My cooling system refresh is coming up. How deep do I go?

[SoCalZman]

I have decided to try to get the cooling system out of the way as I am just past 90k and its almost summer (in California).

My general list is below. Hope this helps anyone else looking for some part numbers. If you click on it a few times it will expand:
http://img.tapatalk.com/d/14/04/16/y4ujy5eq.jpg


A few questions:
1) A manual car has how many of these little blue drain plugs (17111437361)? One for the radiator and one for below the expansion tank or....?
2) Has anyone included the coolant return hose in their overhaul (11531436410)? It goes from the bottom of the expansion tank to some plastic tube midway down the engine block. I havent seen pictures of the routing, but I am wondering how involved it is to include this in my project. It sounds like the air filter box needs to come out at least, right? Anyone who has replaced this chime in on your experience?

There are a few things on the list I wont be replacing. Auxiliary fan switch for one. I will just replace the o-ring with the alternate made of Vitron. Also wont bother with the coolant level sensor as I hear these rarely fail. I already replaced the expansion tank when I first got the car as it was seeping, so that is taken care of.

As for the pulleys/tensioners, I am debating whether I should just do the pulleys or if I should replace the tensioners as well. There doesnt seem to be a consensus that I can read on the various forums.

[TigerTater]

Just did it today. I used ECS stage 1 plus some addition goodies like new belts and the coolant return hose you speak of. It was a very easy hose to change in addition to the others. Whole thing took roughly 2.5 hours taking my time. I used this DIY ( http://www.bmw330ci.net/maintenance/completecoolant.php). I also have an auto so I had to deal with the clutch fan removal, yours will be much faster! I only had one blue drain screw, and drained the coolant using it and just disconnecting the lower radiator hose...did not want to use the engine block drain screw as I did not purchase a new crush washer for it. I did not change pulleys or tensioners. Mine are spinning easily without binding or noise, my tensioners are very tight (I found this out when I did the OFHG). Hope this helps!!

[SoCalZman]

It does, thanks. Regarding that specific coolant return hose, can you give a few details about replacing it? Is the airbox the only item you needed to remove to change it?

[ZHPRegistry.net]

I am probably going to have to face some flame throwers but I'll say the following...

E46's cooling system is unbelievably awesome problem for every parts store. I can hardly recall any other mass paranoia that concerns BMWs than the over the top overhaul of the cooling system.

It all started when BMW made the mistake of sticking a plastic impeller into the water pump. The problem with that particular type of plastic was that it really proved to not be up to the challenge of wide temperature swings and/or vibrations that the pump was exposed to. Starting from 03/2003 the composite impellers used in the BMWs have proven to be bullet proof. They look virtually new even after 100K miles.

In addition to the water pump problem, there were a series on expansion tank blow ups, and to this date there is no clear indication whether those were expansion tank problems or the older caps on top did not properly bleed excess pressure.

Somehow parts dealers have convinced the e46 owners that virtually every part (aside from the engine block) that comes in contact with the coolant needs to be replaced at 60ish K miles.

Aside from the expansion tank cap everything else on my 90K 3-er is original. I periodically check the water pump area for traces of dried coolant which is an indication of a slow progressing bearing failure. I do not intend to do any massive overhauls but replace parts as needed. I can respect the "while you're in there" mentality as long as it is used rationally.

Mind you, the so called "complete overhaul kits" sold by many friendly specialist call for such ridiculous things as replacing all water temp related sensors too... which by the way are used on many many other BMW models and have proven to last forever.

flame suit is on :)

[SoCalZman]

I can agree to an extent. Even if I owned the car since new, I dont think I would have done this work at 60k. My car is pushing 100k now though, 40k more than the cooling evangelicals say is good. Summer is coming up. My expansion tank was already leaking fluid and thus replaced around 87k. My water pump has shown signs of dried coolant nearby according to my indie (but they said it wasnt actually leaking when they were looking at it). I think the signs are there that various parts of my cooling system are nearing the end of life. Yes, a hoses here or there may develop a slow leak over time which would require me to go in to change it. Then go in again for the next leaky hose, or for a thermostat throwing a code, and so on and so forth. I dont want to do that. Same for the pulleys. I see enough threads of them just failing to make me want to change them at the same time. I can save a lot of money on labor if I knock this out in one weekend myself instead of breaking down and having a mechanic do it for me in the middle of no where.

