[lethbridge]

Hi, just interested in whether others have needed to top up their coolant at all? Mine is a 2015 with just coming up to 60k miles. I've never had to top up before but I guess this may have been done at routine servicing (I've done high mileage on 2 other 35ds + a number of other BMWs). Anyway I've just got the alert that the level is low... I've checked & the coolant is low in the tank (so not a faulty sensor) but at least it isn't empty!! I will top it up and monitor it & then get it checked over when it goes in for its next service in 2k if all is well...

[onstat]

Never on mine (2016 and 23,000 miles)

[EvilDrPorkChop]

Low coolant in a 335d is usually an EGR cooler problem. Parents X3 35d just had to have theirs replaced, due to the same issue/symptoms you describe.

Also think Tengocity has had his replaced?

[Mr Whippy]

If you get VRM of MOT age 335d on Autotrader etc you can look what advisories they have.

I've seen a few with slight leak from radiator.

Then again that could be dodgy mot tester observations.
But it's not unknown for BMW rad end tanks to fail/leak.

Dave

[Tengocity]

Originally Posted by EvilDrPorkChop

Low coolant in a 335d is usually an EGR cooler problem. Parents X3 35d just had to have theirs replaced, due to the same issue/symptoms you describe.

Also think Tengocity has had his replaced?

I've had a cracked EGR pipe replaced a couple of years back but no coolant loss due to it.

However MarkG_M3CP had a more substantial EGR issues that involved coolant loss IIRC, as I think he needed to roadside rescue from BMW!

[Mr Whippy]

I can't believe they use the same loop for EGR which leaves the entire engine coolant loop exposed.

Given the excess capacity in intercooled charge air at the same duty cycles you'd want EGR cooling, why not blow EGR over another heat exchanger post intercooler?
Or go BMW M style with an air water charge cooler and share that?

In either of those cases any EGR failure isn't a potential complete engine failure.

Hmmm

[Ross_T_Boss]

I had a low coolant light and topped up about 1l, can't recall exactly but it was about 40k miles on the clock as it was shortly after the second service.

Now at 72k miles and it's not come on again, and doesn't appear to have dropped by much.

Keep an eye on it, if it comes again it's an issue to be looked into further.

[R330dx]

I’ve had coolant loss with egr cooler failure, egr cooler replaced, not used any coolant since. Not sure if the coolant was lost through The cooler cracking or the coolant connection to the block which is a very simple arrangement of o rings on 2 tubes .

[1966-TR4]

I had this (330d) about two weeks after major service. Needed about a litre to bring it up to Min. Keeping an eye on it.

[Kal101]

I had the egr cooler leak on my 335xd. Required topping up on a more frequent basis as I presume the leak got worse.

Luckily repaired under warranty.

[lethbridge]

Thanks for the feedback all - suspect I've got the EGR coolant leak issue too as I've topped it up and the level has dropped nearly an inch after 500 miles. It's due an oil change in a few weeks so I'll get it sorted then (under warranty)...

[lethbridge]

Just an update on this - car went into dealers for a service and I asked them to check coolant leak and that I suspected the EGR Cooler issue. They have just confirmed that the EGR Cooler does need replacing (under warranty for me). Thought it worth mentioning as I think one or two have had similar symptoms to mine & have possibly then ignored as the issue can appear to go away: I had the alert that coolant was low. Topped up & monitored. After my next 500 mile trip it dropped 1cm. I topped up again and since then (probably another 1000 miles) it had dropped a negligible amount.

So I would recommend that you don't ignore it or at least get it sorted while you are under warranty. The symptoms suggest it leaks into somewhere that is sealed - i.e. you get an initial loss & then that seems to be about it - I assume it will recur in a bad way if you don't get it fixed!

Also, I have had the issue a few have commented on where you get random blasts of cold air out of the mid level vents when set to red & heating at auto (only noticeable on longer journeys). The dealer has suggested that this could be a symptom of the issue - not convinced so I'll see once I get the car back..

[Dizzle]

Annoyingly I have these symptoms. My '14 335xd (now on 61k) outside of warranty, only had it for about a month . I got 'drivetrain' problem on the idrive "drivetrain issue...please drive moderately" plus the coolant low warnings, observed a few tiems after a run. steam coming from the engine, difficult to locate where exactly......... taken it to a local indy, error codes diag'd as faulty EGR valve. Had the EGR valve replaced, system was pressure tested with no noticable leaks, coolant checked, drove away (plan to take up the bill with the garage I brought it from) only to get the coolant low warning again Taking it back to the Indy on Friday.

There is still little coolant in the bottle, but 'top' it up and its guzzles about half a litre or more. Trying avoid using it until it goes in...

