Author Topic: RE: Coolant Leak/Expansion Tank Question (Read 3060 times)

Colo318IS · « **on:** June 20, 2007, 07:16:13 PM »

Hello to the M42 Club!- first off, you've got a newbie to the club here so my apologies up front if I'm posting this question in any way considered "not cool" and if I have, just let me know...

OK, having said that, a little background on my issue:

I have a 1991 318IS and bought it a few months ago. I have checked this site and bimmer forums when researching my recent buy so I think this question hasn't specifically been asked...

...my question is what are proper coolant levels in the expansion tank? (note: I currently don't have an owner's manual)...I know the coolant level is gonna fluxuate when cold & operating, so specifically what I'd like to know is where should the coolant level be:

1-when the car is dead cold,
2-after it's idled for a 4 or 5 min, and
3-at operating temp?

The reason I ask is I have recently discovered a coolant leak and after checking things out, believe it's coming from the expansion tank-both top & bottom (everything else is checking out OK so far) I read the other post from the guy in Cali with the same issue (the one who repainted the valve cover/etc on his 318i-WOW btw!)...so I'm planning on draining, removing the tank/sealing it with silicone/etc...so once I get it reinstalled & refilled, I'd just like to know what the proper levels should be so I can continue to monitor things going forward...

Right now my level when dead cold is about 3 inches below the engrained mark (I'm referring to the mark I believe says Halt/Cold?)...should it actually be at the Halt/Cold level when cold? (I'm guessing so?)

Thanks so much for any insight-I'd been specifically looking for a 318IS for several months so am happy to have it...am enjoying working on it & driving it...and am happy to have joined the club!

So far it's been an invaluable source of info!

Thanks.

Jay

PS-eventually I'll get a pick or two posted on here-

gearheadE30 · « **Reply #1 on:** June 20, 2007, 08:05:42 PM »

Welcome to the club! No need to apologize for being new, we were all there at some point

.

My coolant is even with the "cold" mark on the tank and gets within a few inches of the cap at operating temp, which it usually reached in about 4-5 mins. Don't know if this is normal, but my car has no problem with it.

BTW looking foreward to seeing pics

Colo318IS · « **Reply #2 on:** June 21, 2007, 07:06:45 PM »

OK, good to know, thank you.

The car is d-schwartz in color, they are cool lookin little cars though-I've been constantly amazed at the amount of people I see drivin newer bimmers that stop and stare in traffic. (I just smile inside)

Thanks again!

Jay

Colo318IS · « **Reply #3 on:** June 26, 2007, 01:49:00 PM »

An update on the expansion tank:

I drained the coolant, pulled the expansion tank, sealed it with sealant, reinstalled and let sit for 24 hours-so far so good, no more leaks.

Still wondering & monitoring the coolant level in the expansion tank though.

I refilled & bled it, level was sitting good at Kalt/Cold mark after bleeding. Drove it for about 25-30 min, temp guage stayed right around 1/2 tick. Got home, never overheated, no leaks, but also there's no coolant in the expansion tank. I let it sit overnight...got up this morning, the coolant level in the expansion tank rose and is sitting about an inch above the kalt/cold mark...just wondering if my level when operating is normal or not? That is to say, is it normal to have no coolant in the expansion tank when operating or shouldn't there be at least "some" coolant in the expansion tank?

Thanks for any insight.

Jay

RED IS 91 · « **Reply #4 on:** June 27, 2007, 08:07:45 AM »

Isn't your expansion tank connected to your radiator :confused:

I replaced my radiator and the new one came with the expansion tank attached .After I installed the new radiator the expansion tank leaked because it was defective . The supplier sent me a replacement.

Colo318IS · « **Reply #5 on:** June 27, 2007, 01:16:53 PM »

..yes, it is connected to the radiator.

An update to bring closure...everything seems to be in order now. I drove it last night for about 45 min-hour, it never got above the 1/2 tick, when I got back,no leaks and the coolant level in the tank was right at the Kalt/Cold mark...I'll continue to monitor..