M54 cooling system

[Ahmedsinc 414]

So the 530i decided to blow its radiator about 75m from my gate this evening. Shut the car down as soon as I saw the needle start to nudge the red zone, 99.999% confident it hasn't overheated. Will be picking up a new radiator from Brent tomorrow morning, can anyone give me some pointers in how to correctly bleed the E39? I'm not going to have enough time to get to McMillans before the parts dept closes, can anyone recommend a coolant from Ripco etc that won't rot out the plastics in the cooling system?

Thanks

[Allanw 1051]

The needle moving means it IS hot (At least 115C), if it getting up to red, it getting hot hot. E39 gauges are VERY buffered.

To BMW's credit, the coolant temp sensor is low in the cooling system (on the M54 at least), so at least it does still read as the level gets low (most cars have them mounted high, so coolant loss means the gauge doesn't even SHOW the temperature increase!).

The fact it crept on the gauge up makes me wonder if it was already getting hot (the gauge won't move remember, until 115C) and the radiator let go from the additional pressure, rather than the radiator causing the overheat.

Bleeding the M54 is piss easy. Open the bleed screws (top hose side of thermostat housing and top of radiator/expansion tank). Tipp in correct amount of coolant. start adding water. When it dribbles out of a bleed screw, close it off (not tight). Then do the other.

Next, turn the heater up to max, fan onto low, leave ignition on, but engine off. Secondary pump will run.

Coolant will squirt out the little orifice in the top of the expansion tank opening. Keep the level up in the expansion tank by adding water. Gently open the thermostat bleeder and let any air out, then check the expansion tank one.

If you get a lot of foam at any time, shut it off, and wait a while for it to settle.

Once the coolant stream is constant/bubble free in the tank, and the level is nearly up to normal, start the engine and leave it to run for a while.

Once you're happy, put the cap on (important), make sure the bleed screws are snug (they're plastic, DON'T overtighten!) and go for a drive (round and round the block is good, take your phone! Leave the windows down too - leave the heater at the same settings it was on). When you drive it, watch the KTMP (http://bimmersport.co.nz/topic/47848-e39-obc-secret-menu-ktmp-coolant-temperature/) and watch for anything funny. The temp can fluctuate, but it info is in that thread.

If all is well, keep it running for a bit to get the engine properly "hot" (as in normal), then go home, shut it down and leave the bonnet up to cool down WAY faster. Once it's cold (overnight is good, but at least 3 or 4 hours) check the coolant level (it may need a little bit added). for the next couple of trips, I always check the coolant before leaving, and then once it's cold again.

That's a lot of words, for what is really very simple on the M54 E39's

[Allanw 1051]

Oh yeah... for coolant... I couldn't decide, so got BMW stuff. It's not that expensive. If you go aftermarket, be wary of the long life ones and fancy labels. Some of them are not suitable.

If it were me, I'd go to the warehouse and buy the "autohaus" basic stuff (I use it in the Model A), or something similar.

People waffle on about what coolant is "right", but at the end of the day, BMW specs say their coolant and just about any water (Most NZ tap water complies). In reality, most workshops (not speacialist) use the coolant they buy in the big drum (whatever it is) and tap water.

You can always run straight water for a week or so, to check for problems, then drain it, put in BMW stuff and re-bleed.

[Ahmedsinc 414]

Oh marvellous, 115 deg eh? Have to admit that a little poo came out when I removed the header tank cap to discover that the bottle was dead empty. Will be pulling the water pump to see if it's the impeller thats sh*t itself. Will an M50 pump fit? Have a new metal impeller pump downstairs but have no idea if old bits will fit the newer motors. How prone are the alloy engines to blowing HGs once they've gotten a little hot under the collar?

Rhetorical question, but why do these things happen when you can least afford them / the mrs has been vomiting for the past 38 hours / you were meant to be seeing Ray tomorrow to collect your new diff & ask questions about having the MS43 DME rewritten to allow a viable M54 -> e36 transplant?

FML.

Cheers for the info mate, wish I'd paid attention to your OBC thread earlier!

[twisted 45]

Red zone is 125c iirc.

[Ahmedsinc 414]

Fark me, that's warm!

[polley 916]

Head bolt threads are known to strip out of the block when overheated

[Allanw 1051]

IF the head has to come off, its best to get the bolt holes time-serted before even TRYing to glue the head back down.

