Coolant leak - quick question

[shadowpuck]

Our '93 525i appears to be leaking some coolant. not much, and it doesn't appear to be affecting the level - which has me a bit baffled.

every once in a while, after sitting in the garage overnight, we find coolant drops dead center, right at the front of the car. stand directly at the front of the car, right in the middle (basically at the kidney grilles) and that's about where the leak appears. it's almost always two small drops - that's it.....

expansion tank, hoses, water pump, t-stat housing, all were replaced within the last 13k miles and are less than 2 years old....

could it be migrating from someplace else? nothing else appears to show any trace of leaking. the only thing i can even think of at the center of the front of the car that could be leaking would be the radiator itself...

any thoughts?

[whiskychaser]

Think you answered your own question-the rad. Have a look at the chanel underneath. Coolant may be collecting there and dripping down now and again. If you are lucky its just the seal where the low level sender unit fits in. Small mirror on a stick may help

[shadowpuck]

thanks for the quick response!

yeah, i suspected that's probably what it was.....i wanted to confirm my thinking! :)

i'll double-check the level sensor; that's a good thought....

[Dave M]

I'm sure whisky means the drip pan when he stated "chanel underneath", but just in case, just raise the front of the car, get under there and feel around in the drip pan for coolant while also looking at the bottom of the rad and resevoir for tell-tale drips or white crusties,

Dave M

[whiskychaser]

I'm sure whisky means the drip pan when he stated "chanel underneath", but just in case, just raise the front of the car, get under there and feel around in the drip pan for coolant while also looking at the bottom of the rad and resevoir for tell-tale drips or white crusties,

Dave M
Think we are probably talking about the same thing. But just to clarify- what Dave is calling a drip pan I would call a sump guard - a big steel plate bolted on underneath. I dont mean that. Right underneath the rad is a 3 sided section of bodywork. It has a couple of drain holes drilled in it. Unfortunately mine seems to be dripping from there:( So Dave, I'm interested in 'white crusties' - mine has a white deposit around the base of the bottle though the drip seems to be coming from the bottom of the rad. I'm hoping you are going to say its a seal?:)

[shadowpuck]

makes sense; i know exactly what part you guys are talking about. i'm suspecting that's where mine is leaking as well; and the likely culprit is the radiator....

i'm going to double-check the level sensor on mine, i don't think that's the source; but, it's nice to think that's it instead of the radiator.....:)

[shadowpuck]

a quick update; the problem appears to be the radiator drain plug itself. there's a small drip right below the drain plug when the car sits. I'm suspecting that's why the level also isn't changing dramatically because the amount is only about the size of a US quarter over several days.

in looking under the car, that's the only thing i can find wet. everything else is dry; well, other than a power steering leak i'll be fixing.

we'll be swapping out the radiator (it appears to be the original and the car has 140k on it) and also replacing the 4-way cooling hose. i'll also be fixing the power steering leak....haven't yet figured out where that's leaking....

[Dave M]

a quick update; the problem appears to be the radiator drain plug itself. there's a small drip right below the drain plug when the car sits. I'm suspecting that's why the level also isn't changing dramatically because the amount is only about the size of a US quarter over several days.

in looking under the car, that's the only thing i can find wet. everything else is dry; well, other than a power steering leak i'll be fixing.

we'll be swapping out the radiator (it appears to be the original and the car has 140k on it) and also replacing the 4-way cooling hose. i'll also be fixing the power steering leak....haven't yet figured out where that's leaking....


Replacing the rad is a great idea at that mileage, so I will not try to discourage you from doing so. However, just for kicks, below is a drain plug removed, which shows a missing o-ring which caused mine to leak. How do show a mising o-ring?? Good question) ;).

Anyhow, if you need to sell a child to replace the rad, this might be a cheaper option. Otherwise, good idea replacing the rad and hose and such.

http://img.photobucket.com/albums/v11/dave_macisaac/Bimmer/Misc/Rad_Plug.jpg

Dave

[e34.535i.sport]

I done mine recently and had to unscrew the plug the whole way then it wobbled but felt stuck... I just pulled harder and it came right out, had some little protrusions on the end to keep it from falling in the drain pan (I assume that's their purpose!).

the Air conditioning is supposed to lose a few drops of liquid isn't it, don't suppose that could be related to your leak if you have A/C?

