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2021 Santa Fe


Supatramp
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Yeh but.........

 

If the system is that sensitive, and restarts automatically if extra electrical load is required, why the need to switch it (ISG) off in the first place? 

 

You could have a point, I am just being a bit of a devils advocate. 

 

My stop start system reduces heater/aircon fan speed when it kicks in (can’t remember if it turns the wipers off though) but if I apply the slightest pressure to turn the steering wheel it instantly restarts. Headlights on or off doesn’t seem to make any difference, which sort of negates the electrical need theory.

Edited by Mr Plodd

Experience is something you acquire after you have an urgent need for it.

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There isn’t an industry standard for operation of stop-start. Even the same manufacturer can have different solutions across their cars. My Passat was set up such plugging in the caravan automatically cancelled S/start. My Volvo hybrid makes no distinction. The FL2 I had was a very sensitive set up such it rarely worked. 

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3 hours ago, Mr Plodd said:

Can anyone provide a definitive and factual reason (rather than personal  guesswork, opinion, theory or supposition) as to why some, but by no means all, manufacturers issue advice to turn of stop/start when towing whilst others programme their vehicles to do it automatically? And even more make no mention of doing it at all?

 

 

 

For VAG EA288 EU6 Diesels it's thermal management of the turbo. The turbo bearings are oil cooled and the oil system has an oil/water intercooler separate to the main cooling circuit running an electric water pump. 

This is deemed acceptable to manage thermal loading of the turbo during stop start in normal driving conditions but with the high loads during towing it's not ideal to cut the oil flow through the turbo. 

  

2 hours ago, Flatcoat888 said:

 

The FL2 I had was a very sensitive set up such it rarely worked. 

 

Same as my XF.

 

If it had new fully charged batteries, all the cars parameters were met out side temperature was just right, you didn't have the music too loud, it wasn't a full moon, a month with 30 days and a leap year it might just work.  

 

It's a JLR thing when you ask around the forums. 

Yeti 2.0TDi EU6 150 DSG 4X4 L&K, Octavia TSi Manual, Fabia TSi DSG, Swift Challenger.

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20 minutes ago, logiclee said:

 

For VAG EA288 EU6 Diesels it's thermal management of the turbo. The turbo bearings are oil cooled and the oil system has an oil/water intercooler separate to the main cooling circuit running an electric water pump. 

This is deemed acceptable to manage thermal loading of the turbo during stop start in normal driving conditions but with the high loads during towing it's not ideal to cut the oil flow through the turbo. 

  

 

An entirely understandable explanation, I recall when turbocharged cars first came on the market many years ago all of the dire warnings being issued about not blipping” the throttle at engine switch off because that would spool the turbo up to high revs and then starve it of an oil supply to its bearings. 

However is the above a documented fact from VAG, or just supposition? (Not that I can see much wrong with it being a supposition) 

 

Again it seems bizarre that some manufacturers state its a necessary course of action, and others make no mention of it at all despite the fact that turbos can, and do! Sometimes glow bright cherry red due to the heat they are subjected to.

 

Having  said that it requires some serious and sustained high speed turbo work, (just like towing a caravan up a long hill then !)

 

 I would imagine that there would be some form of sensor input to ensure that in the event of turbo temperature being very high the stop/start would be inhibited in the same was as a less than fully charged battery, or cold engine temperature, currently does. So many possibilities aren’t there?  

Edited by Mr Plodd
To correct “autocorrect”

Experience is something you acquire after you have an urgent need for it.

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46 minutes ago, Mr Plodd said:

 

An entirely understandable explanation, I recall when turbocharged cars first came on the market many years ago all of the dire warnings being issued about not blipping” the throttle at engine switch off because that would spool the turbo up to high revs and then starve it of an oil supply to its bearings. 

However is the above a documented fact from VAG, or just supposition? (Not that I can see much wrong with it being a supposition) 

 

Again it seems bizarre that some manufacturers state its a necessary course of action, and others make no mention of it at all despite the fact that turbos can, and do! Sometimes glow bright cherry red due to the heat they are subjected to.

 

Having  said that it requires some serious and sustained high speed turbo work, (just like towing a caravan up a long hill then !)

 

 I would imagine that there would be some form of sensor input to ensure that in the event of turbo temperature being very high the stop/start would be inhibited in the same was as a less than fully charged battery, or cold engine temperature, currently does. So many possibilities aren’t there?  

