Help! Overheated!
#1
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Help! Overheated!
So, I just overheated the Miata. It hit 240F, I immediately went into procedures to cool it down.
I had no problem whatsoever keeping it cool after that under freeway speeds, and I noticed no boiling coolant in the overflow - although if I took it to freeway speeds, it sure wanted to overheat. There's nothing coming out of the exhaust. However, I have no way of diagnosing anything further or even doing anything on the Miata until I get back to where all my tools are stored, which is a good 2.5-3 hours away.
What do I do guys?
I had no problem whatsoever keeping it cool after that under freeway speeds, and I noticed no boiling coolant in the overflow - although if I took it to freeway speeds, it sure wanted to overheat. There's nothing coming out of the exhaust. However, I have no way of diagnosing anything further or even doing anything on the Miata until I get back to where all my tools are stored, which is a good 2.5-3 hours away.
What do I do guys?
#3
Use a paperclip to jumper ten and TFA with the ignition on to see if your fans are operating properly. I had a similar situation where the fan would come on, but wasn't spinning fast enough because of a loose connection.
Could also be a waterpump failing or cavitating, but that's harder to diagnose on the road.
Could also be a waterpump failing or cavitating, but that's harder to diagnose on the road.
#4
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Could also be a waterpump failing or cavitating, but that's harder to diagnose on the road.
#5
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If this was a fan problem, I'd expect it to be fine on the highway but overheat at lower speed, not the opposite. He should be able to drive non-stop at 80 MPH with no fans at all.
OP- Has the cooling system ever been flushed out in your history of ownership of the car? Have any modifications been made to the cooling system? Anything you can think of that would cause it to not quite be up to par in general?
OP- Has the cooling system ever been flushed out in your history of ownership of the car? Have any modifications been made to the cooling system? Anything you can think of that would cause it to not quite be up to par in general?
#7
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If this was a fan problem, I'd expect it to be fine on the highway but overheat at lower speed, not the opposite. He should be able to drive non-stop at 80 MPH with no fans at all.
OP- Has the cooling system ever been flushed out in your history of ownership of the car?
OP- Has the cooling system ever been flushed out in your history of ownership of the car?
Have any modifications been made to the cooling system? Anything you can think of that would cause it to not quite be up to par in general?
I'm thoroughly facepalming at the moment.
What does it do at idle? does it continue to heat up after the fans have kicked on? And are you absolutely sure it's climbing that high and not a false reading?
Depending on how high it climbs and how fast would be the real test of if you can get it to the parts store or not.
Depending on how high it climbs and how fast would be the real test of if you can get it to the parts store or not.
#8
It is possible to limp home with a compromised cooling system, but it's a real test of patience.
#9
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That's it.
Even with better than stock ducting, my massive intercooler core just doesn't allow enough cool air to get to the rad.
Turn the heat on full. Limp it back.
Even with better than stock ducting, my massive intercooler core just doesn't allow enough cool air to get to the rad.
Turn the heat on full. Limp it back.
#10
This being the case, it sounds to me like an air flow/heat exchange issue. Added stress on the engine (over 70mph) may just be enough to push the engine over it's current cooling limits with a missing shroud and intercooler blocking some airflow. The radiator was just replaced, perhaps it has a blockage from the factory? It is possible to have a bum part.
Edit: Erat beat me to the punchline.
Last edited by dieselmiata; 07-06-2013 at 09:10 PM. Reason: Slow typing
#11
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I had a heater hose blow apart and lost all mo coolant once, leaving me to drive the car home nearly 15 miles. Filled with water, started car, drove until hot, stopped. Rinse, repeat, all the way home.
It is possible to limp home with a compromised cooling system, but it's a real test of patience.
It is possible to limp home with a compromised cooling system, but it's a real test of patience.
This being the case, it sounds to me like an air flow/heat exchange issue. Added stress on the engine (over 70mph) may just be enough to push the engine over it's current cooling limits with a missing shroud and intercooler blocking some airflow. The radiator was just replaced, perhaps it has a blockage from the factory? It is possible to have a bum part.
Thank you everyone. I'll wait for it to cool down outside and limp my way back.
#13
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The engine is properly sucking back coolant. I lost no coolant, I have no air in the system, and as far as I can tell I can see no oil in the coolant nor other indications of a compromised head gasket in the system.
I do appreciate the help guys, I think I'm just going to wait until it gets late (And cools down a lot!), then limp it where I need to be.
#14
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To add to the above: I'm pretty confident the brand new radiator cap is bad now.
Which is seriously aggravating. To anyone that searches this thread: CHECK YOUR RADIATOR CAP, even if it's brand new.
Which is seriously aggravating. To anyone that searches this thread: CHECK YOUR RADIATOR CAP, even if it's brand new.
#15
The big trouble with a bad rad cap is that the max temp of the coolant goes down. IE with a completely blown cap the highest temp a 50/50 mix can reach is 233, then its boiling and the temperature will not increase until all the coolant is vapor. Which means of course that while the coolant isnt getting any hotter the rest of the engine is. So when you're expecting 240 to be OH **** temp, but the rad cap let go, 230 is your new OH **** temp.
#16
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Thanks again folks. Everything seems okay, at least as okay as it could be - but I'm definitely making plans for a engine rebuild ASAP with a new head.
Thanks Leafy! Great info! I read during my googling that "percolator noises" were a sign of a bad rad cap, but they ended up coming from my heater core (wtf?) once I had an opportunity to really start tracking them down.
The big trouble with a bad rad cap is that the max temp of the coolant goes down. IE with a completely blown cap the highest temp a 50/50 mix can reach is 233, then its boiling and the temperature will not increase until all the coolant is vapor. Which means of course that while the coolant isnt getting any hotter the rest of the engine is. So when you're expecting 240 to be OH **** temp, but the rad cap let go, 230 is your new OH **** temp.
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Engine rebuild? Pffft It's fine.
Mines tapped 240 before. It still works fine.
In fact, i found out my stock temp gauge doesn't even start to move up until after 230f.
Mines tapped 240 before. It still works fine.
In fact, i found out my stock temp gauge doesn't even start to move up until after 230f.
#20
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By hood louvers you mean vents right? The cooling system should work just fine without them. Even here in PHX at 120 degrees I don't over heat on the highway or in traffic. And I don't have any hood louvers.