[JPC-BMW]

Hello, the Mrs has a coolant leak somewhere on her 116i 2012 F20. It seems to be getting worse but I can't for the life of me find where it is leaking from.

Been waiting to book it in a BMW, however wanted to try and find the problem first so I could get an idea of price if it wasn't a simple fix.

I can't see any gunk around the oil filler cap, so hoping that rules out a head gasket.

The carpets aren't wet in either footwell, I've had the lower trim off the dash and can't see any obvious leaks around the heater matrix.

The coolant bottle itself is intact and the pipes leading away have no signs of leaks on them.

The radiator from what I can see is the same no obvious leaks etc.

There doesn't appear to be any puddles on the floor when the car is parked up. I thought it may have been because of the cover at the bottom of engine bay stopping coolant dripping to the floor but removed most of that cover today and couldn't see anything obvious to suggest it had been dropping down.

I'm guessing the water pump is at the front of the engine bay? Can't see any signs of leaking around the belts / front of the engine etc.

Today when I parked up with the engine hot and opened the bonnet, I could hear a faint hissing sound and the sound of water or something fizzing.

In this picture where the red circle is, was where it sounded like it was coming from. A closer look and could just about see some white water stains in that area which could be coolant, or could be a coincidence. The sound could have been from water dripping off the bonnet into a hot engine bay / exhaust manifold etc.

This next picture is just a close up of the area.

I can't seem to get to it from the top to have a better look.

I'm not sure what is back there, if a coolant pipe even runs back there? However if that is where the leak is from and if it is dripping onto something hot and evaporating then that would explain why I can't see any obvious signs of coolant dripping anywhere.

From a bit of research, there is mention of a T- piece connector which is a common problem - is that where that is located?

Anyone know how I could get a better look / fix it?

Any advice or thoughts allways very appreciated.

Sent from my iPhone using Tapatalk

 

[Octavius]

Are you having to top the coolant up :?:
The Coolant problem, is a known issue of the F20 with petrol engines. BMW will change the expansion bottle, coolant level sensor and coolant for free, all as warranty work. you should go to your dealer and ask them for that. It is a know problem

 

[JPC-BMW]

Yes we had the sensor and expansion bottle replaced a while ago (over a year). However currently have had to top it up several times, between first and second time it was a month, and now it has been 2-3 top ups within a month.

 

[Fraggle]

I've recently had mine investigated for coolant loss with no visible trace of the leak, it was diagnosed as a leaking header tank (coolant bottle) and changed under warranty, had no loss at all since.

 

[JPC-BMW]

I am hoping for a cheap fix however I'm 99% certain there is no leak around the bottle

 

[JPC-BMW]

So it's now dropped down to just a week between top ups! The trip to BMW on Monday can't come soon enough!

Any other ideas where the coolant could be leaking from?

 

[JPC-BMW]

So car is in BMW as we speak and they have updated to say it is leaking from the "coolant housing" at the rea of the engine and it requires replacing.

What is the coolant housing? And what should I be expecting to pay?

 

[JPC-BMW]

Car all fixed just for the benefit of anyone who suffers similar problem. It was leaking from what was described as "coolant housing to rear of cylinder block" I'm not sure if this is the T-piece connector I have seen mentioned elsewhere.

As for cost of repairs, the service advisor called and said parts and labour would be £560-ish! But in the next sentence said that she had got BMW to agree to contribute and ultimately the whole repair cost £214.

Considering diagnosing the fault was quoted at£90 and we had a courtesy car, thought the price was quite reasonable. Especially as the car is out of warranty.

Hope the information comes in useful to someone.

 

[MaseMCR]

I have recently had a couple of F20 116i sport in for a coolant leaks and both have been in the same locations now, so am assuming it might be common on them.

First leak was on the small aluminum coolant pipe on the cylinder head that sits beneath the turbo. It is a push on connection on one side and has a small hose on the other side. You will need to disconnect the small hose from the bigger aluminum pipe it connects to. There is a small o-ring on the big that the pipe pushes on to on the head that needs replacing.

Second leak was right at the back of the engine. If you follow that big aluminium pipe that lead around to the back of the engine, it leads to a small plastic housing on the back of the engine. The gaskets go dry and on both cars the bolts where not quite tight enough! I don't know if this is a production **** up or what??? I replaced the full housing and seals and it was an absolute nightmare to change with the gearbox still in place

 

[BMWLE]

MaseMCR do you have an pictures/ part numbers for the part at the back of the engine?? my 116i is leaking about 1ltr every other day and it seems to be coming from the back of the engine

 

[Shamdogg]

Same issue aswell, hopefully MaseMCR replies as I can head it from the rear of the engine 😣

 

[edbutler]

Why does this thread have 12,000 Views!??

Guys, take a look on RealOEM and just find the part you think is leaking. If your's is the 3Cyl 116i however, i cannot see any coolant pipes at the rear of the engine itself. The thermostat module is to the front and the WP is on the side. It could be the hose going to the heater matrix perhaps?

 

[Shamdogg]

MaseMCR do you have an pictures/ part numbers for the part at the back of the engine?? my 116i is leaking about 1ltr every other day and it seems to be coming from the back of the engine

For all who are interested I have sorted my coolant leak. It was the thermostat housing at the rear of the engine. Was a ******* to do but did it and was only £45 for the actual housing and thats including the thermostat and rubber hose as it comes in one unit.
I believe the actual failure point was the thermostat seal as it had become hard and brittle meaning it would become less likely to be able to maintain a seal.
is quite a ******* to do but if I can do it anyone can.
If anyone wants anymore details just ask. Cheers

 

[McTrucky]

MaseMCR do you have an pictures/ part numbers for the part at the back of the engine?? my 116i is leaking about 1ltr every other day and it seems to be coming from the back of the engine

For all who are interested I have sorted my coolant leak. It was the thermostat housing at the rear of the engine. Was a b**tard to do but did it and was only £45 for the actual housing and thats including the thermostat and rubber hose as it comes in one unit.
I believe the actual failure point was the thermostat seal as it had become hard and brittle meaning it would become less likely to be able to maintain a seal.
is quite a b**tard to do but if I can do it anyone can.
If anyone wants anymore details just ask. Cheers

Nice Shamdogg, I love seeing conclusions and fixes posted, not just problems. 😊

 

[aydhayeth]

Hello,

I registered just to say thanks for this post. Having the same issues and PM'd you about it.

CHeers

 

[Muckiy]

For all who are interested I have sorted my coolant leak. It was the thermostat housing at the rear of the engine. Was a b**tard to do but did it and was only £45 for the actual housing and thats including the thermostat and rubber hose as it comes in one unit.
I believe the actual failure point was the thermostat seal as it had become hard and brittle meaning it would become less likely to be able to maintain a seal.
is quite a b**tard to do but if I can do it anyone can.
If anyone wants anymore details just ask. Cheers
[/quote]

Hi, this very same issue has happened to mine. I ideally don't want to get bent over by the garage in labour fees... Are there any instructionals or anything which you used or could recommend?
Any help would be massively appreciated.
Thanks

 

[nathanseaman]

Following this

Where is the best place to get the thermostat housing ?

 

[Hydracor]

Also would like to know how to fix this issue at home, any help would be greatly appreciated!

 

[NoodleKing]

Also having this problem, any info on how to fix this/ballpark figure would be much appreciated!
Thanks

 

[whodareswins1]

I had a coolant leak that progressively got worse. Got it repaired for about £280 all in. It was the lower coolant/thermostat pipe housing. The seal was leaking at the back of the engine. Bit of a bugger to replace from what he said but it's all good now.