overheating

Submitted by alfie on

Forum: 

Hi People,
I need advise my 1991 sporty keeps overheating I've changed the therostat but after a short run the rad is very hot and bubbles over into the exspansion tank, the pipe going into the thermostat is not that hot so it seems to me that the new thermostat is not working even though I've just changed it.
Any Ideas

Take the 'state out

Submitted by Nev. K on

Take the 'state out compleatly and do the same run. At least that will prove or disprove you theary.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.

Any veiws expresed in this thread by me are purely from my own experience, and (sometimes) falible memory. Hope my comments help, but please don't take them as gospel.

Overheating

Submitted by oldminiman on

Try flushing and then back flushing the rad to clar any blockage in the radiator. Check for a good seal on the cap and check the general state of the fins on te Rad. After a time , and my 1991 did this 2 years ago the fins dissappear and cooling is ineffective.

Have you checked your oil for water contamination indicating a possible head gasket gone?

Check all the cheap solutions first before assuming head problems. To see if the rad seal is operating check that the hoses are hard when the vehicle is at running temp.

I suspect if it is the original rad that it is blocked of knackered. There is a firm on ebay item 150151174251 that have rads for £105 new. They have an additional outlet on the lower tank that can be blanked off with heater hose, 2 Jubilees, a bit of 14-15 mm copper tube with and endstop soldered on the end. It works perfectly and has cured my overheating 100%

OLDMINIMAN

M J Young

Thermostat .... or .... major problem.

Submitted by Mace on

Did you replace with the correct type of thermostat?
Diahatsu must have the correct type fitted. Any old thermostat will not do the job,it will overheat.
If you used a correct thermostat and coolant continues to be forced into the overflow reservoir then anticipate a major problem ......... blown head gasket or cracked cylinder head.

Overheated

Submitted by assassin on

Sounds possibly like an airlock in the system, ensure you have the heater set in the hot position, and you bleed the system properly.
Check this first before parting with cash.