At the same time, I am not buying into everything. Like the sensors. I am also not one to buy new bolts, etc unless the consensus is I must. If you look at my list, I think its a very rational, balanced 100k cooling service.

Its not just BMWs that have cooling overhaul people. My last car, a Nissan Z, had people saying to refresh the cooling system when the timing belt was changed: every 60k.

[TigerTater]

I am probably going to have to face some flame throwers but I'll say the following...

E46's cooling system is unbelievably awesome problem for every parts store. I can hardly recall any other mass paranoia that concerns BMWs than the over the top overhaul of the cooling system.

It all started when BMW made the mistake of sticking a plastic impeller into the water pump. The problem with that particular type of plastic was that it really proved to not be up to the challenge of wide temperature swings and/or vibrations that the pump was exposed to. Starting from 03/2003 the composite impellers used in the BMWs have proven to be bullet proof. They look virtually new even after 100K miles.

In addition to the water pump problem, there were a series on expansion tank blow ups, and to this date there is no clear indication whether those were expansion tank problems or the older caps on top did not properly bleed excess pressure.

Somehow parts dealers have convinced the e46 owners that virtually every part (aside from the engine block) that comes in contact with the coolant needs to be replaced at 60ish K miles.

Aside from the expansion tank cap everything else on my 90K 3-er is original. I periodically check the water pump area for traces of dried coolant which is an indication of a slow progressing bearing failure. I do not intend to do any massive overhauls but replace parts as needed. I can respect the "while you're in there" mentality as long as it is used rationally.

Mind you, the so called "complete overhaul kits" sold by many friendly specialist call for such ridiculous things as replacing all water temp related sensors too... which by the way are used on many many other BMW models and have proven to last forever.

flame suit is on :)

Haha. I started a similar thread on e46 fanatics it was locked within 2 days...after 150 posts. I somewhat agree but as you said had all disassembled for headers and proceeded accordingly.


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[ELCID86]

I'd do the pulleys and tensioners a while you have it apart. The bearings will go at some point.


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[Nivo]

I have 143k miles on mine now. I replaced the upper radiator hose and the expansion tank. I pressure tested my cooling system and held good. I was going to replace the water pump but it was replaced at bmw with a newer pump at 64k miles. Original radiator and thermostat still holding up.

I know I have seen lower pressure expansion tank caps but BMW runs the higher pressure to raise the coolants boiling point. They do so to run hotter coolant temps for better efficiency in the mpg department.

[Avetiso]

I have 143k miles on mine now. I replaced the upper radiator hose and the expansion tank. I pressure tested my cooling system and held good. I was going to replace the water pump but it was replaced at bmw with a newer pump at 64k miles. Original radiator and thermostat still holding up.

I know I have seen lower pressure expansion tank caps but BMW runs the higher pressure to raise the coolants boiling point. They do so to run hotter coolant temps for better efficiency in the mpg department.

Is that nivo?! :o

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[danewilson77]

Radiator?

[SoCalZman]

ah, right. I forgot to mention the radiator. I am going to wait on that. I havent seen them leak that often on the forums.

[gmurphy]

ah, right. I forgot to mention the radiator. I am going to wait on that. I havent seen them leak that often on the forums.

If you can afford to do it I would just go ahead and replace it. I replaced mine even though it wasn't leaking. It's peace of mind I guess.


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[SoCalZman]

I can afford it. oooookay, Ill do the radiator too.

[QC_ZHP]

The radiator is a part of the point that ZHPRegistry was trying to make (I could be wrong). From what I've seen they can fail at 50k or last until 200k, they're pretty hit or miss. If you have the spare cash, go for it, but if you need to spend it elsewhere, then you'll be alright holding off until any notice of leaks or overheating.

[gmurphy]

I can afford it. oooookay, Ill do the radiator too.

Haha good choice! Unless you want my old one? http://img.tapatalk.com/d/14/04/17/a5uhygeh.jpg


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[danewilson77]

Bout what mine looked like at 130k miles.

Samsung Galaxy S5...

[SoCalZman]

Yeah I will do it. I only want to service the cooling system (other than coolant) once during my ownership of the car so might as well get as much as I can.

[SoCalZman]

Heres a random question: is our lower front grill easily accessible after the radiator is taken out? I ask because if one could get it on and off easily after the radiator is out, I would like to take it out and paint it black.

[danewilson77]

I don't think it's any easier. I think the access is covered by bumper pieces.

