Coolant level

[Joez4]

Hi,

I've recently woken my zed up from it's winter sleep
And have been giving it a check over anyway I've noticed that my coolant level has dropped from the float been 2cm above the fill neck to it now been just below the minimum mark.

The last time I checked tho was in September before a 200 mile drive into Wales and back which the car managed without issue

I also noticed slight mayo on the oil cap but I suspect that its from the car only been driven 8 miles to work and back the last few months before winter kicked in and the odd drive over Christmas.i cleaned the mayo off and have driven the car a few times since and pulled the oil cap to find slight moisture on the cap I've no other reason to suspect head gasket failure as the car runs fine.

Also my coolant is red not blue it looks pretty clean to me I've owned the car just under a year and have no history on when it was changed so for now I'm planning to top up with distilled water and keep an eye on it would this be OK and would that much coolant loss be considered normal or not?

Sorry for the long post.

Joe

[Street]

I’d just keep monitoring over time. It could be a simple air bubble/lock in the heater matrix that has blown through with your long drive.

[Chris_D]

Give it a good run to get rid of any condensation buildup in the engine.

[Joez4]

I did suspect I might have an air lock as the heater never really gets hot even when the car is upto temperature it gets warm only.

Is it worth topping up and bleeding the system, if so how do I do that?

Thanks

Joe

[colb]

Get the car as high as you can at the front so the filler and bleed screw are the highest part of the cooling system, a good pair of drive on ramps is ideal to get it high enough. With the filler cap off check level and then start the car run up to temp, guage should be at 12
o'clock with thermostat fully open once hecar is up to temp. Keep an eye on the open filler and bleed screw watching for escaping air, the heater controls should be set to fully hot so the heater matrix is getting flow. Depress the radiator top hose to help push the coolant through the system keeping an eye on the open filler and bleed screw for escaping air. Once you see no more air bubbles put the filler cap on and close the bleed screw so the system pressure builds up. Loosen the bleed screw after a while and see if any more air escapes, once you see no air comming out tighten the bleed screw and monitor the temp guage and check the heat output from the heater, bleeding should be complete. If the car takes ages to warm up then consider a failed thermostat in the open position, the car will take ages to warm up and the guage will sit below the 12 o'clock position if this happens on your car then put a new thermostat in and repeat the bleeding sequence.

[Joez4]

Thanks for all the useful information I will bleed the system this weekend and see what happens.

Out of interest does anyone know if the red coolant I have in my car could be a suitable alternative to the bmw stuff, same type just different manufacturer used a different colour etc or more likely someone couldn't be bothered with the bmw stuff and put what they wanted in?

[Mr Tidy]

It's far above my technical ability to understand the different chemical make-up of different brands of anti-freeze, but my ex-Sytner BMW Indy said anything blue will be fine!

OE BMW coolant is blue.

[Z4Mariner]

This is likely not your problem, but don't overlook the expansion tank (ET) cap as a path for disappearing coolant. I owned a 128i convertible with no visible leaks and no head gasket issues, but each week the coolant float was down a bit. Installing a new ET cap solved the coolant loss. Fresh O-rings on the new cap required noticeably more torque to screw it into the ET.

[Joez4]

I'm planning to now bleed the system whilst doing an oil change, clutch delay valve removal and if time allows change the serpentine belt, I'm wondering how other owners jack and support the front of the car safely?

I have a 2.5 ton rated low profile trolley jack and a pair of 2 ton each rated stands and 4 wheel chocks, when I rotate my wheels I jack the car from the rear pad which lifts the entire side so I can put a jack stand under the front pad and one at the rear by the jack incase it fails.

Would it be better to get both sides of the front of the car off the ground and supported with stands before going under the car and if so can I jack from anywhere other than the jack pads so I can use them for the stands and still have the jack supporting the car too?

Sorry for going off topic abit

[enuff_zed]

I think I would be considering raising the front but with the wheels on. As in, using ramps etc. it’s a safe end result and also a safer way to achieve it.

[Joez4]

I have toyed with the idea of getting some ramps and jacking the car up onto them but the ones I saw didn't fill me with confidence after reading a few reviews etc,

Can anyone recommend a good pair?

[Joez4]

So having replaced the coolant expansion tank due to the infamous hairline crack I also decided to replace the thermostat too, which was a good idea as it was covered in gunk and the gasket had failed but with no obvious sign of a leak.

Now I'm flushing the system to get as much of the red coolant out as possible without touching the block drain, and I have a couple of questions if anyone could help me out that would be great,

The thermostat opens up at 97c so does that mean the live data for coolant temperature needs to read 97c? The car temp gauge hits 12 o'clock after 10 mins at idle now at a temp of 75c it was taking over 20 mins on old thermostat, I've noticed that the bottom radiator hose is cold at this temp so does that mean the thermostat hasn't opened yet?

Also I now have plenty of heat coming through the driver and middle heater vents but not the passenger does this mean I still have air in the system?

[smorris_12]

The centre position on the temp gauge represents a range of temperatures. If the live data says 75C then it's too early for the stat to open and the hose will be cold.