Don't fear though, it may never have happened. I once drove a Subaru about 40 kms at speed (mostly open road, a fair amount of thrashing at times) after the radiator had split (After I discovered the coolant was all gone, and dried onto the drivers side of the car, I recalled the noise of it happening!), it started pinking like hell climbing the hill to my house, and I had to put 6L of water in after in cooled down. It just had a new radiator, and continued on running mint until I left the company, when that car had about 360kms on from memory.

The High OBC coolant warning/gong is set to either 125C or 135C from memory.

The plastic impellors on these aren't that bad. Mine was mint, after 130K and 14 odd years. but I put in a new pump from Milland, and it was metal anyway.

FYI: the following is "TOO MUCH INFORMATION" about the bug your Mrs possibly has!!!!

There is a nasty Norovirus on the rampage. Luckily (working at a Hospital) I get buttloads of sick leave that accumulates... but I also get to try new experiences and sicknesses all the time! I had all week off, because I had Vomiting from 2AM monday, until late morning, then the squirts followed - ebbing and flowing until the violent cresendo on Thursday afternoon where I was wondering how much an emergency septic tank service cost.... seriously.

You do NOT build immunity to it - it can go around and around within the people she/you are in contact with, So wash hands, wash everything she gets "grubby" and grab some hand sanitizer and use it often. Wipe the toilets down with disinfectant, plus try to vomit in a sink that's easy to clean - it means you aren't putting both ends near the same receptacle.

It's really nasty, and I truely hope she feels better soon, and that you don't get it!

Good luck!

[Ahmedsinc 414]

IF the head has to come off, its best to get the bolt holes time-serted before even TRYing to glue the head back down.

Don't fear though, it may never have happened. I once drove a Subaru about 40 kms at speed (mostly open road, a fair amount of thrashing at times) after the radiator had split (After I discovered the coolant was all gone, and dried onto the drivers side of the car, I recalled the noise of it happening!), it started pinking like hell climbing the hill to my house, and I had to put 6L of water in after in cooled down. It just had a new radiator, and continued on running mint until I left the company, when that car had about 360kms on from memory.

The High OBC coolant warning/gong is set to either 125C or 135C from memory.

The plastic impellors on these aren't that bad. Mine was mint, after 130K and 14 odd years. but I put in a new pump from Milland, and it was metal anyway.

FYI: the following is "TOO MUCH INFORMATION" about the bug your Mrs possibly has!!!!

There is a nasty Norovirus on the rampage. Luckily (working at a Hospital) I get buttloads of sick leave that accumulates... but I also get to try new experiences and sicknesses all the time! I had all week off, because I had Vomiting from 2AM monday, until late morning, then the squirts followed - ebbing and flowing until the violent cresendo on Thursday afternoon where I was wondering how much an emergency septic tank service cost.... seriously.

You do NOT build immunity to it - it can go around and around within the people she/you are in contact with, So wash hands, wash everything she gets "grubby" and grab some hand sanitizer and use it often. Wipe the toilets down with disinfectant, plus try to vomit in a sink that's easy to clean - it means you aren't putting both ends near the same receptacle.

It's really nasty, and I truely hope she feels better soon, and that you don't get it!

Good luck!

Speaking of the high OBC, the one in my car is so dim as to be virtually invisible....... is this likely a dead LED screen or is it merely the backlight bulbs that have pooped?

As I mentioned in an earlier post I was fortunate enough to have turned the engine off as it started climbing, so I'm as confident as I can possibly be that it hasn't baked itself to a gooey, leaking mess.

The 530i I bought as a parts car had its cooling system overhauled in the recent past, so gleaned the water pump etc from that. The metal impeller might not be essential, but given my experience with M5x cooling systems it's worth the peace of mind.

As for wifey I don't think it's Norovirus, thank Christ. Possibly a poorer cousin as her temp has been fluctuating quite a bit, but she's still well enough to be moving about under her own steam (complaining loudly wherever she goes) so I reckon it's not too serious. I'd survive if I get it too, it's the wee man getting sick that worries me.

New radiator in place, now to swot up on your instructions and refill the bugger. Wish me luck!!

[Ahmedsinc 414]

Hmmm...... in the process of refilling the radiator I have noticed there is quite a dribble coming from the upper inlet neck. Have tried swapping o-rings around but to no joy.

Any ideas? Will gasket cement (the black goo made by Holts in the little red bottle) help? Have used it on other cars with great results in the past, but I assume it merely seals any gaps as opposed to 'bulking out' an o-ring?? Help!

