Continuously loosing coolant - but no leaks !! - United Bimmer Community

**championc** · 05-16-2010, 10:58 AM

Hi all,

I'm continuously needing to top up my coolant level - even though I have no leaks anyhwere. I have a 1.9 M43 (316 Compact). I am almost 100% certain that I have an airlock trapped somewhere in the system but I still can't get rid of it.

My driveway is on quite a slope so when parked, it's exactly like being jacked up (as stated in the Pelican procedure). This morning (no different to many others), I started the car and I immediately heard this flapping / tapping noice which I am 99% convinced is coming from the water pump. Once the car is running for 5 seconds, the sound stops.

I have now just started poking around the engine (to try and get to the bottom of this once and for all). When I squeezed on the water hose in a few places, I could hear a small tapping sound coming from the part indicated on the photo below. I've no idea as to what this part is or does.

Please Help

Cormac

**bimrpwr** · 05-21-2010, 11:04 PM

have you checked your oil?

**renald12345** · 05-21-2010, 11:58 PM

Check your oil, you head cylinder may be crack or need new gasket. if it did over heat than your head need replace.

**championc** · 05-22-2010, 06:01 AM

The oil is perfect. I know the E36 Compacts don't auto bleed air and that if you have any air in the system, it basically leads to the car overheating buy obviously boiling off the water.

Have you any idea as to what the part is that I have circled in the photo ?

C

**renald12345** · 05-22-2010, 08:18 AM

The E36 cooling systerm is know to fail with in 60 milles causing over heeting. they sale an overhall kit with a hight performance pump. not too costly if you do the work yourself.
That what I would do.

**championc** · 05-22-2010, 11:12 AM

And this is compatible with a year 2000 BMW 316 E36 Compact - yes ?

Mind you, the doesn't overheat once I keep an eye on the water level. I typically seem to lose about 1/4 mug of water over a 1 hour journey so it's not as if it's spilling out somewhere.

Anyone know where the temperature sensor is ? The one that gives the temp on the dash

**championc** · 05-25-2010, 03:19 AM

I might have stumbled on something. After parking the car (with the engine hot) I started to look around again for any signs of water / leaks. Around the back of the engine, between it and the bulkhead, I could hear a gentle hiss (boiling spitting hissing sound). It's difficult to see around there so I can't see if there is a water pipe that exits.

Any ideas ?

C

**kazamali** · 06-04-2010, 01:58 PM

If you're seeing coolant residue around that area, then I'd say you've found your problem.

**championc** · 06-05-2010, 09:43 AM

Quote:

Originally Posted by kazamali

If you're seeing coolant residue around that area, then I'd say you've found your problem.

No coolant residue anywhere. Anyway, I've just replaced the Thermostat (damn expensive) and so we'll see does this sort the problem out. In addition, by changing this, it obviously meant draining the system completely. I'll know better in a few days.

C

**kevzep** · 06-10-2010, 09:55 AM

Hi, how's it going?
Have you found out what that part is yet? http://www.realoem.com/bmw/partgrp.d...52&hg=11&fg=45
Are there any part numbers or makers name on it?
There should be a bleed screw on the thermostat housing, this should be left open when filling the system untill you get coolant with no air bubbles.
There are hoses at the back of the engine for the cars heater, it could be leaking from there.

**championc** · 06-10-2010, 05:37 PM

Hi all,

I changed the thermostat on Monday but by Wednesday the water in the rad was very low so it looks like I'm no further. When I look at the realoem diagrams, there's feck all pipes in the circuit so I'll just have to disconnect each one and re-connect then in case one has a bad connection. The one thing I do know is that there's no leak at the connector into the engine block on the underside of the inlet manifold.

I'm wary of touching the pipe into the heater matrix since one pipe collar broke years ago but there was just enough of a stump to clamp the pipe with a jubilee clip.

C

**championc** · 06-29-2010, 10:26 AM

Finally, problem solved.

That boiling spitting hissing sound that was coming from the back of the engine (where it meets the bulkhead) - while there was no water squirting out nor any steam, but it was tiny amounts of water just boiling away. So yes, there was a tiny leak in the head gasket.

There was only one thing for it - a bottle of Wondarweld. A friend told me to dump it into the tube close to the engine block so it circulates quickly into there so I took the hose off the Rad on the right hand side (down where the date and time are in my engine photograph). The Holts Wondarweld did the trick and no more spitting or hissing and no more water loss. Obviously, a hell of a lot better than needing to get a head re-skimmed.

C

**yiddo1959** · 06-29-2010, 04:21 PM

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