924Board.org

[timstar92404]

Today I moved my car and ran it up the ramps under covers so I can work on it when it rains. while going up the ramps suddenly lots of coolant started running and spilling on the floor. Its from behind the engine , drips on the clutch bellhousing and also exhaust but I can't see where it is. It would drip slowly when the engine is not running but now it was really coming out. I didn't see any loose hoses in the back.

there is a hose which has a white screw on cap at the back of the engine I thought it may be coming out of the cap. obviously I can't get under the car when it is running and have boiling hot coolant spilling on my face.....

what else could be leaking from the back? heater core? not sure where that is located.

someone here said to remove the ignition coil to access those hoess so I'll do that tomorrow. I think it may be the screw on cap which may be leaking but it's on tight.
_________________
78 924 sold.
85.5 944

[leadfoot]

Ok Tim...
Here's the deal...
there is a problem spot at the back of the head in which all 924's will suffer from at some stage of their lives. There are multiple problems that can occur in this area but you can do them all at the same time and not have to worry about them for years ifd you do it right.
To save lots of time and anguish I suggest you do the following but I'll understand if you find another alternative.

When the engine is COLD:
Drain a little coolant from the bottom of the radiator, around two litres should do it.
There is a coolant flange on the back of the head installed with two bolts. Remove the two hose clamps and hoses from it. Remove the electrical connector underneath to the coolant temp sender.
Take out the two bolts and remove the flange.

IMPORTANT: If you dont do this you are wasting your own time...

1. Buy new lengths of hosing in the same diameter and length as the two you just removed.
2. Buy new hose clamps at the same time (at least 4)
3. buy a new coolant flange gasket and some liquid gasket


Check the coolant temp sensor for cracking around the plastic body as this has happened to me. Replace if broken, and install with a new copper crush washer after you've cleaned the flange (read next step).

Now clean the coolant flange with a wire brush but don't scratch up the mating surface that attaches to the head OK

apply liquid gasket to the flange hose connectors and to the flange gasket on both sides and bolt back in place. Attach the elctrical connector to the coolant sensor
attach the new hoses to the flange connectors. put the clamps onto the hose and screw tighten.
Remove the old hoses at the other end and THROW AWAY WITH the OLD CLAMPS...
wipe off the hose connections with a rag and apply some liquid gasket to the outside. Attach your new hose with the new clamps.
TOP UP THE COOLANT
If this doesn't fix it then your problem may be the heater valve: this is extremely unlikely though and you would see coolant dripping out of that valve as it is fairly accesible.
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[timstar92404]

I'll look in haynes so what you said makes more sense to me.

so it is most likely the coolant flange. what about the hose with the white cap I thought the cap may be leaking.

I'm probably going to have trouble finging the coolant flange gasket, internet sites are only US and shipping ot canada is really expensive for some reason.l

i don't have much time to work on the car so I just want to find the source of the leak and replace that.

what things do I have to remove first to access the coolant flange etc, do I need to remove the distributer/ coil etc?
_________________
78 924 sold.
85.5 944

[timstar92404]

I was hoping I could start driving my car soon because its been sitting for over a month now since my starter broke and I finally replaced that and now I have to fix leaking coolant.
_________________
78 924 sold.
85.5 944

[leadfoot]

Back of the head is a PITA to work on no matter what you remove, there are only two bolts so a 10mm small spanner works best , if you have a small enough ratchet this might work but from my experience I prefered using a combination ring/open ended spanner.
As for gaskets, you can buy sheets of gasket paper, you don't need to get the porsche part number, save that for the sensor if you need it- gasket paper is not that special for these types of parts that's why I said get some liquid gasket too and apply it as well, try talking to your mechanic, he'll probably just give you some if you ask nicely...
You only need a small piece so when you remove the flange measure it and cut out a new one to match the shape.
Just think if your going to fix it yourself, do it properly and it will last for ages.
Yes it's a fiddly job, you'll probably curse alot but it will be worth it...
BTW if the bolts are looking like the've seen better days it might be worth replacing them too, should be a standard M10 just measure the length.
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

[timstar92404]

ok thanks for the help.

yes alot of the things on the car frustrate me (probably due to the fact this is the first car I've tried working on) I've been really pissed off trying to figure out how to remove parts mostly because alot of things seem impossible to get too.

so if i remove the coolant flant and then it will be even harder to reinstall it when You just have to use your hands and can't see anything..... you could easily ruin the gasket and sealant because yo can't see where you are putting it. Probably need a bright light to see in there more easily.

there is an oil leak somwhere back there also, I'm guessing oil pressure sensor but it looks like its a little lower than the oil sensor as it wasn't oily around the sensor.

do you have to out gasket sealant on both sides of the gasket? would gasket sealant like the stuff you use for the water pump (I used blue permatex sealant) be okay?

would gasket paper be sold at parts stores like napa/ lordco?


last question when removing the coolant flange bolts and also the temp sensor I won't be able to use my big torque wrench in there and I'm worried that I'll overtighten the bolts/ sensor and strip the threads on the block. Is there some way to know how tight to make it by hand?
_________________
78 924 sold.
85.5 944

[leadfoot]

If you want to know for sure, top up your coolant with water and get a white rag and place it at the back of the head. Start the car and run for 30 secs/ a miniute keeping an eye on it for visual verification. If your rag comes out soaked then you've found the problem area. You may not need to start the car at all if you think it was dripping before it is pressurised.

So if you do want to take on the process of fixing the problem...
When you reinstall, put the top bolt in the flange and feel for the hole, when you get a couple of turns on (by hand) put in the bottom bolt and screw that one in... then using the bolts as a guide press on the flange.

If your worried about the oil pressure sender remove it and reinstall it with a new crush washer, this will be all it requires. Remember which connections came from where when you remove it.
Unfortunately the easiest process for finding oil leaks is by running a clean engine!! it is not possible for you to do this with the coolant problem so you will either have to guess where your problem is or fix the coolant flange isssue and work on it after.
Or as you suggested remove the distributor and drive housing and replace the gasket for this too.

I get the non hardening liquid gasket, I think it's a wurth product, suitable for a gasket replacement if you wanted to seal bare metals with nothing more. I just use it in conjuction with the paper. Not familiar with Lordco/Napa but it only takes a phonecall to find out...

As for tightening by hand, firm but not overtight, when you feel resistance as the bolt touches the flange you would probably only need an extra 1/2 turn, your right to be cfareful and if you take this approach you'll be fine.
Plus if your using a small spanner it's not that easy to get tremendous amounts of torque onto a bolt.
Leadfoot
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...