Car Trouble (Renault Scenic)

I'm hoping there's some car mechanics on here as I've got a slight problem with the car, it's a Renault Scenic 05.

The radiator fan seems to be over-active and has only started doing this a week ago. No matter what revs, gear or speed I'm doing the fan will spin up a lot. If the car is idle it will calm down but if I rev the engine you can see the fan spin up and then down again once it goes back to idle. Worried the car is overheating. Not enough oil?

Could this be related the radiator now working fully or the dreaded ECU? The ECU was replaced a couple of months ago before we bought it.

Any help is appreciated!

 

Well,,, we had a Renault Scenic when we lived in Cyprus, and I can honestly say it was the worst car we ever bought. After only 4 years we had to buy a new automatic transmission, we had to buy a reconditioned unit as a new one was so expensive. Then one of the electric windows broke. Luckily this was when we were leaving Cyprus, so we got rid of it. Good luck.

 

I agree with FC, its not time to panic yet.

The radiator fan comes on when the coolant temperature exceeds a set threshold. There's several simple reasons why that could be. Granted, it can be an expensive fault, but usually not. Some more questions to add to FC's ones:

* Has there been any recent work on the cooling system?
* Have you checked your coolant level? Is it between the min and max lines when the engine is cold?
* If you put the heater on, does it work ok? I.e. does it blow out nice hot air?
* When did you last have the thermostat replaced? This should be done on every routine service, but often gets neglected?
* If you know the thermostat has been replaced, do you know that the garage used the correct replacement? Sometimes you will get two different rated ones for almost the same car, depending on engine variant. If the mechanic simply order a thermostat for an 05 Scenic, he could easily have got one that is for an 05 Scenic but not your specific model.
* I have to ask this, but if you take the filler cap off the coolant reservoir (NOT when the engine is hot, unless you want to scald yourself), is the coolant the right colour? There is no oily film on the surface or anything?

 

Right, Renault Scenic '05 plate - petrol or diesel? Mileage? Engine size? And has it got a service history? Petrol, 1.4-1.6, 80000-90000 approx (mile-o-meter reset with ECU replacement), not sure on service history but will have a look this weekend!

EDIT - and does it have air-conditioning? Yes, but we never use it. Pressed the btton for it after reading your post, can here it coming on, changes engine rev's and heating a little.

* Has there been any recent work on the cooling system? Not that we know of
* Have you checked your coolant level? Is it between the min and max lines when the engine is cold? Not sure how to check this, help!
* If you put the heater on, does it work ok? I.e. does it blow out nice hot air? All working fine
* When did you last have the thermostat replaced? This should be done on every routine service, but often gets neglected? Not sure, will have to check on this
* If you know the thermostat has been replaced, do you know that the garage used the correct replacement? Sometimes you will get two different rated ones for almost the same car, depending on engine variant. If the mechanic simply order a thermostat for an 05 Scenic, he could easily have got one that is for an 05 Scenic but not your specific model.
* I have to ask this, but if you take the filler cap off the coolant reservoir (NOT when the engine is hot, unless you want to scald yourself), is the coolant the right colour? There is no oily film on the surface or anything? Not sure, will check on weekend

Also, to tag onto clueless1 above, have you tried opening the rad cap, and then running the car up to temperature with the cap off - sometimes if you get an air lock, a the cooling system needs to 'burp'. How do I do this please?

And two more questions - is the temperature gauge showing that the car is getting hot when the fan kicks in (was this the reason that you checked the fan originally)? I'll have a look for the temp gauge (no, you can here it over the radio!) and does the fan come on pretty much immediately that you start the engine? No, maybe a couple of mins after setting off

P.S. - I don't know a lot about cars, I've only been driving for less than a year!

 

nFrost, try the geeks out on their very own forum, I use the land rover sites and turns out they have a vast amount of knowledge on offer.

http://www.renaultforums.co.uk/forumdisplay.php?f=129

Guaranteed they will know a thing or two about your specific problem.



Look for the above image and after the engine is running, undo the cap until it starts to hiss. allow the fluid to rise up and see if the fluid bubbles to release the air in the system. If it does then tighten the cap again and see what the fan does afterwards.

Get in with the geeks they will assist you with any problem you have, but be explicit and long winded with any question. The more information the better.

Temperature gauge is third from the left

 

Thanks Landi, haven't tried on there yet. My dashboard is a fancy-pants one like this, I'd prefer just a normal one really. The fuel gauge drives me mad!

 

nFrost the temp gauge on the left.

Have a good look around your vehicle and see if you have any mates to show you round the vehicle. Check all that you know and ask questions about what you do not.

 

oh dear, I always thought that was for the oil!

 

Somewhere under the bonnet, almost always on one of the sides, you will see a large plastic bottle with a couple of hoses coming from it. It will have lines on it marking min and max. That will be the coolant reservoir (if you go on the car forums, expect them to call it by its proper name, the 'expansion tank').

You should be able to see the coolant level through it, because the plastic will be translucent.

Find the tank/bottle mentioned above. It will be quite large, if you see a very small one (usually more in the middle near the windscreen) leave that one alone, it will be your brake fluid. Definitely a larger bottle to the side. Take the lid off (when the engine is cool), and start the car up. Just leave it ticking over for a while. Wait til its up to temperature (the temperature gauge on your fancy dash should be about in the middle), then leave it a bit longer. It is customary to drink a mug of tea at this point. Occasionally glance into the expansion tank/coolant reservoir, but don't stick your face over the top of it, and you might see bubbles come up and then the level drop suddenly. If that happens, the cooling system has just burped, or dislodged an air lock. Other ways to burp a cooling system include, finding the fat coolant hose from the bottom of the radiator, gripping it in your hand, and sort of repeatedly squeeze and release to pump it. That's my way and it works, but it will eventually harm the rubber so some advise against it, and I would only recommend it if I knew work had been done on the cooling system. There is a proper way to burp a car, which involves taking hoses off, but that's more trouble than its worth.

 

FC, from a safety point of view should nFrost disconnect the battery before tinkering with the electrics?

 

Naaaa sheal. Get someone to hold a ht lead while the engine is cranking over. Always good for a laugh!