You are a legend, this is exactly the kind of information I wanted. I hate when people do cold starts and flick the ignition on and off three times after the glowing light goes out. If you want some real preheat to your glow plugs you put the ignition on and leave it there. And now I know how long my v70 preheat. Thank you
Vladi..Greetings from Bulgaria Very well constructed video demonstrating all aspects of the presented topic, problems and technology on a cold start. The textual explanation is simple and clear, unlike a live explanation, usually in a duet with a camera that moves constantly and loses the object that the viewer must see. Thank you. I have the same car model ... and similar problems. But the service and quality ... are lame around the world, and their prices are dizzying ... I am an electrical engineer by profession with serious experience ... but life now requires me to study in detail the secrets of Volvo...
Just got back from the mechanic, with a new set of glow plugs, one glow plug found dead (possibly other not working as when new.....engine turned 120 000 km, bought as new). Since I have a "press button" instead of a key, there's not much I can do. The ecu does all the sequences. And obviously, it cranks very quickly (under 2 secs...probably being a new, 5d standard, new type of glow plugs ?) Still, your well explained and demonstrated videos made my day. I now finally get to understand how they start, how long they might be still glowing-heating combustion chamber, and why my exhaust pipe started having a bit of a black soot lately, especially after morning starts in colder weather (hence the post glow heating not being applied in at least one of the 4 cylinders) ! 👍
You just saved me having to call a rescue truck. Seriously. Was running out of battery, did a last ditch RUclips search to see if I could find anything helpful and after your vid managed to start her. Thanks!
I was also thinking that the heating stops after the glow lamp goes out but I have experienced this by testing it myself, I wish I had seen your video earlier for dacia logan mcv 2011 the light turns off ~15s after it goes out
I have a 2003 VW Jetta TDI and this is very true because when it's very cold outside I can see the lights dim and come back at least three or four times after a cold start after it's running and driving I believe these are after glow cycles for emissions and to keep the cylinder temperature up until it gets warm I usually make sure I wait longer than the indicator because I know it's just an idiot light.
Actually, the glow plug light is being lit(like any other dashboard light) to ensure that it is working correctly(I have worked in designing clusters) and it doesn't show how long actually the glow plugs are working. Also multiple preheats do a pretty good job(talking from experience) and maybe the only way to start the diesel with very old battery but I would recommend as you did show in the video to make longer intervals until you hear the relay clicking off when it's very cold.
Actually in my case- dash light worked well even when the glow plug relay was burned out and glow plugs didn't got any power. Prolonged preheat helps much better than multiple preheat and saves battery power. Multiple switching just helps to rise pressure in some diesel fuel systems and it helps with cold start.
@@JustMe6904GitarosPamokos I didn't explain it correctly. The light comes on and off to ensure that the LED/bulb that warns you hasn't burned. You have a problem if the glow plug light is constantly on. My dashboard light also wasn't working constantly even with a bad glow plug(I don't know what should happen to glow constantly, ask the manufacturer). Prolonged preheat works even in cold weather for about 20 seconds, which might not be enough to warm-up the engine and start it. So I was combining the two methods and after the glow plug relay was clicking off, I was giving the battery some time to rise the voltage again and repeating the preheat. That's the only way to start diesel at -20°C with a bad glow plug and old battery. Apart from that - nice content, keep the good work!
Good information usefull to know (i didnt know) But too late for me i changed my (still good) glowplug (and it is not easy on jeep liberty). Thx from France.
Super interesting. I now understand this. What if the dash indicator goes back on after start and stays on for 50/60 seconds, then goes off? That's what my car does. Thanks.
It's afterglow, it's normal to help engine to work for first minute. Afterglow starts every time after you start the engine if the engine's temperature is not warm enough about 50°C, even if no preheat.
@@JustMe6904GitarosPamokos Thanks a lot. I always thought it was a sign of glow plug fault that needed to be replaced. Can we then drive safely while after glow is on? I usually wait till light goes off, which can be annoying when in a hurry.