[shadowpuck]

*laughs*

that definitely sounds like the voice of experience! i suppose ours could be the same, but if the e34 radiator is anything like my e36, its just considered a mileage/age replacement item.....

fortunately, a rad replacement won't kill the budget, so the peace of mind is worth it!

just curious, when I last did a coolant flush on this car (2 years ago), I couldn't get the drain plug totally out of the radiator; is there a trick to removing it, or is mine defective? :)

[shadowpuck]

quick update; we did the work yesterday and everything appears to be happy again!

cleaned all the area pretty well from the power steering and coolant leaks. even replaced the 4-way coolant hose (or, spider hose as i call it) and everything went well. no leaks today, topped off coolant - all is happy.

thanks everyone for your suggestions and input; it was quite helpful while doing the work....i printed out the posts and we referred to them often; along with the bentley, etc....

dave - thought i'd let you know everyone loved your sig. :)

[shadowpuck]

Promised update. I don't know that I have anything different to add, or document; but thought someone might benefit from what we did.

Several of my fellow BMW Club members helped out. It's amazing what we can accomplish with a little pizza and no sense! :)

Well, a rapidly increasing power steering leak, coupled with a slow coolant leak gave us the perfect excuse to do some work on our e34, "Gretchen," as she's known by the rest of the world....

So, I gathered a bunch of random part numbers, contacted people that said they sell said parts, and ordered away. I waited and the big brown truck brought the goodies to the house....

Then, it was time to begin!

What was on the agenda? Replace power steering reservoir, two leaky power steering hoses, the radiator, and the long 4-way spider hose that runs the length the engine from radiator to firewall. yay!

[shadowpuck]

Ok, let's get started!

First, we drained the coolant and removed the radiator. This is pretty standard on most vehicles, so no need to really show any pictures. Decoupling the transmission cooler from the radiator is more tricky on the e34 than it is on the e36.

Here's a shot of the radiator removed:

http://www.kcbmwclub.com/gallery/d/20884-2/DSC_0145_1.JPG

The black, smaller radiator with the lines running from it is the transmission cooler. Fortunately, fairly early in the production run, BMW switched to a seperate transmission cooler versus the previous system - which had the cooler integral to the radiator. This meant disconnecting lines and, yes, dumping of transmission fluid. This way is much cleaner!

Here's the view from the bird's eye camera....

http://www.kcbmwclub.com/gallery/d/20896-2/DSC_0150_2.JPG

And, the old radiator gets sent to timeout!

http://www.kcbmwclub.com/gallery/d/20911-2/DSC_0155_2.JPG

Next, came the removal of the power steering reservoir and hoses.

[shadowpuck]

Power steering reservoir is at the bottom of this photo:

http://www.kcbmwclub.com/gallery/d/20908-2/DSC_0154_2.JPG

Another shot of the reservoir, the two hoses coming from it are the ones targeted to be replaced....

http://www.kcbmwclub.com/gallery/d/20965-2/DSC_0182_2.JPG

Removal of the power steering hoses has started:

http://www.kcbmwclub.com/gallery/d/20968-2/DSC_0183_2.JPG

Ta da!! Reservoir and hoses removed.....

[shadowpuck]

http://www.kcbmwclub.com/gallery/d/20977-2/DSC_0186_2.JPG

Partway through the project; yes, there's a mallet laying on top of the engine!! :)

http://www.kcbmwclub.com/gallery/d/20983-2/DSC_0188_2.JPG

Ick.....look at the mess from the power steering leak. We cleaned up a bunch of this and also re-wrapped some of the wiring....

http://www.kcbmwclub.com/gallery/d/20989-2/DSC_0190_2.JPG

Now, time to tackle the party piece; the intake manifold. This is needed to remove the 4-way coolant hose. Some claim they can change this hose without removing the manifold; perhaps that's true, but this appeared to be the best route for us....

[shadowpuck]

Next, we removed the plastic cover on the cylinder head.....Look, it's a six!

http://www.kcbmwclub.com/gallery/d/21037-2/DSC_0208_1.JPG

Work continues on removing the fuel rail and intake manifold....

http://www.kcbmwclub.com/gallery/d/21040-2/DSC_0209_1.JPG

Fuel rail is now loose and can be moved out of the way.....

http://www.kcbmwclub.com/gallery/d/21061-2/DSC_0217_2.JPG

http://www.kcbmwclub.com/gallery/d/21064-2/DSC_0218_2.JPG

[shadowpuck]

Here's where we are now - fuel rail is loose, cylinder head plastic cover is removed, as is the radiator, and power steering reservoir/hoses.

http://www.kcbmwclub.com/gallery/d/21067-2/DSC_0219_2.JPG

Now, we're gonna start on the manifold.

http://www.kcbmwclub.com/gallery/d/21082-2/DSC_0224_2.JPG

http://www.kcbmwclub.com/gallery/d/21088-2/DSC_0226_2.JPG

After disconnecting all the nuts holding the manifold in; we also had to remove two bolts holding the manifold to brackets. We did this from under the car. We also removed the intake hose, airbox, and throttle body already.

