[MadMaxDiesel]

I remember driving my 1.2 Lakh KM Swift Diesel fully loaded to the brim with 4 adults and their luggage to Tirthan Valley, HP. Also it was summer time and route was full of steep inclines and AC was on all the time. I was constantly driving around 4000 RPM in 1st and 2nd gears for extended time periods and I never saw the temp gauge go above half mark.

So I think 1.5 Turbo Petrol should not overheat when driven spiritedly on plains no matter what the ambient temperature is.

[svsantosh]

Did any one understand is the engine overheating or the DCT overheating?

Some pictures of the dash cluster would be nice.

[Dreamlifter.07]

From my experience from Hyundai, if all is well, then they are good. If something does go wrong, then they will do everything possible to wriggle out of any liabilities.

1st experience: My mom’s 2010 Santro Xing AMT, after around 1.5 years of ownership, the car all of a sudden has a very odd sound and we simply cannot drive it at all, takes it to Popular and guess what? The crankshaft broke and apparently my mom had been driving it most of the time above 80 kmph! And Santro cannot handle that! ( There’s absolutely no way that my mom was driving anywhere more that 30-50 in Kochi city)

2nd Experience: My mom sold the santro and got the i10 Asta AMT, which came with a sunroof at that time. Gave for normal service and got it back, all looked well and good. Two months later mom went through a pothole at speed and the sunroof switch falls off, and when we had a look at it, the switch was stuck on with a tape! We called the service centre and was like when we gave you the car for service it was good and working but this is what happened after we got it from service. Popular replies we are not liable for something that we find more than a month after the service!

I have multiple instances but these both were the most brazen attempts at avoiding liability that I have come across.

So from the experience of the OP am not surprised that Hyundai send across such an absurd response.

[blackbandit]

To add to this post. I have not faced overheating issues after that one off incident. I have driven full throttle quite a few times after that and have faced no issues. I don't know if it has to do anything with the pipe replacement or general weather. Also few things to note, it was a really hot afternoon that day and considerable amount of time was spent in b2b traffic before going pedal to metal on the open highway stretch.

However I still did not expect an overheating warning to popup because i've driven much harder in way harsh conditions on my remapped Figo and have never faced any such warnings or issues till date and its run close to 90k kms now.

Originally Posted by svsantosh

Did any one understand is the engine overheating or the DCT overheating?

Some pictures of the dash cluster would be nice.

It was the engine. I was in full throttle and the AC got cut off (this was the first thing I noticed). And then within few seconds the digital temperature dial shot up and the engine overheat warning came up on the dashboard and infotainment.

The moment I let go of the throttle the warning went off and the even the temperature dial returned back to normal in a matter of seconds. AC also returned to its normal state.

[GeeTee TSI]

Very puzzling diagnosis and response which I find it hard to get my head around. It is quite impossible to have sustained driving at full throttle (what with the non existent track culture in our country) and an occasional burst of redline should not overheat the engine in my head. Jabs at the pedal are the perfect means of getting rock bottom fuel efficiency though. The response reeks of getting the monkey off the back and closing the ticket as a tick box exercise.

I know from my brother's personal experience when his Freestyle was revved all the way up Yercaud ghats with a full load and the temperature warning frequently popped up. The root cause was however traced to a damaged radiator fin from a stone chip.

[MT_Hyderabad]

From the mail I understood that they are not discouraging the driver. There is a warning, if he continues and the engine gets damaged, we are here to offer replacement.

No engine component gets cooled down in 10 - 15 seconds if it has overheated.

OP should continue driving with this overheating (may be something else) symbol.

If it is not clear, OP can get this clarification via email.

[Rocketscience]

Originally Posted by blackbandit

It was the engine. I was in full throttle and the AC got cut off (this was the first thing I noticed). And then within few seconds the digital temperature dial shot up and the engine overheat warning came up on the dashboard and infotainment.

The moment I let go of the throttle the warning went off and the even the temperature dial returned back to normal in a matter of seconds. AC also returned to its normal state.

AC cutting off is no big deal with Hyundai and in my Creta 1.6 CRDi, 10/10 time I floor the throttle and even at 2000ish RPM the AC always cuts off, they have for some reason designed it this way to presumably deliver you the full performance when you demand, needless to say it is irritating and uncomfortable but the AC compressor resumes again the moment you ease off the throttle.

