Rover 45 Overheating.

B00056718

Over the weekend I got a Rover 45 as I needed a cheap runabout.

The head gasket was gone but I didn't mind that as it was very cheap and has current Tax and NCT.

So I changed the head gasket and bolts, and intake manifold gasket. The head didn't appear to be warped, so I didn't get it skimmed.

Anyway, I filled the cooleand, bleed it (or so I think), started it and within 5 minutes the radiator fan came on.

I revved the engine to get the coolant circulating better but it started boiling. The temperature needle was at the middle but I could hear it boiling so I stopped the engine and it continued boiling.

I gave it couple of minutes, then started again putting the interior heating at full blast but there was only cold air coming so I stopped the engine again to prevent it from overheating.

The top coolant hose to radiator was hot and top of rad was hot also. The coolant hose going to heater matrix was hot half way. Couldn't see anything wrong with the heater matrix valve or the cable moving it.

Also fitted new timing belt but didn't change the water pump as there was nothing wrong with it.

Engine is 1.4 16valve. Year 2002.

Any similar experiences or ideas? I'm hoping it's just an air lock but getting a little vorried now.

George Dalton

Check the thermostat.

Then sell it.

Or burn it.

Cee-Jay-Cee

What method did you use to check the head wasnt warped?

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CJC999 wrote: »

What method did you use to check the head wasnt warped?

I took the head off, cleaned it and the engine block, then put the head back on without the gasket and went around with 0.12mm feeler gauge, trying to squeez it between the block and head. It did not fit anywhere.

I know it's a mickey mouse method I came up with myself but didn't have a really flat surface or a big ruler.

PyeContinental

You've found the original reason for the engine having overheated in the first place. It's likely that the radiator or one or more of the coolant pipes are blocked with rust and coagulant.

Take the thermostat out temporarily (refit the thermostat housing), remove the top and bottom radiator hoses and check the insides for blockages. Take the radiator out and examine it for any physical damage or excessive rust to the core. You might need a new radiator, but try flushing it right through from both ends and every possible orientation with a garden hose. Flush through with the garden hose from the expansion tank to the end of the lower hose and from the thermostat housing back to to the radiator top hose. Refit the radiator and put water in from the expansion tank. See if you get water coming through on the return pipe eventually. Squeeze and release all coolant pipes to check for water and help the flow.

Rinse and repeat until you get a clear enough flow. Then buy a bottle of coolant flush which will help clear coagulant and debris and help prevent further rust. Check thermostat in a bowl of water above approx 88 degrees C for proper operation. If in doubt, buy another one. Run the engine on water until you are satisfied that it's flowing properly before filling with expensive coolant mix.

Have a look for some youtube videos on engine flushing.

PS - have the heater control set all the way to hot at all times.

FearDark

A Rover overheated?

Well this is one for the books..

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PyeContinental wrote: »

You've found the original reason for the engine having overheated in the first place. It's likely that the radiator or one or more of the coolant pipes are blocked with rust and coagulant.

Take the thermostat out temporarily (refit the thermostat housing), remove the top and bottom radiator hoses and check the insides for blockages. Take the radiator out and examine it for any physical damage or excessive rust to the core. You might need a new radiator, but try flushing it right through from both ends and every possible orientation with a garden hose. Flush through with the garden hose from the expansion tank to the end of the lower hose and from the thermostat housing back to to the radiator top hose. Refit the radiator and put water in from the expansion tank. See if you get water coming through on the return pipe eventually. Squeeze and release all coolant pipes to check for water and help the flow.

Rinse and repeat until you get a clear enough flow. Then buy a bottle of coolant flush which will help clear coagulant and debris and help prevent further rust. Check thermostat in a bowl of water above approx 88 degrees C for proper operation. If in doubt, buy another one. Run the engine on water until you are satisfied that it's flowing properly before filling with expensive coolant mix.

Have a look for some youtube videos on engine flushing.

PS - have the heater control set all the way to hot at all times.

Thanks for your input.

