Over heating still!!!

[nfrey2]

Since I've owned my rover I've be having over heating problems.

1st it was the coolant expansion take cracking and loosing coolant, which in a bind lead me to bypass it to get home which ended up blowing out the water pump seal.

So a new pump and new tank.

Now a month later, the hose from the heater core to the intake of the engine cracks, loose all the coolant again.

Quick fix yesterday was to replace it with a non molded hose. It had kink in but as soon as the thermostat open and hot water hit it it sofetned and no more kink. But now it over heats after about 10 minutes of driving. It doesnt loose coolant anymore. The radiator seems to be clear of debri, the vicous fan and auxillary electrics work. What could it be???

[RageRover]

It could be an air pocket stuck in the block, I have seen it happen to too many V8s. To solve this, "burp" the system by opening that plug on the top of the radiator. Run the engine when it is cold, and you should see the coolant start to rise, don't go away at all during this service. The air pocket will eventually make it to the plug and out comes the air. Once no more bubbles come out, your engine should not overheat anymore.

If this doesn't solve the problem, maybe the heater control valve on the engine is stuck or something, vacuum hose to it doesn't suck vacuum. Not sure. Hopefully this helps man!

[DevynsDad]

I agree with Rage...it's probably (hopefully) an air pocket stuck in the sealed system somewhere. Once that burps out you should be okay. Keep us posted on the solution...overheating is one problem I haven't had with my truck yet

[RageRover]

Originally Posted by DevynsDad

...overheating is one problem I haven't had with my truck yet

x2 man, my truck has not overheated since I got it in December. Probably cause I haven't even drained the coolant or had to ever service the cooling system. But it will soon be time to flush the coolant, change a thermostat, heater control valve, heater core, or change the water pump. LOL

Something will give sooner or later, damnit, I think I jinxed myself.

[OkieRover]

I have to point out that when my head gasket had completely I popped hoses one a day until I stopped driving her.
I was pushing coolant past the cap.
I had a radiator clog up, twice in two years.
And in the final week I lost 3 hoses.

I'm not saying this is your problem just had to share.

[nfrey2]

For future reference, it turns out it was a gradual siezing of the thermostat. It gradually would let less and less water through, because earlier this week it took longer to over heat and the top hose was hot, but yesterday it did very quickly and yuo could feel that just a trickle was running through the top hose as only the bottom of the top hose was hot.

[Geobloke]

Getting air out of a coolant system can be a real pain in the arse! By doing a mixture of overflowing the plug on top of the rad, filling up the block vis the heater matrix hoses and squashing the rubber pipes to try and dislodge any trapped air you can normally do it without any real trouble.

It sould also be noted that the expansion tank cap and thermostat are "consumable" items and should be replaced every now and again.

I change my thermostat once a year and the cap every couple of years.

The importance of the cap is often overlooked but is incredibly essential when needing 100% efficiency out of your cooling system. The cap is sprung loaded and seals the system. The spring is the pressure relief valve that should blow before your gasgets blow, but if your cap is old then this may not be working properly and you'll get over-pressurisation and burst gasgets and hoses popping off.

As for the thermostat, well all that is is a lump of wax (probably plastic these days) that melts at a certain temperature allowing the valve to open ect ect. But these wear out pretty quickly too!

As part of your servicing schedule you should check over the hoses for cracks or coroded jubilee clips.

When was your thermostat or expension tank cap last renewed???

[nfrey2]

just put a new expansion tank cap on it when it blew about a month ago, but by the looks of it was the original thermostat.

[TerryS]

Originally Posted by Geobloke

As for the thermostat, well all that is is a lump of wax (probably plastic these days) that melts at a certain temperature allowing the valve to open ect ect. But these wear out pretty quickly too!

Where on God's green earth did you come up with that idea?

The Thermostat "spring" is a bimetallic coil which contracts as temperature is reached, opening the 'valve'. As the water cools, the coil expands, closing the valve.