Try burping the system

 

That's a good idea, thanks.

Does that explain the ~30° temperature fluctuation? It was instant. That seems like a sensor issue.

 

Unless you have an aftermarket thermostat, 167 is too low. OEM thermostat opens at 90-95C and most engines run around 95-105 (195-220f) in hot climates.

Sensor o r thermostat if burping doesn't help but it looks like you are running at the right temp anyway so it can wait.

 

Cooling system is all stock. You're right, 167 is too low, but as I said it was showing 167 then changed to 196. So don't believe it was actually 167. Sensor must be on its way out or something.

You're also right about the temps. I was just being paranoid. It's within normal operating range. Just never driven this car in the summer desert climate with AC on for sustained periods of time.

I am looking at Koyos though

 

Koyos r nice, especially if u track it. Had a particularly nasty heat wave & 6hr hilly drive at 85-90 today. Oil was at 235-240 most of the time. Gauge doesn't have markings for water temp but safe to say it's close.

 

Oof you must've been on the limit. Pretty sure I'd be close to overheating at 90. New Mexico was particularly hilly. 'Glad' don't have a oil temp gauge. Wouldn't have made it to my destination lol.

Not sure how much a Koyo would improve on the street though if the thermostat is the same. Might just change the sensor, burp, and see.

 

Sorry. Yes it can.

When air is in the system it can fudge numbers around the temp sensor. It's a common issue on a few vehicles with plastic thermostat housings that have cracking issues. That's usually the first sign.

I've found that much of my temp issues over the years always lead back to shit aftermarket thermostats or air in the system.

 

Why does that happen? Air pockets get trapped around sensor and give false readings?

Okay thanks. I was having trouble picturing how an air bubble passing over the sensor would cause that, but I don't know how fast the flow of coolant is or how things look in there with the car running. But you've experienced the same due to air so I hope a burp will solve the issue.

I had used a Lisle Funnel two winters ago so figured I was golden but possible not all the air got out, or maybe some got in somehow. Last winter I replaced the radiator cap with the correct one after noticing it was the same as the overflow tank. Maybe that did something.

 

That would be my guess

 

Check that both fans operate.

Burp the system.

Check for circulation to exclude the thermostat.

 

Check that both fans operate.

Burp the system.

Check for circulation to exclude the thermostat.

Yes good reminder to check the fans. Reading up to make sure I do the burp correctly, but will keep an eye on the fans. Gotta look over the FSM on fan operation.

Multiphase flow is odd. Any cylinder or oval with sharp edges in the flow creates a double vortex that traps any solids or gas bubbles around it.

I didn't understand half the words you used No I get it. Point is an air bubble can very likely be the culprit. Will burp and report back tomorrow hopefully.

 

Concepts are fairly simple, calculations are horrific. F1 or any aero (sails, aircraft, etc.) seems counter-intuitive because air is compressible. The pressure side doesn't do anything except create drag. Vacuum side does all the work. That's why swan neck spoilers work better & aircraft hang everything under the wing.

 

This reminds of of mass transport nightmares in microfluidic applications. Yikes.

 

Medicine or chemical? Pretty cool tech despite the problems.

 

Drug discovery using surface plasmon resonance, in a previous life.

 

^Yes to what you both said lol

Finally got around to bleeding today. Literally an hour before sunset because it was still 100°+ out. After a bunch of reading realized easiest way was with a coolant fill funnel that adapts to the tank.

Anyway, a bunch of bubbles came out. A lot of small tiny ones too. Didn't get a chance to drive after but hoping temps will be down.

Interestingly enough, during initial warmup the temp was at 195F and climbing when I noticed the car stumble. Saw temps drop to 176F and then back to 195F+ and continue climbing. Either air making its way out or the temp sensor in need of replacing. Hoping the former.

 

What do you mean by stumbled? Water temperature should not affect the engine that much during warm up

 

Idle dropped like it was going to stall but then recovered. I read coolant temp is involved in fueling and timing.

 

Positive is always advance, negative is retard.

Cold water would be 8 degrees of additional advance, hence your point. It isn't to "take advantage" but instead because the colder flame front moves slower.

 

Two hour drive today to Phoenix. Something is definitely up. Either sensor, or thermostat, maybe both. Radiator at cooling capacity? Sucks we've planned to drive out of here in the day when temps are 100F+. Might just wait it out and leave at night.

So on the way to the highway temps were climbing as the car warmed up. Stopped at a light where I noticed the RPMS fluctuate. Temp drops to 174 from 196. Once moving, rapidly stepped back up to 196.

Once on the highway things got interesting. 108F outside, cruising at 75MPH, coolant steady at 210. Temps climb to 110F, coolant climbs to 214 and steady. Temps get up to 114F and coolant steady at 216, hitting 217 peak.

On the drive back it got sketchy. 118F outside, 75MPH, coolant at 208?? Then drops to 204, then 198, 196, 194, 190. Then shoot back up to 203, 208, then back down again. Letting off the throttle for slowing traffic seemed to correlate with temps shooting back up to 217. This happened twice, then it held steady and just kept slowly climbing - 219, 221, 223, 225. Hit a peak of 226.

I decided to log since this shit made no sense so if anyone cares to look, I've attached the CSV. I'm convinced the sensor is bad, and maybe this is the limit of the cooling system. A little too close for comfort though. Some research suggests 220F is a safe max. Not comfortable driving with these temps with the car loaded down on hilly highways for hours on end until we slowly escape this hell on earth.

https://docs.google.com/spreadsheets/d/1_Ex95bNP-9sykwsUmDIZQFov_BPSzbJlvXl01WJeIGw/edit?usp=sharing

 

Death drive is a bit dramatic. All those numbers sound big in Fahrenheit. 226F is only 107.7C. Even with a 1.1 bar cap, boiling point is 126.7C for water & 135C for 50:50 water/glycol. See water table for 1.1bar (16psi) column:

https://durathermfluids.com/pdf/techpapers/pressure-boiling-point.pdf

Cooling system is definitely not at capacity at 108F lol or most of Texas would be at home.

 

Lmao. You're in TX right. Raised in Chicago so 118F is death level lol

I should clarify. I meant capacity in the current state it's in. I was wondering if a new thermostat would improve things in case this one isn't fully opening.

There's still the issue with the fluctuating temps. If sensor is malfunctioning it's entirely possible the reading is off (higher than actual). I'm still aiming for a night drive 🤪

 

Given your car's age, it's probably due for new thermostat/sensor/rad hoses anyway just as preventive maintenance. If your temp gauge is roughly in the middle & not climbing over time, you are fine. Anxiety port shows data without indicating what fluctuations are normal.

 

Good point. Idiot gauge never moved from where it always sits, which gave me much needed comfort. As you said everything just needs a refresh. Dad worked at a AC factory and said the radiator fins oxidize and lose efficiency. Might go for OEM, or just get a Koyo, and change sensor and thermostat while I'm in there.