Jump to content

14th Annual SoCal Vintage BMW Meet 2021! “All couped up”

Registration is still open. Rally from NorCal is scheduled for Friday. Post your event photos.

SoCal Vintage is Here! 

Post your photos!

coolant leak


Guest Anonymous
 Share

Recommended Posts

Guest Anonymous

On the way to work today, my '76 ran hot, steam coming out of the hood, and when i opened the hood coolant condensing everywhere. There is a major leak somewhere, because when I fill the rad coolant leaks out, over the driver's side valence. All the hoses seem to be intact.

Unfortunately, because I was in my work clothes and pressed for time, I didn't have a chance to do a close inspection. But I have to decide whether it's a job I can do myself or professionally. Any ideas?

Thanks in advance!

Link to comment
Share on other sites

without risking overheating and damaging the engine by first filling the radiator with water (Don't waste coolant 'cause it's just gonna leak out) and then loosen (but don't remove) the radiator cap. The leak won't be quite as bad when the system isn't pressurized.

It'll also allow you to get a better look at the leak's origin. When you say "driver's side valence" do you mean the front of the car, or the driver's side inner fender well? And overheating car in motion will sling coolant all over the place, so try and observe the leak with the car running but not being driven.

Let us know whatcha find.

mike

Link to comment
Share on other sites

Guest Anonymous

Thanks, Mike. I don't know if depressurizing the system will help much, because when I poured coolant into the top of the rad, the coolant quickly ran out of the system, and it was, of course, depressurinzed then.

It's leaking somewhere in front, and probably on some hot surface, because the coolant vaporized. It seemed to more on the drivers side, but the engine compartment was wet everywhere. If I were able to get under the car I'd probably figure it out, but I didn't have the time to do that!

Hugh

Link to comment
Share on other sites

Guest Anonymous

I don't think it's the hoses. They were fairly easy to check.

The fan hitting the rad is a real possibility. I didn't hear anything when driving, but, now that I think about it, one of the blades was rough on the leading edge. Assuming that's the case, (a) does that mean I need a new rad, and (B) is that a common occurrence? I don't understand how that can happen. Neither the rad nor the engine has moved. ...

Link to comment
Share on other sites

Guest Anonymous

Interesting, because I had the mounts replaced this summer. Enough time ago that I think would have had this problem earlier; not so long ago that the mounts would be worn out ...

Link to comment
Share on other sites

if fan hit rad it will be visible, the back of the rad will be damaged.

the mounts could be ok, but the subframe where the drivers side mount attaches could be broken. another known failure point.

but, if the rad does not look destroyed, it has to be something simple. when you pour the water in, where exactly does it come out? rad? engine? if it is coming out that fast, it "should" be obvious...

Link to comment
Share on other sites

Guest Anonymous

Got a chance to look under the car today in daylight (had it towed home yesterday from work), and I know exactly what happened: One of the plastic fan blades caught the bottom of the radiator. It doesn't look that bad (I'll try to attach a pic) later, but that's where the coolant is leaking out.)

Some history: had the motor mounts replaced this summer. Some time afterwards the AC pulley cut into the lower radiator hose. At the time I didn't think that the motor might be positioned incorrectly; figured the PO installed the hose wrong. But it's clear that the motor is tilted up just enough to come into contact with vital lower parts of the cooling system. There's no evidence that the mounts or supporting metal are loose or fatigued.

So here are my questions:

1. Has anyone had this happen to them before? They guy who replaced the motor mounts was a reputable '02 guy, so I don't want to assume that he installed them wrong. But I can't think of any other explanation.

2. If there's a 1" to 2" cut in the rad, does it necessarily have to be replaced? or can these be salvaged? Man, these things are expensive, and mine was in great shape -- no rust.

3. A 1/8" sliver was sheered off one of fan blades. Should that be replaced?

4. I had coolant condense everywhere in the engine compartment, though it's dry now. It also dissolved some of the deteriorated foam under the hood, leaving black dust on alot of surfaces. Anything to worry about my electrical system or air intake?

I realize a picture or two would help, but in the meantime, any comments would be greatly appreciated.

Thanks!

Link to comment
Share on other sites

Guest Anonymous

OK, I think I solved the mystery. The tranny mount was replaced along with the engine mounts. But one of the PO's had a couple of washers stacked on top of the old tranny mount. My mechanic thought it was odd, but neither of us gave much thought to it, assuming that they were just compensating for a worn out mount. But now I think those washers were there for a reason: I'm assuming that if the end of the transmission is pulled up, the engine tilts down forward, with the forward engine mounts acting as a fulcrum.

If the diagnosis is correct, the lesson is that with these old cars you sometimes have to finesse things a bit. A valuable lesson, only if it weren't so damned expensive ...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...