Coolant peeing out, help!!

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Wanting Z3
Joined: Sun 28 Apr, 2013 20:57
Posts: 36

  Z3 roadster 1.9i

Coolant peeing out, help!!

Post by Wanting Z3 » Sun 16 Jun, 2013 20:23

Any help would be appreciated here. Car was loosing coolant and over heating. Garage replaced radiator and said it had a hole in it. Got car back took for run and found puddle of coolant below the filler tank. Thinking it was spilled coolant from garage filling.
Took car for 30 min drive today got back and left car running to check fans kicked in, no leaking or signs of coolant. Then fans kicked in and immediately coolant was peeing from the filler cap which appears to be on tight.

What's going on?

Wanting Z3
Joined: Sun 28 Apr, 2013 20:57
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  Z3 roadster 1.9i

Re: Coolant peeing out, help!!

Post by Wanting Z3 » Sun 16 Jun, 2013 21:00

I'm thinking there is an issue with either the filler screw cap or the plastic expansion tank itself. It looks like there is a small nick at the top of the plastic thread on the bottle.

Should the cap have some sort of seal as its just plastic to plastic.

Cheers

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Daz3
Joined: Wed 15 Sep, 2010 20:57
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  Z3 roadster 2.8
Location: Spilsby

Re: Coolant peeing out, help!!

Post by Daz3 » Sun 16 Jun, 2013 21:04

What your temperature gauge doing? It's not unusual to get some coolant seeping out the cap after the systems been filled and bled. The caps are designed to let excess out until the systems pressure is correct. May be worth bleeding the system out again once cold or take it back to the garage and let them sort it.
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Daz3
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  Z3 roadster 2.8
Location: Spilsby

Re: Coolant peeing out, help!!

Post by Daz3 » Sun 16 Jun, 2013 21:05

Just another note only open the filler cap when cold else air can be drawn into the system causing airlocks.
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sirius-c
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  Z3 roadster 2.8
Location: Eeh ba gum lad, 'ow do?

Re: Coolant peeing out, help!!

Post by sirius-c » Sun 16 Jun, 2013 21:06

have they cross threaded your filler cap perhaps or not put it backon correctly?, i did this and when engine was up to temp coolant pssed out. i was lucky.... i unscrewed it and the second time i screwed it back on it was fine, but i could feel the difference between not screwed on right and screwed on right
1997 2.8L Z3 Roadster

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Designed or not designed, that is the question.

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TitanTim
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  Z3 roadster 1.9i
Location: Stafford

Re: Coolant peeing out, help!!

Post by TitanTim » Sun 16 Jun, 2013 21:08

I seem to remember there is a seal at the bottom of the expansion tank which can fail and weep so check that if its not the cap. It could be when the radiator was swapped out they damaged the seal when disconnecting the tank etc. Have a feel around the bottom of the tank and see if its wet.

Tim.
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2001 Z3 1.9 Roadster Sport - 2012 Z4 sDrive 2.0 M Sport

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sirius-c
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  Z3 roadster 2.8
Location: Eeh ba gum lad, 'ow do?

Re: Coolant peeing out, help!!

Post by sirius-c » Sun 16 Jun, 2013 21:09

they may have overfilled the cooling system, as Daz3 says, the cap is designed to release any excess
1997 2.8L Z3 Roadster

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Designed or not designed, that is the question.

Del
Joined: Sat 19 Nov, 2011 18:35
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  Z3 roadster 1.9

Re: Coolant peeing out, help!!

Post by Del » Sun 16 Jun, 2013 21:18

Sounds like a radiator cap issue. The correct release pressure is (I believe) 2 bar. However, see the attached link - a forum member bought a replacement radiator from Eurocarparts (commonly used in the trade) and had a problem with his OE BMW cap not fitting the new expansion tank properly.

http://www.zroadster.net/forum/viewtopi ... 62#p341562

Wanting Z3
Joined: Sun 28 Apr, 2013 20:57
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  Z3 roadster 1.9i

Re: Coolant peeing out, help!!

Post by Wanting Z3 » Sun 16 Jun, 2013 21:25

It's only started to happen since the new radiator has been fitted. When cold the coolant is about 6" from the top of the bottle

Jonco
Joined: Sat 04 Jun, 2011 08:24
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  Z3 roadster 1.9
Location: Cheshire

Re: Coolant peeing out, help!!

