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Coolant shows low on MFD at start up but no puddle...

Uberryan

Banned
As the title states, it was really cold this morning in South FL, and I've never actually topped off the coolant res as I've never needed to. Went to get in my car this morning and I got a coolant level low flash on the MFD. Engine was cold. Checked the level and it was a centimeter below the min line. The fork inside had fluid around it but most of it was exposed.

Panicking about another potential serious problem, I checked everywhere for coolant around the hoses and line, ground, tray, nothing. Checked oil... Still oily. No white on the cap or anything. Engine is only a little over a year old anyway. Doubt it's the head gasket. So I poured in a little water to bring up the level and grabbed some g13 from AutoZone. Went to pour it in and noticed the level had risen higher than the min line. It was at min and now about halfway to Max line. Am I saved?
 
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CHerna

Ready to race!
Coolant shrinks in the cold. My old MK4 did this every so often in the winter. You should be ok. Be wary nonetheless.
 

Carlosfandang0

Autocross Newbie
Fill the coolant to the max line when the car is stone cold then monitor it, you state you had a new engine so if you have not checked or topped it up since then it could just be from air escaping since the engine was put in as the coolant should be checked for a while after it’s drained and refilled incase of air locks, the coolant however is a sealed system and shouldn’t really drop unless there’s a leak so top it up and keep an eye on it.


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Uberryan

Banned
True, that's where my original panic came from. However, being a sealed system, if it was leaking anywhere, it shouldn't rise either. New engine was dropped in April or May of 2016 and south FL had it's first freeze warning in almost 8 or 9 years last night. Possibly air, possibly cold fluid shrinkage, but if there's a leak, I can't explain the rise in fluid.
 

Carlosfandang0

Autocross Newbie
True, that's where my original panic came from. However, being a sealed system, if it was leaking anywhere, it shouldn't rise either. New engine was dropped in April or May of 2016 and south FL had it's first freeze warning in almost 8 or 9 years last night. Possibly air, possibly cold fluid shrinkage, but if there's a leak, I can't explain the rise in fluid.



It will still rise with a leak due to expansion, (the leak [if there is one] may just be very small at present)! It’s just that the high and low points will migrate down the level marker until all the coolant has escaped, as said, top it up when cold and monitor [emoji106]

As it’s your first cold spell in a good while it could just be that it was low and that has highlighted it!


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Uberryan

Banned




Since everyone loves pics. This is the coolant level as it stands now. Maxed out and sitting above the max line, apparently to compensate for the water I added. I'm going to check it in a couple hours, and see where we're at.

Here's my timeline:



Blue: This morning's starting point roughly

Green: Where the level sat after adding some water

Yellow: The level after driving a couple miles to secure fluid... roughly 4 miles

Red: The level as it sits right now after some casual driving, stop and go traffic, moderate pulls, parking and turning on/off (usual behavior)


Still no drips, noticeable leaks, or fluid found anywhere. Oil still good. If there had been some sort of leak it would've definitely been lower than the max line even after expansion.
 

Carlosfandang0

Autocross Newbie
It’s probably ok, just it got low from air escaping maybe, once it’s cooled make sure it’s at the max mark then monitor!


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Uberryan

Banned
Alright I think I've found the issue. The coolant reservoir is failing. All over, I have these spots from where fluid has boiled and corroded the plastic housing, so it looks like maybe some fluid or at least pressure is escaping through these points as I found sticky fluid near one of these patches. These patches are bad enough that I can push on them and feel the material flex easily.

Looks like I'll be having to swap this out.

 

Carlosfandang0

Autocross Newbie
I would be confident that’s your issue.


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U-20T

Go Kart Champion
coolant evaporates (well the water) over time. and i would replace the ball. Go OEM only. Had a rad line blow of on the drag strip one time a few years ago almost hit the wall since the aftermarket one didn't bleed the air off properly (cap too tight). oem and never had an issue after.
 

Uberryan

Banned
Yup ordered an OEM one, but it doesn't come with the cap apparently, no biggie as I'll just use the original one.


To update, the picture above that shows a little bit of fluid actually pictures very small/faint stress cracks. The ball definitely needs to go, and this is the source of what little fluid leak I found. I imagine they expand when hot and more fluid is able to evaporate off. It's sitting between the min and max line on a stone cold engine right now.
 
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