Spontaneous overheating !! - CorvetteForum - Chevrolet Corvette Forum Discussion

C7 Tech/Performance
Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

Spontaneous overheating !!

Thread Tools Search this Thread
Old 07-16-2017, 06:37 PM   #1
Junior Member
Thread Starter
Member Since: Aug 2015
Location: Escondido CA
Posts: 6
Thanks: 0
Thanked 1 Time in 1 Post
Default Spontaneous overheating !!

Hi guys, been a while since I posted, I have been terrible busy in grad school near the end now.
My 2014 C7 Z51 M7 (30,610miles at the time of occurance) spontaneously overheated, within a 5 minute period normal tempt to 285+, when cruising in traffic (73 degreees out).
Here's the back story:
I Live in LA county and had was just arriving back home from a road trip to Flagstaff, AZ. The trip home was about 500 miles total with 2 stops along the way. I am an **** person when it comes to temp monitoring and maintenance, I periodically check temps and typically run it in Eco mode on touring setting during highway trips to display all the temps. As I entered LA, as mentioned 73 degrees out, traffic slowed to a slow cruise/stop and go. Before this, all temps were normal: engine-200-205, engine oil-198-203, trans 150-160. Admittedly, A few times I got antsy and accelerated (maybe 50% throttle to 4k rpm max) to cover distance if traffic got moving again, before slowing, nothing hard. After about 5 min in traffic, a loud chime and the light "engine overheating, pull over and idle engine" popped up. Immediately I look at gauges, 285 engine and then oil was 210. I got over within 30 seconds to side and stopped and idled with the hood open. After about 5 minutes, I noticed steam and the coolant leaking out my passenger front fender and the engine had not dropped a degree and by this time the oil had gone up to 240, I waited another minute or 2 and then the oil was at 260, So I decided I had to turn it off before I ruin more systems. I waited patiently, probably another 10 or 15, watching fluid spew out. Turned on accessory mode to see temps, hadn't gone down. Unfortunately, I had planned this trip home on the day of my final and only had 2 hours to get home, clean up and get to school (stupid in hindsight now, yes). So I knew I needed to do something to get it home, which was less than 2 miles away. I bundled up a jacket on my arm and opened the overflow, again stupid I know, the fluid shot out, kid you not, 15 feet in the air. I wiped as much of the fluid off the car as I could and then shut the hood and turned it on, luckily, it had cooled down to 225, enough for me to waddle home (never went above 240 on way home with fan on full time). I thought it would be smart to leave car exactly as is until (no fluid added) I tow it to dealer. Fast forward to a few days after being ta dealer- The first tech told me they believe it to be a leak from the water pump, though they weren't able to directly pin point it, so as a precaution (best guess) replace the water pump, and change the oil since it went immediately down to zero life. As I reflected on this experience, something occurred to me, I don't recall hearing the fan on during the overheating. Furthermore, once I opened cap and cooled it, then turned it back on, the fan was at full tilt extremely noticeable, and continued to run for bout 30-45 sec after I turned engine off at home, which I did not do when I was overheating. I don;t think the fan had switched on, which is what I believe the reason the car overheated. The water pump is on nationwide back order with no ETA of getting car back in sight (I am writing this 33 days later, still in shop, no eta). I went in a week after and told a different tech (1st one up and quit) what I think happened and what my options were to take car back until pump arrives. He firmly tells me it was a leak from water pump which caused low fluid level, which then caused the overheating. I said how much fluid would have had to be missing for it to overheat with a substantial amount still in there (it leaked from fender for over 10 minutes, then shot out 15 feet! and still leaked)? He said, "Sir, when you brought your car in, there was no fluid in it at all." LOL. I said I know because I leaked it all out to cool it down enough to get home. He either didn't believe me or just didn't think I was right, and again affirmed that the water pump is bad, they tested the system which it failed (pressure test) and it overheated due to low fluid from leak. Because of this, I will void my warranty if I take car back until it is fixed, which in all likelihood will not be for another few weeks to a month or more, already being over a month (yes i have a cheap rental car, IDC it is not the same, especially for this long). So at this point I am very frustrated that not only do I not have my car, and won't for a while, but even when I do, I am worried the issue that occurred was not resolved and may arise again. I believe it was the fan not turning on, which caused the overheat, thus too much pressure in system which if system is bad, it was because of that not the other way around.
--Long breathe--sorry for the long winded description.
So now my question is this- do you agree with him it is the water pump that failed/leaked that caused this and thus it will be resolved, and also, I am considering filing lemon law as this is an unreasonable amount of time to be without my vehicle (especially since it is sitting outside 24 hours a day to the elements) and am worried there may be internal engine damage they aren't seeing/checking for that will arise later, presumably out of warranty since it was soooo hot for that period of time?
Thanks in advance guys.
7spdZ51 is offline   Reply With Quote
The Following User Says Thank You to 7spdZ51 For This Useful Post:
1ccrider (07-17-2017)
Old 07-17-2017, 12:33 PM   #2
CF Senior Member
DAVE396LT1's Avatar
Member Since: Jul 2003
Location: Redmond WA
Posts: 6,005
Thanked 1,055 Times in 701 Posts

For your advisor's sake, all I can say is... add a few line breaks!

I'd let them replace the water pump and see where you're at afterwards.

Last edited by DAVE396LT1; 07-17-2017 at 12:34 PM.
DAVE396LT1 is online now   Reply With Quote
Old 07-17-2017, 01:20 PM   #3
CF Senior Member
Support Corvetteforum!
NSC5's Avatar
Member Since: Aug 2012
Posts: 3,444
Thanked 766 Times in 534 Posts

My biggest concern would be it was operated without coolant so when you drove it after your overheat event the temperature gauge reading was well below actual. it isn't as easy to warp the heads on a modern engine as it was in the 1960s and 70s but operating with no coolant is one way to have this happen.