Post by Jonco » Sun 16 Jun, 2013 22:18

Wanting Z3 wrote: It looks like there is a small nick at the top of the plastic thread on the bottle.
I fitted a new expansion tank from carparts4less last week due to bottom seal leak and the new one leaked from a flaw in top capilliary connection. You can temporarily remove the top retaining plate on the expansion tank to get a better view and then squeeze the top radiator hose to create an overflow to tank. My leak point was obvious when I did that. Ended up refitting old tank with new seals and now ok :head:

BIG DAVE
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  Z3 roadster 1.9i
Location: MOTHERWELL

Re: Coolant peeing out, help!!

Post by BIG DAVE » Sun 16 Jun, 2013 23:37

sound like system not blead properly had the same problem. front of car needs to be higher when refilling to stop air being trapped, end up took me five days to fix before i found this method out started with engine cold heater to max slowly add water with engine running good luck
big dave
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
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  Z3 roadster 1.9

Re: Coolant peeing out, help!!

Post by BladeRunner919 » Mon 17 Jun, 2013 08:00

If you've paid a garage to fix it, then the sole responsibility for diagnosing the problem is theirs. Take it back and have them sort it.

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Southernboy
Joined: Thu 07 Oct, 2010 13:39
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  Z3 roadster 3.0i
Location: Johannesburg

Re: Coolant peeing out, help!!

Post by Southernboy » Mon 17 Jun, 2013 08:34

...one more small item to check...and one which is often overlooked...check the hose connection to the bottom of the expansion tank...it's a bit difficult to get to, but it's often the leak point for just that reason. Once the cap is on, and fitted correctly, there should not be any leak at any temperature. Also, check the bleed screw on top is fitted / threaded and tightened correctly. It's the one which has a large "+" on top of it. It must seal as well as the screw on cap to create pressure in the system. Pressure raises the boiling point of the coolant, which means that it won't boil under normal use. Lack of pressure lowers the boiling point, and is a result of a leak.
However, as you have had the system repaired by a workshop, I would take it back immediately, and have them do the job properly.
The radiator has a drain outlet at the bottom right (when facing the motor with the bonnet open) It has a large hose at the top right, a small hose at the top right which feeds from / to the expansion tank, and a large hose which comes from the motor to the bottom of the expansion tank / bottle.
So, those are the only points where you can possibly have a leak into / out of the radiator / expansion tank configuration. There are other hoses / connections where you may have a leak, but they are related to the heater and depending on your car model, there are hoses which run hot water into the bottom of the throttle to ensure it doesn't freeze up in winter / extreme cold. (Later models have an electrical heating system for the throttle)
In any event, all the water hoses are on the right hand side of the engine as you would see them if you were facing the front of the car with the bonnet open, with the exception of the expansion bottle / tank hose which is on the opposite side of the radiator.
To get to the hose connection under the expansion tank, you will need to remove the 2 locking pins at top L & R of the cowling / radiator. This will allow the radiator to be lifted up with the cowling and give you access to the bottom of the expansion tank. The expansion tank fits into a housing at the bottom of the cowling. It's a tight fit, and is aggravated by the hose clamp down there on the large hose. It's important to position the clamp so that the expansion tank will fit into that housing without the hose clamp screw fouling when you fit it in....a real B*%"ch in a confined area to work in....
"Normal is overrated"
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Wanting Z3
Joined: Sun 28 Apr, 2013 20:57
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  Z3 roadster 1.9i

Re: Coolant peeing out, help!!

Post by Wanting Z3 » Mon 17 Jun, 2013 18:10

Fitted a new coolant cap and the lead seems to have gone.

There was a tiny, and I mean tiny nick in one if the ring seals on the cap thread do you think this would have been enough to cause coolant leaking out of cap, about 2mm

SeriousRikk
Joined: Thu 06 Jun, 2013 17:10
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Re: Coolant peeing out, help!!

Post by SeriousRikk » Mon 17 Jun, 2013 18:16

When under pressure, a nick in a rubber seal will likely let stuff through.

Good spot, glad it's sorted
Richard - Old Zeddy's new home...

Wanting Z3
Joined: Sun 28 Apr, 2013 20:57
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  Z3 roadster 1.9i

Re: Coolant peeing out, help!!

Post by Wanting Z3 » Mon 17 Jun, 2013 19:33

With a bit of luck I can now look forward to my 2000 mile round trip to the Le Mans 24 Hour starting tomorrow.

Thanks for all your help this is a great forum

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