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.



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?