Engine fan on constantly

iamana1ias

Ebe_Scrooge wrote: »

That's good advice RE the Haynes manual. Once you've got the manual, it's probably worth giving the cooling system a flush through. Fairly simple to do, basically it involves draining the system, flushing through with a hosepipe and refilling with the correct mix of antifreeze. The antifreeze is important - during the summer you still need it as it contains corrosion inhibitors, and come the winter you'll be safe in the knowledge that your engine won't freeze up.

Flushing and re-filling should be done every so often anyway, as antifreeze deterorates over time, and doing this will remove any build-up of sludge which may be making your engine run a bit hotter than it should.

If you're still finding the engine is running hot, then the next thing would be to check / replace the thermostat. But I'd do the flush first as it's simple and pretty cheap - just the cost of the antifreeze to refill - and will certainly do your engine good anyway.

I wouldn't recommend this incase the new, full strength coolant finds weaknesses in the metal in the engine head. Vauxhalls of this age will have weakened metal and the coolant will eat through it, flooding the spark
plugs and stopping the car from firing on all cylinders. Seen it happen with a 2001 model.

vaio

Yep, it might find any “almost” leaks but that’s better than a frozen/corroded engine.

OP..... Does the fan come on as soon as you start it or only when it has warmed up? Do you have air con?

gazfocus

Ok now I'm confused as to what to do lol. Change the coolant or not?

The car doesn't have air con and the fan starts when the car's warmed up.

cyclonebri1

100 deg is too high, the fan shoul come on at 89 to 95 on almost all cars, it should bring the temp down to a few degrees below the trigger temp very quickly, if it doesn't you have a problem. Talk to the gargae now so that it doesn't become a terminal one.

Could be simple, airlock, duff thermostat, clogged rad, iffy rad stat switch. All easily sorted, but terminal if not fixed. :beer:

vikingaero

I would take it to a garage and get it checked out. Could just be a dodgy thermostat or sender.

Ebe_Scrooge

Well, the thing with antifreeze is that it will cause a leak if a part of the system is very weak - say, a hose that's on the way out, or a radiator that's partially rusted. So in that respect it's a bit of a pain.

However, over the long-term, a frozen or rusted system will cost a lot to put right, so I'd say it's worth putting fresh antifreeze in.

The other thing to bear in mind, if there is a weak spot ready to pop, would you rather it went in the middle of a long motorway journey, or would you prefer to find out about it just after you've refilled the antifreeze and the car is nice and conveniently at, or close to home, where you can sort it out ? To that end, I'd recommend change the antifreeze, take it for a run out for just a few miles, get back home and check for leaks. Then just keep an eye on it for the first couple of weeks. If a leak does develop, it's easier to sort out there rather than at the side of a motorway :-)

mikey72

I wouldn't do anything yet, give the garage you bought it from first sight of the problem.

gazfocus

I've tried to get hold of the garage but they've moved premises so unfortunately the phone number has changed and I don't know where they've moved to.

However, after 15 miles into a journey yesterday, the temperature gauge went to red and we had to turn the heating on full heat in the car to reduce the engine temperature (in this weather!!!) so I took it to a garage this morning and they've said it's the water pump and it's gonna cost me £130 to be fixed

Lokolo

Sounds about right (the water pump anyway), makes sense anyway.

Water is constantly being rotated through the engine to cool (water is a liquid which takes longer to heat up/cool down). If its at 100c that's bad as water evaporates at 100c!!!

The fan aims to cool water as it passes it.

This then goes around the engine taking heat away from various parts.

I think that's how it works!

If the water isn't being pumped around but staying still, the water just keeps heating up and never passes the fan 'junction' to cool.

iamana1ias

Lokolo wrote: »

Sounds about right (the water pump anyway), makes sense anyway.

Water is constantly being rotated through the engine to cool (water is a liquid which takes longer to heat up/cool down). If its at 100c that's bad as water evaporates at 100c!!!

The fan aims to cool water as it passes it.

This then goes around the engine taking heat away from various parts.

I think that's how it works!

If the water isn't being pumped around but staying still, the water just keeps heating up and never passes the fan 'junction' to cool.

Yep, with no water pump the engine basically becomes a very big kettle.