Just a trait of Hyundai 1.6 CRDi, but the coolant temperature never went above normal, but then I have never driven this near the redline or for extended periods since this just doesn't need it, I upshift at 3000-3500 tops even when going quickly with occasional bursts to 4000 ish which is still well below the redline.

Closely watching this thread for any updates.

[Jeroen]

Originally Posted by blackbandit

It was the engine. I was in full throttle and the AC got cut off (this was the first thing I noticed). And then within few seconds the digital temperature dial shot up and the engine overheat warning came up on the dashboard and infotainment.

The moment I let go of the throttle the warning went off and the even the temperature dial returned back to normal in a matter of seconds. AC also returned to its normal state.

The AC cutting out on full throttle is normal behaviour on many modern cars. It just ensures every ounce of HP/Nm goes to your wheels and nowhere else!

How big a temperature swing did you observe in what time frame?

Quick changes in temperature are often more problematic for an engine than just running hot for a little while. In all honesty, I find the answer from Hyundai ridiculous. Check what the owner manual says! Any warning in there?

I wonder if you actually have temperature fluctuations. When you press the accelerator in of course there is an extra amount of heat produced in the cilinders. But it takes some time for it to seep through the cilinder walls, into the cooling fluid. At the same time your thermostat will start mixing lower temperature in the cooling liquid as weel. Also, with a bit of delays. At the same time as you press the accelerator, the engine revs shoot up and so does the rpm of your cooling fluid pump. And this more cooling liquid is circulated as well.

Not sure what kind of cooling fluid pump you have. Sometimes these things come with clutches so it depends a bit on when they engage. ( e.g. on a Mini, Peugeot)

The temperature sensor itself has a a bit of delayed response time too. So I find it very puzzling that by pressing the accelerator you see the temperature shooting up almost immediately. That is not how cooling works at all.

If the shooting up of the temperature is almost in sync with the accelerator being pressed and only lacks a few seconds or less behind, I would suspect an electronic interference issue rather than a cooling issue.

Check if your engine has two temperature sensors. One drives the dashboard indication, the other is input to the motor management system. If you have two, get an OBD scanner that shows you the temperature reading and see if you get the same response as on the dashboard.

Even it has only one temperature sensor it would be good to check what the input signsl to the motormanagement system is compared to your dashboard indication.

Good luck
Jeroen

[blackbandit]

Originally Posted by Jeroen

The AC cutting out on full throttle is normal behaviour on many modern cars. It just ensures every ounce of HP/Nm goes to your wheels and nowhere else!

How big a temperature swing did you observe in what time frame?

Quick changes in temperature are often more problematic for an engine than just running hot for a little while. In all honesty, I find the answer from Hyundai ridiculous. Check what the owner manual says! Any warning in there?...

As mentioned, it was a one-off event. I was driving quite spiritedly for a decent 30-40 minutes before this occurred. When I floored it on a straight, empty stretch, the digital temperature gauge instantaneously shot up and gave me a warning within a minute. The temperature came down at the same rate the moment I let go of the throttle and began coasting, and I never encountered it again after that.

You can refer to this post where I posted about this event: https://www.team-bhp.com/forum/offic...ml#post5758608 (2023 Hyundai Verna Review)

I reported this one-off issue to my service advisor when I visited for my routine 10k service a few weeks back. They mentioned no issue was found on inspection, but they changed the coolant reservoir hose as part of a general replacement drive. I don't have more details on this. I assumed it was a recall by Hyundai, but it doesn't seem to be a recall as of yet, as other service centers have denied knowledge of it for other BHPians.

[svsantosh]

Hyundai Bashing aside...

Companies like SPD Performance makes AFM performance Thermostat for 3.5 V6 Ecoboost Raptors Gen2. I have personally sold 100s of them in Dubai during my offroading career days.

There is a reason why a Raptor itself needs AFM parts - Full throttle in 55'C Desert is not something a Ford can take. I left that industry when the TRX came in with 702Hp from factory. I am sure that also has some AFM parts.

May be the Hyundai is "Not" tested for WOT for long distances, especially last month was very hot in India.

