Help me diagnose this coolant issue (long)

Naturalhoosier · 01-23-2007, 10:57 PM

Here's my story:

I was heading to work this past Friday. I live in Denver and the temps have been in the single digits to teens as of late. I live 10 miles from work. I got about 2 or 3 miles out and my blowers starts blowing cold *** air. It changed just in the blink of an eye. I'm like WTF and think it's the blend door issue that is all too common. I get to work and think nothing much of it.

After work (I park in a parking garage temp is probably mid-60s on the 2nd level), I start up my Jeep and my coolant light turns on. On my way to the Autozone I try my heat again, my temp gauge is at normal and it's still blowing cold freaking air. I get to the nearest Autozone to pick up some antifreeze (i know I should have had some in my off-road kit...bad off roader!

). My coolant overflow bottle is at the low level, but is no means empty. I fill it up and head home. I'm scared to death of opening the radiator cap. Me no likee steam burns...I know...I'm a Sally, right?!?!

After Autozone everything is fine. It's running good and it's blowing hot freaking air like normal. Fast forward to today. I fire up the car this morning (high teens outside this morning) and my heat just won't work. I mess w/my heater controls as I'm driving for about 5 mins, turning them off/on, trying different airflow settings. It finally starts blowing hot air. I get to work and think nothing of it...busy at work, no time for thinking!!!

So tonight I'm heading home, and my heater is blowing cold air, even though the heater's on (again thinking blend door maybe). Then all of a sudden my temp gauge starts to rise....it stopped at about 230-240 (I think about 210 is the norm) and lo and behold the low-coolant light turns on. I turn off the heater for a couple seconds and turn it back on. It starts blowing hot air right away like it never skipped a beat or something....and the temp gauge drops back down to the norm. Weird!

I get home and let a couple hours pass. I fill up the radiator and I fill up the overflow tank. It certainly drank a lot. I fired it up for about 10 mins and it was blowing warm air. I got down to check for any signs of obvious leaks, but aside from where I missed the fill hole, there were no signs of coolant leaks. The exterior of the radiator was dry, no visible leaks around the water pump or anywhere between the block/head.

I have absolutely no difinitive idea as to what this could be. Hear are my thoughts and I will certainly entertain the thoughts from you folks who I know are more mechanically inclined then I.

I noticed the a/c pulley was running for about 10 secs and then would stop for 5, run for 10, stop for 5. I'm not sure if this is normal or not.

--No leaks, but loss of coolant. Blown head gasket maybe? I would be smelling that sweet sweet smell of radiator fluid when I'm driving and I don't. Plus I've never noticed any smoke trailing behind me in the parking garage from it.

--Water pump or thermostat taking a dump? I dunno, could be.

--Serpentine belt is slipping and not turning the waterpump pulley? I know my belt is nearing a need for changing and have one in the back in case it decides to go, just haven't changed it yet.

I appreciate all insight that can be provided. If I was unclear on anything please ask away.

**ArloGuthroJeep** · 01-23-2007, 11:10 PM

What does the oil look like?

Any color to the exhaust gasses once warmed up?

The coolant has to be going somewhere - UNLESS, you are just reallllly low on coolant and as you add coolant, you're just burping the coolant system.

Your lack of heat just screams coolant not running through the heater core to me.

The fact your temp rose to 240 says your thermostat is busted, but the fact that it fixed itself suggests perhaps your water pump is working sometimes?

Not sure on that one...

Hey greasefingers...where are ya?

Naturalhoosier · 01-23-2007, 11:12 PM

The oil is fine.

The exhaust is normal color...it's white because it's cold as hell but it's not a thick white, just that it's-cold-outside white that happens to everyone.

I plan on changing the serp belt and water pump this weekend, so we'll see what happens I guess.

It very well could had been that the coolant was just really REALLY empty.

**ArloGuthroJeep** · 01-23-2007, 11:18 PM

Quote:

Originally Posted by Naturalhoosier

I plan on changing the serp belt and water pump and thermostat this weekend, so we'll see what happens I guess.

Right? Good.....

Naturalhoosier · 01-23-2007, 11:18 PM

And thermostat huh....ok, sounds good! Thanks Ryan.

-Joe- · 01-23-2007, 11:29 PM

Unless the waterpump is leaking its not going to fix the low coolant. It shouldnt be low unless its leaking or being burned due to an internal leak.

Could be the heater core leaking.. Any smell of coolant inside? (Passenger floor wet)

Its gota be going somewhere.

j.love · 01-24-2007, 12:25 AM

Quote:

Originally Posted by Naturalhoosier

I noticed the a/c pulley was running for about 10 secs and then would stop for 5, run for 10, stop for 5. I'm not sure if this is normal or not.

