed screw, and put it back in when coolant started flowing out of it.

Also, the temp. seems to be okay when cruising...it heats up alfter a while in stop and go traffic, and will even dip into the red when idling after running on the freeway.
_________________
-1977 924, 4-Spd...Gone
-1987 Toyota Supra Turbo, Pearl White, BPU, 300RWHP @ 10psi.
-1989 Mercedes-Benz 300SEL

WARNING: MAY CONTAIN TRACES OF AUDI OR VW!

Ozzie · Posted: Sat Oct 27, 2007 8:19 am Post subject:

A toothed belt is ok for both.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Lizard · Posted: Sat Oct 27, 2007 8:38 am Post subject:

regarding your overheating issue,

the way the fans are wired in these cars is that when the key is off the fans run at about 1/2 steam, I think it is possible that the ign switch isnt turning on the bypass relay and the fans arent getting full power.
_________________
3 928s,

!tom · Posted: Sat Oct 27, 2007 9:01 am Post subject:

johnathan1 · Joined: 08 Oct 2007 Posts: 308 Location: Downey, Ca

Awesome info! But my car only has one fan... :[

I was under the impression that the fan only ran at one speed? Where is this relay located?

I also just ran the car a bit around town...and when I put my handd on the lower part of the radiator, it feels cooler than the upper portion...not COLD, but the top of the rad was hot enough that it hurt to touch it, and bottome was warm but not to the burning point...not sure if that is normal or not...
_________________
-1977 924, 4-Spd...Gone
-1987 Toyota Supra Turbo, Pearl White, BPU, 300RWHP @ 10psi.
-1989 Mercedes-Benz 300SEL

WARNING: MAY CONTAIN TRACES OF AUDI OR VW!

Ozzie · Posted: Sat Oct 27, 2007 11:29 am Post subject:

That sounds like a thermosat problem.
maybe u/s or removed or wrong one fitted.
These cars need the correct type fitted always. Removing them causes problems.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance