* E46 Cooling Guide (Information w/parts list/bleeding) *

Originally Posted by mkodama

Why does this sticky tell people to replace certain parts blindly or based on mileage instead of doing a proper diagnosis? Like belts, bearings, and thermostats for example? It's a pretty wasteful use of money and time prematurely replacing those parts...

So, how do you diagnose a water pump, wait until you hear it scream? What if it dies before it screams? Thermostats fail open, so you can run them to failure. However, you might as well replace it when replacing the water pump, since you're that deep into the engine.

Expansion tanks are notorious for cracking the length of the tank with no apparent warning. I suppose you have a strain gage attached to yours so that you will be warned of impending failure. How much did that cost?

Belts, you can see, so periodic visual inspection is okay. I just like to do it all at once and not worry about it until the next inspection interval, which is the subject of another debate.

It's a balance. Figure out the interval that you can live with, then replace the other components under the "while I'm at it, might as well...." category.

Well, my radiator started leaking a few days ago. The typical hairline crack near the upper hose connection. I replaced it and the expansion tank only. I got @88k on it. When it gets to 100k, I'll probably splurge for a pump and t-stat as preventative.

Originally Posted by wildirish317

So, how do you diagnose a water pump, wait until you hear it scream?If you have no engine cooling problems, check for leaks and bearing play. If there is a leak, determine if it can be repaired, and if not, or excessive bearing play, replace it. What if it dies before it screams? Thermostats fail open, so you can run them to failure.If you follow your car's service booklet, during inspection 1 you read engine diagnostics, and a faulty thermostat will give you a message about how the engine is taking too long to reach operating temperature. If you are getting this message, replace the thermostat. However, you might as well replace it when replacing the water pump, since you're that deep into the engine. That's not very deep into the engine. Fan shroud and fan off, takes about 15 minutes.

Expansion tanks are notorious for cracking the length of the tank with no apparent warning. I suppose you have a strain gage attached to yours so that you will be warned of impending failure. How much did that cost?

Belts, you can see, so periodic visual inspection is okay. I just like to do it all at once and not worry about it until the next inspection interval, which is the subject of another debate.

It's a balance. Figure out the interval that you can live with, then replace the other components under the "while I'm at it, might as well...." category.

Answers included above.

You just inspect everything to make sure it's operating as it should. If it's failing, showing signs of failure, or it's near or past BMW's recommended service interval, replace it. Some parts will randomly fail, and you just replace them when they do.

BMW doesn't list "replace the entire cooling system when you feel like it" in their service booklet for a reason; you don't need to.

Originally Posted by mkodama

BMW doesn't list "replace the entire cooling system when you feel like it" in their service booklet for a reason; you don't need to.

Without disagreeing with any of your conclusions, let's get real. BMW does not list 'reinforce rear subchassis mounting points by dropping entire rear end out and welding in Turner Motorsports steel plate kit' either. Nor 'replace window regulators regularly' because we refuse to redesign a deficiently engineered part.
Certain design mistakes or weaknesses are not going to be incorporated into the official TSB catalog.

Originally Posted by Stinger9

Without disagreeing with any of your conclusions, let's get real. BMW does not list 'reinforce rear subchassis mounting points by dropping entire rear end out and welding in Turner Motorsports steel plate kit' either. Nor 'replace window regulators regularly' because we refuse to redesign a deficiently engineered part.
Certain design mistakes or weaknesses are not going to be incorporated into the official TSB catalog.

But BMW does have a whole procedure for reinforcing the rear subframe mounting points. One procedure if damage is minimal, another if damage is extensive. This was incorporated like 10 years after the creation of the E46.

If you think window regulators fail only on E46s, you'd be mistaken. Also considering window regulators go probably 10 years between failures, I really wouldn't worry about them much. When it does fail, BMW has a procedure for replacing it, just like every other part.

Originally Posted by mkodama

But BMW does have a whole procedure for reinforcing the rear subframe mounting points. One procedure if damage is minimal, another if damage is extensive. This was incorporated like 10 years after the creation of the E46.
You said it all! They fought like the devil to avoid responsibility for this fail for years. Tried very hard to sidestep paying for these.

If you think window regulators fail only on E46s, you'd be mistaken. Also considering window regulators go probably 10 years between failures, I really wouldn't worry about them much. When it does fail, BMW has a procedure for replacing it, just like every other part. Many many others here have memorialized that they've owned lots of cars that never had a regulator fail. And many here have replaced regulators around their cars, and then had to repeat the process over and over. Shameful that BMW never revisited this with a better part. Admittedly they did stop supplying the WP with plastic impeller.

Other issues exist.

Originally Posted by Stinger9

Other issues exist.

Yes, many BMW parts do fail over time. It seems you are unhappy with BMW about this, but lets keep not get too far off track. I am debating when to replace these parts because I think the advice given is wasteful, not debating that parts never fail.

Originally Posted by mkodama

It seems you are unhappy with BMW about this, but lets keep not get too far off track. I am debating when to replace these parts because I think the advice given is wasteful, not debating that parts never fail.

