Sportrak Overheating


After driving through town, the water temperature gauge on my Sportrak started to rise. Within 1 min, it was at the top of the gauge.

I pulled into a garage to check the water, and it was low. I let it cool down and then put warm water in.

Drove 12 miles and the gauge started to go up again, it then fluctuated from nearly at the top to half way.

After staying normal for 5 miles or so, it suddenly went to the top again.

I pulled into garage again to check water and it was low again.

Refilled after leaving to cool again.

Water was a rusty brown colour.

Drove another 15 miles and it was fine, never moved from half way.

I noticed that after I refilled it the first time, the fan belt was slipping and screeching, also when driving along at times.

Also, radiator cap wasn't letting excess water in to expansion tank.

I can't see any water leaking anywhere, and the oil looks ok.

Can anyone give me any advice as to what to look for, as I've only had it a week, and its my first 4x4.



Symptom of a blown head gasket. Is the hot vapour from the exhaust coloured white whilst the engine is running very hot? Tip - hold a dry rag over the exhaust and check if the rag gets wet. Also any signs of bubbles rising in the coolant in the radiator - hot engine and engine revved high [ care when removing radiator cap whist engine is hot etc]

But ... could be a radiator leak. Is there any sign of coolant having leaked from the level on the radiator below the rad's cap. Leaking collant collects/discolours the radiator flange just below the top hose to the right of the radiator's cap. The metal tube into the radiator often fractures due to engine shake. Also the hose clip to the radiator sometimes works loose.
But ... is the rad cap fitting very snug? Try replacing the rubber seal inside the cap. Cut one from an inner tube etc. The caps lugs might need squashing so it pulls the cap firmly onto the radiator. If its a bad fit the coolant steams away. However you loosing a lot very quickly!

Sportrak Overheating

Theres no white smoke and there doesn't seem to be any lack of power.

The radiator cap doesn't seem to let any coolant into the expansion tank.

Could this be something to do with it?

Its an expansion tank ... min

Expansion tank has minimal coolant increase when the engine is hot but the tanks contents will be drawn/emptied into the radiator if the coolant is leaking from the engine.
Radiator cap has a pressure valve. If the coolant pressure is too high the coolant gets released. Expansion tank is not the problem.
1. Still sounds like a cylinder head gasket is blown. Any white/grey gunge on the oil dip stick of oil filler cap?
Remove the spark plugs and look at the electrode colour. What colour are they ... are each the same colour????
Did you look at the expansion tank whilst the engine was revved ... any bubbles?
2. Have you flushed the radiator and engine block? There is a plastic drain tap on the bottom of the radiator. Take care you dont snapit off. Flushing the rad via the filler might not do the trick. You will need to pull off the top hose. Flush into the radiator until clean water comes out the drain hole. Also flush into the hose so the clean water goes into the engine block and circulates to the bottom of the radiator. Again thoroughly flush for show of clean water.
3. A good chance the thermostat is rusted shut. Your coolant is reported as rusty/brown. If so the thermostat is probably stuck closed and coolant circulation is blocked --- water will overheat and boil. You will need to remove the coolant thermostat - test the thermostat by placing into a boiling pan of water and watch that the wax-valve opens fully. If it remain closed when boiled [85C degrees it starts to open], its broken and replace it. New thermostat gasket probably needed unless the old one comes away undamaged.

Sportrak Overheating

i checked the oil, and it seems OK. I will do a compression test later and check the spark plugs.

I forgot to say that another thing I noticed was that, when it first overheated, the engine idle speed was higer than normal. Its normally at 850rpm, and it was idling around 1500 - 1800 rpm. As soon as I put my foot on the accelerator, the fan belt shreaked and it dropped down to 850 again.

You say you've only had it a

You say you've only had it a week? Could be it had a minor leak and the previous owner popped some Radweld leakstopper in it. This would give the water a rusty brown colour (it's not rust, it's the coagulent) but due to the leak an air lock developed which caused the chaos you described which then cured itself on further topping up. Another possibility is that the water pump has given up the ghost and maybe seized or snapped it's shaft. I had this happen on a Volvo and it confused me for ages. The thing to look for is water flow when the engine is running. Start it up from cold with the rad cap off. You might see the water flowing when the thermostat opens??

