Bleeding cooling system...do not overfill...
 

...but if the bleeding procedure calls for you to fill the reservoir till water comes out of the bleed screw hole, isnt the float showing way over-filled then (6cyl M54)?

The bleed process is done with the motor running, and the bleeder is removing air from the res return line connected to the upper rad hose (highest point in the cooling system).

NEVER over fill the system.

The M54 requires the bleed process to be without the motor running. Heater on high, and lowest fan speed. Fill coolant with bleed screw open and continue to fill until you see coolant flow out of bleed screw. Stop filling it at that point and let the fan run until you do not see any more air bubbles. Close the screw.

I then start the car with the cap off and if the coolant level starts to go down I turn the car off and restart the procedure. If the level does not go down I put the cap back on and turn the fan to the highest setting and run the car till it hits operating tem ( and I have lots of heat coming out). Let the car cool and check your level.

I was done in 15 minutes tops with my e46 m54. No air and the coolant level did not go down.

It's been several years since I did the bleed process on a 6 cyl BMW, my bad.

To be honest... I've never had a problem bleeding an M54. I typically fill the system. Heat full, fan full, and leave the fill cap off. Start the car and top off coolant until float comes back up. Close fill cap... let car continue to run until up to temp. After it reaches full temp... crack bleed screw until no more air bubbles come out and heat in the car is blazing hot. Finally, let the engine cool, top off system, and you're done. :thumbup:

I've been debating whether to do the water pump myself preventatively - I don't hear any bearing noise from it, but don't want to let it fail either - I was going to buy an extra gallon and mix it up so I can crack the radiator drain and "flush" the system with some of the fresh coolant once I button everything up.

Then that opens up the well should I do the radiator hoses, expansion tank, and thermostat while I'm in there, and I know these parts were replaced at least 6-8 years ago, the water pump is original -

I have a cold belt squeal on startup so I may be doing the idler and tensioner pulleys and belts anyway, might want to just do it all at once -

And then I'm sure I would have an OFHG leak about a year later LOL

RB my original water pump went 260,000 miles before it ever leaked. I always stuck with BMW coolant though, with the addition of 12oz of Redline WaterWetter after any cooling system service was performed (Definitely helps deal with the Texas heat). I don't let any of the hoses go past 150,000 miles, but that only take me 6 years to do, so you're probably okay on those items for a little while longer. The tell-tale sign on those is the plastic connectors starting to look brown instead of black. I'd be most concerned with the age of your expansion tank.

You're 100% on with the OFHG situation - definitely easiest and most labor saving to do cooling system hoses, CCV and OFHG at the same time.

2002 X5 3.0 312,200 miles
2014 428i 22,800 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

You have offered so much help and so many good tips on this forum that I think no one would have minded.

Yeah I'm at 5 years of ownership as of next month and I think he did the cooling hoses/system about a year or two prior - so I might be hitting the age threshold and not necessarily the mileage threshold (my miles are still super low at 90k)

How long until you did the OFHG? I didn't notice any leaks when I did my CCV in June of 2014, but will check it out again.

I just ordered INA idler pulley and tensioner pulley and a set of conti belts so it will give me a good opportunity to really inspect the tank, hoses, and spin the water pump and listen for noises - if anything needs addressing I'll just leave it open and get the parts -

My gasket went 176,000 miles just fine, then it turned into a gusher.

^^Good to know - I won't worry about it for a while then -

Thanks all for the info!

I did do it with the engine running and not. Both times when I checked coolant the next day it was overfilled, meaning the float was above max Kalt.

I just let it run and opened the bleed screw for a while to let the excess coolant escape.

Here's another tip on the bleed screw - don't overtighten it until it cracks. Learned that one the hard way. They are more fragile than one might think, maybe more so after many miles.

Secondary tip to that one... I replace all of my bleed screws with the brass ones that are available. Never have to drill another broken bleed screw out again. :thumbup:

Thanks for the tip guys, I actually keep spare bleeder screws handy in the tool box.

dunno if the water pump is the same on all makes....

I've replaced mine 2X. Worst part is when it failed the 1st time. 50 or 60K on the clock.
95 degree day. Hot as F. Days like this, everybody sorta breaks down. Waited 4-5 hrs for a tow. It was not a fun day

IIRC the M54 and M52 have the same pump.

How did yours fail, and what brands were they?

M54 pump is different I believe - I'm a firm believer in do it right or do it twice so when mine goes its getting an EMP Stewart unit

Buy Once Cry Once.
:rolleyes:

I've been getting roofing quotes all week
There goes the extra ~play~ money for a very long while.

