coolant and temps (1 Viewer)

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Joined
Dec 15, 2014
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Location
Atlanta, GA
Having some interesting leaks on my 06 LX. I think everything is normal but thought I would put this out there for advice.

Background - newer radiator. New radiator cap. New fan clutch. Unsure on thermostat (probably changed when radiator was changed - both prior to my ownership). Until a few days ago, no leaks and constant coolant level.

Took my truck to the dealership for recall notice. Pick tuck up and see that they performed 'safety check' and probably topped off fluids. Truck drove normal, no issues. Early the next morning, I drove to Asheville, NC from Atlanta and back (about 425 miles round trip). It was quite cold in Asheville and drove through snow/ice. Again, no issues.

Yesterday, my leak starts. Came out in the morning - no fluid on ground. Started truck, let it warm up, turned on rear heater for my son. Initially, air will blow hot when set at approx. 75, then will cool down. Understandable as the auto climate is working. When truck was warm, I had to turn temp up to about 80-85 to get actual hot air to blow. When it blew hot, it was damn hot.

Anyhow, got to work and noticed a puddle (about 6 inches across) under truck. Looked like anti freeze to me. Popped my hood and the overflow bottle was sitting above full (this was when truck was cold). Thinking that the dealership over filled, I decided to keep my eye on it and drive home. This morning, no leaks, no puddle. I thought all was well. Parked after driving my son to school (and turning on the rear heat) and found another, similar puddle.

It still looks to me that there is too much coolant in the reservoir. Hard part is that I can't verify whether the dealership added too much or none at all. Also, only seems to leak when I run the rear heat. Running heat without rear does not produce a leak. Before taking in for recall, I never leaked when running the rear heat. Leak is dripping off of the hose that runs from bottom of radiator to top of engine block. But it could easily be dripping from above and traveling down hose before dripping off.

Hooked my ultragauge up this morning. Truck got up to temp pretty fast (in about 2-3 minutes of normal driving). After that, it held 190-195.8 the whole drive. Had it up to 75 mph and then stopped at a light. Ambient temp was about 45 degrees.

Anyhow, really long question but does any of this seem normal? Like I have too much coolant and the overflow will sort it out? Or is this indicative of another problem? What is normal operating temps on these rigs?

Many thanks!
 
Is radiator cap OEM?

Yes. Guys at ACC put it on when I took truck for service last month. Had an after market cap that was maintaining a higher than recommended PSI. OEM now.
 
The over follow reservoir has an overflow blow off canal in cap. That is right over the low radiator hose. This could be where coolant is coming from. Why IDK! Defective cap is a possibility.

Possible over filled;
Your coolant should be at low line after 8 hour cold down, and at or near (not above) high after engine hot and shut down. The engine will get a little hotter after shut down for a few minutes, and expand more coolant into reservoir.

I've never heard of rear heater causing this kind of issue. I could be wrong, but it's my understanding coolant runs through front & rear heating system all the time. Something I've been wondering about lately. Hopefully someone else can confirm this.:hmm:

But's it's generally recommended to run heat temp/fan on full if overheating, and can't pull over and stop. This extracts heat from coolant by air passing over heater core. So don't no why it would cause what seem to be blowoff from over heating. Older cars had valve to control heat by opening or closing coolant flow in hose, we don't to my knowledge:hmm:

Since your getting 190 to 195.5 sound like thermostat's ok.
 
@2001LC Thanks for the responses/help. My gut says you are right - overflow coming from reservoir cap. Nice to hear someone concur.

I'll keep driving and reporting. Coolant level was just below 'full' when cold this morning and well above when warmed up. Think I'm just going to have to drive/cycle until levels normalize.
 
@2001LC Thanks for the responses/help. My gut says you are right - overflow coming from reservoir cap. Nice to hear someone concur.

I'll keep driving and reporting. Coolant level was just below 'full' when cold this morning and well above when warmed up. Think I'm just going to have to drive/cycle until levels normalize.

Yes, just keep an eye on it. The fluid in my overflow bottle rises a good 1-1/2" to 2" when the engine is hot. IF it had been overfilled...it might well have spilled over.

Fluid (if correct) will be pink/reddish looking coolant.

Pretty sure the rear heater receives circulated coolant all the time, so any leaks back there (or along the way) would show up under all conditions (except for pin holes).
 
Checked it again this morning. All was well. Guess I just needed something new to worry about. Thanks for the responses.

Out of my own curiosity, what is accepted temp range for these trucks? I watch mine pretty closely in my 80 but imagine this engine has slightly different characteristics.
 
So what was level in reservoir with engine cooled down to ambient temperature? What was ambient temp at the time?
176 - 203F, your 190 to 195 is optimal "IMHO"
 
So what was level in reservoir with engine cooled down to ambient temperature? What was ambient temp at the time?
176 - 203F, your 190 to 195 is optimal "IMHO"

Thanks! Temp this morning was in the mid 40's. Level was right at 'full' when cold. Still technically overfilled but looks like system is doing its job and leveling out.
 
Thanks! Temp this morning was in the mid 40's. Level was right at 'full' when cold. Still technically overfilled but looks like system is doing its job and leveling out.
I like all fluids set by the book. That way when I do my fluid checks, if level not as I set, I know something up!
 

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