ZX: overheating: help still needed!

James.UK · Post by **James.UK** » 13 Mar 2004, 21:43

It sounds as though you have a blocked radiator, at the temp your car is reaching it should be very very hot from top to bottom.. So you still have no water circulating through it..
Maybe the new stat is faulty? or the wrong one for the car? try leaving it out and see if your rad gets hot? Pull the plug off the rad thermostat and short the plug out, that should kick your fans into life. If it doesn't then you may need a new thermostat as well.

TomH · Post by **TomH** » 13 Mar 2004, 21:50

Radiator isn't blocked because I emptied it and flushed it with a hose and it all came out of the bottom. Incidentally there wasn't a lot of coolant that came out, only a couple of litres perhaps, a lot less than I put in after!
I wasn't told at the time that the head gasket was replaced, but the receipt includes "new gasket set including bolts"...or are there other gaskets?
New thermostat works as I found out about the test putting it in boiling water... it opens. (so does the old one actually, ho-hum)

TomH · Post by **TomH** » 13 Mar 2004, 21:52

could there still be air in the system somewhere?

CITMAN · Post by **CITMAN** » 13 Mar 2004, 21:53

The headgasket must always be replaced when you lift the cylinder head on any engine. Just as a matter of interest did you use a header tank when refilling your zx with coolant.

TomH · Post by **TomH** » 13 Mar 2004, 21:55

makeshift lemonade bottle thing yeah. Had all the bleed screws open until coolant came out. The level rose back up into the header tank when I started the car and warmed it up, with quite a few bubbles coming up too

CITMAN · Post by **CITMAN** » 13 Mar 2004, 22:03

I think you should try a new radiator cap they are cheap as chips. You can get these from gsf, your local branch of halfords or any good car parts shop. Because as they get older the spring within the cap becomes weaker, and then allows the valve to open up at a lower pressure hence coolant loss and overheating due to air entering the system.

David W · Post by **David W** » 14 Mar 2004, 01:58

<<the temperature shot up again so I had to abandon it. (still no cooling fans or hot radiator.)
I also noticed that there is some oil bubbling and steaming/smoking out of a couple of places on the cylinder head (don't know what parts exactly by name, sorry!) which I wondered if it is related, plus a slight tapping noise I don't think I noticed before at higher revs (unless that is my imagination!)>>
Tom,
This could be quite serious given your above comments. It may be the time to stop trying to sort it with forum help and get it back to the guys who did the head.
It does sound like you've bled it through OK so it is quite likely the lack of a warm rad and fans on is the result of combustion gasses from the head/gasket producing an airlock at the thermostat housing area.
These heads will not stand constant boiling events like this.
David

CITMAN · Post by **CITMAN** » 14 Mar 2004, 02:45

I AGREE. GET DOWN THE GARAGE ASAP

TomH · Post by **TomH** » 16 Mar 2004, 22:58

yup, I think it could be the head gasket... did the test I read about on here where running the engine for 30 secs from cold is really pressurising the cooling system. It was on minimum level at cold where I topped it up on saturday before a test run, and following the start up rose to the top when I undid the cap again, lots of bubbling.
Have phoned the guy to look at it on friday, but I don't know where I stand really if he botched it up last time because it shouldn't fail after 2000 miles, right? He's only a backstreet mechanic who I went to because my parents use him and seem to rate him...
Its a very sick car. May have to take up the offer of the free low mileage Astra mk3 I have been offered. Oh dear!

CITMAN · Post by **CITMAN** » 17 Mar 2004, 01:11

get it sorted, because if its done properly the car should be reliable. Its the mechanics fault for not doing the job right in the first place.

zxspare · Post by **zxspare** » 25 Sep 2005, 01:44

does anyone know where the coolant bleed screw is located on a ,94 ZX Aura petrol 1.4 L engine ??!

citronut · Post by **citronut** » 25 Sep 2005, 01:56

did the level rise up into the tank as soon as you started the engine whilst it was stone cold,if it did you have most certainly got head gasket gone
regards malcolm

jeremy · Post by **jeremy** » 25 Sep 2005, 18:11

zxspare - you are much more likely to get the answer you want on a fresh thread rather than at the bottom of an old one dealing with boiling engines.
jeremy

Simon Canfer · Post by **Simon Canfer** » 25 Sep 2005, 18:42

Every Citroen diesel owner becomes a cooling system expert, given time!!!
Simon
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by TomH</i>

To be honest I know little very about the cooling system etc... I've never done anything under the bonnet myself apart from check levels/ top up etc
It did have a new gasket in December when the cylinder head had to come off and be sent away to remove a broken glow plug, but I've done less than 2000 miles since then.
Have to get myself a Haynes and look at the radiator then!
I'll see how it behaves later!
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Post by **Peter.N.** » 25 Sep 2005, 18:59

Oil bubbling on the head can only be caused by a complete lack of water in the head, the temperature wouldn't get high enough to do that if there was water in it. These heads are notoriously difficult to bleed and unfortunatly if they are not full of water the head gasket will fail again as may well the head casting.