Engine Overheating... briefly?

[geraintthomas]

Hi all, first post.

A little different from other 'Engine Overheating' threads, as this seems a little quirky.

I purchased my 197 last week and it's been a joy to drive. The garage had fitted a new radiator the morning of purchase, but every now and again I'll have an 'ENGINE OVERHEATING' message pop up. When this happens, the temperature gauge moves to about 3/4.

Here's the catch. It doesn't happen every time - I could be sat in stop/start traffic for 30 minutes and it won't appear. The last time it appeared was in a car park after 5 minutes of idling. As soon as I drove to the end of the car park (what must have been 5mph), the temperature gauge went back to normal, message disappeared, and never appeared again. This has also happened in traffic - a minute or two later will cause the gauge to drop again, and it won't appear again even if I'm in continued stop/start traffic.

If this were a thermostat issue, surely this would happen every time I'm in traffic?

I've put this down to simply air in the system; the garage could have been rushing and didn't bleed the system properly. Moving the car, even slowly, gets the pump moving the coolant around and the car returns to normal. That's far too slow and far too soon for air to cool the engine/radiator.

But I then realised that my fan never turns on. In stop/start traffic, even when the engine told me it was overheating, the fan wasn't turning on. If it were air in the system, I'm guessing it wouldn't turn on as the thermostat wouldn't be open. If it were air, the sensor would think it's overheating (message on the screen) but the radiator fan wouldn't engage (thermostat was closed, it's not actually overheating). However, I read that turning on the air conditioning should force the fan to start. This doesn't happen. No matter what I do, I can't seem to get that fan to turn on.

Possible causes then, considering the radiator was recently changed:

- Fan isn't plugged in
- Air in the system
- Sticky thermostat

I don't think it could be the fan resistor as it's not turning on at all, let alone slowly.

Any ideas of how I could problem solve this? My first thing is to re-bleed the system and see if the fan turns on. If it starts to overheat, it could be fan/thermostat.

Thanks!

 

[Sean197]

My fan wasn't turning on at all, even with the aircon switched on. I changed the fan resistor and now it works fine. Very easy job, less than 10 minutes to change.

For Vauxhall Vivaro Renault Trafic II Clio Mk3 Radiator Blower Heater Resistor | eBay UK

VIVARO, 01-06. VIVARO, 06-14. TRAFIC, 01-06. TRAFIC, 06-14. CLIO, 05-13. 1X New Radiator/Blower Fan Heater Resistor. RENAULT 7701049661. RENAULT 8200045082.

ebay.us

 

[turkie172]

You might have bought a problem engine car keep that in mind.

1. Why was the radiator changed.
2. Was it changed to a new one or a used one, the forward radiator is the air con and the rear is the water.
3. 3/4 mark is way too hot for a 197 and a warning message is way too much as well, the center mark is about 90 degrees and the engines thermostat is 75 degrees standard.
4. There are two fan speeds low ( the resistor) and high full power direct relay. Sounds like the fan is not working at all.
5. Is the car using water as there is a very likely area that can leak rapidly and fool you to think radiator.
6. Is the car from a dealer (warranty) or private sale.
7. The logic of a faulty thermostat and the over heating, the fan which is separate should be running all the time to correct and it's not according to you.

Link to temperature reading guide

 

[geraintthomas]

My fan wasn't turning on at all, even with the aircon switched on. I changed the fan resistor and now it works fine. Very easy job, less than 10 minutes to change.

For Vauxhall Vivaro Renault Trafic II Clio Mk3 Radiator Blower Heater Resistor | eBay UK

VIVARO, 01-06. VIVARO, 06-14. TRAFIC, 01-06. TRAFIC, 06-14. CLIO, 05-13. 1X New Radiator/Blower Fan Heater Resistor. RENAULT 7701049661. RENAULT 8200045082.

ebay.us

Thanks for that. Any guides on how to do this? Couldn't see any at first glance.

You might have bought a problem engine car keep that in mind.