The glow plugs have a low inner resistance in order to obtain faster heating and consequently a rapid start of the engine and low emissions. The glow plugs are designed for a continuous voltage of 4.4 volts. Rapid heating is obtained by supplying the glow plugs with an "overvoltage" of 12 volts. A temperature of approx. 1000°C is reached after approx. 3 seconds. After the glow plugs have initially been supplied with power at 12 volts the voltage is reduced after approx. 1.5 seconds to approx. 9 volts. After a further few tenths of a second the voltage is reduced further to a nominal 4.4 volts. Control The ECM calculates when/how the glow plugs should be supplied with power. The required voltage level is sent as a PWM signal to the glow plugs' relay/control module. In turn the glow plugs' relay/control module controls the glow plugs, also using a PWM signal. The glow plugs' voltage level is controlled based primarily on engine speed, outside temperature, engine temperature, injection quantity (mass) and time. Example: Heating "Pre glow" and "Readiness" When the ignition key is turned from position 0 or I to position II the glow plugs are activated for a maximum of 15 seconds if the outside temperature falls below + 5°C. Above + 5°C no heating is allowed. This temperature limit is however adapted to the current altitude. At an altitude of 3000 metres above sea level for example heating is permitted at an outside temperature of +20°C. The first three seconds of the preheating period are indicated in the DIM and this is called "Pre glow". After three seconds the heating changes over to a mode called "Readiness". "Start glow" and afterglow "Post glow" The glow plugs are also activated in ignition position III. The period is called "Start glow". Maximum time in this phase is 90 seconds. When the engine has started the control of the glow plugs changes over to afterglow, the so-called "Post glow" mode. Good starting properties are obtained by means of the glow plugs also being activated after the engine has started (i.e. reaching approx. 400 rpm = CAN signal "Engine running"). The temperature is initially 1000°C. After 15 seconds the temperature is lowered to 950°C. After a further 75 seconds the temperature is lowered to 850-900°C. In "Post glow" the glow plugs are activated for a maximum of 180 seconds. Several examples that affect the heating: • No heating is allowed if the engine temperature exceeds +30°C. • "Post glow" is calibrated for different environments and continues for a maximum of 180 seconds. Included in the calculated time are parameters such as coolant temperature, outside temperature and altitude. • The heating is switched off at an engine speed above 4000 rpm. If the engine speed decreases then heating is resumed. The period for which the glow plugs were not activated is also included in the total glow duration. • If the injected quantity exceeds 50 mg per operating cycle and cylinder then the heating is temporarily halted. (Full load is approx. 65 mg). If the injected quantity returns to below 50 mg then heating is resumed. The period for which the glow plugs were not activated is also included in the total glow duration. • Irrespective of the glow duration, the glow plugs' relay/control module compensates for voltage variations during heating, both high and low voltages. This is so that the glow plugs shall always work with the correct output. The glow plugs have full functionality down to 8 volts and limited functionality from 8 volts down to 6 volts. • There is a function in the engine control module (ECM) that calculates the amount of energy in the glow plugs during "Pre glow". When heating is interrupted and then resumed after a short time then the amount of energy supplied is adapted so that the glow plugs attain the required energy. This is to prevent the plugs from being supplied with a too high voltage and thereby reaching too high temperatures. (The glow plugs can manage 1130°C and are destroyed at approx. 1200°C). By calculating how much the temperature of the plugs has fallen during the shutdown period the supply voltage is adapted so that the temperature of the plugs does not become too high. • During regeneration the glow plugs are activated with a small load for example. By increasing the engine's load the temperature of the exhaust gases also increases which is necessary to obtain a correct regeneration process. Glow plug relay/control module for glow plugs The relay/control module for glow plugs contains powerful transistors (MOSFET) which each supply their own glow plug. There is a shunt for each glow plug that is used to diagnose the plugs in the event of short circuit and open circuit. Any diagnostic trouble codes (DTC) are sent to the ECM where they are stored.
