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(SOLVED) 2005 300c overheating suddenly.

785 Views 7 Replies 4 Participants Last post by  eternal3plans
05' 5.7 started overheating the other day 2 miles from home. Got it home and inspected it. Coolant level fine. Smaller fan passenger side not coming on checked fuses and relays wiring fine. Ran without reservoir cap on. And notice air bubbles not when looking in but on the side of reservoir towards engine one comes up makes a glug sound then another then moments later again. It gets worse as it gets warmer.

Started it back up about 15 minutes later to check the heater. Went around to engine bay to check on stuff first was looking at the side of reservoir to see coolant level etc and it was up because it was still warm. All of a sudden the coolant got sucked down out off the reservoir in one swift motion, then gurgling noises. I backed up because I didn't know what was going on I continued to watch and the level rose back up in the reservoir after nearly a minute. What the heck.
So after that got in the car and turned the heaters on full blast they didn't get hot right away then the drivers stayed cooler and the passenger side got very hot 188°f hot. I am confused still stuff to check obviously. I order a head gasket test. To either confirm or rule out. Any thoughts ideas opinions appreciated 🤞

No other issues, she starts up no sputtering no noises. Purrs like a kitten.
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I'd start with bleeding the coolant using a no spill funnel/crack the bleeder screw, I had to rev it up to 4k and hold in increments to really push the air out and get the heater core bled. I'm not sure why the fan wouldn't be operating if all the electronics were good, but they seem like separate issues contributing to the overheating. Did you check all connections with a multimeter?
I'd start with bleeding the coolant using a no spill funnel/crack the bleeder screw, I had to rev it up to 4k and hold in increments to really push the air out and get the heater core bled. I'm not sure why the fan wouldn't be operating if all the electronics were good, but they seem like separate issues contributing to the overheating. Did you check all connections with a multimeter?
No honestly I do not have a multimeter and no idea how to use ir(not mechanically inclined) but I exchanged each fuse and switched out the relays and still the same. Checked wiring no sign of damage.
I'd start with bleeding the coolant using a no spill funnel/crack the bleeder screw, I had to rev it up to 4k and hold in increments to really push the air out and get the heater core bled. I'm not sure why the fan wouldn't be operating if all the electronics were good, but they seem like separate issues contributing to the overheating. Did you check all connections with a multimeter?
I did not check with a multimeter.(do not have one) The fuses are see thru and they look good. I switched the relays around and nothing changed. I ran it and turned heaters full blast passenger side got up to 188°f drivers side was 108°f??

No smoke from tail pipes and does not smell like coolant.

The third time I started it (shut of due to engine getting above normal temperature) I went out to the asses the engine bay after starting and witnessed upon looking at the reservoir the coolant being sucked down in one swift motion. And slowly returned with a minutes timeframe?
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Going to drain it and replace thermostat fans and water pump this week. ( bought in November severely neglected and cared for). Will update.
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While you have the system empty.... replacing the temp sensor is a good idea. It's drivers side, top .... and the radiator cap. They're both relatively cheap. The stock t-stat is 203 degree's. It's not a bad idea to drop it down to 190, while some go to 180. The rated temp is when the stat starts to open. It's not full open for another 15-20 degrees. A Diablo i3 tuner or other would be needed to change the fan settings. No harm to put a lower stat in, but no real gain till the fans are set lower.

Our rides are prone to catastrophic failures in over heat situations. The valve seats weren't so secure as later years. When in doubt, shut it down. Far better to call a tow than rebuild an engine. At least for myself, this is why a 190 t-stat was installed along with a better radiator. It now runs well below the oem temps and gives me a chance to see a temp rise before it gets to critical.

There's a hidden menu to the evic. If you hold steering wheel music note & compass buttons down for 5-10 seconds, you'll see the menu change. Think there are screens you can arrow thru, but there's one that displays engine temp, voltage, rpm's, speed... It's much useful info, and better than watching a needle.
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Good advice/concur with all above.

If the level is dropping/changing, then it is going somewhere, and seeing you aren't losing coolant, it is most likely that air in the system is being compressed when revved/reacting and flowing back as revs drop and moving the level.

Even after bleeding, there is often some air left in the system in pockets that gets "burped" or shifted back to the header tank; so after a coolant change on newer cars I normally check/monitor for a while after, as sometimes have to top up a small amount to compensate.

I saw newer cars, as my ancient ones don't have the ultra low bonnet (hood) lines that new cars do that make for "high spots" that trap air.
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Hello all so far I spent today (first off day I could) ripping her apart. Honestly with my lack of mechanical experience and knowledge it went well.

Going to work on her some more tomorrow 🤞😬

05/22 still waiting for a new wiring harness for radiator fan(s) the one fan plug was melted together. Have a new coolant temp sensor water pump and thermostat on. Just waiting to get the fans in connect it all and will update.
UPDATE *

BERTHA IS FIXED!

WATER PUMP WAS LEAKING AT THE BOTTOM BADLY (LETTING IN AIR), LOWER FAN MOTOR BURNT OUT MELTING THE PLUG ON HARNESS.

CHANGED.
ENGINE COOLANT TEMPERATURE SENSOR.
WATER PUMP.
THERMOSTAT.
FAN(S)
FAN WIRING HARNESS
DRAIN/FILL AND BURPED COOLANT.

3 DAYS NOW SHE IS RUNNING GREAT NO COOLING ISSUES.

THANK YOU EVERYONE FOR YOUR HELP!
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