924Board.org

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

the problem:

water pump is OK, thermostat is OK...just took them both out...
but i get no heat in the cabin...and the engine gets quite hot very fast !

I found sparkling metal shards and sand...i'm thinking that this is leftover from a previous owner trying to fix a leak in the heating/cooling system by pouring that "stop the leak" stuff you can buy.

i never could drive this car at hight speeds for long without the water temp climbing too high.

so...overheating...no heat in the cabin.....a bit of pressure builds in the expansion tank....water is missing from circuit.
no oil in the water, no water in the oil, exhaust smells normal...no sweet smell. i'm guessing the gasket didn't let go.

i started the car last week and the level of the water climbed up like something was clogging the tubes.
i wonder if that "stop the leak" stuff clogged something in the cooling system.

any ideeas?
_________________
Supercharger and EFI kits
https://www.the924.com

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

Maybe the cable that is connected to the "Heat"lever in the cockpit is dis-connected? Check under the hood close to the firewall if the water circuit is open.If not move lever by hand.

Nobbi
_________________
NA 924 - april/1977- 4-speed-audi gearbox.
500.000 km with fun.....and new toy:Porsche 944 S2 Cabriolet.Other car Daimler c-class cabby,brandnew..Plus : DEUTZ 4005 tractor Built 1967

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

thanks. i just checked, cable is ok.

i'm thinking that maybe some water passage is clogged and thats what causes this..but i don't want to risk running the engine with all the refreshments and a bigger turbo and have a broken head gasket....so..

i'm taking the head off next week. i have a Cometic multilayer head gasket that will replace the old one. i'm going to clean the water passages in the head and in the block with compressed air...also radiator and heating system
_________________
Supercharger and EFI kits
https://www.the924.com

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

Clogged radiator.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

924RACR · Posted: Sun Jan 16, 2011 3:41 am Post subject:

I would expect you'd get lots of heat in the cabin still, if the rad was clogged; the heater is basically a little radiator that's in parallel to the engine.

However, if the steel water transfer pipe on the side of the block (under the intake) is clogged - and I've seen some pretty rusty - that might just shut down about all cooling...

Should be easy to remove and check...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

Vaughan, thankyou !! that sounds like something i must check, because if i let the engine warm up..and it does warm up quite a bit...AFTER i shut it down i can hear water dribbling and flowing its way inside the engine.

PS: glad to see you replying to my posts, i thought i pissed you off with that high powered turbocharged engine debate a few weeks back

_________________
Supercharger and EFI kits
https://www.the924.com

924RACR · Posted: Sun Jan 16, 2011 4:04 am Post subject:

Dude, I haven't even had time to keep track of the stuff going on on the board these days!! I've been at work solid the last 2 weeks, 11-hr days, 6-day weeks... just got home and have time again to have a life. For a week. Then back at it... winter is our busy season...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Smoothie · Posted: Sun Jan 16, 2011 4:36 am Post subject:

I had the radiator-stop-leak clogged heater plumbing syndrome some years ago (long story here: http://www.924board.org/viewtopic.php?t=5584 ), but it only caused a no-heat situation. There was no engine overheating.
Your metal bits suggest a possible water pump problem..

The stop-leak stuff I'd flushed out of it was more like mud, with no sandy or metallic ingredients.
_________________
"..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

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

ManicCycle · Joined: 30 Sep 2009 Posts: 97 Location: earth

Drain system. Fill. Drain. Fill. Drain. Fill. Drain. Fill Drain.
Or you can back flush with a water hose. I forget the name of it but there is an effective and safe coolant flush chemical.

I've seen clogged heater cores fixed with a backwards flush out.

leadfoot · Posted: Sun Jan 16, 2011 10:05 am Post subject:

If the radiators clogged then the return line from it will be cold, you can feel where things are hot and cold pretty quickly after the thermostat opens up.

Also the heater switch for the cabin has to be open in order to bleed the system properly, assuming you know this already...

water pumps are stuffed when they start weeping water from the hole in the lower part of the casing, this is built into the design.
Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

jbwheele

This is a ridiculous thing, the water pump is sucking from rear to front (according to haynes) and it has to come through a small pipe at a T joint on the transfer pipe. Its fairy easy to remove mine is clogged also....you might have to get a bent scribe or long allen key and open it up again. Im doin a heater delete and running a larger tube from the rear housing to the transfer pipe , should suck better then. Good luck not finding it nearly or fully blocked, you should be able to blow through it easily .

_________________
Joe
82 932 Stripped bare full rebuild
80 932 GT Lookalike Engine S2 swap

MRPETE · Joined: 07 Nov 2010 Posts: 67 Location: CALGARY AB CANADA

It sounds like you may have a vapor lock.There is a screw (10 MM bolt)
on the front top point of the cooling system that goes to the rad.
Loosen it until all the air is gone.Let the engine cool down and do it again.
Keep your coolant full .
Air in the system makes things screwy.It may take a few attemps but see
what happens Pete
PS let me know I Had the same problem....Blown head gasket...cheeck Ideola he seems to know his #hit Pete
_________________
'77 924
"81 924
Lots o' Corvairs

Slam · Posted: Wed Jan 19, 2011 2:15 am Post subject:

The big question is, if there's air in the system, how did it get there? I'd do a compression check - cold and then hot. Go from there.

As disheartening as this may sound, it's nice to know a car as gorgeous as your has it Achilles' heel.

_________________
'88 944 Auto - may or may not resurrect