Very informative video! I have an old diesel hilux with a manual glow plug switch. Would hitting the glow plugs after it fires help it run smoother at all?
Hello my friend, I live in northern Norway and the temperatures reach 20 below zero sometimes and we have difficulty starting the car early in the morning and frankly I did not understand which is better? Thank you
Watch this one, turn on subtitles there is experiment with multiple preheat. Good luck ! 😉👌 ruclips.net/video/59xxQZNOHjg/видео.htmlsi=NQZPCFQT9QB8bTq2
No, use this only if you are sure that will be a hard cold start. To save battery, one good preheat is better, than several short preheats and long kranks. Normal engine with strong battery starts normally without prolonged preheat.
do you think I have a problem with glowplugs? when cold, my first start on glowplugs is OK, but, when my trip is short and the engine is not warmed up, it does not start for the second time many times (glowplugs are not lit then), I replaced the fuel filter, battery is 12V, Volvo V70 D5 as well. When it's warmed up, it starts normally every time. (in summer, no problem at all, it starts in September and ends in March)
One of the main things to start the engine is cranking speed, it must be about 200-250 rpm. Especially when the engine is not hot yet, but preheat is already OFF.
@@JustMe6904GitarosPamokos Sorry but I am confused among the same. Here in India we have a car which hold the glow plug sign for nearly 15 seconds of ignition and it starts in -20°C on twice holding to glow plug on ig itio while other competition cars fail miserably as it hold no glow sign and everyone cranks the ingine within seconds. So like wise like me many believe that if the glow plug sign goes off, the heater is off. Please correct me. I am attacking the video.
Different cars may have different glow plugs and pre heat systems. Ceramic glow plugs reach max temperature in 2-5 sec. If your indicator is on for 15-20 seconds - its enough time for glow plugs to heat up. To be sure you have to make the same experiment on your car, so then you will know if inducator off cuts the power to the glow plugs.
Есть системы, как у Опеля (по коментариям) там лампочка на приборке горит пока подается питание на свечи или очень близко к этому. Видео для того чтоб сами смогли разобраться как работает прогрев, а уж выводы делайте сами. Стандарные свечи полностью прогреваются около 25 сек, а ведь надо и камеру сгорания и воздушно-топливную смесь прогреть. Еслиб хватало 4-секундного прогрева, как показанно в видео- то свечи и делали чтоб они нагревались как паяльник, а не до бела и так срок их службы был бы в десятки раз дольше.
You are a legend, this is exactly the kind of information I wanted. I hate when people do cold starts and flick the ignition on and off three times after the glowing light goes out. If you want some real preheat to your glow plugs you put the ignition on and leave it there.
And now I know how long my v70 preheat. Thank you
Oh my i m one of those who keeps flicking it on and off like 5 times😂
Vladi..Greetings from Bulgaria
Very well constructed video demonstrating all aspects of the presented topic, problems and technology on a cold start. The textual explanation is simple and clear, unlike a live explanation, usually in a duet with a camera that moves constantly and loses the object that the viewer must see. Thank you.
I have the same car model ... and similar problems. But the service and quality ... are lame around the world, and their prices are dizzying ... I am an electrical engineer by profession with serious experience ... but life now requires me to study in detail the secrets of Volvo...
Just got back from the mechanic, with a new set of glow plugs, one glow plug found dead (possibly other not working as when new.....engine turned 120 000 km, bought as new). Since I have a "press button" instead of a key, there's not much I can do. The ecu does all the sequences. And obviously, it cranks very quickly (under 2 secs...probably being a new, 5d standard, new type of glow plugs ?) Still, your well explained and demonstrated videos made my day. I now finally get to understand how they start, how long they might be still glowing-heating combustion chamber, and why my exhaust pipe started having a bit of a black soot lately, especially after morning starts in colder weather (hence the post glow heating not being applied in at least one of the 4 cylinders) ! 👍
Hey, Inhaber the Same Symptoms in my 3.0tdi...have solved the Problem with waiting Like 30sec?