[B.M.W Ltd 950]

Gasket goo will not hold 2 bar pressure when the engine is running. You have a problem that you need to identify correctly and repair properly. You do not need and should not use a sealant to carry out this repair if done correctly with quality parts.

A picture might help

[Ahmedsinc 414]

Ignore the browning of the hose elbow, I've taken a photo of the old parts as it's now too dark out. I think the problem might be the radiator inlet neck is a tiny bit smaller in diameter than the old OEM one. I've used a little bit of loctite rtv sealant in the interim to stop it piddling out overnight, can new o-rings be sourced locally?

Edit: rtv ain't stopping the dribble either. Poo!!

Edited May 17, 2014 by Ahmedsinc

[allan 295]

Hi,

Have you checked both the radiator and hose connections for any fine crack's ( these parts become brittle and can give way no warning ). Have tried replacing the "o" rings on these before with other ones and it doesn't work the o ring gets hard and flattened such it cannot seal. It needs to be a new "o" ring of the same size dia and thickness even then their is no guarantee it will work I just bought a new hose in the end. A poor hose connection system all round in my opinion.

[Ahmedsinc 414]

Hi,

Have you checked both the radiator and hose connections for any fine crack's ( these parts become brittle and can give way no warning ). Have tried replacing the "o" rings on these before with other ones and it doesn't work the o ring gets hard and flattened such it cannot seal. It needs to be a new "o" ring of the same size dia and thickness even then their is no guarantee it will work I just bought a new hose in the end. A poor hose connection system all round in my opinion.

Radiator is new, hoses are secondhand from my parts car but appear to have been replaced with new OEM parts sometime in the recent past. So used o-rings but all seemed to be nice and pliant, though without a set of calipers at hand I cannot confirm size. Just seemed a bit odd that the hose connection was nice and snug on the lower neck but quite loose at the top neck. Tried three or four different hoses to make sure I wasn't going crazy but all attempts had the same result.

Is there any difference between the E46 & E39 M54 radiators? Only explanation I can come up with so far is E46 upper neck could be a slightly smaller diameter than E39 (though I can come up with no plausible reason why) or the radiator I've bought isn't within OEM spec I agree entirely that it's a pretty sketchy way to design a coupling system for engine cooling. Certainly doesn't fill me with confidence anyway!!

[Ahmedsinc 414]

The needle moving means it IS hot (At least 115C), if it getting up to red, it getting hot hot. E39 gauges are VERY buffered.

To BMW's credit, the coolant temp sensor is low in the cooling system (on the M54 at least), so at least it does still read as the level gets low (most cars have them mounted high, so coolant loss means the gauge doesn't even SHOW the temperature increase!).

The fact it crept on the gauge up makes me wonder if it was already getting hot (the gauge won't move remember, until 115C) and the radiator let go from the additional pressure, rather than the radiator causing the overheat.

Bleeding the M54 is piss easy. Open the bleed screws (top hose side of thermostat housing and top of radiator/expansion tank). Tipp in correct amount of coolant. start adding water. When it dribbles out of a bleed screw, close it off (not tight). Then do the other.

Next, turn the heater up to max, fan onto low, leave ignition on, but engine off. Secondary pump will run.

Coolant will squirt out the little orifice in the top of the expansion tank opening. Keep the level up in the expansion tank by adding water. Gently open the thermostat bleeder and let any air out, then check the expansion tank one.

If you get a lot of foam at any time, shut it off, and wait a while for it to settle.

Once the coolant stream is constant/bubble free in the tank, and the level is nearly up to normal, start the engine and leave it to run for a while.

Once you're happy, put the cap on (important), make sure the bleed screws are snug (they're plastic, DON'T overtighten!) and go for a drive (round and round the block is good, take your phone! Leave the windows down too - leave the heater at the same settings it was on). When you drive it, watch the KTMP (http://bimmersport.co.nz/topic/47848-e39-obc-secret-menu-ktmp-coolant-temperature/) and watch for anything funny. The temp can fluctuate, but it info is in that thread.

If all is well, keep it running for a bit to get the engine properly "hot" (as in normal), then go home, shut it down and leave the bonnet up to cool down WAY faster. Once it's cold (overnight is good, but at least 3 or 4 hours) check the coolant level (it may need a little bit added). for the next couple of trips, I always check the coolant before leaving, and then once it's cold again.

That's a lot of words, for what is really very simple on the M54 E39's

Thread dredge!

