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Coolant leaking, but from where???

SS FORCE

SS FORCE

Active Member
Messages
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Location
West Jordan utah
I went to go start the truck a couple weeks ago and smelled a little antifreeze while I let it warm up. Looked underneath it and saw a small puddle. The puddle was on the front passenger side of the truck and looked to be dripping off the corner of the skid plate. I made note to check it again once I got to my fathers place that morning. Got there, checked again and nothing. Nothing for the rest of the day, or several days after. Since then the temps dipped back down to the low 30's and the leak has reappeared. I haven't driven the truck in several hours so its mostly cooled off, I removed the cap to check the level in the overflow tank and there was a slight bit of pressure in the tank, coolant level was mid bottle.

A google search just brings back results to turn my stomach and after scouring the forums I am here to ask for help. So far I see it could be something as simple as the cap being bad, or the dreaded head gaskets or water pump. The oddity here is its only when the outside temps are cold and the truck has sat cold overnight or at least a number of hours after operating. I have stuck my head under the truck several times trying to determine where this leak is coming from and I'm not finding anything, today when I looked I could see antifreeze in the trans cooler lines at the front pass side of the engine right where they go from rubber to the crimped aluminum, also looks like there is antifreeze on the idler arm. Any ideas as to what the problem is here?
 
I should also note that the truck does not seem to be having any temperature issues, I did notice what looked like a small amount of possible spray in the intake tube past the air cleaner that at first glance just looked like water spots as its been raining here on and off the past couple of weeks, now I'm wondering if its spray from the overflow, although again it looks like its at the normal level.
 
Cold leaks are the hardest to find. With the truck ice cold, you can try pressure testing, but usually the hoses swell up under pressure and seal the leak like when it is warmed up.- give it a try though.

Pouring in some a/c dye into the radiator might turn something up, but it takes a whole bottle to do it.

No smell of antifreeze in the exhaust, right?

Look at the freeze plugs really good.

Sometimes I just drain the system. Remove all hoses-clean their connection points and new clamps.

If you have or can borrow a mightyvac mv4525, they are friggin nice. Vacuum out the coolant, keep the system on a vacuum, and you can hear where it starts sucking the air in. It's kind An a/c system under vacuum and you can hear the bad seal...
 
Will L. said:
Cold leaks are the hardest to find. With the truck ice cold, you can try pressure testing, but usually the hoses swell up under pressure and seal the leak like when it is warmed up.- give it a try though.

Pouring in some a/c dye into the radiator might turn something up, but it takes a whole bottle to do it.

No smell of antifreeze in the exhaust, right?

Look at the freeze plugs really good.

Sometimes I just drain the system. Remove all hoses-clean their connection points and new clamps.

If you have or can borrow a mightyvac mv4525, they are friggin nice. Vacuum out the coolant, keep the system on a vacuum, and you can hear where it starts sucking the air in. It's kind An a/c system under vacuum and you can hear the bad seal...
Click to expand...

I will stick my nose the in the exhausts tomorrow and double check but I haven't caught any odd smell out of the rear end, HA

Where can I get me some of that dye? local parts store I presume? I am thinking I might go the drain/refill route. Oil change and greasing the front end is due in the next couple hundred miles and would be a good time to flush the system and check everything. I will climb under it and check the freeze plugs and have another look around. With where its leaking I am more leaning towards the water pump or loose fitting somewhere that when cold weeps
 
I mean, umm, er, not just the waterpump seal starting to seep is it?

Smell...rearend... I'm pickin up what your layin down there. Or to say - I smell what you're steppin in...
 
Get a mirror and a good light, my bet is the water pump gasket on the Pass port to the block. Had one go there and had a drip in the same spot.

Wouldn't hurt to take the fan and pulley off to get a good look at the weep holes.
 
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No need to add dye if it has dex cool anti-freeze. Every jug I've checked glows like no tommorrow under a black light. Water pump seals are famous for leaking when cold. Also check to see if the fittings going into the radiator for the trans cooler lines are tight. A few have had the o-ring for the lower radiator hose quick connect leak. Unfortunately you're going to have to dig in when it's cold out to find the leak.
 
