Coolant reservoir tank missing float stick!

[Al's540i]

Before leaving on a road trip to San Antonio I checked all my fluids including my coolant. When I opened my expansion tank, to my surprise my floaty stick was missing. I took a flashlight and looked down in there but no joy. I'm not sure if it broke off somehow or what. I have no idea if I'm low or just right on coolant.

So I purchased some coolant and a jug of distilled water and off I went on my road trip (coolant and water sitting on my floor board in case I needed it on my trip). No problems what so ever. No overheating, no "check coolant" message..nothing. Car ran like a top.

I got back this morning and again, no problems.

Anybody ever heard of this float stick disappearing in your expansion tank? Should I have the tank replaced? Should I leave it alone if everything is working just fine?

Al

[Doru]

Hello Al.
I remeber reading a couple years ago a very old post concerning those expansion tanks.
It said that once the dipstick starts leaning towards one side something starts breaking inside (the OP did cut that exp tank open and posted pics too) - he first thought that it was normal to have the dipstick leaning on one side. Then the exp tank gave - that's when he cut it open. Prolly yours starts going too. Have one at the ready. Maybe the whole cooling system (if you have time and $$$)?

[fastone27]

I had this happen to my 98 540 and so i replaced the whole tank. But when i shook it it sounded like it the whole inside of the tank had broken into several pieces. I would say its time to replace because mine started leaking out of the botton hole when this happened.

[e39dream]

http://www.eactuning.com/parts/produ...ls/17111741167

[PatrickW]

[Al's540i]

Thanks all.

Anyone have a DIY for expansion tank replacement?

[eflo]

Thanks all.

Anyone have a DIY for expansion tank replacement?

i did mine. its super easy. just clamp the 2 coolant hoses. pop your hood and take a look at it

[Al's540i]

i did mine. its super easy. just clamp the 2 coolant hoses. pop your hood and take a look at it

you didn't have to remove the fan shroud or anything additional?

[PJB]

you didn't have to remove the fan shroud or anything additional?

Not for the expansion tank, no. Just pop the hood, clamp the hoses, remove and replace, top up antifreeze and do a simple bleed. It would also be a good idea to replace the two OEM snap-type hose clamps with the screw-type if this hasn't already been done. This job is simpler than it sounds.

[Doru]

Not for the expansion tank, no. Just pop the hood, clamp the hoses, remove and replace, top up antifreeze and do a simple bleed. It would also be a good idea to replace the two OEM snap-type hose clamps with the screw-type if this hasn't already been done. This job is simpler than it sounds.

Maybe remove retaining plastic clip at expansion tank bleed screw and the bleed screw. Pay attention to the retaining plastic clip - it can desintegrate itself (these are at the top, on the shroud).

[PJB]

Maybe remove retaining plastic clip at expansion tank bleed screw and the bleed screw. Pay attention to the retaining plastic clip - it can desintegrate itself (these are at the top, on the shroud).

Good point Doru. These two items DO NOT come with a new expansion tank, so you need to transfer them. I thought it would be obvious once the part comes in the mail but best to point these things out beforehand. Also, swap your coolant temperature sensor from the old to new tank, since you have a 540i (no need to do this on the lowly 528i).

[Al's540i]

Good point Doru. These two items DO NOT come with a new expansion tank, so you need to transfer them. I thought it would be obvious once the part comes in the mail but best to point these things out beforehand. Also, swap your coolant temperature sensor from the old to new tank, since you have a 540i (no need to do this on the lowly 528i).

where is the coolant temp sensor located?

Edit: nevermind. My guess is it's somewhere in or on the expansion tank.

[scbimmer]

Maybe remove retaining plastic clip at expansion tank bleed screw and the bleed screw. Pay attention to the retaining plastic clip - it can desintegrate itself (these are at the top, on the shroud).

I'm replacing my expansion tank next weekend. Going to buy from eactuning. How do you remove the plastic retaining clip around the vent screw? Do you swivel it off or pull from above? Sorry, i just don't want to break it while messing around.
Will I find the temp sensor at the bottom of the expansion tank? Replace or reuse it?

Thanks in advance

[5mall5nail5]

Patrick - SO over priced!

[scbimmer]

I'm replacing my expansion tank next weekend. Going to buy from eactuning. How do you remove the plastic retaining clip around the vent screw? Do you swivel it off or pull from above? Sorry, i just don't want to break it while messing around.
Will I find the temp sensor at the bottom of the expansion tank? Replace or reuse it?

Thanks in advance

Any instructions on how to remove the clip?

[PJB]

Any instructions on how to remove the clip?

The clip is broken in this pic, but see the two retaining tabs at the 5- and 11-o'clock positions on the clip? Press those in and carefully lift the clip up, while maintaining even pressure around the periphery. If you try to pop out just one side you might break it.

[Al's540i]

Not for the expansion tank, no. Just pop the hood, clamp the hoses, remove and replace, top up antifreeze and do a simple bleed. It would also be a good idea to replace the two OEM snap-type hose clamps with the screw-type if this hasn't already been done. This job is simpler than it sounds.

Once everything is replaced, how do I perform the "simple bleed" of the system?

[Qsilver7]

this has been covered many, many times...and I'm POSITIVE if you go to www.e38.org (they have the same m62/m62TU engines as in the e39) or www.e38.org/e39 ...you will find a DIY write-up with pics and everything!

It may help to also do a page search [Ctrl+F] and type "bleed" as your search word...this will allow you to skip past all the links that have nothing to do with "bleeding" the coolant or any other "bleeding" procedure on the site.

Good luck.

[Al's540i]

this has been covered many, many times...and I'm POSITIVE if you go to www.e38.org (they have the same m62/m62TU engines as in the e39) or www.e38.org/e39 ...you will find a DIY write-up with pics and everything!

It may help to also do a page search [Ctrl+F] and type "bleed" as your search word...this will allow you to skip past all the links that have nothing to do with "bleeding" the coolant or any other "bleeding" procedure on the site.

Good luck.

Cool, found it. Thanks!

I just ordered my expansion tank and clip to replace this weekend. My car is still running good with no coolant leaks but better safe than sorry I guess.

[PJB]

Once everything is replaced, how do I perform the "simple bleed" of the system?

Park your car on either a level surface, or a slight incline with the front of the car higher than the rear, i.e., on a driveway. Loosen the rear bleed screw near the thermostat just a bit - a few revolutions max. Open the cap on the expansion tank reservoir, take a deep breath, place lips fully over hole (yes, I'm serious), and blow hard and steady. Your ears will be close to the hoses and if there's air in the system you can hear it migrating through and eventually out of the bleed screw. Tighten the bleed screw while still blowing and when escaping air is replaced by a small stream of antifreeze; this will be an awkward maneuver.

Thermostat bleed screw:


Expansion tank bleed screw already directed to in Post #16

[Doru]

Any instructions on how to remove the clip?

Sorry, I didn't check the forum lately.
Take 2 small flathead screwdrivers and gently press towards the inside on the 2 wings (retaining clips). Then lift up. Very easy.

image007.jpg

[Doru]

Hey Al, here's the updated sig. It's right off their site.
rmadrid.gif

[Al's540i]

Hey Al, here's the updated sig. It's right off their site.
rmadrid.gif

Thanks Doru!