overheating V8

[Baz B]

Hi, I've been working slowly over the last few months re-commissioning V8 Soarer ,91 with the help of Lextreme.
I am almost there, it still runs a bit rough sometimes, but getting there. But now it overheats after about 10 kms. with warning chimes and steam. The steam comes through the overflow pipe from the radiator cap. I have replaced the water with green stuff, the fan works, it has had some radiator stop leak added because of a leaking welsh plug at the back of the motor, they say the motor needs to be moved forward to replace it, but the system does not leak. On the top expansion tank is a white plastic thing with wires attached that is sticking up about 15mm, what's it for? Any help would be welcome.

 

[Zuffen]

If it's overheating after a few K's I'd look at the thermostat.

If it failed shut it will overheat fairly quickly.

If there's a leaking welsh plug fix it as it will only get worse and fail when you're away from your tools. A stich in time and all that.

Stop leak won't help cooling either.

Not owning a Soarer i can't be definitive but a WAG would be it's a level sensor for the coolant. A light should show on the dash when the coolant level drops too far.

 

[Baz B]

Thanks Rod,
Yep, it was the thermostat, but with the extra water pressure put on the engine block, it burst the weak welsh plug at the rear between the block and firewall. If anyone has any slick trick I can use to fix this without removing the motor would be great. I only have car ramps and nothing to take the weight of a motor. Bloody bush mechanics, we are always learning.
Thanks again.

 

[Zuffen]

I don't have an answer for the leaking welsh plug other than replace it.

There isn't an easy and permanent solution other than doing the job properly.

Could you try half removing the engine by lifting it off it's mounts and sliding it forward.

Should be simple enough to pry out the old plug and insert a new one.

Google how to insert a welsh or freeze plug first.