The overheat in traffic could have been due to low coolant level but usually this would show up in at least somewhat elevated temperature in normal driving. I didn't even realize the display could go to 285 degrees engine coolant temp. At a 60% ethylene glycol to water mix boiling occurs at 285 degrees at 24 PSI which is well above the relief pressure of the C7 cooling system so it would be boiling like old faithful and of course flashed off when you removed system pressure.

At this point you basically have to let them replace the pump and go from there to see if any other damage occurred. I would not be at all surprised with a warped head under these conditions and I would be surprised if there isn't head gasket degradation.
NSC5 is offline   Reply With Quote
Old 07-17-2017, 02:10 PM   #4
Bill Dearborn
Tech Contributor
Bill Dearborn's Avatar
Member Since: Oct 1999
Location: Charlotte (formerly Endicott, NY) NC
Posts: 29,850
Thanked 1,820 Times in 1,273 Posts

Water pump could easily have been the issue. They start leaking small amounts and leaving little drops on the floor that might not be all that noticeable. Then the leaks get a little more liberal and it leaks a small inch in diameter puddle as the car cools down.

Then after an extended drive the leak becomes much greater although the temperature may not increase greatly because there is a lot more cooling air going through the radiator while you are on the highway. Once in town the fan is limited (even on full) in how much air it can pull through the radiator. With a leak like that the system can't hold pressure properly and the boiling point is reduced at the same time you have reduced cooling air flowing through the system. C7s come with a 40/60 coolant to water ratio so the boiling point is lower than the older cars with 50/50 ratios so the system will boil over sooner.

However, there is still a high probability there is enough pressure in the system to initiate a geyser when the cap is removed. Ever since the automakers went to 15 psi systems back in the 60s there have been warnings printed on the caps or near them about not removing the pressure cap on a cooling system that is hot. Next time you get into an overheat situation you will know enough not to take the cap off the system. You found out those warnings really do mean something.

Bill Dearborn is offline   Reply With Quote
Old 07-18-2017, 01:44 PM   #5
Junior Member
Bruce_K's Avatar
Member Since: Oct 2016
Posts: 39
Thanks: 0
Thanked 6 Times in 3 Posts

I had the same Issue, with my 14z51. Last week driving then sitting in traffic. Boom the overheating, idle Engine Happened. I cut the car off and steam rolled out the coolant ressy. The temps didnt go back down and mines wouldnt start. I towed it home... Call the dealership they said they think i blew my engine. A starter and Radiator later. Im getting the car back today... We shall see.
Bruce_K is offline   Reply With Quote
Old 07-20-2017, 11:10 PM   #6
Junior Member
Thread Starter
Member Since: Aug 2015
Location: Escondido CA
Posts: 6
Thanks: 0
Thanked 1 Time in 1 Post

Thanks for all the reply guys.
They gave my car back yesterday (unwashed, yes filthy after 30+ sitting outside lol).
Ive ran it a bit, pushed a little and its running great as of now. My fingers crossed it will continue to run well. With regard to the head gasket degredation, I agree, I am keeping all my files and making sure to keep thorough records in case in the near future the heads or gasket or anything related go out, we will have a solid basis for warranty.
7spdZ51 is offline   Reply With Quote
Old 07-21-2017, 11:20 AM   #7
CF Senior Member
blue_bomber697's Avatar
Member Since: Oct 2013
Location: Fort McMurray Alberta
Posts: 800
Thanked 54 Times in 46 Posts

Originally Posted by 7spdZ51 View Post
Thanks for all the reply guys.
They gave my car back yesterday (unwashed, yes filthy after 30+ sitting outside lol).
Ive ran it a bit, pushed a little and its running great as of now. My fingers crossed it will continue to run well. With regard to the head gasket degredation, I agree, I am keeping all my files and making sure to keep thorough records in case in the near future the heads or gasket or anything related go out, we will have a solid basis for warranty.
So what did they fix? New water pump? I just got mine fixed yesterday as well. Culprit was a sticking LMR thermostat.
blue_bomber697 is offline   Reply With Quote
Go Back   CorvetteForum - Chevrolet Corvette Forum Discussion >
Reload this Page
  • Spontaneous overheating !!

    Related Topics
    Thread Thread Starter Forum Replies Last Post
    Overheating issue, any ideas? chrisbell C7 Tech/Performance 16 01-03-2018 11:24 PM
    2014 Overheated to 260 eboggs_jkvl C7 Tech/Performance 25 11-28-2017 11:13 PM
    My Oil cooler delete DIY that is strictly FYI LuckyC7Z06 C7 Z06 Discussion 7 11-07-2017 07:27 PM
    Update on Cooling Issue..2004 Corvette MajorMike C5 Tech 3 09-08-2017 02:49 PM
    Symptoms of Water Pump Failure? VETFEVER C6 Tech/Performance 8 05-04-2017 08:49 PM

    Thread Tools Search this Thread
    Search this Thread:

    Click for Advanced Search

    Posting Rules
    You may not post new threads
    You may not post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are Off
    Pingbacks are Off
    Refbacks are Off

    Forum Jump

    Sponsored Ads
    Vendor Directory

    All times are GMT -4. The time now is 12:19 PM.

    We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
    • Ask a Question
      Get answers from community experts
    Question Title:
    Your question will be posted in: