Dennis Burford

OK my son has brought his 84 944 (bought 3 months ago) home for a TB and WP replace, 'cause the previous mechanic was a hack and way over tensioned the TB. Yesterday, before his 6 hour ride up the state, ne noticed he was low on coolant. He added about a quart of coolant to the minimum mark on the reservoir and drove it home.

This morning I pop the hood and the reservoir is empty. So I add distilled water (figuring we'll be draining the coolant anyway)to the max mark and start the car and let it warm up. It sites there fine, the e-fans come on, and I pop the cap on the reservoir.A bunch of bubbles and the water disappears before our eyes, dropping well below the min mark.

I add more to the max mark, put the cap back on, leaving the car idle (idling just fine). The e-fans kick in again and the water starts disappearing again, down below the min mark, right in front of our eyes. Freakin' weird!!! No leaks, no puddles anywhere. And I figure it can't possibly be feeding that much water that fast through the combustion chambers or the engine would stall, or even fluid compression lock.

I filled again to the max mark and now it has remained steady, with no change for about 30 minutes. So far have put a little over half a gallon of water. Could it be possible that the system was never properly bled of air, and somehow we've managed to do that now?

Your thoughts are greatly appreciated. If a head gasket (I still don't see how that would be possible) I obviously want to know before I do a TB and WP.

Thanks,
Dennis

JohnKoaWood

Sometimes it is a pain to get ALL the air bled out.. and air pockets will cause overboard purge while driving (seen it a few times)..

The full system capacity is a touch below 2 gallons, so adding half a gallon isn't too bad..

YES it is entirely possible it was never properly bled, and has been purging overboard while driving leaving little to no evidence behind (follow the purge line from teh neck under the cap .. on both my cars it free hangs under the car.. an overboard p[urge from the overflow will go unseen!

krystar

yea totally possible it was never bled fully. keep on filling and bleeding it from the screw.

also turn the heater to full hot. get the heater core bled too

Dennis Burford

Thanks John, that's what I'm going with. 45 minutes now and no further coolant level change, no coolant in the oil, or vice versa, and absolutely no change to engine idle speed during the previous coolant drops. It's the only thing that makes sense.

Dennis Burford

Thanks Yuliang, Yep, did the heater too. OK, Now for some lunch, and then to go after the TB and WP. This is my first time at these (haven't done a TB on my 928 yet either) so I may be back in a separate post if I get stumped.

JohnKoaWood

If you managed to bleed the cooling system, I have a hard time believing you will get stumped by the TB or WP.. they are pretty much straigt forward!

tensioning on an early car... takes a bit, but isn't anything too difficult!