Calling all Mechanics - Need help!

sleepyhead · 11-09-02, 10:53 AM

Here's my situation...

Last winter, while my vette was tucked away in the garage, she developed a coolant leak. The strange thing is, it was nothing constant. I put her away and start her up every week or 2 until the oil temp gets up to 200 degrees. For the first few weeks, everything was fine...until one day, I go out and there's a smallish puddle of coolant underneath her. I cleaned it up and it didn't happen again until about a month or 2 later. At this point, it was around February and I figured I'd wait until Spring to bring her into a mechanic and get it checked out. Well, this past April I took her out of storage but had absolutely no problems with the coolant leaking. I drove from April until 2 weeks ago when I tucked her back into the garage for winter storage and found nothing wrong. Well, I came out today to check on her and wouldn't you know it - a decent size stream of coolant running into the drain in the middle of the garage floor!

Now, this problem only seems to happen in cold temperatures. I'm going to try to attach a picture of where the leak is coming from. The picture was taken from just underneath the front of the car.

Thanks in advance for any help you can offer!

-J.

vettl83 · 11-09-02, 11:07 AM

Could it be running out of the weep hole on your water pump? That would be an indication that the seal has gone bad and dried up when stored. The only other items to check in that location is the lower radiator hose and the coolant recovery bottle. I'm thinking if it was a leak in the radiator it would spray out when it pressured up. 84 CF 91 ZR-1

sleepyhead · 11-09-02, 11:31 AM

Someone else had said that it sounds like a problem with the water pump. The only thing is, I'm just a wanna-be mechanic...and I have no idea where the water pump is even located!

If it is a bad seal, do I need to get a new water pump or can the seal be replaced? Also, do you think that it's a project that I should turn over to a professional seeing that I'm only minimally mechanically inclined?

Oh...and if I do need a new water pump, should I go with AC Delco or are the Edlebrock "super-cooling" water pumps any good? (They are both $180.00...)

Thanks!

-J.

sleepyhead · 11-09-02, 11:40 AM

Thanks a lot for the input. In the event that I do decide to tackle it, do you happen to know of any step-by-step directions online to replace the water pump?

vettl83 · 11-09-02, 12:16 PM

Your best bet if your going to do it yourself is to purchase a factory shop manual from Helms. www.helminc.com will hook you up. The manuals are specific to the year of Vette you own and not generic like the ones sold at Auto Zone i.e. Haynes, Climbers, etc. There not cheap, but niether is your Vette. Maybe one of the forum members in your area would be willing to lend a hand. It's not that difficult to do once you've done it a time or two. Good luck 84 CF 91 ZR-1

sleepyhead · 12-02-02, 01:47 PM

Well, I decided to wait until Spring to replace the water pump. But I still find it odd that it's only leaking once every great while. For example, a month later and it hasn't leaked a drop!!! (I've even started the car and ran it until oil temp got up to 200*.)

Does anyone have an explanation on why it would leak every so often at seemingly random times? (The only commonality there's been when it decides to leak, is that the car is sitting for a month or 2 and it's cold outside.)

Just curious...thanks for any advice you can offer.

-J.

JonM · 12-02-02, 03:07 PM

Look at the pic below...see the tiny hole in the middle of the pump? That is the weep hole. If the seal or bearings are about to go due to wear, it will leak sometimes very slowly. If you try to drive it, it will wait till you are in the middle of nowhere and break alltogther

The weep hole is GMs way of saying..."Look into this before its to late"

Here is a doc explaining the removal of the waterpump and the timing chain...just ignor the timing chain stuff.

http://www.corvettefaq.com/c3/T-ChainTechPaper.doc

sleepyhead · 12-02-02, 03:17 PM

Thanks!

12-02-02, 05:34 PM

Chiltons manual at Autozone is 14.95

BigRed · 12-03-02, 12:45 AM

I learned a NEAT trick today at my shop. (I should make this a thread,)

If your looking for a coolant leak and your a hippy from the good ol days try this.

Wipe down everything as to start fresh. Try and make it leak again. NOW the cool part. Take a BLACK light or LED and scan the radiator/Hoses/Head/Pump the green coolant will turn NEON and you could see it a mile away.

Snap on makes a pen light with a black light LED in it for this exact reason.

(Scan that Rad as well bud you might have devoloped a crack)

12-03-02, 09:11 AM

You are evidently experiencing the classic "cold weather leak." The shaft shrinks enough in really cold weather to allow it to leak out the weep hole.

Unless you depend on the car in cold weather or it also leaks in warm weather, I would just keep the radiator full and forget it.

Good luck,

sleepyhead · 12-03-02, 02:57 PM

No opti-sparks on the L-98 engines, though! (One of the bonuses of having an "older" C4...)

flier32 · 12-03-02, 05:17 PM

I had a simular problem. Sometimes it would leak, sometimes it wouldn't. Check the radiator drain plug. They are plastic and I found a hairline crack in mine. Hope this helps.

lt1george · 12-09-02, 11:09 PM

check your hose clamps, make sure they are tight. Save the Wave .>George

spyysee · 12-10-02, 04:00 PM

If your wp is original, and you really love your car, change it anway,(use oem only) 'cause a guy named MURPHY has you in his sights.
That goes for hoses and thermostats.