^^It could be worse - My dog starts his radiation on Monday - the plus is that he will live out his senior years cancer free but there goes the gun budget and the bathroom remodel for the next year

Godspeed in Recovery RB for you ~little one~

Thanks brother he should be fine - he beat a Grade 3 tumor in March (needed radiation and chemo), this was a Grade 1 on his leg, so radiation only - thank god this type doesn't ever tend to metastasize (he had a 40% chance with the one on his shoulder due to Grade 3) - the Grade 1 was there when he did his shoulder treatments but I didn't want to put him through much at the same time, and it tested ok, luckily I said to my wife lets just get it off so we know whether its ok or not and sure enough it was same type -

He just turned 10 and they said the rest of his body inside and out looks like a puppy, so I hope we have many more years. I appreciate your prayers for him, he is in my avatar

Not sure if they are the same either, I just sorta remember reading a bunch of M52 cars on the applications list of the water pump I had installed, but could be recalling wrong lol.

I did almost get a Stewart but with OEM pumps lasting as long as they do the math just didnt work out on it for me.

You have a nice looking pup RB, hope it all goes well with him.

Sorry to hear about the pup RB. We almost lost our "Shadow Demi Lee" this spring to a bizarre blood toxin that shut down her bone marrow for month. Scary when they can't tell you what's wrong, but it keeps things like car repairs and gun collections in perspective. Best wishes for a speedy recovery.

Love those happy faces!

Yes, hope your pup gets cleared after the next round of treatment RB. You guys are better men than I when it comes to health care for the dogs.

Now that our son and daughter are grown up with families of their own, there's a new batch of youngsters to worry about, but the dogs become the "kids in the house" for us empty nesters as they takeover when the children are gone!

Great pic of the CEO and your adorable babies! Is she ok after the blood toxin?

Total derailing this thread which I feel bad about but that's why this forum is great -

After six weeks of massive steroid use (Which pumped her up from 48 pounds to 63 pounds) and strong antibiotics, her blood chemistry finally went back to normal. Then it took four months to get her weight back down! Funny side effect though was her coat went from black to gray on her back, so we have been giving both dogs the Dinovite supplement since then and wow, Shadow's color came back and both dogs have nicely improved coats and energy levels. Best benefit of the Dinovite though is the blonde one, Sadie Diamond Lil, has a lot less of a "gas" issue! You might take a look at that RB as the Dinovite is an immune system booster too.

And now I have to get back on thread and determine why I detected the sweet smell of anti-freeze under the hood last evening!

OMG all my radio guys advertise Dinovite every day on the radio ( you can imagine what station I listen to on Sirius) - D-I-N-O-V-I-T-E.com (woof)

Its funny how their bodies bounce back and amazing - Chad had to do 5 rounds of chemo spaced 3 weeks apart for each back about 4 months ago after his radiation was done on his Grade 3 tumor site, the chemo rounds were for any potential cells remaining that could metastasize. He actually got some black freckles under his white coat which I thought was hair loss, but his hair is thicker than ever, he just has some "freckles" - I'm going to put up a recent pic - but he is doing great, and as sad as it sounds, its wonderful news that we only have to do radiation this time and we can be done. The chemo really tired him out and made him extremely picky of an eater. 2 weeks after he was done though, back to 2 mile walks a day.

The bleed procedure as published by BMW is for a dry fill from factory when they need to prime the secondary water pump etc.

For routine bleeding, such as after cooling overhaul (WP replacement etc.), I just do simple things:

1. Engine Cold and Off.

2. Open bleeder screw near the tstat (remove it but don't lose it).

3. Fill the reservoir with the 50-50 mixture until it is 1" above KALT or roughly about 2" from the rim. Now, be patient! It is a slow process and coolant will flow out of the bleeder hole.

4. Re-install the bleeder screw (just snug it, don't force it!), then make sure coolant is still about 2" from the reservoir rim.
Replace the cap.

Now go for a test drive in the neighborhood with heat on etc., drive until the engine is hot.
Then go back home, park the SUV.
Wait 1-2 hours, then check coolant level, it should settle down to MAX area.

I have done this trick many times (overfill just a tiny above KALT when COLD) and it works. Very very easy.

If you overfill the pressure will build to either lift the 2bar (29psi) cap or burst / break something. An older system will typically have a part failure before the cap lifts. Many install a 1.2bar (17psi) cap. Better to slightly under fill than overfill.
A 50/50 glycol mix at 1.2bar has a boiling point of 270F. A 50/50 glycol mix at 2 bar is about 295F ( couldn’t find the exact number so used the estimate of 3F/psi from 280F@24psi)

Where would one buy a 1.2bar cap that fits our reservoir?

I’ve been using an e30 1.4 bar cap for 5 years now. I feel way safer with it. The only retarded car in the world with a hose / expansion tank / radiator / valley pan exploding 2 bar cap.

Cool, thanks for the pointer! Got it from dealer for only $17.