Coolant Leaking - Can't find where

[dbailey]

Guys I have coolant that slowly leaks after I park it and I've looked EVERYWHERE and can't find where its coming from. I have a 2000 with the 3.4 and around 180,000+ miles. Have had the LIMG gaskets replaced by the stealership maybe 100,000 miles ago. The coolant leak is on the passenger side and from the looks of it from underneath, it is coming from somewhere sorta above the crank pulley. I've checked all of the hoses I can see, pulled the pulley off of the water pump to check that and no wetness anywhere, checked the reservoir and no cracks or evidence of coolant anywhere around it and the overflow hose shows no sign of overflow. The cap on the rad won't tighten down like the threads are cross threaded on the tank and they may be but there is no evidence of any leaking anywhere near the tank. What else could it be? No coolant in oil. Any ideas orsuggestions? Thanks guys.

[clutch1]

Put dye in the coolant and hit it with a blacklight.

[dbailey]

I've ehard of doing that with freon but not coolant. I can sorta see where it is coming from but too much in the way to tell for sure. I think I've checked everything top and bottom that I can see or touch.

[zzyzzx]

Have you tried looking for leaks with it running?

How sure are you that it's not the water pump? I mean if it's still the original one I'd be highly suspicious of it, and you might need a new one soon anyway.

[dbailey]

Replaced water pump like last year and it was bone dry all around it when I checked it.

[Nate's Alero]

The overflow neck. check under it.

[Redog]

^^ Nate, you didn't say head gasket :eek:

Check the overflow hose on the coolant bottle.

You said something about the cap not fitting right. I put some Veggie oil around the thread of the cap and I haven't had a problem since :D

[clutch1]

I've ehard of doing that with freon but not coolant. I can sorta see where it is coming from but too much in the way to tell for sure. I think I've checked everything top and bottom that I can see or touch.

Works the same way, helped me find a leaking thermostat housing on a dodge truck the other day. Couldn't figure it out, then hit it with the blacklight / UV glasses after the dye had a few days to circulate , and bam, it slapped me in the face (and still wasn't really noticeable without it.. just looked dirty).

Works really good if all else fails for sure.

[dbailey]

Thanks for the suggestions guys. Where would you get dye and a uv light though? As for the overflow, there isn't a drop fo anything anywhere near the overflow tank. I've pretty much ruled that area out. There would be some sort of residue if it were coming from there wouldn't you think? :( I really looks like it is coming from the passenger side of the block and there is too much in the way to tell where from. :cry:

[clutch1]

http://www.uview.com/ProductPage.php?Category=Professional+UV+Leak+Dete ction

[zzyzzx]

Replaced water pump like last year and it was bone dry all around it when I checked it.


New or rebuilt water pump? Purchased where, and brand name please.

I wouldn't trust any water pump sold by Autozone, Pep Boys, Advance Auto, unless it's new, made in USA, not a store brand, and probably special ordered.

[comanche]

I'm gonna go with the water pump idea as well...

[WorkAlero]

I just fixed a major coolant leak on my car (2000 3.4 w/128k miles) a couple of weeks ago. My leak was coming from the passenger side, rear of the engine. When I jacked it up and got underneath to check it out I still couldn't see exactly where it was coming from but it was somewhere toward the top of the block around the head gasket area. Once I started taking things like the alternator and the power steering pump off we found that it was the gasket for the timing chain cover. That cover has a coolant passage on top that circulates coolant through the block. The gasket had deteriorated and blown out causing the big leak. Same symtoms as OP. Hard to spot exactly where it's coming out because everything is in the way. There was no coolant in my oil either. Wasn't expensive to fix but was a big PITA. Good time to replace the serpentine belt too.

[zzyzzx]

I just fixed a major coolant leak on my car (2000 3.4 w/128k miles) a couple of weeks ago. My leak was coming from the passenger side, rear of the engine. When I jacked it up and got underneath to check it out I still couldn't see exactly where it was coming from but it was somewhere toward the top of the block around the head gasket area. Once I started taking things like the alternator and the power steering pump off we found that it was the gasket for the timing chain cover. That cover has a coolant passage on top that circulates coolant through the block. The gasket had deteriorated and blown out causing the big leak. Same symtoms as OP. Hard to spot exactly where it's coming out because everything is in the way. There was no coolant in my oil either. Wasn't expensive to fix but was a big PITA. Good time to replace the serpentine belt too.