You just saved me having to call a rescue truck. Seriously. Was running out of battery, did a last ditch RUclips search to see if I could find anything helpful and after your vid managed to start her. Thanks!
😉👌
Besta vid ever about diesel.glow plugs....
Good video if I wait 20 seconds my van starts lot better thanks
I was also thinking that the heating stops after the glow lamp goes out but I have experienced this by testing it myself, I wish I had seen your video earlier for dacia logan mcv 2011 the light turns off ~15s after it goes out
Really useful information, thanks for posting.
Actually very useful. Thank you.
Thanx 👍😉
I have a 2003 VW Jetta TDI and this is very true because when it's very cold outside I can see the lights dim and come back at least three or four times after a cold start after it's running and driving I believe these are after glow cycles for emissions and to keep the cylinder temperature up until it gets warm I usually make sure I wait longer than the indicator because I know it's just an idiot light.
I like "idiot light" it's good one 😉👌😆😅
Actually, the glow plug light is being lit(like any other dashboard light) to ensure that it is working correctly(I have worked in designing clusters) and it doesn't show how long actually the glow plugs are working. Also multiple preheats do a pretty good job(talking from experience) and maybe the only way to start the diesel with very old battery but I would recommend as you did show in the video to make longer intervals until you hear the relay clicking off when it's very cold.
Actually in my case- dash light worked well even when the glow plug relay was burned out and glow plugs didn't got any power. Prolonged preheat helps much better than multiple preheat and saves battery power. Multiple switching just helps to rise pressure in some diesel fuel systems and it helps with cold start.
@@JustMe6904GitarosPamokos I didn't explain it correctly. The light comes on and off to ensure that the LED/bulb that warns you hasn't burned. You have a problem if the glow plug light is constantly on. My dashboard light also wasn't working constantly even with a bad glow plug(I don't know what should happen to glow constantly, ask the manufacturer). Prolonged preheat works even in cold weather for about 20 seconds, which might not be enough to warm-up the engine and start it. So I was combining the two methods and after the glow plug relay was clicking off, I was giving the battery some time to rise the voltage again and repeating the preheat. That's the only way to start diesel at -20°C with a bad glow plug and old battery.
Apart from that - nice content, keep the good work!
@@electronflow2716 Hello, I want to know that does normal glow plugs also have pre heat system ?
Good information usefull to know (i didnt know) But too late for me i changed my (still good) glowplug (and it is not easy on jeep liberty). Thx from France.
I love you my friend, thanks a lot!
you are a star my friend
My greatest video of the year
to bad u did`t use a laser temp sensor on plugs; maybe next time ! Keep up the good work! Thanks!!!
Why, just look it up on manufacturers spec. Lazer thermometers are not accurate anyway.
thx. I was always curious about this
Great video, thanks!
Super interesting. I now understand this. What if the dash indicator goes back on after start and stays on for 50/60 seconds, then goes off? That's what my car does. Thanks.
It's afterglow, it's normal to help engine to work for first minute. Afterglow starts every time after you start the engine if the engine's temperature is not warm enough about 50°C, even if no preheat.
@@JustMe6904GitarosPamokos Thanks a lot. I always thought it was a sign of glow plug fault that needed to be replaced. Can we then drive safely while after glow is on? I usually wait till light goes off, which can be annoying when in a hurry.
The glow plugs have a low inner resistance in order
to obtain faster heating and consequently a rapid start
of the engine and low emissions.
The glow plugs are designed for a continuous
voltage of 4.4 volts.
Rapid heating is obtained by supplying the glow
plugs with an "overvoltage" of 12 volts.
A temperature of approx. 1000°C is reached after
approx. 3 seconds.