Samsung Galaxy S5...

[wsmeyer]

I don't think it's any easier. I think the access is covered by bumper pieces.


+1

Don't be intimidated though, it's really easy to take off. I believe JupiterBMW has a DIY here on the sight.

[mLuMaN83]

Do the OFHG while you got things apart. I did mine and glad I did, it was hard as a rock!

[SoCalZman]

lol, man you guys are really piling it on to me. "oh and another thing! Change the engine too! it'll be RIGHT THERE once you take the radiator out!" :P

Ok I will add the OFHG gasket to my order if I can find the part number.....my PPI mechanic did say it was leaking a little.

Ok, I will do the bumper grill another time. I feel like I am going to have my hands full doing all this as it is.

Oh, another thing I will change since its so easy and Ill be under the hood anyway is the timing chain tensioner. Long thread over on e46fanatics about it getting compressed with age. here is the thread if anyone is interested. You can change it in 10 minutes. http://forum.e46fanatics.com/showthread.php?t=985489

[Avetiso]

OFHG isn't really "while you are in there" material, though... I don't recall touching anything related to the cooling system when I did mine.

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[Nivo]

OFHG isn't really "while you are in there" material, though... I don't recall touching anything related to the cooling system when I did mine.

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You are right. It can be done on a different day.

[WOLFN8TR]

I just did my entire cooling system at 110K except the radiator. Everything was original and NO leaks anywhere. If I lived in a place that wasn't hotter then Hell I would of probably let it go untill 150K.
Oh and second that on taking the front bumper off its easy, especially with a buddy helping.

[Hermes]

OFHG isn't really "while you are in there" material, though... I don't recall touching anything related to the cooling system when I did mine.

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This is what happens with the "while you're in there" mindset

http://i29.photobucket.com/albums/c288/jhermes/320i/F776AFB5-5DD9-4561-88AA-7AAF3D7E1A83.jpg

http://i29.photobucket.com/albums/c288/jhermes/320i/2B28CA2A-8727-4FA8-8F61-6D57F607E4D8.jpg

[SoCalZman]

Well the intake and intake tubes have to come out to get the lower coolant hose from the expansion tank to the plastic tubing. Maybe he is like, just keep going and move the alternator and PS res. and get at the gasket.

[gmurphy]

This is what happens with the "while you're in there" mindset

http://i29.photobucket.com/albums/c288/jhermes/320i/F776AFB5-5DD9-4561-88AA-7AAF3D7E1A83.jpg

http://i29.photobucket.com/albums/c288/jhermes/320i/2B28CA2A-8727-4FA8-8F61-6D57F607E4D8.jpg

:rofl


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[Hermes]

I only had to replace the starter

[Don]

I just did this on my 2004 ZHP coupe with MT.
My first major work on it, besides a fuel pump.
I used the kit from Bavaian Auto-- I really like those guys.
My car haas 126k on it, and everything was original.
I did the whole deal, to include new stewart pump, new pulley, all new tensioners, exp tank, radiator, hoses, etc.
While you are in there-- I'd go ahead and do it all.
My wife loves this coupe, and we plan to keep it for 10 years-- so I just wanted to be done with it all.
I also replaced the power steering resevoir, and I also drained and refilled rear diff, and MT gearbox.
I purchased the bentley manual, but most of what I needed to see was available online.
I hope this helps.

[ELCID86]

So do you guys recommend doing the Fluid Level Sensor (http://www.eeuroparts.com/Parts/PartDetail.php?partCode=17137553919) (17137553919)?

[danewilson77]

Sure. Or roll the dice. Temp sensor as well.

Samsung Galaxy S5...

[ELCID86]

Sure. Or roll the dice. Temp sensor as well.

Samsung Galaxy S5...
thanks, i'll do both.

Still trying to decide between these ETs though. I called and he said both are made in China and recommended the Behr (not BMW).

http://www.eeuroparts.com/Parts/28608/Expansion-Tank-17117573781/ (behr)
http://www.eeuroparts.com/Parts/57417/Expansion-Tank-17117573781G/ (BMW by Behr)

[danewilson77]

I have the Behr in my car. Installed in last month.

Samsung Galaxy S5...

[ELCID86]

I have the Behr in my car. Installed in last month.

Samsung Galaxy S5...

Thanks. That's the way leaning but didn't want to make a costly $40 mistake.


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