Not sure if the temp gauge is working?

[Bringit96]

Hey everyone!

I'm looking to fix a few more bits on the Zed starting with the temp gauge, if it is broken. I just want to make sure because I plan on taking it for a track day and I don't want it to overheat because the dial isn't working

If I leave the car standing or it is in traffic the temp gauge will sit in the middle. I believe this is how it is meant to be. It's never gone past the middle either so I guess that's a good thing.

However, when I'm driving on a clear road or on the motorway, the gauge drops all the way down to cold. Obviously the engine is hot but does this mean that it's not overheating? If it were would the gauge go back up?

So is this just the gauge or the thermostat as well?

*Off topic*
I am going to basic track prep i.e change all the fluids, get bigger brake pads and change tyres
Hoping to deal with suspension, hoops, steering wheel at a later date but for now I think that's all I need to do from what I've read!

 

[Ianmc]

I would change the thermostat first, these symptoms are not uncommon with these cars.

 

[Stevo7682]

Sound like i would initially be looking at a possible thermostat problem .
When the the temp gauge drops what are the the cabin heaters like do they also lose temp.
Basic check would be start engine cold after a few mins as temp gauge starts to rise 2 pipes into heater at bulkhead should start to heat slight heat to top radiator hose ( thermal transfer) bottom radiator and radiator should be cold till the engine gets up to proper temp and the thermostat opens .
Any heat before would indicate jammed open .
Could still be operating not at right temp though.
Had similar problems with my skoda a couple of years ago new thermostat fixed it .
Stephen.

 

[colb]

To test the guage for full swing across the range find the temp sensor wire on the engine and with ignition on take the wire off the sender and put it to a good ground on the engine. Watch what the guage reads, grounding the wire should cause the needle to swing across its full range.
The symptoms you are having would usually indicate a duff thermostat, best put a new one in and see if that puts it right.

 

[Sean d]

Where abouts in Lincolnshire are you, are you doing a track on Cadwell.

 

[Antm72]

Mine did this the thermostat was the issue in my case replaced it and has been fine

 

[NZ00Z3]

I agree with the others, you have a duff thermostat. Had the same symptoms a while back and a new thermostat fixed it.

The temp gauge is heavily dampened in the middle of its range and its not a linear scale. Its a comfort guide, once it gets right of 12 o'clock, you've got problems. Can't remember all the details (degrees C etc), do a search on the E46 forums and you'll find details on how they reprogram their temp gauge.

An easy way to get the real coolant temp is to plug an OBDII dongle into the port below the steering column and run an OBDII app on your phone. People tracking their cars sometimes set up a small table on the dash with various important gauges this way.

 

[Bringit96]

Awesome, thanks for the replies. When I get a chance I'll run the tests and most probably change the thermostat.

The cabin heaters only get hot at the hottest setting. It's that or cold air no matter the temp on the gauge. Until today, maybe my Zed has a 6th sense

Where abouts in Lincolnshire are you, are you doing a track on Cadwell.

I'm near in between Boston and Spalding when I'm home, but I'm in London during the week for Uni. No I'm going for the Silverstone in March hopefully

 

[mrscalex]

Most Z3s only blow hot on the highest heater temp. setting.

 

[UKKid35]

If you haven't changed it already, then bring the car over next time and we'll do it then

It is definitely worth fixing as it will be killing your mpg in this weather, and the cabin will never heat up

Looks like the thermostat is not a cartridge, but a complete assembly - £30 in Eurocarparts - or £20 with the current online discount code

Seems to include a rubber seal, and has four securing bolts - are they prone to corrosion/seizing?

What is access like on a 1.9? Any significant disassembly needed?

How much coolant do you have to drain?

 

[UKKid35]

I forgot to check You Tube - seems like a fairly straightforward job, perhaps the most awkward part is removing/refitting the fan cowling

View: https://www.youtube.com/watch?v=EJdSW3pSby4

View: https://www.youtube.com/watch?v=5c0i5fXnOJM

 

[Bringit96]

Just a quick update. Thanks for all the help first of all!

I've changed the thermostat and everything seems to be working well! Driving down to London tonight so a nice run on the A1 should spring up any problems.

This is the first engine work I've ever done and apart from it taking me hours it was quite fun and satisfying to do. Now got the bug to jump in and do more work!

 

[BMBabe]

@Bringit96 now your Zed is fixed
Come down to SILVERSTONE on 2nd April if you are free The taster track got moved due to the snow

 

[Bringit96]

@Bringit96 now your Zed is fixed
Come down to SILVERSTONE on 2nd April if you are free The taster track got moved due to the snow

I'll make the call tomorrow!

Well I made it down, my heating is working and the temp gauge sat nicely in the middle the whole time.

 

[Jaa3409]

Awesome, thanks for the replies. When I get a chance I'll run the tests and most probably change the thermostat.

The cabin heaters only get hot at the hottest setting. It's that or cold air no matter the temp on the gauge. Until today, maybe my Zed has a 6th sense



I'm near in between Boston and Spalding when I'm home, but I'm in London during the week for Uni. No I'm going for the Silverstone in March hopefully

I live in Quadring Eaudyke, not far from you , funnily enough the z I have just bought is having the same issues lol

 

[Bringit96]

I live in Quadring Eaudyke, not far from you , funnily enough the z I have just bought is having the same issues lol

Well it's a relatively easy job to do at home if you want to do some DIY! Have fun with the Z!