Is there anything on this car that doesn't have a coolant line going through it?

[dbailey]

I just fixed a major coolant leak on my car (2000 3.4 w/128k miles) a couple of weeks ago. My leak was coming from the passenger side, rear of the engine. When I jacked it up and got underneath to check it out I still couldn't see exactly where it was coming from but it was somewhere toward the top of the block around the head gasket area. Once I started taking things like the alternator and the power steering pump off we found that it was the gasket for the timing chain cover. That cover has a coolant passage on top that circulates coolant through the block. The gasket had deteriorated and blown out causing the big leak. Same symtoms as OP. Hard to spot exactly where it's coming out because everything is in the way. There was no coolant in my oil either. Wasn't expensive to fix but was a big PITA. Good time to replace the serpentine belt too.

Hmmm........that must be where mine is coming from becuase I can't imagine where else it could be coming from. Would have NEVER thought to check there. Guess I'll wait til it gets worse to start ripping into it since its my daily driver. Got any lessons learned that I need to pay attention to when I do start taking it apart? Thanks for the info.

[dbailey]

New or rebuilt water pump? Purchased where, and brand name please.

I wouldn't trust any water pump sold by Autozone, Pep Boys, Advance Auto, unless it's new, made in USA, not a store brand, and probably special ordered.

Must admit it was an Advance Auto water pump I think or possibly NAPA but there is not even the slightest evidence of a leak anywhere near the pump.

[WorkAlero]

We didn't find it until we took everything apart and put some air pressure through the radiator hose. Then we could see where it was coming out from. The Haynes manual will tell you to take half the suspension off so you can get the oil pan off but you don't need to take the oil pan off. You will need to support the engine somehow since you have to remove the motor mount on that side. The bottom of the timing chain cover seals itself against the oil pan and there is a rubber gasket all around the oil pan. We just put a thin bead of black silicone between the cover and the oil pan and it sealed up just fine.

[dbailey]

We didn't find it until we took everything apart and put some air pressure through the radiator hose. Then we could see where it was coming out from. The Haynes manual will tell you to take half the suspension off so you can get the oil pan off but you don't need to take the oil pan off. You will need to support the engine somehow since you have to remove the motor mount on that side. The bottom of the timing chain cover seals itself against the oil pan and there is a rubber gasket all around the oil pan. We just put a thin bead of black silicone between the cover and the oil pan and it sealed up just fine.
OMG! Its gonna have to leak alot more than it is before I'm gonna go to that extreme. Thanks for sharing the process.

[dbailey]

We didn't find it until we took everything apart and put some air pressure through the radiator hose. Then we could see where it was coming out from. The Haynes manual will tell you to take half the suspension off so you can get the oil pan off but you don't need to take the oil pan off. You will need to support the engine somehow since you have to remove the motor mount on that side. The bottom of the timing chain cover seals itself against the oil pan and there is a rubber gasket all around the oil pan. We just put a thin bead of black silicone between the cover and the oil pan and it sealed up just fine.

Still no leaks?

[WorkAlero]

Still no leaks?

Still no leaks. That appears to have fixed my problem. Haven't been back under the car for an oil change yet but I will definately check it close when I am. No more puddles on the garage floor though.

[dbailey]

Still no leaks. That appears to have fixed my problem. Haven't been back under the car for an oil change yet but I will definately check it close when I am. No more puddles on the garage floor though.

If mine gets worse, I will have to rip into it. How did you put pressure in the system? Can only imagine what a garage would charge to fix it. Glad your leaking stopped. :yahoo:

[WorkAlero]

Sorry dbailey, don't get over here very much. We took the coolant line that went from the overflow tank to the radiator, removed the overflow tank side, and put an air hose with a blower handle we could control into the hose. you have to hold it tight to try and keep the air going into the system (redneck I know). We just shot VERY small bursts of air into it until it forced the coolant out of the leaking area. We had most everything apart so this let us see exactly where it was coming from.