After the glow plugs have initially been supplied with power at 12 volts the voltage is reduced after approx.
1.5 seconds to approx. 9 volts.
After a further few tenths of a second the voltage is reduced further to a nominal 4.4 volts.
Control
The ECM calculates when/how the glow plugs should be supplied with power. The required voltage level is
sent as a PWM signal to the glow plugs' relay/control module. In turn the glow plugs' relay/control module
controls the glow plugs, also using a PWM signal.
The glow plugs' voltage level is controlled based primarily on engine speed, outside temperature, engine
temperature, injection quantity (mass) and time.
Example:
Heating "Pre glow" and "Readiness"
When the ignition key is turned from position 0 or I to position II the glow plugs are activated for a
maximum of 15 seconds if the outside temperature falls below + 5°C. Above + 5°C no heating is allowed.
This temperature limit is however adapted to the current altitude. At an altitude of 3000 metres above sea
level for example heating is permitted at an outside temperature of +20°C.
The first three seconds of the preheating period are indicated in the DIM and this is called "Pre glow".
After three seconds the heating changes over to a mode called "Readiness".
"Start glow" and afterglow "Post glow"
The glow plugs are also activated in ignition position III. The period is called "Start glow". Maximum time
in this phase is 90 seconds.
When the engine has started the control of the glow plugs changes over to afterglow, the so-called "Post
glow" mode.
Good starting properties are obtained by means of the glow plugs also being activated after the engine has
started (i.e. reaching approx. 400 rpm = CAN signal "Engine running").
The temperature is initially 1000°C. After 15 seconds the temperature is lowered to 950°C. After a further
75 seconds the temperature is lowered to 850-900°C.
In "Post glow" the glow plugs are activated for a maximum of 180 seconds.
Several examples that affect the heating:
• No heating is allowed if the engine temperature exceeds +30°C.
• "Post glow" is calibrated for different environments and continues for a maximum of 180 seconds.
Included in the calculated time are parameters such as coolant temperature, outside temperature and
altitude.
• The heating is switched off at an engine speed above 4000 rpm. If the engine speed decreases then
heating is resumed. The period for which the glow plugs were not activated is also included in the
total glow duration.
• If the injected quantity exceeds 50 mg per operating cycle and cylinder then the heating is
temporarily halted. (Full load is approx. 65 mg). If the injected quantity returns to below 50 mg then
heating is resumed. The period for which the glow plugs were not activated is also included in the
total glow duration.
• Irrespective of the glow duration, the glow plugs' relay/control module compensates for voltage
variations during heating, both high and low voltages. This is so that the glow plugs shall always
work with the correct output. The glow plugs have full functionality down to 8 volts and limited
functionality from 8 volts down to 6 volts.
• There is a function in the engine control module (ECM) that calculates the amount of energy in the
glow plugs during "Pre glow".
When heating is interrupted and then resumed after a short time then the amount of energy supplied
is adapted so that the glow plugs attain the required energy.
This is to prevent the plugs from being supplied with a too high voltage and thereby reaching too
high temperatures. (The glow plugs can manage 1130°C and are destroyed at approx. 1200°C).
By calculating how much the temperature of the plugs has fallen during the shutdown period the
supply voltage is adapted so that the temperature of the plugs does not become too high.
• During regeneration the glow plugs are activated with a small load for example. By increasing the
engine's load the temperature of the exhaust gases also increases which is necessary to obtain a
correct regeneration process.
Glow plug relay/control module for glow plugs
The relay/control module for glow plugs contains powerful transistors (MOSFET) which each supply their
own glow plug. There is a shunt for each glow plug that is used to diagnose the plugs in the event of short
circuit and open circuit. Any diagnostic trouble codes (DTC) are sent to the ECM where they are stored.
