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        General >> Give/Need advice to/from others >> Overheating 1994 Scoprio 2.0i DOHC
        
(Message started by: meeko on Nov 5^th, 2008, 12:04am)

Title: Overheating 1994 Scoprio 2.0i DOHC
Post by meeko on Nov 5^th, 2008, 12:04am

Hi,

My Scorpio overheated on the weekend so much so that it was towed home (it was mis firing badly and kept spewing coolant through expansion cap). They suspected a head gasket, but I think it's due to an airlock in the cooling system. After it totally cooled, it ran fine, but the heater never seems to get hot (it's always been like this, but worse lately after thermostat change).

I've confirmed the matrix and rad aren't blocked, and have now removed the thermostat. After topping back up with coolant (it took over 3 litres, and I noticed the rad was nearly empty) it didn't overheat but the heater only gets slightly warm, followed by getting cold, and warming up again. There are no leaks in the system.

Does anyone know how to remove airlocks? The Haynes manual doesn't tell you much...

Thanks in advance,

Steve

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by Jonnycab on Nov 5^th, 2008, 1:40am

Do you know if the water pump is working okay ?..... if so & you are certain that the heater matrix isn't blocked or restricted then the following procedure works wonders for getting airlocks out :D......

1) Pull the small hose off the expansion tank that goes to the large top hose.

2) Insert a piece of transparent pipe (the same diameter of the small expansion hose & about 3 feet long) into the small expansion hose & attach the other end as high up as it will go, i.e...top of bonnet.

3) Then start engine & wait for it to warm up properly.

4) When the engine is hot then give it a few revs & you will see the water rise up the pipe. If there is an airlock then the water will be followed by air pockets.

5) Once all the air pockets seem to have dispersed, then switch off the engine & wait for a couple of minutes to see if anymore air in the system makes it's way out on it's own. If you want, you can repeat the procedure, just to make sure.

6) Once you are happy that no more air is in the system then replace the small hose & top up the tank.

The whole procedure takes about 20 minutes & hopefully it will sort the problem out :)

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by meeko on Nov 5^th, 2008, 11:03am

Hi,

Thanks for the tip! I presume the water pump is working? Do you know how I'd check this?

The small hose conencted to the expansion tank doesn't conenct to the top hose - it connects to the thermostat housing. I presume your method will still work?

When I checked the matrix, I blew all of the water out to confirm there was no blockage. Will this method allow water to fill the matrix again? (Or do you have to manually fill it as some people suggest?)

Many thanks - much appreciated.

Steve

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by Jonnycab on Nov 5^th, 2008, 12:20pm

The method should still work, give it a try ;)

When filling, according to the Haynes manual, on your model Granada you may or may not have a bleed spigot screw on the T-stat housing. If you do then open it up & close it when coolant starts coming out, if you don't then you shouldn't have to fill the matrix manually.

The reason for the pipe being attached high up under the bonnet is to create the highest point in the cooling system, so any air in the system will naturally make it's way to this point. It may be an idea to do it with the car facing up hill or on ramps, just to make sure that the matrix won't trap any air inside it :)

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by meeko on Nov 5^th, 2008, 11:00pm

Hi,

I tried your technique and after about 20 minutes the bubbles stopped. I couldn't determine if the engine overheats though as the temp. guage is now off the scale for some reason. Disconnecting the sender wire makes the needle drop right down, and connecting it makes it go right up. Perhaps I damaged the sender last night when the engine over heated?

Anyhow, the heater still blows cold, so I guess I'll need to manually fill the matrix? I'll remove the hose from the pump and fill it there as it's quite tight to reach the connections on the bulk head.

Thanks for your help,

Steve

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by Jonnycab on Nov 6^th, 2008, 12:38am

Blowing through the matrix may be a good way to determine that it isn't blocked, but it won't tell you if it's restricted with limescale etc.

If the veins in the matrix are furred up with scale/gunk etc, then yes, you will be able to blow through it, but the coolant flow through it will be restricted & in turn there will not be alot of heat produced because the matrix will not have the proper volume of water flowing through it :)

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by Jonnycab on Nov 6^th, 2008, 12:56am

Erm, slightly confused here :-/..... Is it a 94 2.0 Scorpio or a 94 2.0 Granada Scorpio ?

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by meeko on Nov 6^th, 2008, 9:03am

It's a Granada Scorpio. I presume it must have a fair amont in common with the 2.0i Scorpio though?

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by Highlander on Nov 6^th, 2008, 1:49pm

Yes and no ;D

You'd be better trying here

http://www.granada-and-scorpio-online.com/

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by Jonnycab on Nov 7^th, 2008, 12:00pm

I thought it was a Granada when you mentioned the Haynes manual, but then wasn't sure if you may have been using it just for reference :)

Hopefully the G&S site can give you better advice :)

Title: Re: Overheating 1994 Scoprio 2.0i DOHC
Post by meeko on Nov 7^th, 2008, 1:12pm

You suspected right!

From the other site it seems the dreaded airlock is the biggest problem of the MK3!

Mine's still not sorted, but hopefully will when I flush the rubbish out of the system.

Thanks again for all of your help.

Steve