New owner - coolant leak :(

J

jeffers

Member
 South Wales
Hello all,

After picking up my 2008 Z4 Coupe yesterday, today I noticed what looks like coolant on the garage floor. Its leaking from around the screw on the underside of the passenger side fog light and is a blue/green odourless liquid. The coolant level also seems to be lower than I would expect - the float doesnt protrude any higher than the cap. Firstly, am I right to assume its coolant? Secondly, is this a common issue? Its almost in line with the end of the radiator so I'm wondering if its a loose clip or something. Is there an easy way to access it? Everything seems to be covered up.

Some pics:
https://www.dropbox.com/s/u4qsnzotqd8gtk1/2015-06-28%2012.23.36.jpg?dl=0
https://www.dropbox.com/s/egag0674nphisfr/2015-06-28%2012.29.32.jpg?dl=0

I bought the car privately from another forum member so dont really have much recourse when it comes to getting it sorted, although I will drop them an email to see what they say.

Is standard unipart "super-blue anti-freeze and summer coolant" ok to use to top it up? I know some types of coolant cannot be mixed (OAT?) but not sure what the Z4 uses.

Not a great start to ownership unfortunately :(

Thanks for the help
Jeffers
 
Hi jeffers....

Could be the coolant temperature sensor leaking! The 'O' ring perishes!

A mate of mine had the same leaking problem and it was the sensor, we removed the sensor, which obviously dumps the coolant & replaced the 'o' ring on the sensor (think it was green), unfortunately BMW don't sell just the seal & only supply these with a new sensor unit! Luckily we had some 'O' rings in our workshop at work :D

Maybe worth a look! :thumbsup:

Item '5 http://www.bmminiparts.com/DiagramView.aspx?DiagramId=158520&MOSP=49421
GetGraphic.aspx


Terry
 
Thanks for the info. Is the sensor on the right side of the car (drivers side)? the leak on mine appears to be coming from the left hand side of the car
 
Do you have headlight washers. Could be the seal gone in the jet very common have a look and see if you have any liquid in the washer bottle.
 
The coolant stuff is on the passenger side, where the leaks are usually most common.

Common leak problems are usually caused by o ring as above, hairline crack in expansion tank or thermostat.

The thermostat is at the front centre of the engine, so it won't be that. Check expansion tank, although you won't see it leaking until the coolant is up to running temperature and the crack expands.

I ended up changing the expansion tank on mine. Doesn't leak anymore so must have done the job.
 
By the way, the colour on the floor in your pic is the exact colour of BMW coolant, so must be that.
 
Rich61 said:
Do you have headlight washers. Could be the seal gone in the jet very common have a look and see if you have any liquid in the washer bottle.
Click to expand...

This, or a split pipe on the headlight washers, again not un common.
 
Rich61 said:
Do you have headlight washers. Could be the seal gone in the jet very common have a look and see if you have any liquid in the washer bottle.
Click to expand...

Think it could be this. I dropped the previous owner an email and he called to say that he had recently reconnected a dodgy connector to the newly replaced fog lights and that the pipework was in the same area. He said that hes not had to replace any coolant in his ownership. He seems a genuine bloke and put a new MOT on it earlier this week so I dont think its coolant. The washer fluid is the same shade of blue so its very possible.

I've taken the access panels off in the wheel arch and there is water in there but I cant see where the leak is coming from. Strangely I cannot get the washers to pop out to see if they spray equally - arent they supposed to actuate every ~5 pulls of the washer button? Any way to force them out? Something's not right
 
If your lights are on and you wash the windscreen then they should operate every few cycles. Mine always wash the lights the first time I spray the window on a journey if lights are on.
 
Yep - didnt realise the lights needed to be on. Both washers seem to be working ok so I guess theres a split in the pipe somewhere. Ive done all I can through the access panel, i think i need to take a look from underneath. Does the panel just unscrew?
 
Take the front bumper off. Easiest and quickest way in terms of definitely diagnosing a headlight washer fault.
 
If you take the small hatch off that allows you to change the bulbs you should be able to see enough inside the bumper. you can certainly see the light washer jets from here.
get some one to activate them while your looking if its this you should see something
 
After fiddling with the offside hose last night it looks like both sides are leaking this morning :violent1:
 
Could be the coolant temperature sensor leaking! The 'O' ring perishes!

Yep, just had that diagnosed on mine. Already had the radiator and water pump replaced with less than 70k on the clock. Why is the quality of Z4 parts so bad?
 
You must log in or register to reply here.
Back
Top Bottom