 

 

It's fact. I've read it in training documentation on the EA288 while trying to find how the integration of a variable  mechanical water pump and two electrical water pumps work.

 

Some manufacturers employ an auxiliary electric oil pump so wouldn't have the same issues. These are more common on hybrids.

 

Turbo design has come a long way since the 80's though and diesel exhaust temps are much lower than petrol especially the high boost high performance cars of the 80/90's, Cosworth's / Subaru's etc.

 

As for sensors.

 

Yes common to have oil temp, water temps in a number of circuits and charge air temperature but not really reading the temperature of the turbo or the temperature of the oil sitting in the turbo bearings at the time stop/start stops the engine. A temperature which could exceed the oils maximum rating and start to break it down.

It's easy enough to do an algorithm of temperatures and boost pressure against time. Then you can disable stop start if prolonged high boost is detected prior to a stop start request.  This may or may not be done, I couldn't say but knowing towing usually means prolonged high boost situations it's easy just to disable stop start while trailer is attached. But the trailer may only be a 300kg rubbish trailer.  

 

Charge air temperature and heat soak can be another issue with stop start as you air intake just sits cooking. VAG on the EA288 moved to a water cooled charge cooler and fitted an electric water pump so this does dissipate heat even when stationary with the engine off.

Edited by logiclee

Yeti 2.0TDi EU6 150 DSG 4X4 L&K, Octavia TSi Manual, Fabia TSi DSG, Swift Challenger.

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On 12/07/2021 at 21:51, Mr Plodd said:

Has any other Sant Fe owner been advised ( by their dealer) to turn off the stop start function when towing?  

 

I am not trying to have  pop at Duncan, rather I am trying to see if the manufacturer, who will have intimate knowledge of the  systems fitted,  rather than a third party, issues the same  recommendation.  If they do I will happily apologise to Duncan’s and his towbar fitter! 

 

Out of interest I have very carefully checked my cars handbook (Mazda) and there is no mention of disabling the stop start when towing :unsure:

 

not the stop start, however on my Santa Fe after the last towing session resulted in a failed BSD system, Hyundai have told me it can/does trigger from towing (which makes sense) not quite sure what resulted in it failing though - being replaced with a new sensor tomorrow and I shall be manually disabling this from now on! 

@Supatramp I have never changed out of 'normal' mode on mine. I'll be honest, even without towing I can't say i've ever noticed much difference in the modes.... 

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Oil technology has also come along way too especially with synthetics. 

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Posted (edited)
1 hour ago, bnar21 said:

 

not the stop start, however on my Santa Fe after the last towing session resulted in a failed BSD system, Hyundai have told me it can/does trigger from towing (which makes sense) not quite sure what resulted in it failing though - being replaced with a new sensor tomorrow and I shall be manually disabling this from now on! 

@Supatramp I have never changed out of 'normal' mode on mine. I'll be honest, even without towing I can't say i've ever noticed much difference in the modes.... 

Thinking hard, but what's the BSD system?

Re the different modes, from reading the hand book, it would seem that the main thing is a difference in the distribution of power to the rear wheels.  In Sport mode, it's 50% front and back, so basically 4wd, unless I understand wrongly?  Interestingly, the Comfort setting gives I think 20% power to the rear wheels, so only Eco mode is 100% to the front.

And I must confess that I've never let the car idle before switching off, and that applies to the last Santa Fe, Sorentos, and Jeeps, and never suffered any ill effects!

Edited by Supatramp
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@Supatramp the blind spot detection system. The sensors live just behind the tailgate bumper. There's a button to disable it by the right of the steering wheel (unless thats changed on the latest model) 

 

 

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Posted (edited)
11 minutes ago, bnar21 said:

@Supatramp the blind spot detection system. The sensors live just behind the tailgate bumper. There's a button to disable it by the right of the steering wheel (unless thats changed on the latest model) 

 

 

Ah. that does make sense actually, might be an idea to switch it off as well as the ISG when towing.

Edited by Supatramp
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On 13/07/2021 at 20:39, DUNCAN123 said:

City Towbars and electric?

They’re based in Hamilton but offer a mobile service

 

Duncan 

 

I can't work out how to PM here, and this post went quickly off-topic, although it was very helpful and informative.

Just a quick update on the towbar fitting, both Discount towing and also City were fully booked and unable to help me, I've a ferry booking on the27th, Buchan eventually came to the rescue squeezing me in on the 23rd.  So provided everything goes ok, I should be sorted.