Will L. said:
I mean, umm, er, not just the waterpump seal starting to seep is it?

Smell...rearend... I'm pickin up what your layin down there. Or to say - I smell what you're steppin in...
Click to expand...

Stuck my head back there, thankfully no surprises. Shes clean. :woot:

NVW said:
Get a mirror and a good light, my bet is the water pump gasket on the Pass port to the block. Had one go there and had a drip in the same spot.

Wouldn't hurt to take the fan and pulley off to get a good look at the weep holes.
Click to expand...

If this is the case, will the gasket be just as fun to replace as the pump itself?

THEFERMANATOR said:
No need to add dye if it has dex cool anti-freeze. Every jug I've checked glows like no tommorrow under a black light. Water pump seals are famous for leaking when cold. Also check to see if the fittings going into the radiator for the trans cooler lines are tight. A few have had the o-ring for the lower radiator hose quick connect leak. Unfortunately you're going to have to dig in when it's cold out to find the leak.
Click to expand...

My truck does have the orange dex cool, so ill get my hands on a black light if it comes to that and see what it turns up. Ill check the connections and see where that gets me.


Thank you all for your input. I am happy to read that none of you suspect the head gasket. I can't afford the time to do that myself or the $$$ to pay someone else to do it right now either, at least if its a water pump it seems manageable. Good ol life has thrown a curve ball at me, medically speaking, and is currently eating up all my money, so my time is spent making more. I will check all you have suggested and see what I end up with.
 
If you are looking to do the water pump, make sure to buy a flywheel holding tool ahead of time. Goes right through the inspection hole. A real time saver when pulling the balancer.
 
ak diesel driver said:
hope everything works out for you. Sucks having to worry for that long
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Thanks AK, I am hoping for some good news in the next couple of months to ease my worry but, until then, one day at a time.

btfarm said:
If you are looking to do the water pump, make sure to buy a flywheel holding tool ahead of time. Goes right through the inspection hole. A real time saver when pulling the balancer.
Click to expand...

I will definitely be getting me one of those. Work smarter not harder right. :smuggrin:
 
My 2006 LBZ with 70 some thousand miles, was leaking around the valley area of the engine, had the dealer to fix it and so far I have not smelled it anymore or had to add coolant. I was told the valley had a drain line and we saw visible evidence where the anti freeze had been draining down on the lower area of the truck. Some of those cheap hose clamps on the coolant lines they said were prone to leak. I think I told you guys that I had been loosing coolant and had to add some every so often. I could smell anti freeze real strong on the drivers side, especially like at a bank drive thru where I was up close to the wall on the drivers side. That might be something you might look at.
 
NVW said:
Sorry SSForce, I was thinking of your 6.5, not a LBZ.
Click to expand...

No worries NVW, I should probably update my avi picture to make it less confusing. Its just that old 6.5 looks so damn good.

BIGR said:
My 2006 LBZ with 70 some thousand miles, was leaking around the valley area of the engine, had the dealer to fix it and so far I have not smelled it anymore or had to add coolant. I was told the valley had a drain line and we saw visible evidence where the anti freeze had been draining down on the lower area of the truck. Some of those cheap hose clamps on the coolant lines they said were prone to leak. I think I told you guys that I had been loosing coolant and had to add some every so often. I could smell anti freeze real strong on the drivers side, especially like at a bank drive thru where I was up close to the wall on the drivers side. That might be something you might look at.
Click to expand...

Thank you BIGR I will check into that as well. My truck is currently at 85000 miles, so, around the mileage you experienced your issue. Ever since I opened the cap on the overflow the leak has stopped. But at the same time, temps have climbed back up to where either could be reason for the leak stopping. When it was cold last month during warm up I could smell antifreeze burning off so its very possible the leak could be where yours was.
 
Was the upper hose collapsing when it cooled down? Make sure the cap is blown out with some compressed air. That still doesn't rule out the pump but it can alter the diagnosis
 
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