coolant leak

[jooset]

So even after reading a lot of threads on this topic, I'm still confused on what my prob is. I have a pan in my garage to catch the 2 drops of oil that come out after every drive. 2 days ago my wife calls me at work and says the pan is half full of water. Never seen that before - it had rained that day...maybe just run off. Today, another pile of water in the pan (a pint or so). It's coolant (I use RMI and distilled water).

Okay, so it's not a leak per se. Ran the car today - no leak at work, no leak back at home (but I came home early with no traffic, i.e. car wasn't idling a lot or running hot). Checked all hoses - dry. Overflow was empty so I topped it off. Ran the car again to get it nice an warm and let it sit in the driveway running for a while until the temp got up to 185. Tried heater and air conditioner. No leak. Turned car off and about a cup of coolant spilled onto the ground - came out the holes in the cross member. Doesn't look like there are any leaks from overflow or radiator or hoses that I can see. Definitely some wetness low on the block passenger side. In fact there were a few drops/spray on the intercooler bracket (maybe flung around from fan or belt?). Definitely not a drip drip leak. It pisses then stops.

So as of now...seems to only happen when hot. Drove 15 miles this evening to pick my son up from school and not a drop - (radiator and overflow still full).

I have a 160 deg thermostat and engine always runs very cool when moving. When stopped and idling (traffic, lights) and the car is warm/hot, temp creeps up to 180-85. When it was 110 this summer and I was stuck in DC traffic, I would get up to 200-205. As soon as the car starts moving, temp drops back down.

I'm sure it's obvious and I'm just stupid. Tstat? freeze plug? heater core? water pump? Any assistance/recommendation appreciated!

 

[Turbotre]

Intermittent leak,sounds like the water pump.

 

[jooset]

I think you're right. I watched the car last night for about 30 minutes after I got home - not a drop. Went out this morning into the garage - another pint of coolant - no dripping. I'm thinking as the seals contract after it cools down - it spits out the weep hole. I think that's the way it's designed to work when the seals and bearings are going bad. Have a new pump on the way - will advise how it turns out.

 

[Red C5]

Good info if its the pump. Subscribed for results.

 

[Silver Fox]

Had a similar issue years ago. Nick Micale advised me to replace the heater control valve and that fixed my problem.

 

[CGASTON]

Take a look at the metal coolant line on the intake. They will get rusted and corroded and have a small pin hole leak. My 86 was doing that and I though it was a head gasket. Get yourself a coolant pressure tester and check your system. When it is pressurized, you will see the leak. Also it can be coming from the valve, but testing is cheaper than buying a lot ofparts!!

 

[SS/GN]

Water pump weep hole,hard to find because it usually evaporates befor hitting the shop floor.I put a NAPA new replacement on.

Kevin

 

[GNRick]

I just had my front cover and water pump replaced by a local mechanic. Car ran fine for a couple months, now I also have a coolant leak. I pressurized the radiator and the coolant appears to be coming from the front cover by the oil pump...kind of in the corner where the oil pan bolts up. I have a combustion leak detector which I will use tomorrow to see if it is a head gasket....I'm hoping it is the water pump...does this sound like it could be the water pump? don't mean to hijack this thread, just trying to spread the knowledge!!

 

[SHADOWII]

I just had my front cover and water pump replaced by a local mechanic. Car ran fine for a couple months, now I also have a coolant leak. I pressurized the radiator and the coolant appears to be coming from the front cover by the oil pump...kind of in the corner where the oil pan bolts up. I have a combustion leak detector which I will use tomorrow to see if it is a head gasket....I'm hoping it is the water pump...does this sound like it could be the water pump? don't mean to hijack this thread, just trying to spread the knowledge!!

Not if it's by the oil pan. Maybe a cracked f/cover? Hopefully it's not mixing w/the oil.
Are you sure it is not just lightly running down the front cover and puddling at that point from the weep hole in the pump?

 

[Pronto]

Try some coolant dye.

 

[GNRick]

Ok I can't say for sure if it is running down from the weep hole or not. I will give the coolant dye a try. I bought a combustion leak tester and tested for a blown headgasket. Liquid stayed blue so that is a good sign. I had also done a compression test and all cylinders were about at 150 except for the #6 which I couldn't test (couldn't screw the hose into the spark plug opening). I also have another problem. Fans aren't coming on, gauage shows 225. When I put on the a/c the fans come on for a short while then turn off before the temp gets to 200. So the fans do work. I replaced the temp. sending unit on the front of the manifold but that didn't help. I'm thinking the wire might be bad that plugs into the sending unit. What can I do to the wire to send the signal to the ecm and turn on the fans? Would I touch it with a hot + wire or a negative - wire? I don't want to fry the chip in the ecm. Thanks.

 

[jooset]

Well, just to follow up with my original posting. I'm pretty sure it was the water pump (in my case). Replaced this weekend and I made a 50 mile trip (each way) today and no leakage. Granted it was in the 50s (maybe 60) and I didn't run into traffic, but it's a good sign that she held together. I didn't press my luck with any hard runs (frankly wanted to make sure I mad it back). Will keep an eye on it over the next few days. Replaced a couple of hoses that I happened to have on hand as long as I was at it (even though I didn't see any that were imminently failing). The one from the water pump to the heater core rail was a royal pita and was the only part of the job that took way longer than it should have.

 

[GNRick]

Glad to hear you got it figured out. Mine was leaking from the temperature sending unit on the front of the intake, that sends the signal to the VDO gauge in the gnx style dash.