Installed the new OEM radiator from Pelican last Saturday. Perfect fit, followed your instructions on bleeding (that secondary pump is handy, innit!!), car seems to be happy again

BUT

The LCD display below the odo is so dim as to be unreadable. How does one sort this matter out?

Would be nice to see the messages hat the car is trying to warn me about

[Allanw 1051]

Good outcome!

The LCD is backlit with bulbs - some are probably blown. I can't recall the code for them, but the aren't really cheap (as bulbs go) as they have moulded bases, but aren't a wallet killer. Buy a set and replace the lot. Google should tell you the code and amount. I think I brought a 10 pack... maybe.

[Ahmedsinc 414]

Good outcome!

The LCD is backlit with bulbs - some are probably blown. I can't recall the code for them, but the aren't really cheap (as bulbs go) as they have moulded bases, but aren't a wallet killer. Buy a set and replace the lot. Google should tell you the code and amount. I think I brought a 10 pack... maybe.

You're telling me! Was having nightmares of HG replacements.

Good to know. Have seen squiliions of threads related to dead pixels and ribbon replacements but hadn't come across any regarding lcds that are just dark. Can read messages if you get your nose as close as possible to the steering wheel and squint but I'm not so keen to try it while driving

[Ahmedsinc 414]

Good outcome!

Update

Took the car out for its maiden run with the new radiator this evening. Let the car idle up to nearly operating temp in the driveway, had a bit of exhaust scented vapour at idle, thought nothing out of the usual. Moved car 15 metres, hopped out to close the gates and saw quite a bit of vapour, had a good sniff and it smelled 'wet'. Pretty sure I noticed a tiny bit of steam coming out through the grills on the bonnet so shut engine off immediately.

Checked reservoir and the coolant level is the same as last time I checked it. Strangely the upper hose was warm / hot to the touch where the bottom hose was cool.

Suggests to me a blocked rad but that's impossible as it's brand spanking BMW approved new.

Parts replaced so far are new OEM Behr radiator, upper and lower rad hoses, thermostat, reservoir return hose, water pump and reservoir. Hoses, pump, reservoir and thermo are from the parts car I wrecked, have checked all the parts from the wreck for any signs of browning or perishing and were all good.

I'm shitting myself at the prospect of the HG having failed, are there any other possible causes?

Engine seems to run well, no hesitation at idle but as I haven't been able to road test it I can't say for certain. Help!!

Edit: No visible leaks either

Edited June 22, 2014 by Ahmedsinc

[twisted 45]

Would smell of coolant If coolant was getting into the exhaust. Car could also miss at startup if hg.

Bottom hose would still be cold because tstat hasn't opened yet as car not up to temp.

[twisted 45]

When you say up to temp, is that via the gauge, or the ktemp menu?

[Ahmedsinc 414]

Cheers Sam.

I guess there is a remote chance the steam may have drifted from the rear to the front of the car, though I'm probably clutching at straws here. Needle never made it to halfway, panic response saw to that! I had thought the top hose would remain cold until the thermostat had opened as well?

[Ahmedsinc 414]

Via the gauge. I need to replace the bulbs on the OBC dash cluster, can't see the messages well enough to tell what it's saying

Was looking to do that this week if bulbs can be found locally

[twisted 45]

Just about to put my boy to bed, so gotta run, but quickly - iirc, operating temp is about 20deg hotter than when the gauge hits the middle. Steam from the exhaust could still be very normal at this temp.

[Ahmedsinc 414]

Good to know, thanks mate. Just swapped bulbs in the obc and can read the display, will follow Allan's write up and see what I can discover

[Ahmedsinc 414]

Ok, ran the motor for a bit and KTMP reached 93* before I turned it off (had to run inside for another spew )

Amusingly, the bulbs are the same as the E36 OBC & dash items........

Exhaust still producing steam, not billowing as it was earlier, but as it's 8* outside and dropping quick it's no major surprise. Does smell 'wet' but doesn't seem to have the sweet smell of coolant, or at least not to my nose. Used 3 litres of the genuine BMW concentrate stuff, though a fair percentage of it was drained back out after having to swap radiators. Saved as much as I could in a clean bin and reused, so won't be at 25% concentration but still pretty close.

Long story short, temp climbed at a steady rate whilst at idle. Will give it another run after work tomorrow (after checking reservoir) and see if it climbs beyond the 92-98 range as mentioned in Allans thread http://bimmersport.co.nz/topic/47848-e39-obc-secret-menu-ktmp-coolant-temperature/ . Fingers crossed it sits steady and this has all been a mad panic for nothing