Forum:
I am new to the Daihatsu Sportrak but I love it to bits, my model is 1990 Sportrak 1.6 Petrol Carb EL. My problem is that my sporty was overheating and the coolant in the expansion tank would boil over and out the overflow. I fixed this problem with a new Rad Cap as the old ones seal was rotten and useless. Although it does not boil over it does still get unusually hot (on the guage) but I don't know what it's normal temperature should be (I assume around centre). I was wondering if it may just be the temp guage, although I am quite worried about it.
Also, are there any usual things that may go wrong to cause the model I have to overheat.
overheating
Hi,
It might be your thermostate sticking try changing that it should sort it.
I've had my 1990 sporty for about 4 years now no real problems only just running repairs.
Alfie.
overheating sporty
The common item that goes is the head gasket and this would be obvious by "salad cream " in the oil.
Both of my Sporties remain just too the cool side of centre on the guage and will rise to normal if climbing or towing.
My older sporty 1991 had persistant heating problems and I discovered that the lower fins of the radiator were completly rotten. I obtained a new one from a company on ebay, for 109£ and the problem was solved. having owned the car since 1995 and still getting great service this has been the only problem, not bad for 100,000 miles.
You can try back flushing the system but if the cooling fins are wrotten obviously their effect is lost.
I think the company was Arron of London and I found them under FEROZA.
OLDMINIMAN
M J Young
Hot under the collar
Have you refilled the cooling system correctly?
Check the obvious first, thermostat, blockages in pipes, and is the radiator blocked, or partially blocked.
To flush the system, drain the radiator (engine cold) by unscrewing the drain plug on the bottom of the radiator, or removing the bottom hose.
Check the heater setting is in the hot position, as this will cause an airlock, or water will run from the engine into the heater radiator, leaving a low coolant level in the system.
Close the drain bung, or refit the bottom hose, fill the system with clean water, slowly, as not to allow airlocks to form.
Run the engine until it is at full operating temperature, and drain the water off again; repeat this three times to ensure all debris and contamination is removed.
Fill the system with clean water, and a good cooling system cleaner, and follow the instructions on the can.
Drain and flush again, remove as many coolant pipes on the engine, including those that run through the bulkhead to the heater radiator, flush these thoroughly with a hosepipe until they run clear.
Refit all hoses and fill with water and anti-freeze in a 50-50 mix.
Your cooling system should be fine, and your heater will be hotter than ever; if this continues, it could be the head gasket, porous block or head, or cracking between the valves.
Worrying times .........
Steaming from the cap does reduce the water level - change the cap or change the caps seal.
Main reason for overheating is a faulty thermostat. DIY about £18 but get the CORRECT TYPE. Its not a standard thermostat but is elongated. I suggest you remove the old thermostat and get it matched at the local motor shop - available in their catalogues. Fit it with the jiggle [hole] at the highest poiont so the air gets ventilated from the engine block. Easy job but do not over tighten the 3 bolts [5LB]
Check the coolant pump is working. Carfully remove the rad cap and get someone to rev the engine. If the coolant 'rises' the the pump is probably OK. If not the pump could be rusted and needs replacing.
Also check if the radiator is leaking along topside of the upper radiator tank ... adjacent to the upper inlet hose. Rads frequently fracture along this seam.
Boiling in the reservoir is more worrying since a faulty rad cap should not result in a boiling reservior. It suggests a thermostat fault, water pump or head problem.
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You have changed/repaired the rad-cap:
If the reservoir coolant continues to boil then the cylinder head gasket is leaking or the cylinder head is warped.
If the reservoir coolant continues to disappear but does not boil then check for a leak. Check the radiator, all hoses and the heater matrix [is the floor in the footwell wet]
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Sporty Overheating Problem
Ok all every good points and ideas? I agree with back flushing the system but I don’t think that’s the problem, but still its worth while doing to remove any silt of rust built up and always use anti-freeze.
leaks and such well the easiest way to check is to pressure test the system, this will show up any leaks as a drop in pressure, unless you have the kit to do this any decent garage should be able to do it for you. And check the temp with a probe at the rad
as for the problem I would suspect the clutch on the water pump behind where the fan is fitted is slipping , that’s would mean that the fan would turn normally but would not have the guts to pump the water around the system thus causing it to boil and run hot as the only way that water would run through the system would be by expansion when the stat opens, thus the water in the block and head would boil and escape via the rad cap and expansion tank or the internal blades on the pump have broken off and thus the pump is just spinning but doing nothing