1. Why was the radiator changed.
2. Was it changed to a new one or a used one, the forward radiator is the air con and the rear is the water.
3. 3/4 mark is way too hot for a 197 and a warning message is way too much as well, the center mark is about 90 degrees and the engines thermostat is 75 degrees standard.
4. There are two fan speeds low ( the resistor) and high full power direct relay. Sounds like the fan is not working at all.
5. Is the car using water as there is a very likely area that can leak rapidly and fool you to think radiator.
6. Is the car from a dealer (warranty) or private sale.
7. The logic of a faulty thermostat and the over heating, the fan which is separate should be running all the time to correct and it's not according to you.

Link to temperature reading guide

It really isn't a dud. Hopefully this clarifies a few things:

1. The old radiator had a minor leak
2. Brand new, with receipts to prove (and the fact it's clearly a brand new radiator)
3. Already aware, hence the reason for this thread. The car runs at operating temperature and only raises to that mark if left idling for a while
4. Correct
5. Oil and coolant are both fine, engine is healthy
6. Covered under dealer warranty, dealer is repairing next week
7. Agreed

Appreciate the tips. The car is fantastic condition and covered by warranty, it seems like it could well be the fan not plugged in with how the car reacts. Driving slowly when it starts to overheat brings the temperature back down. If the thermostat were bad, the coolant wouldn't be reaching the radiator for the wind to cool it.

The radiator was replaced the morning of collection (this was already agreed and discussed as a condition of sale), so my guess is that they could have rushed it.

I was going to look at this myself (hence this thread asking for help) but I've just decided to hand the car back for them to fix. I'll report back with what the issue was as the solution may help others.

 

[turkie172]

To test the high speed fan is easy start the car pop the fuse box lid left of the battery box the Purple relay pull it out short between the two marked spade holes brings the fan on full speed use something like pointed Pliers that will be the fan tested.

 

[geraintthomas]

To test the high speed fan is easy start the car pop the fuse box lid left of the battery box the Purple relay pull it out short between the two marked spade holes brings the fan on full speed use something like pointed Pliers that will be the fan tested.
View attachment 161213

Interesting! Will this force the fan on, or does the fan need to be running under certain circumstances for it to be tested?

 

[Sean197]

@geraintthomas the resistor is on the bottom right of the radiator (standing in front of the car looking at it). Take the undertray off and slide under and you'll see it. Unplug, unbolt, and fit new one. It's self-explanatory when you see it.

 

[geraintthomas]

@geraintthomas the resistor is on the bottom right of the radiator (standing in front of the car looking at it). Take the undertray off and slide under and you'll see it. Unplug, unbolt, and fit new one. It's self-explanatory when you see it.
View attachment 161214

Great stuff, thank you. It could be this that they had forgotten to plug back in - the weather is good today so I may give this a quick check to see if this is indeed the case.

 

[R20BTG]

Welcome, I saw your post on PH and wondered if you'd end up here. Your MX5 was nice

 

[geraintthomas]

Tested the fan by bridging the two contacts - nothing. The fan is also plugged in, as is the fan resistor found in that photo above.

If the resistor fails, would the fan stop operating entirely? Or would it still function if the relay contacts are pinned?

Technically it's not my problem, it's the dealers, but it's also nice to have some idea what's wrong with it.

 

[turkie172]

The resistor drops the power to the fan so it turns at a lower speed the relay overrides that with full power high speed fan.

Good that you don't have to worry about fixing it, but it seems now like you have a better (easier) problem that needs fixed.

Forget the wiring at the moment so it's down to dead fan or no power so the rest is optional all the above was to be done with the engine running so power was provided.

1. You can jump 12Volts directly from the positive battery terminal to the front spade position with the relay removed engine off that helps prove fan or power.
2. If the fan runs then the fuse for the relay is the F3 fuse battery box front fuse board.




There is a how to section on the forum for members if you want to sign up from one of the options. If you do I'll stop helping you and leave you alone