E90 330d LCI losing coolant

[maverick328]

Hi everyone,

As the title says, I have lost at least 750ml of coolant over the last 8 days or so. I noticed that the tank was low after having the OFHG changed last month, I though it was odd but topped up and drove.

Last week, on a routine check at home, the coolant level was low again but by about 400ml. Yesterday, I had to top up at least 750ml. I also noticed some sticky stuff on the underside of the coolant reservoir cap.

I must say though, when I purchased the car in October 2021, I was topping up about 100ml every month. It was bad at that time so I didnt have it checked out. Now, obviously its a large noticeable amount of coolant being lost.

There are no visible signs of a leak neither is there any coolant on the floor where it parks overnight.

Where do I start checking?

Many thanks

 

[///M Individual]

Hi everyone,

As the title says, I have lost at least 750ml of coolant over the last 8 days or so. I noticed that the tank was low after having the OFHG changed last month, I though it was odd but topped up and drove.

Last week, on a routine check at home, the coolant level was low again but by about 400ml. Yesterday, I had to top up at least 750ml. I also noticed some sticky stuff on the underside of the coolant reservoir cap.

I must say though, when I purchased the car in October 2021, I was topping up about 100ml every month. It was bad at that time so I didnt have it checked out. Now, obviously its a large noticeable amount of coolant being lost.

There are no visible signs of a leak neither is there any coolant on the floor where it parks overnight.

Where do I start checking?

Many thanks

Hi bud

It may be escaping via the EGR and subsequently exhaust which is why you don't see any coolant leaks.

 

[maverick328]

Hi bud

It may be escaping via the EGR and subsequently exhaust which is why you don't see any coolant leaks.

I also suspected that, thanks for confirmation bud

 

[maverick328]

Nevermind, I found the leak, its leaking on the plastic flange on the top of the radiator inlet

 

[Denver_J]

having the same problem, on my E90 320d, any recommendations, this pipe is like under the intake, did you get it changed?

 

[maverick328]

Not familiar with that pipe, mine is the 330d. Advice though, if it's leaking, get it replaced.

 

[tdi_stig]

Also ensure expansion bottle is not cracked. They split on the seam and let steam out when hot. Dont see the coolant but it goes missing

 

[Solo Man]

So Denver, did you have your pipe replaced. Bought a similar pipe yesterday as my car is losing about 100ml per week. I thought to replace the pipe from below but seems the top bolt is impossible to reach from below. Will now have to remove the inlet manifold (again, as i recently removed the swirl flaps). Bit of a schlep but not so bad. Just a pity i did not do the change when i noticed the pipe leaking when removing the swirlies. Did not think that they would have the pipe in stock at the time but yesterday when i wanted to order it they had it in stock. Was surprised to say the least. Must be a common problem on the N47 and assume the N57 as well?

 

[maverick328]

On the N57 the culprit is usually the top radiator hose. The rubber seals become brittle over time and the coolant starts to leak.

The seals are not sold separately AFAIK, and I ended buying the the whole pipe from The dealer as GW don't stock it.

A few weeks later I changed the radiator and guess what, the seals for that very pipe are supplied with the radiator from GW

 

[Denver_J]

So Denver, did you have your pipe replaced. Bought a similar pipe yesterday as my car is losing about 100ml per week. I thought to replace the pipe from below but seems the top bolt is impossible to reach from below. Will now have to remove the inlet manifold (again, as i recently removed the swirl flaps). Bit of a schlep but not so bad. Just a pity i did not do the change when i noticed the pipe leaking when removing the swirlies. Did not think that they would have the pipe in stock at the time but yesterday when i wanted to order it they had it in stock. Was surprised to say the least. Must be a common problem on the N47 and assume the N57 as well?

Hi, Yes, I got it changed this past weekend, My mechanic took under 20 minutes to change the pipe under the intake. Quick fix but common problem on the E90.