"Like the first monkeys blasted into space, sacrificing themselves for the good of mankind.." Tyler Durden.

Sportrak Overheating

I drained the radiator out this morning, and it was FULL of brown sludge. I had to flush it with clean water 5 times before the water came out clean. I have put some rad flush in to it, to clean out the rest of the system. The radiator cap wasn't working either.

I would imagine the belt was slipping because the water pump would have had a real job to pump the water with all that sludge in it.


Sound like you might have found the solution to the problem. Hope you also flushed through the engine - method as described.
Suggest you just run with coolant water for a few days, then thoroughly flush again and include anti-freeze/coolant additive when your certain its cured. Let us know.
PS .. how do you know 'the radiator cap was not working'? Was it loose?

Radiator cap

The spring and rubber seal were rock solid and would not move at all. It was stopping the pressure escaping from the radiator.
Also the rubber seal was perished and had bits flaking off.
I went to Halfords and got a new one for £3, and it works now.

I'm going to leave the flush in there until monday, and then I'll drain it out and flush it again. I bought some coolant which is designed to work with aluminium heads, so I'll put that in as well.

I've been out and about and it seems OK so far. The gauge is just under half, and the only time it went up is when I was sat in traffic for 10 minutes, and then it only moved a fraction.

Sportrak overheating

Found another problem now.

Now that the radiator and pipes are clear of sludge, its leaking from somewhere now.

I have checked all the pipes on the top, and thay are OK.

I can't feel any water around the bottom pipe.

When I put my head over the radiator and fan looking down, I could feel water spraying up.

Could this be the leak poring on to the belt or fan, or could it be the water pump leaking, ie. the gasket?


The most likely leak is from the radiator below the top hose. Where the top hose' metal tube enters the radiator it fractures. Water leaks along the seam between the radiator top tank and the radiators core [the fins]. The fan drives the water into your face! When cold there is no sign of water on the radiator .. it evaporates as the engine cools but there is probably a remaining deposit from the anti-freeze - seen as a blue/green streak. To check ... smear chalk along the radiator seam. Next time your driving it will wash off/streak where water has leaked along the seam.
First try tightening any hoses since they work loose. The bottom hose is a pig to reach. If the leak continues and your certain its the radiator, then remove the radiator and take it for repair. Motor-rads [repair depts - telephone book]are common and a re-core is about £90. You can get a radiator soldered but if its been as blocked/rusted as you report then its not worth soldering - a few months and it will leak again. So get it reconditioned and it will be as good as new.
Removing the radiator is very easy. You will need to remove the bumper [bolted] and front plastic grill [screws and plastic poppers - care needed] to access the radiator bolts. The difficult task is getting the bottom hose removed - dont damage the hose! After the top & bottom hoses are off, its a few minutes task to unbolt the rad and pull it upwards out the bonnet.
PS .. there is a motor-rad depot in Redditch Worc.

Water leak

Thanks for all the advice everybody gave me.

Its not overheating anymore, which is something.

I have checked the radiator and all the hoses, and they seem to be OK.

There is still a coolant leak, and I think it is the water pump.

It only leaks when the engine is running.

I can see the water flying off of the water pump pulley when it is turning.

Once the engine has stopped, I can feel water on the pulley.

It is only leaking very slightly.

I think one of the seals on the water pump shaft which the pulley is attached to is leaking.

It looks as though all that gunk in the radiator was somebody filling it with radiator sealent trying to stop the leak.

Is a water pump very expensive, and how difficult is it to fit a new one?

I was thinking of taking it to a garage and getting a new timing belt put on as well, as I don't know how old the current one is.

Where is the best place to get one?

Any help would be much appreciated.


Water pump is behind the fan [fluid coupling]. Whilst there you may as well renew the timing belt. Should take a few hours.
A relatively easy task made simpler with removal of the bumper, grill, and radiator. You need to have access and sight for replacing the belt. You will find info about timing belt replacement on this web site. Note that the engine's timing marks are often 'missing'. Change can be done by setting to tdc and counting the ribs between the pulley blocks. A new timing belt is about £20 from any reputable motor shop. Check the pump rather than getting a replacement. Gasket will need replacing.
Garage job -- expect a few hundred pounds plus vat --- plus any replacement pump etc.
PS ... if you need torque settings then repost here.