Thread: 93 Disco overheating issues?

Originally Posted by sickgm

Greetings,

Just after some advice, my 93 Disco (3.5 V8 on LPG) is having some heating issues.

Around town (60-80kph) the temp gauge sits between just under half and on half. When it come to a stop it drops under half. However on the hwy after about 10-15 minutes it starts to shoot up towards 3/4. A needle width off the 3/4 mark.

I have had the radiator unblocked, thermostat changed, viscous changed and my mechanic assures me it is not a head gasket. There is no coolant leaking or oil and coolant mixing from what I can see.

It does get a fair bit of heat coming in to the cabin around my feet???

Any ideas?

Heat issues are really based on the following

Radiator blocked = heating up
Thermostat = heating up
Blown head gasket = loosing coolant / air bubbles in radiator

Hate to say this but if your not loosing coolant then

Remove thermostat ...... drive it for a while / see what happens .... if running cold then stick in new thermo ..... Also check what degree thermo stat it is ..... Should be 88 degrees??

When you had the radiator unblocked .... You mean the top cap taken off and they "rodded the cores" ..... Did you check via washing the radiator out that the "Radiator joint" actually cleaned out or the cr**p that dropped to the bottom.... Sometimes they forget to do this, and this means all the debris just recycled itself back to the top of the cores ..... Happened to me / Lucky I had checked before installing

Also if you have taken you fresh radiator and then went on a bone shaking drive in the bush then this also could undo all the good work as rust shale is shaken off the side of the block (Steel bore sleaves) and sent to the cores .... Hence blocked radiator AGAIN

Take the radiator and have them check it again ..... And run a "filter sock" (available at all good radiator repair shops) in the top radiator to filter debris before it hits the radiator

Lastly ..... Engine timing ..... Check vacuum advance unit works (suck on hose) and engine is timed properly and mechanical advance weights work properly ..... All easy to check .... very "visual" and cheap to do (free)


But I believe it is in the end ...... the Blocked radiator or wrong / broken thermostat
OR you have a rag / plastic bag stuck IN FRONT of the radiator blocking air flow

Mike

Just remembered this one Also ..... Check that the hose's are holding pressure ... IF not then replace cap on expansion tank

Phew ....

Mike

Thanks for the info.

I have had the thermo changed and from my understanding they drilled a heap of wholes in it to help the water flow.

The radiator hopefully has not been clogged again..... as they assure me that they had unblocked it thoroughly.

No plastic bags that I can see......

Thanks, I will keep you posted once it finally works itself out!

Originally Posted by sickgm

Thanks for the info.

I have had the thermo changed and from my understanding they drilled a heap of wholes in it to help the water flow.

The radiator hopefully has not been clogged again..... as they assure me that they had unblocked it thoroughly.

No plastic bags that I can see......

Thanks, I will keep you posted once it finally works itself out!

Another thought .... You are running gas , which means they have advanced it (the timing)

Advancing can make it run hot (lean fuel mix) .... and check in general, that there is the right amount of gas being supplied to the motor .... IE not running lean

Mike

I once had a similar problem on a range rover. I did everything youve done. Got the rad rodded, put numerous thermo stats in it, put new viscous couple still had the same problem. Start driving on the freeway and temp would jump to 3/4. I knew something was a miss when i was still able to open the radiator cap while gauge was showing 3/4's. Ended up buying a new temp gauge and sender and problem was fixed. I think from memory it was actually the sender unit that was faulty, but i changed the gauge as well just to be sure. Stayed on 1/4 after that till the day i sold it.

mmmm very interesting, thats sounds right because after a hwy run i can open the header coolant box and it is not bubbling or anything. Interesting, might try a after market temp gauge? The only heat I get is heat in near my front feet after a long drive.

Hey Guys,

We have narrowed it down to the sender unit possibly being faulty. After a good drive and the needle going up to 3/4 my mechanic stuck a infared thermometer in the engine bay and had a poke around. Hottest point (except for the exhaust) was 92 degrees which seems pretty normal.

Does anybody know what the standard operating temp is for a disco like this??? (93 V8 3.5lt)

My old disco used too sit on 95deg with the aircon on

Change your sender or fit an aftermarket type.

Adam