Let's focus here, you wrote: BMW doesn't list "replace the entire cooling system when you feel like it" in their service booklet for a reason; you don't need to.
And I took issue with your conclusion, not with anything BMW ever did, said, or made. That BMW doesn't say something does not prove you don't need to do it. They don't say replace your VCG, but many do because they have a finite life whereupon they begin to leak. BMW does not say to replace your radiator hoses but many do because when they get up in age, they will burst. They don't say to replace your DISA valve, but it is advisable because in some instances they fall apart and the steel pin falls into the valves.
So need is a matter of individual choice, not for you to say it's never valid to interpret things that way. Tell the owner whose car warps a head that he didn't need to replace cooling system parts. If you don't want to do anything prophylactically, so be it, but no one knows which cars needs this care in advance.

Originally Posted by Stinger9

Let's focus here, you wrote: BMW doesn't list "replace the entire cooling system when you feel like it" in their service booklet for a reason; you don't need to.
And I took issue with your conclusion, not with anything BMW ever did, said, or made. That BMW doesn't say something does not prove you don't need to do it. They don't say replace your VCG, but many do because they have a finite life whereupon they begin to leak. BMW does not say to replace your radiator hoses but many do because when they get up in age, they will burst. They don't say to replace your DISA valve, but it is advisable because in some instances they fall apart and the steel pin falls into the valves.
So need is a matter of individual choice, not for you to say it's never valid to interpret things that way. Tell the owner whose car warps a head that he didn't need to replace cooling system parts. If you don't want to do anything prophylactically, so be it, but no one knows which cars needs this care in advance.

I think if BMW doesn't say to do anything, it's pretty good reason not to do anything. If you decide to go against a manufacturer of any product, you better have some pretty good evidence to prove otherwise, and not just theories and guesses.

I don't think it needs to be written down that a visibly failed part needs to be replaced, so your leaking valve cover gasket example is pretty poor. Unless you are talking about replacing it just because you feel like it, in which case that is just silly.

Originally Posted by mkodama

If you think window regulators fail only on E46s, you'd be mistaken. Also considering window regulators go probably 10 years between failures, I really wouldn't worry about them much. When it does fail, BMW has a procedure for replacing it, just like every other part.

But why none of my japanese cars have failed window regulator? Some of them are 10-15 years old. My current 10 year old Nissan's window movement feels really solid, unlike this E46 which is developing clicking sound and feels much weaker.

Any thoughts on the Cool Experts expansion tank? BMA does not have the OEM at this time.

Joe

Go somewhere else where they do have the oe.

Plenty of vendors to pick from:

www.furiousmethod.com

I'll be doing my cooling system overhaul soon and will be replacing many parts before they fail.....why?? Because it is called a PM...preventative maintenance! !! I do my own repairs, and would rather have a car that I feel comfortable going on a 9 hour trip from home. Cost of parts is nothing compared to overheating or having the cooling system fail while say 7hours into the drive...and not even considering a warped head.. makes sense to me.

Risks replacing a part that will never fail in your lifetime, but it's called insurance. Some disagree with this approach, but I say to each his own.
Rather not break down in the middle of Utah 1800 miles from home!

Originally Posted by TonyJ

But why none of my japanese cars have failed window regulator? Some of them are 10-15 years old. My current 10 year old Nissan's window movement feels really solid, unlike this E46 which is developing clicking sound and feels much weaker.

My Toyota's window regulator failed.

Originally Posted by dirty vert

I'll be doing my cooling system overhaul soon and will be replacing many parts before they fail.....why?? Because it is called a PM...preventative maintenance! !! I do my own repairs, and would rather have a car that I feel comfortable going on a 9 hour trip from home. Cost of parts is nothing compared to overheating or having the cooling system fail while say 7hours into the drive...and not even considering a warped head.. makes sense to me.

Originally Posted by TonyJ

But why none of my japanese cars have failed window regulator? Some of them are 10-15 years old. My current 10 year old Nissan's window movement feels really solid, unlike this E46 which is developing clicking sound and feels much weaker.

Even if a single part in your Corollas, Civics, and Sentras never failed, they're still Corollas, Civics, and Sentras. Do you want to drive those instead? Go right ahead!!

(BTW, some Japanese cars can and do fail... in major ways.) I can write bibles about personal experiences with Japanese car failures. My E46 had to rescue a brand new Inifnity G37 several times.

It can happen to any car but its good to not think in too simple of terms.

Pretty much just purchased everything except for two pulleys and a new radiator...

Mango I wrote you an essay..

Originally Posted by E46Mango

Even if a single part in your Corollas, Civics, and Sentras never failed, they're still Corollas, Civics, and Sentras. Do you want to drive those instead? Go right ahead!!

(BTW, some Japanese cars can and do fail... in major ways.) I can write bibles about personal experiences with Japanese car failures. My E46 had to rescue a brand new Inifnity G37 several times.

It can happen to any car but its good to not think in too simple of terms.

I sooooo agree. My coworkers 2 year old Jeep has had two window regulators fail already.
He looked at some online forums and it seems its a regular thing with his model.
All cars have issues.
If you cant work on it yourself or afford to have it worked on then sell it and buy another brand that makes you happier.

thanks guys, I have a 330 ci that has a problem of overheating since 2010, been all over with our local mechanics/garage but to no avail. thus- am in Gaborone Botswana (southern Africa)
could anybody in southern Africa advice.

velaphi

If you want us to give you an educated opinion, let us know what the history of what you have already tried is?
Give as much detail so we do not duplicate thinking and recommendations that has already taken place!