Should I use Coolant Mix or Just Water?

[montyismonty]

Just got a 525i 2006. The the reservoir is filled with water only, should this be water/coolant? I've been working on cars for quite some time now and I know it's ok to use distilled water by itself. But I live in "K"alifornia and it does get hot as hell - literally hell! Should I do a flush? If so what is the proper procedure? Thanks in advance.

[thejlevie]

It is not okay to just use distilled water in an engine. Distilled water has no corrosion protection package and thus can lead to problems with the engine and cooling system. You may not need anti-freeze for freeze protection, but its elevation of the boil point and corrosion protection are necessary.

Best to always top up a cooling system with a 50:50 mix of antifreeze and water (preferably distilled). If you don't know what the current concentration is, or how long it has been in the engine, fully drain the system and fill with fresh coolant.

[bmwdirtracer]

+1.

Open the block drains and the rad drain. Buy the poor thing a new thermostat, maybe a water pump, too. After you've removed the thermostat, and with all drains open, stick a garden hose in every orifice. How long has the car been filled with plain water?

To determine just how bad the damage might be, try measuring the voltage in the coolant system/ With a multimeter sets on voltage, the scale reading 0.000. dip the red lead in the coolant while the black's firmly attached to a REALLY good body ground, or battery negative.

In my race car, I use a weak solution of blue BMW antifreeze, with half a bottle of water wetter, and the rest distilled water. But the coolant gets changed every single year, without fail.

In my road car, I change the coolant every two years, using 50/50 BMW blue/distilled, with half a bottle of water wetter.

There is an advantage to running less antifreeze ( lies in the ability of water and water wetter to remove more heat, with less antifreeze involved.) However the disadvantages of using less antifreeze are truly outweighed (in almost every circumstance) by using a 50/50 mixture. Figure you're going to top it up occasionally, and you'll probably end up putting off the coolant flush in a year or two, so err on the more protective mixture - use 50/50.

[montyismonty]

+1.

Open the block drains and the rad drain. Buy the poor thing a new thermostat, maybe a water pump, too. After you've removed the thermostat, and with all drains open, stick a garden hose in every orifice. How long has the car been filled with plain water?

To determine just how bad the damage might be, try measuring the voltage in the coolant system/ With a multimeter sets on voltage, the scale reading 0.000. dip the red lead in the coolant while the black's firmly attached to a REALLY good body ground, or battery negative.

In my race car, I use a weak solution of blue BMW antifreeze, with half a bottle of water wetter, and the rest distilled water. But the coolant gets changed every single year, without fail.

In my road car, I change the coolant every two years, using 50/50 BMW blue/distilled, with half a bottle of water wetter.

There is an advantage to running less antifreeze ( lies in the ability of water and water wetter to remove more heat, with less antifreeze involved.) However the disadvantages of using less antifreeze are truly outweighed (in almost every circumstance) by using a 50/50 mixture. Figure you're going to top it up occasionally, and you'll probably end up putting off the coolant flush in a year or two, so err on the more protective mixture - use 50/50.

I have no idea how long she ran this way. But i'm sure it was done at the dealer where i got it. I bet the idiots topped it off with water or did a flush and just dumped water in there. Well i'll buy a new thermostat as you suggested, but I'll wait on the water pump for when I do the timing belt, or for when the thing gives up. It only has 65k miles but I believe the last time it saw the mechanic was about a year ago at the BMW dealer.

Well this weekend will be a long one, have to service the Jetta for the wifey too.

One other thing, what kind of coolant should i use? I know for the jetta its some kind of red crap with dextrol dexmol dexol whatever the hell its called. Thanks again.

[thejlevie]

The best choice in anti-freeze is the BMW stuff.

[bimmer_boyis]

I would hold off on replacing t-stat and waterpump. Waterpump for n52 is hella expensive
and both are a bit of a PIA to replace just for sake of replacement. Make sure you follow the correct bleeding proceedure after replacing coolant.

[bmwdirtracer]

To be honest, the N52 flew right by me, I haven't worked on very many. On the other hand, I seem to recall the N52 having lots of water pump issues, doesn't it, bimmer boyis?

Either way, as bimmer boyis said, the bleed procedure is crucial.

[bimmer_boyis]

To be honest, the N52 flew right by me, I haven't worked on very many. On the other hand, I seem to recall the N52 having lots of water pump issues, doesn't it, bimmer boyis?

Either way, as bimmer boyis said, the bleed procedure is crucial.

I wouldn't say that it has lots of problems. You know it seems BMW always has a weak point somewhere in it's cooling systems....expansion tank in anything before NG engines, valley pans in m62(i've been seeing the seals bad out of the box), coolant pipe in n62. There are occasional failures of the new electric water pumps though leading to an engine malfunction warning and overheating, but at least the driver is given a CC message before any other real damage is done. I just wish they hadn't put it in such a rediculous place.