This is how it works on the euro 4 engines, the one in the video is a Euro 3 engine with 'old-school' 12V glowplugs 👍
Based video thanks man
Very informative video! I have an old diesel hilux with a manual glow plug switch. Would hitting the glow plugs after it fires help it run smoother at all?
yeah absolutely , just check if they are 6v plugs or 12v. the 6v ones need a resistor or you cant run them longer than 5 seconds on 12v
Hello my friend, I live in northern Norway and the temperatures reach 20 below zero sometimes and we have difficulty starting the car early in the morning and frankly I did not understand which is better? Thank you
Watch this one, turn on subtitles there is experiment with multiple preheat. Good luck ! 😉👌
ruclips.net/video/59xxQZNOHjg/видео.htmlsi=NQZPCFQT9QB8bTq2
I'm sorry, but I forgot to ask - do you have similar videos about problems and their solution, of course related to VOLVO V70 2,4 D5 120 hp
Yes i have several videos about volvo D5 P2 on my channel, but it's RU, check it.
So can it be harmful to just skip the preheat on a warm day? Or if it was just running? I was told this destroys the glowplug
No, use this only if you are sure that will be a hard cold start. To save battery, one good preheat is better, than several short preheats and long kranks. Normal engine with strong battery starts normally without prolonged preheat.
I will try this at my diesel generator
do you think I have a problem with glowplugs? when cold, my first start on glowplugs is OK, but, when my trip is short and the engine is not warmed up, it does not start for the second time many times (glowplugs are not lit then), I replaced the fuel filter, battery is 12V, Volvo V70 D5 as well. When it's warmed up, it starts normally every time. (in summer, no problem at all, it starts in September and ends in March)
One of the main things to start the engine is cranking speed, it must be about 200-250 rpm. Especially when the engine is not hot yet, but preheat is already OFF.
Can I replace my normal glow plugs with pre heating glow plugs ? Would it work fine ?
What you mean normal and pre heating glow plugs ??? What the function is of "normal" glow plugs and what function of "pre heating" glow plugs ? 🤔
@@JustMe6904GitarosPamokos Sorry but I am confused among the same. Here in India we have a car which hold the glow plug sign for nearly 15 seconds of ignition and it starts in -20°C on twice holding to glow plug on ig itio while other competition cars fail miserably as it hold no glow sign and everyone cranks the ingine within seconds. So like wise like me many believe that if the glow plug sign goes off, the heater is off. Please correct me. I am attacking the video.
@@JustMe6904GitarosPamokos ruclips.net/video/l7QVAlb8u8U/видео.html
Different cars may have different glow plugs and pre heat systems. Ceramic glow plugs reach max temperature in 2-5 sec. If your indicator is on for 15-20 seconds - its enough time for glow plugs to heat up. To be sure you have to make the same experiment on your car, so then you will know if inducator off cuts the power to the glow plugs.
hello my friend do you know how to import a volvo diesel engine ?
Can I start engine after glow plug off ?
It's easier for starter to crank when glow plugs are off.
ty
I still think multiple preheat is not bad variant
Good luck !!! 😆
ruclips.net/video/Kjuicmc6-ZA/видео.html
@@JustMe6904GitarosPamokos Nice, this video explains more, thanks!
Тоесть все не правильно заводятся))
Есть системы, как у Опеля (по коментариям) там лампочка на приборке горит пока подается питание на свечи или очень близко к этому. Видео для того чтоб сами смогли разобраться как работает прогрев, а уж выводы делайте сами. Стандарные свечи полностью прогреваются около 25 сек, а ведь надо и камеру сгорания и воздушно-топливную смесь прогреть. Еслиб хватало 4-секундного прогрева, как показанно в видео- то свечи и делали чтоб они нагревались как паяльник, а не до бела и так срок их службы был бы в десятки раз дольше.
@@JustMe6904GitarosPamokos капец я лично проверил после того как лампа потухла подождал ещё 15 сек и завёлся реально лучше. Спасибо
I don’t click on a video so I have to read thumbs down
Legend