Here, the manifold is about to come out:

http://www.kcbmwclub.com/gallery/d/21094-2/DSC_0231_2.JPG

[shadowpuck]

And, yes, finally - it's out! Well, enough for our purposes....

http://www.kcbmwclub.com/gallery/d/21103-2/DSC_0236_2.JPG

http://www.kcbmwclub.com/gallery/d/21115-2/DSC_0241_2.JPG

Here's an overhead shot:

http://www.kcbmwclub.com/gallery/d/21106-2/DSC_0237_2.JPG

http://www.kcbmwclub.com/gallery/d/21112-2/DSC_0239_2.JPG

[shadowpuck]

Now, we start working on removing the coolant hose. This hose has four connections - one on the firewall, one on the throttle body, one on the engine, and one on the radiator. We started at the firewall and throttle body.

http://www.kcbmwclub.com/gallery/d/21124-2/DSC_0245_1.JPG

The hose was really baked onto the throttle body, so we had to cut it.....

http://www.kcbmwclub.com/gallery/d/21127-2/DSC_0246.JPG

Everything has been disconnected and we are starting to remove the hose....

http://www.kcbmwclub.com/gallery/d/21133-2/DSC_0249_1.JPG

Finally - it's out!! Comparing old to new....

http://www.kcbmwclub.com/gallery/d/21139-2/DSC_0252_1.JPG

[shadowpuck]

It's about now you begin to wonder if this thing is ever gonna work again! :)

http://www.kcbmwclub.com/gallery/d/21142-2/DSC_0253.JPG

Overhead shot:

http://www.kcbmwclub.com/gallery/d/21145-2/DSC_0254_1.JPG

[shadowpuck]

Installing the new hose begins; we started with the rearmost connection and path.

http://www.kcbmwclub.com/gallery/d/21151-2/DSC_0259_1.JPG

http://www.kcbmwclub.com/gallery/d/21154-2/DSC_0260_1.JPG

http://www.kcbmwclub.com/gallery/d/21160-2/DSC_0262_1.JPG

In the photo above, see, actual proof that you can find good info on the internet!! That's a printout we used to compare hose routing. Right from this here forum!

Installation continues - don't forget, put those hose clamps on before starting!!

http://www.kcbmwclub.com/gallery/d/21166-2/DSC_0264_1.JPG

[shadowpuck]

Installing hose clamps, also installing new intake manifold gaskets...

http://www.kcbmwclub.com/gallery/d/21187-2/DSC_0272_1.JPG

Books, parts, tools, and plastic bag - all on the windshield; yup, it's a tech session! :)

http://www.kcbmwclub.com/gallery/d/21202-2/DSC_0278_1.JPG

Replacing the gasket for the throttle body:

http://www.kcbmwclub.com/gallery/d/21223-2/DSC_0290_1.JPG

[shadowpuck]

Look at that! The hose is installed!

http://www.kcbmwclub.com/gallery/d/21238-2/DSC_0296_1.JPG

http://www.kcbmwclub.com/gallery/d/21235-2/DSC_0295_1.JPG


From there, installation, as they say, is the reverse of disassembly. Or, just run the pictures in reverse order! yeah.....:)
Anyway, we connected everything together, tightened everything down, filled up the radiator and power steering, bled both systems, and went out for a drive....Yup, everything works again!! Pretty amazing!

Thank you to all that helped - I never could have tackled this project on my own; I'm constantly amazed at what we here in the club can achieve!

[alex 1993 525i auto]

Expansion tank overflow that is discarded as it should?

[shadowpuck]

Expansion tank overflow that is discarded as it should?

If you are asking about disposing of the coolant; yup, taken care of.....
We used all new parts on the new radiator...

[shadowpuck]

follow up.....

i still have a persistent dribble of coolant at the lower radiator fitting. i've repositioned the hose, tried a new hose clamp, everything. any ideas?

it's the strangest thing i've run into. the bottom of the hose clamp forward to the radiator connection is wet. right after the hose clamp, everything is dry. i've now repositioned the hose twice, cleaned everything, reconnected and tried a new hose clamp.

every once in a while, it'll leave a spot right below there. so odd.

i drove it about 140 miles yesterday, it was dry all day. parked it in the garage at home, dry that night. go out today, car hasn't been touched, and its wet in that same spot....

any ideas? i'm about ready to take the thing out back and shoot it....
i've done multiple radiators on various BMW's and never had anything like this before. the radiator is brand new through BMA - a Behr. the hose is brand new, new hose clamp...

[shadowpuck]

well, final update...

finally, in desperation - working with my favorite shop, we removed the 4-way hose and discovered a small hole in the hose itself. so, replacement hose was procured and installed. all is happy now....

the hose was new, and sat in my garage - with nothing around it, for a year or so....very strange....

oh well, it's all fixed and happy now.....another one to add to the memory banks! :)