Every CANBUS should be and can be tweaked about from the service center laptop/high end OBD scanner. First get a cheap OBD scanner + paid App to see at what temp the console hits the top. My guess is, Hyundai being a family car maker has set that point at 90'c. See if you can tweak that kick off point to 95'c or even 97'C.

Edit - Jeroen spoke of that other part of the coolant system, the water pump, there too there are AFM brands. I have personally driven a insane-kitted out proper-full-on-mad Hyundai Veloster N-Line MANUAL GB (3 door hatch) - other than the engine block, every damn thing in that car was AFM. Intercooler included. That was a beast on Dubai roads.

Back to Hyundai Bashing ....

[snappysam]

Originally Posted by Dreamlifter.07

From my experience from Hyundai, if all is well, then they are good. If something does go wrong, then they will do everything possible to wriggle out of any liabilities.

1st experience: above 80 kmph! And Santro cannot handle that! ( There’s absolutely no way that my mom was driving anywhere more that 30-50 in Kochi city)

2nd Experience: the sunroof switch falls off, and when we had a look at it, the switch was stuck on with a tape! We called the service centre and was like when we gave you the car for service it was good and working but this is what happened after we got it from service. Popular replies we are not liable for something that we find more than a month after the service!

With Popular Hyundai Kochi, I expect even more ludicrous responses/behaviour.

From Sales to Service they are in a league of their own. In fact, I regret buying a Hyundai Creta from them with painful episodes almost every time I visit them.

[dhanushs]

Originally Posted by svsantosh

...My guess is, Hyundai being a family car maker has set that point at 90'c. See if you can tweak that kick off point to 95'c or even 97'C...

Opening the thermostat at higher temps will only make the high temp window smaller to cool. It's better open it before. In anycase, for a 1.5L Hyundai it should mostly be mechanical only.

Full throttle is nothing but high torque. High torque output for prolonged periods of time will need some intelligent pedal map, cluster logic, thermostat, engine fan/speed, torque control caliberation.

Gone are the olden days when you can just revv the nuts out of a Di Turbo engine in 4L 2 gear!

[Dreamlifter.07]

Originally Posted by snappysam

With Popular Hyundai Kochi,

From Sales to Service….. painful episodes almost every time I visit them.

You could give PPS Hyundai Edapally a try. I had just given them the i10 for servicing and they seemed to be good.

[svsantosh]

Originally Posted by dhanushs

Opening the thermostat at higher temps will only make the high temp window smaller to cool. It's better open it before. In anycase, for a 1.5L Hyundai it should mostly be mechanical only.

Gone are the olden days when you can just revv the nuts out of a Di Turbo engine in 4L 2 gear!

Hi Bro, My bad, i got it completely opposite. Yes the AFM racing thermostat will open much earlier I guess I really changed careers now eh! Forgot my basics.

PS - A Jeep used to be called cold at 95'c, warm at 105'c, Ok-Hot at 115'c

[wooka]

So accelerating hard (with plenty of airflow through the radiator and along the engine) is disallowed on a turbo.

What if we throw in a few compounding factors that can be the real final straws, like:

1. Corrosion in the radiator will slow down cooling at a future date.
2. A saturated air filter.
3. Lower net speeds (say, accelerating hard in a city)
4. Higher ambient.
5. Driving at high altitude.

And here I thought the braking issues with the Jimny at altitude was lack of similar 'rigorous testing' (go back to the official Hyundai statement in the first post.)

Potential fixes: I'm surprised there's no discussion on the coolant - water mix and ambient temps. There are surely other ways to deal with this. A simple software update should get the pump to be more aggressive, yes? Assuming it's an automatic, shouldn't temperature feed some logic to shift early?

Hyundai's approach: Least of all, at least try to replicate this on another car (as MnM practically always tries to do, at times to my distaste) before coming up with a statement throwing caution to the wind. A graph or sampling chart of actual RPMs over time and all would help.

Other cars : I drive the punch pretty much on full throttle most of the time to get it to chug around Dehradun and esp up the hills. I wonder why it doesn't overheat. I recently ran a manual Baleno at 6k+ RPM for three hours straight. No such symptoms. Back when I had a Santro Xing, I sustained 5k+ RPMs all day on that eRLX.