[moonshine]

Originally Posted by lethbridge

Just an update on this - car went into dealers for a service and I asked them to check coolant leak and that I suspected the EGR Cooler issue. They have just confirmed that the EGR Cooler does need replacing (under warranty for me). Thought it worth mentioning as I think one or two have had similar symptoms to mine & have possibly then ignored as the issue can appear to go away: I had the alert that coolant was low. Topped up & monitored. After my next 500 mile trip it dropped 1cm. I topped up again and since then (probably another 1000 miles) it had dropped a negligible amount.

So I would recommend that you don't ignore it or at least get it sorted while you are under warranty. The symptoms suggest it leaks into somewhere that is sealed - i.e. you get an initial loss & then that seems to be about it - I assume it will recur in a bad way if you don't get it fixed!

Also, I have had the issue a few have commented on where you get random blasts of cold air out of the mid level vents when set to red & heating at auto (only noticeable on longer journeys). The dealer has suggested that this could be a symptom of the issue - not convinced so I'll see once I get the car back..

The heated issue is not related to the EGR.
Search for posts about fluctuations in AC temp. I had the same issue and it was sorted by a software update that reprogrammed the heater sensitivity

[Mr Whippy]

Can anyone take pics if their EGR heat exchanger?

It's easily visible at front of engine.

My Oct 16 car on 5k miles has light corrosion on heat exchanger to end cap welds basically.

It seems to me like a cheap part and/or part not made up to spec.
These elements on primary coolant circuit shouldn't be failing so early imo.


I'm curious if these heat exchangers begin weeping from the end tank joins and slowly using coolant.

[sensible]

Mine is a B48 petrol engine, so probably slightly different. Less than a week after having my first service (2 years and 19,800 miles) My low coolant light came on. I took it back to the dealers. There was no visual leaks and they pressure tested it and it was fine. They topped it up and said it required a very small amount. I believe the other petrol B58 cars on this forum have had it too.

[Kal101]

Originally Posted by Mr Whippy

Can anyone take pics if their EGR heat exchanger?

It's easily visible at front of engine.

My Oct 16 car on 5k miles has light corrosion on heat exchanger to end cap welds basically.

It seems to me like a cheap part and/or part not made up to spec.
These elements on primary coolant circuit shouldn't be failing so early imo.


I'm curious if these heat exchangers begin weeping from the end tank joins and slowly using coolant.

Think Mine was actually leaking into the engine intake system as I had to have the engine decoked and cleaned out once repaired.

Ran it on a tank uk of Bp ultimate as well just to make sure.

[EvilDrPorkChop]

Originally Posted by Dizzle

Annoyingly I have these symptoms. My '14 335xd (now on 61k) outside of warranty, only had it for about a month . I got 'drivetrain' problem on the idrive "drivetrain issue...please drive moderately" plus the coolant low warnings, observed a few tiems after a run. steam coming from the engine, difficult to locate where exactly......... taken it to a local indy, error codes diag'd as faulty EGR valve. Had the EGR valve replaced, system was pressure tested with no noticable leaks, coolant checked, drove away (plan to take up the bill with the garage I brought it from) only to get the coolant low warning again Taking it back to the Indy on Friday.

There is still little coolant in the bottle, but 'top' it up and its guzzles about half a litre or more. Trying avoid using it until it goes in...

If it has full service history at BMW, you'd of more than likely got it done as a gesture of good will at BMW or some contribution.

[Dizzle]

As an update the Indy has taken the cooler off to find a split in the bypass pipe and it is wet on the inside of the cooler. Recommended replacing, unit proce for the part estimated around 450.

[Ajs_435d]

Originally Posted by Mr Whippy

Can anyone take pics if their EGR heat exchanger?

It's easily visible at front of engine.

My Oct 16 car on 5k miles has light corrosion on heat exchanger to end cap welds basically.

It seems to me like a cheap part and/or part not made up to spec.
These elements on primary coolant circuit shouldn't be failing so early imo.


I'm curious if these heat exchangers begin weeping from the end tank joins and slowly using coolant.

What exact pictures do you need? i can take some.

Cheers

[Mr Whippy]

Originally Posted by Dizzle

As an update the Indy has taken the cooler off to find a split in the bypass pipe and it is wet on the inside of the cooler. Recommended replacing, unit proce for the part estimated around 450.

I'd be interested if they/someone could pressure test the heat exchanger to see if it's leaking.

If you do replace it it'd be worth checking yourself. Just seal the end tanks with a T off for an air line and then see if it'll hold even a few psi.

If the heat exchangers start leaking inside that's not a reassuring situation.

[Mr Whippy]

Originally Posted by Ajs_435d

What exact pictures do you need? i can take some.

Cheers

I'll figure out how to post pics soon and post mine up so you can see.


PS does anyone know where the big turbo coolant in/or return line is? Does it run through the manifold and/or the EGR heat exchanger route?


All this for inert gas cylinder in-fill to reduce NOX. I wonder why they can't have fancy valves to just let intake air get pumped out at low throttle... a bit like valvetronic.
Seems better than recirc'ing exhaust gasses.

Hmmmmm