924Board.org

[gml]

Hi all. Noticed a ton of bubbling yesterday out of the crater/dimple of my coolant expansion tank while I let my 924 NA idle yesterday. It seems like the tank is cracked, probably inside that crater/dimple just behind the cap.

Is this something that can be repaired, and if so how? Or do I need to spring for an expensive replacement? Or, is there a different tank that is compatible? My worry sourcing on eBay is that those used tanks are also cracked or compromised.
_________________
George

1982 924 NA 5-speed

[924RACR]

You could consider upgrading to the 944 expansion tank? From what I remember, it requires as well replacing the main hose to the tank and the overflow (from the cap itself).

A little cheaper new, more likely to be intact as a used part (since it seems to be a better design, perhaps), and frees up a nice chunk of space under the hood as well...

I'm not aware of any options to repair, unless you were to maybe use a plastic welder gun and melt the material back together, perhaps cutting up a broken one to provide scrap material...

I have to deal with this on my racecar, and I think we'll likely be sticking with the stock/original tank design... did swap to the 944 style on the Turbo, for street use...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Raize]

Anyone know what material these are actually made from?

The 944 tank would interfere with the 924 NA air box and fuel supply line I think.

I have fibreglassed one and it held 1 bar full of boiling water as a test but I never tried to use it long term. These tanks swell up alarmingly when pressurised and soft due to being hot!

[gml]

It turns out that brand new ones are available, I contacted my local Porsche dealer and they're available at the Germany warehouse. PCG121405A is the new part number (028121405A being the original number in the parts catalogue). I don't actually think a 944 tank is much cheaper — maybe used ones are easier to find but I'd rather stick with OEM. Thanks for the suggestion though!

As expected they're pricey (around $380 CAD) so I think I'm going to hack it with JB Weld and avoid driving until I get all my problems sorted out, I've got one cooling fan that isn't running, a brand new water pump, and thermostat that I should install...
_________________
George

1982 924 NA 5-speed

[924RACR]

$380 CAN? Good God, I know the exchange rate isn't great right now, but you should tell your dealer to sharpen their pencils!!!

https://www.porscheatlantaperimeterparts.com/products/porsche/expansion-tank-RESERVOIR/3668982/028121405A.html?srsltid=AfmBOoqZ7cLBwsaM9nPXMb6KkTZt_DsBjV_e7waJGcMhbQ5gTouJCtzL

$200, or less, in the US at the dealer... just google the part #... even cheaper at Rose Passion:

https://www.rosepassion.com/en/pcg121405a-p5194-expansion-tank-028121405a-P5194
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[copeina]

Calgary 1978 owner here - check FB Marketplace for used. There are a few folks in BC and Ontario parting cars out presently.

I picked up a tank locally for $50 a couple of years ago. Felt steep at the time, but I guess it was a good price.

Hope that helps!
_________________
1978 924 NA Project

[gml]

Lazily misremembered, the correct price is $363 CAD all in from Porsche…

Or $200 USD ($275 CAD) plus shipping (~$20 CAD), import duties (every time I order from Pelican I end up shelling out $50 or so in duties… no idea what impact new tariffs would have) and whatever taxes. We’re being gouged up here either way. I saw the Rose Passion listing too, 182 GBP comes out to $284 CAD before everything…

Yeah I’ll have to keep an eye on FB Marketplace as well.
_________________
George

1982 924 NA 5-speed

[924RACR]

Bummer to hear all the add-ons... but OK, yeah, the match checks out... we don't I think get socked quite as hard with duties, but pay for it in the extravagant amount of time it seems to take US Customs to process and clear things. Not to mention some pretty bad handling of contents during inspection... we've had things go missing, much to our discontent...

It's gonna be fun when my new seat covers come from the UK in a month... that'll be a pricey customs bill for sure... if only I had a trip over there in a suitable time window...

I'm actually going to swap back to my old, beat-up but time-tested part this morning for racing this weekend, as the other I'd swapped in has a REALLY ugly-looking crack on it... and I think I likely will be ordering one of the new from dealer parts before long here, since we need a guaranteed reliable bit...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[copeina]

[924RACR]

Well, no great help to anyone else in the thread, but this thread ended up helping me, by providing the motivation to deal with the cracking tank on our racecar... found actually what turned out to be a very good condition spare in the parts stash and swapped it in - particularly after pressure testing the already-installed part to find it leaking around the cap neck...

Definitely feeling like the new stock part is worth it, unless you can luck out and stumble across a good spare old part like I did...

So, instead of fighting with cooling system problems all weekend... we fought with wiring/electrical gremlins!

If it ain't one thing...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Nobbi]

Hello,

the part was also available for the Volkswagen K 70 and the Audi RO 80.If it helps someone....

regards ,

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 1969