Safe to drive? Temp gauge fine, blinking temp light and STOP

[92drobinson]

Hey!

Newbie post by someone with little experience with cars.

I’ve recently purchased a VW Passat Estate 140 TDI, 2006, 200k Miles.

It’s been running great until today the engine cooling light came on flashing. Said to stop which I did (when I got to the garage).

Picked up some new coolant fluid, undid the cap and the coolant level was fine but it was all rusty brown.

Now, the weird thing is that the temp gauge in the dash showed 90 for the whole journey, even when this light came on and the atop warning came up.

I’ve booked in for this Saturday to have it flushed and refilled. Is it safe to drive between now and then?

Reason I’m thinking it might be is that the temperature gauge didn’t move at all off the 90 once it’s reached that temperature, even with this warning lamp flashing.

I don’t really want to have to get on the motorbike with the weather as it is.

Any advice would be appreciated, thanks 😊

[E-bmw]

If your temperature gauge worked as normal, as in rose as the car warmed up & dropped as the car cooled down, it is likely that the sensor that tells the ecu to bring on the warning light is the defective one.

If you have plenty of coolant, the engine temp gauge reacts as it should, you will be fine.

Don't forget to tell them the full story including the gauge behaviour and they should get to the right fix.

[92drobinson]

E-bmw said:

If your temperature gauge worked as normal, as in rose as the car warmed up & dropped as the car cooled down, it is likely that the sensor that tells the ecu to bring on the warning light is the defective one.

If you have plenty of coolant, the engine temp gauge reacts as it should, you will be fine.

Don't forget to tell them the full story including the gauge behaviour and they should get to the right fix.

Hey! Thanks for the response. The temp gauge rose as normal and fell normally as it cooled. It’s got the right level of coolant but it is rusty coloured, with that in mind is it still okay to drive?

I noticed it normally happens going over 45mph.

Just don’t want to kill the car after only having it two days haha

Thanks again

[Megaflow]

If the coolant header tank is a round ball type looking thing, the VAG cars around this area had a coolant level sensor in the tank that was know to fail. That brings on the coolant light and a stop warning, but it is coolant level not temperature.

I had an Octavia vRS that developed the problem and it would do it first thing the morning, so plainly couldn’t be temperature related.

Cheaper fix, tank was about £15 if memory serves and a few minutes to fit.

[92drobinson]

Megaflow said:

If the coolant header tank is a round ball type looking thing, the VAG cars around this area had a coolant level sensor in the tank that was know to fail. That brings on the coolant light and a stop warning, but it is coolant level not temperature.

I had an Octavia vRS that developed the problem and it would do it first thing the morning, so plainly couldn’t be temperature related.

Cheaper fix, tank was about £15 if memory serves and a few minutes to fit.

Oh yeah! Hadn’t thought of that, the first time it happened was about 20seconds into the drive at 5am very cold. Doh!

I’m going to have it flushed anyway, don’t like the looks of the colour in there and see if they’ll also replace the tank.

Thanks

[E-bmw]

92drobinson said:

E-bmw said:

If your temperature gauge worked as normal, as in rose as the car warmed up & dropped as the car cooled down, it is likely that the sensor that tells the ecu to bring on the warning light is the defective one.

If you have plenty of coolant, the engine temp gauge reacts as it should, you will be fine.

Don't forget to tell them the full story including the gauge behaviour and they should get to the right fix.

Hey! Thanks for the response. The temp gauge rose as normal and fell normally as it cooled. It’s got the right level of coolant but it is rusty coloured, with that in mind is it still okay to drive?

I noticed it normally happens going over 45mph.

Just don’t want to kill the car after only having it two days haha

Thanks again

Yes, it will be fine, it sounds like it does need a coolant flush/change & see the other post about level, that sounds likely the ACTUAL issue.

[92drobinson]

E-bmw said:

92drobinson said:

E-bmw said:

If your temperature gauge worked as normal, as in rose as the car warmed up & dropped as the car cooled down, it is likely that the sensor that tells the ecu to bring on the warning light is the defective one.

If you have plenty of coolant, the engine temp gauge reacts as it should, you will be fine.

Don't forget to tell them the full story including the gauge behaviour and they should get to the right fix.

Hey! Thanks for the response. The temp gauge rose as normal and fell normally as it cooled. It’s got the right level of coolant but it is rusty coloured, with that in mind is it still okay to drive?

I noticed it normally happens going over 45mph.

Just don’t want to kill the car after only having it two days haha

Thanks again

Yes, it will be fine, it sounds like it does need a coolant flush/change & see the other post about level, that sounds likely the ACTUAL issue.

Awesome, thanks again for the advice. I’ll get them to flush, look at the sensors and connectors etc

I work at Stagecoach so just wish I could leave it with our mechanics and come back off shift to a fixed car 😂

[GreenV8S]

If you have doubts about the cooling system, it's a good idea to check that the cabin heater works. If it does, that proves you have at least some coolant circulating regardless of what the gauges tell you.

[E-bmw]

92drobinson said:

I work at Stagecoach so just wish I could leave it with our mechanics and come back off shift to a fixed car ??

Or if not, take a courtesy bus home.

[Peanut Gallery]

92drobinson said:

I work at Stagecoach so just wish I could leave it with our mechanics and come back off shift to a fixed car ??

Having been stuck a couple of times in a stagecoach bus due to temps, you might want to double check things!

You mention rusty coloured coolant - rusty, or red? - If rusty, then definitely flush and refill.