My first thought was to remove thermostat but then I thought that the coolant should travel trough the heater matrix even with broken one.

Will actually do it tomorrow, and the flush.

Filled it with nice, clean waterless coolant. Probably going to spill half of it on the ground now when draining the system.

PyeContinental

The heater matrix will be near the passenger footwell, behind the dash or glovebox area. Having the heater control set to hot opens the valve to allow flow through it. Hopefully the heater matrix is fine anyway. It's much more likely to be something like a blockage in a radiator hose and/or a silted up and rusted radiator.

JohnBoy26

Even if the head appeared fine, it really should of been skimmed. All your hard work and effort could be wasted as a result of not getting it skimmed.

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JohnBoy26 wrote: »

Even if the head appeared fine, it really should of been skimmed. All your hard work and effort could be wasted as a result of not getting it skimmed.

If I need to take the head off again, would it be ok to use the same gasket with new bolts?
Or does it need to be thrown out once tightened?

pheelay

B00056718 wrote: »

If I need to take the head off again, would it be ok to use the same gasket with new bolts?
Or does it need to be thrown out once tightened?

No. The compressed gasket will be damaged when the head is removed. Don't remove the head again unless you're certain there's still a problem with the gasket (oil/water leaking or mixing). It's NOT always necessary to skim the head, it's just advised to be certain that the new gasket seals correctly first time round. If the engine didn't severly overheat and the surfaces are clean, likely the head is ok.

The overheating could be as simple air trapped in the system. Squeeze the top radiator hose loads to help move any trapped air, while making sure the coolant tank never goes empty.

The gasket to fail on the K-Series is known to fail without any other root problems, as was my case a couple years back. Otherwise, they are a fairly bulletproof engine and well specced for their age.

pheelay

PyeContinental wrote: »

Having the heater control set to hot opens the valve to allow flow through it.

Actually, on the 2004/2005 model, the heater matrix is permanently plumbed in and it won't matter if the heater control is set to hot/cold. The cabin air temp is controlled by flaps that send incoming air through, or around, the matrix depending on the setting.
On the pre-facelift model, I think it's controlled by a valve in the plumbing

martinr5232

Sounds to me like its air locked did you open the main bleed screw down beside the airbox ??

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Well, I followed the advise and removed the thermostat (bit of a pig to get to it), dropped it in to boiling water and nothing happened.

So I went to local motor factors, bought a new one, came home and for whatever reason decided to drop the new one in to boiling water. Nothing happened.

The water came straight from boiling kettle. Would it be faulty?

Anyway decided to to put it back toghether without thermostat, fill it, bleed it and the engine ir running perfect. There is plenty of hot air from the heater. Until I drive on to a motorway that is.

So I was thinking that since the root cause has been found I should fit a working thermostat to keep the engine warm on a motorway but should I bring the one I bought today back and request another one?

Also.
While removing the termostat, I noticed that there is a slight oil leak from speedometer sender unit.
I thought i'll try to tighten it a little. So it's broken now. Speedometer still works but the sensor is cracked and still leaking.

Question is - will I loose much oil when changing it? Should I get a new one or a second hand one with a new O ring?

PyeContinental

It's certainly possible to have got a new thermostat that's bad. Did you get an OEM or known brand or spurious part?
The movement is subtle though, so you might miss it - especially if you immerse completely it in water. Warm the bowl like you're making tea. Rinse out and place the thermostat in the centre of the bowl, then put in water slowly so it reaches just under half way up the thermostat. Then reboil the kettle and very gently top up the water so gradually that you can see the surface tension of the water cling around the side of the thermostat. Watch for a small movement as it closes the inner aperture.

The above isn't a very exact method, but if you have good eyesight you should see if there's movement at any stage. The operating temp of the thermostat is usually embossed on the metal surround. If you have a thermometer you can be a lot more accurate with the temperature of the water in the bowl.

Re the speedo cable, all the oil should be in the gearbox below it so I don't imagine you should lose any.