Bleed proceedure is as follows:

key on, engine off
heater temp set to max
medium fan speed
push accelerator pedal to the floor and hold for 10 seconds

The electic water pump should start to bleed, check in the expansion tank to make sure you are getting a stream. It is best to have a charger on the car while this is going as the bleed will stop short as battery voltage drops.

[bmwdirtracer]

That's exactly what I've got committed to memory, from other techs here. I'm assuming that my vacuum bleeder isn't going to do it for me. I've been well warned about the golden shower, and bought the appropriate swivel e-torx for when I get one - likely tomorrow.

Well, not tomorrow: I'm in the middle of a huge Mercedes wiring harness swap: rats ate the harness. Damned thing wraps from center of bumper, both sides, up each fender, through the e-box (completely disassembled) across the firewall, through the center of the main fusebox (completely disassembled), into the car, under the carpets, to the instrument cluster, and more. Then there's another harness eaten though on bunches of wires for me to fix, when I'm done. Yeehah.......

[bimmer_boyis]

My swivel e-torx are my best friend for alot of jobs on NG engines. Makes trans bolts a breeze to get to as well. Snappy will get you for $300 a set though. Have fun with the harness, jobs like that need a blank check.....

Your vacuum bleeder will get most of the air out. BMW now wants techs to use one when filling all engines. I would go through the bleed proceedure to ensure customers don't come back with low level warnings

[montyismonty]

Just took it to BMW and had it done. Tech said there was coolant in there but more water than coolant. I can definitely see a difference in consistancy and smell/taste HAHA. No i did not taste the coolant. Problem solved and thanks for the input gents.

[ElleShooTiger]

That's exactly what I've got committed to memory, from other techs here. I'm assuming that my vacuum bleeder isn't going to do it for me. I've been well warned about the golden shower, and bought the appropriate swivel e-torx for when I get one - likely tomorrow.

Well, not tomorrow: I'm in the middle of a huge Mercedes wiring harness swap: rats ate the harness. Damned thing wraps from center of bumper, both sides, up each fender, through the e-box (completely disassembled) across the firewall, through the center of the main fusebox (completely disassembled), into the car, under the carpets, to the instrument cluster, and more. Then there's another harness eaten though on bunches of wires for me to fix, when I'm done. Yeehah.......

What Mercedes model is that? Just curious, I've been used to US cars where each major area of the car has its own harness and are relatively easy to replace. The German design of a single harness from headlights to taillights makes me scratch my head lol.

[bmwdirtracer]

This was a '99 420, in nice condition. Harness included horns, headlights, washer bottle, brake fluid level sensor, primary O2 sensors, a couple of plugs way up under the dash, and the cluster, the fuse box, the e-box, and a main hot under the gas pedal. I also repaired two other harnesses which were less severely damaged. After clearing codes, can was perfect, went away Friday. Twenty one hours total. For posterity: repaired wires were crimped, soldered, heat shrunk, and then friction taped for correctness.

Bimmerboyis: took a brief look at a guy's N52 325, just acquired cheap. Never mind the valve cover pissing, I found milkshake in the coolant. No coolant in oil, so I advised first immediately checking the trans for milkshake, having had a brief look and seeing two heat exchangers. Wasn't my car to diagnose, so that's about all I know, at the moment.

Any words of wisdom? I really wish BMW had avoided these heat exchangers.

[ElleShooTiger]

Ah, so you didnt have to replace the harness? I guess anything is better than having to gut a car out. I pried aroud some 90s E-Class's at the junkyard, the engine bays just look way overly complicated, and the wiring inside is crazy, especially the boxes of wiring running under the door openings, huge bundles of wires in there lol.

Lmao, who buys a car with a missing valve cover??!

[bmwdirtracer]

I replaced one of the several huge harnesses in the car, completely. Then I repaired the dozen chewed wires in two other harnesses. Hey, at least I got a whole bunch of various colored really nice wire, including a lovely factory 4-guage eight feet long.

I've not worked on many Mercedes, in this level of complication, but I must say that the job was reasonably straightforward, being familiar with BMWs. And unlike Volkswagens, not a single electrical connector broke.

[300kplus]

Is that BMW stuff readily available in the marketplace or dealer only?
Thanks

[dworthy]

You can get it from Amazon too. I would say the next best thing is Zerex G-05, which is not the same color, but does the same job for less cost.

[300kplus]

You can get it from Amazon too. I would say the next best thing is Zerex G-05, which is not the same color, but does the same job for less cost.

Cool. Thanks

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