Your ac pump is doing what it is supposed to do! It runs when the defroster is running. It dose that to remove moisture from the air. Dry air defrosts better.

This sounds like you just ran out of fluid. Since you had to RE-fill the overflow tank, after you did the first time I would say that It was extremely low.

Filler up. drive her and look for leaks! you probably have a small enough leak that you didn't notice.. got low and the fluid steamed off after that. Once it gets too low It won't circulate. No circulation temp goes way up and no heater! The first time the heat went out, you still had enough circulation to cool the motor.

When was the last time you checked the fluid level?

phasewolf · 01-24-2007, 03:52 AM

My ZJ did the same thing and it turned out to be the radiator tank had a small crack in it. But it was in a spot where you could not see it to well until it blowed. Also the cap was bad and my overflow tank had a crack too. It was a real mess.

Turbonut · 01-24-2007, 06:01 AM

Make certain there is enough antifreeze in the cooling system as the rad will be the first to freeze and impede the flow. If OK I would start on the following:
A/C is fine
Water pump is operating (I'm not saying that it's not leaking) OK as is the Serpintine belt
Thermostat is good
No heat, low coolant, Low Coolant=LEAK

Have someone test it with a pressure tester when cold, you'll find the leak.
Check radiator for leak, water pump leaking at seal, or if a 5.2, check the by pass hose also. I've also seen hoses leaking at the connections, especially on top of the thermostat housing if a 5.2 as it's a bear to keep tight because of the location, and all hoses need to be retightened when HOT. If only tightened when cold, a tight seal cannot be achieved. Could also be a hose though I doubt that.

greasefingers · 01-24-2007, 07:00 AM

j.love & turbonuts have a good point. Since you said it drank a lot of coolant, I think that she was just too low and you may be reading more into this than needed. Time will tell.

Naturalhoosier · 01-24-2007, 08:27 AM

Thanks guys. I think I agree w/the majority. I was freaking out over it. My wife always says I'm not the master of the obvious and after reading all of your input (Thanks BTW), I think that the fluid was incredibly low.

I completely filled it up last night and burped the system, so I'll keep a watchful eye on it. Thanks again for the help fellas!!!

**ArloGuthroJeep** · 01-24-2007, 08:29 AM

Quote:

Originally Posted by greasefingers

j.love & turbonuts have a good point. Since you said it drank a lot of coolant, I think that she was just too low and you may be reading more into this than needed. Time will tell.

Ahhhhh come on here, I said the same thing

greasefingers · 01-24-2007, 12:26 PM

Quote:

Originally Posted by ArloGuthroJeep

Your lack of heat just screams coolant not running through the heater core to me.
D

Somehow I failed to see what was right in front of me

Naturalhoosier · 01-27-2007, 10:49 AM

I've been keeping a good eye on my coolant level the last few days and it has dropped a little since my original post. I filled her up this morning and went on my merry way.

My daily drive to work is 10 miles each way. This morning however I had to drive on the other side of the city and w/the snow fall it made driving slow. I drove for probably an hour straight before stopping for gas. I got out and I could smell the coolant. So that pretty much confirms a seepage. While I was adding gas I popped the hood and gave it a quick inspection. STRONG smell of coolant now. It looks like it's leaking out from under the water pump and burning up between the crank pulley and the block.

The only thing I can think of as to why I didn't see it before is because during the original test the Jeep was only running for 10 or so minutes.

**Woody** · 01-27-2007, 10:53 AM

That now sounds like a bad pump.

01-24-2007, 03:52 AM	#8
phasewolf Registered User Join Date: Apr 2005 Location: Michigan Posts: 279 Profile Gallery Classifieds My Jeeps	My ZJ did the same thing and it turned out to be the radiator tank had a small crack in it. But it was in a spot where you could not see it to well until it blowed. Also the cap was bad and my overflow tank had a crack too. It was a real mess.

01-24-2007, 06:01 AM	#9
Turbonut Registered User Join Date: Nov 2004 Posts: 1,828 Profile Gallery Classifieds My Jeeps	Make certain there is enough antifreeze in the cooling system as the rad will be the first to freeze and impede the flow. If OK I would start on the following: A/C is fine Water pump is operating (I'm not saying that it's not leaking) OK as is the Serpintine belt Thermostat is good No heat, low coolant, Low Coolant=LEAK Have someone test it with a pressure tester when cold, you'll find the leak. Check radiator for leak, water pump leaking at seal, or if a 5.2, check the by pass hose also. I've also seen hoses leaking at the connections, especially on top of the thermostat housing if a 5.2 as it's a bear to keep tight because of the location, and all hoses need to be retightened when HOT. If only tightened when cold, a tight seal cannot be achieved. Could also be a hose though I doubt that.