Rad

cantdecide

My brother's poor legacy is overheating. Is there a way I can decide if it's the rad, a head gasket or what...

mickdw

Id say check to see is rad getting hot. If not it could be thermostat or water pump.

crosstownk

You need to do a pressure test on the cooling system and you need to have the thermostat checked.

Can you see a leak? Is the oil level mysteriously rising? Have you a mayonnaise substance on the underside of the oil filler cap?

cantdecide

crosstownk wrote: »

You need to do a pressure test on the cooling system and you need to have the thermostat checked.

Can you see a leak? Is the oil level mysteriously rising? Have you a mayonnaise substance on the underside of the oil filler cap?

It never really took any water before. The level has never dropped but for some reason it's overheating in minutes flat. Having checked, the fan is coming on when the needle goes up but it's trying to cool a stone cold rad... so thermostat or pump, methinks.

But which- anything I can do to check that doesn't involve a mechanic?- I'm not determined to fix it, I'll take it off him if I know it's a relatively easy fix.

crosstownk

cantdecide wrote: »

so thermostat or pump, methinks

Yep- both could be responsible. I'd start by replacing the stat first as it's the cheapest repair. You could always remove the current stat and test in a pot of boiling water. If it behaves correctly then you can assume that the pump is suspect.

cantdecide

A quick googling makes it seem relatively easy to get at the stat so I think I have a job for tomorrow.

Thanks to all

Dirty_Diesel

Just remove the stat and replace the housing. Start her up and up it overheats without the rad heating then it looks like the pump is gone. If it heats up very slowly but doesn't overheat then the stat is gone.