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2 hours ago, Supatramp said:

 

I can't work out how to PM here, and this post went quickly off-topic, although it was very helpful and informative.

Just a quick update on the towbar fitting, both Discount towing and also City were fully booked and unable to help me, I've a ferry booking on the27th, Buchan eventually came to the rescue squeezing me in on the 23rd.  So provided everything goes ok, I should be sorted.

Good to hear you got sorted.

Hopefully not too expensive and onwards to your holiday 

 

Duncan

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Our Santa Fe BSD  sometimes switches off after  a while towing.

The handbook actually states if you have a wider trailer that it will do so. Switching off and restarting resets it. Not stop start!

Ours actually cut off the first time when I was in a slow moving traffic jam, there was a truck quite close behind so it picked it up!

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On 12/07/2021 at 21:51, Mr Plodd said:

Has any other Sant Fe owner been advised ( by their dealer) to turn off the stop start function when towing?  

 

I am not trying to have  pop at Duncan, rather I am trying to see if the manufacturer, who will have intimate knowledge of the  systems fitted,  rather than a third party, issues the same  recommendation.  If they do I will happily apologise to Duncan’s and his towbar fitter! 

 

Out of interest I have very carefully checked my cars handbook (Mazda) and there is no mention of disabling the stop start when towing :unsure:

From an ex mechanic point of view I personally would turn of start stop on any vehicle. It puts a lot more strain on starting components in particular timing chains/belts and starter motors. Main problem being for the first second or so in most vehicles there is no oil feed from the pump to the top of the engine where the chain/belt pulleys and guides  are and frequent use of stop start just compounds this issue. Saw lots of various engines throwing chain guides since start/stop came in circa 2010. 
let’s face it it’s only on there for the  Euro IV rating  whilst it’s on a test bench in the factory. Real world use it results in very few mpgs saved.

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I for one have never heard of anyone having issues with starter motors etc on stop/start engines. I expect the manufacturers have got it a bit right or they would be flooded with warranty claims if they haven’t 

As for the top of the engine being starved of oil that’s simply incorrect. The various components are supplied with the engine running. As soon as the engine stops the oil doesn’t suddenly disappear! It sits there, and as soon as the engine starts the oil pump supplies plenty more. Cars are left standing, sometimes for many days (or longer) they don’t suffer from copious amounts of engine failures because tge oil has drained out!

 

Like I said I expect the manufacturers have thought of the issues, if they haven’t Why are we not hearing about all of these engine failures? 

Experience is something you acquire after you have an urgent need for it.

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On 12/07/2021 at 21:51, Mr Plodd said:

Has any other Sant Fe owner been advised ( by their dealer) to turn off the stop start function when towing?  

 

I am not trying to have  pop at Duncan, rather I am trying to see if the manufacturer, who will have intimate knowledge of the  systems fitted,  rather than a third party, issues the same  recommendation.  If they do I will happily apologise to Duncan’s and his towbar fitter! 

 

Out of interest I have very carefully checked my cars handbook (Mazda) and there is no mention of disabling the stop start when towing :unsure:

Coming to a halt towing with a very hot engine and letting the auto stop - stop the engine is not a good idea for the  turbo.

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Always switch my start/stop off for exactly the reason above.

 

"Coming to a halt towing with a very hot engine and letting the auto stop - stop the engine is not a good idea for the  turbo."

 

Always let engine idle for a short while before switching off too.

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Having to disable stop start when towing shows how lazy the manufacturer has been with engine calibration, if hot turbo is an issue the engine management should already know the turbo temp and not allow stop start to happen, just the same as having to manually disable rear parking sensors and blind spot monitoring. Sheer lack of consideration by the manufacturer of the vehicles operating envelope, shows how little consideration they make for towing.

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2 hours ago, Barney1 said:

Having to disable stop start when towing shows how lazy the manufacturer has been with engine calibration, if hot turbo is an issue the engine management should already know the turbo temp and not allow stop start to happen, just the same as having to manually disable rear parking sensors and blind spot monitoring. Sheer lack of consideration by the manufacturer of the vehicles operating envelope, shows how little consideration they make for towing.

True, but how many owners will tow? And would the extra cost of a turbo timer be worth it?

I know back in the day drivers of performance cars were always advised to let the turbo cool down before switch off .

I always allow the engine of our Santa Fe to cool for thirty seconds before switching off, maybe not necessary but won’t do any harm.

Duncan

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No physical timer required, just a couple of lines of software to restrict stop start from cutting in.

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