hello just wondering if anyone else is getting high 500 - 650degrees celcius pulling 2-3 tonn trailer loads up hills. The egr is blocked and also have 3inch straght through exhaust the temp probe is directly behind the turbo thanks
high exhaust temp
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The temps you're getting sound normal to me.
EGR reduces the temp by cooling the combustion process. I've no figures on how much it actually reduces the EGT by, but at full belt up a hill you won't have the EGR valve open anyway so it's not an issue. The higher flowing exhaust will help cool it a bit by letting the gas out faster but really that difference is going to be marginal, especially where you've mounted the sensor.
Just before the inlet of the turbo (where the 4 exhaust ports meet and combine into a single outlet) the temp is at its highest and should read about 750C when the car's working. There should be about a 100-150C drop across the turbo, so the exhaust temp should become 600-650C where you're measuring it.
Doesn't sound like you're in any danger! With temps up there though, letting the turbo spool down is important. Might be a lot of value in a temperature-based turbo timer in your rig.
The temps you're getting sound normal to me.
EGR reduces the temp by cooling the combustion process. I've no figures on how much it actually reduces the EGT by, but at full belt up a hill you won't have the EGR valve open anyway so it's not an issue. The higher flowing exhaust will help cool it a bit by letting the gas out faster but really that difference is going to be marginal, especially where you've mounted the sensor.
Just before the inlet of the turbo (where the 4 exhaust ports meet and combine into a single outlet) the temp is at its highest and should read about 750C when the car's working. There should be about a 100-150C drop across the turbo, so the exhaust temp should become 600-650C where you're measuring it.
Doesn't sound like you're in any danger! With temps up there though, letting the turbo spool down is important. Might be a lot of value in a temperature-based turbo timer in your rig.
thanks for the replies fella's so I shouldn't start to worry until I start seeing 700+ then. I also noticed it takes a lot longer to cool down after a drive with the egr unblocked around 3 mins to go down to 170 degrees and with the egr blocked it only takes 30 seconds to go down to 170 degrees at idle
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E bay has some nice looking turbo timers to suit d40's specifically. They look like a good option.
I always just let mine cool down till the egt gauge reads under 200c but I don't trust the missus. I have told her to watch the gauge after driving before turning it off but do ya think she cares! lol
Might have to invest in a timer. Or ban the missus!!!
I always just let mine cool down till the egt gauge reads under 200c but I don't trust the missus. I have told her to watch the gauge after driving before turning it off but do ya think she cares! lol
Might have to invest in a timer. Or ban the missus!!!
the temps are certainly up there but after the turbo can be a bit inaccurate as you don't know the temp drop across the turbo.
its certainly as high as you want to go. with temps like that i would be keen to fit the probe before the turbo and get a much more accurate reading.
EGR is not on a full throttle (ie max egt temps) so is irrelevant. egr may cool the flame temps but due to increasing the inlet air temps, it tends to increase egt temps. tho cooled egr system are not to bad as far as that goes.
its certainly as high as you want to go. with temps like that i would be keen to fit the probe before the turbo and get a much more accurate reading.
EGR is not on a full throttle (ie max egt temps) so is irrelevant. egr may cool the flame temps but due to increasing the inlet air temps, it tends to increase egt temps. tho cooled egr system are not to bad as far as that goes.
If you're seeing over 700 on the south side of the turbo, it means you're developing 800-850 on the north side and that's an issue. I have doubts that the turbo cooling system (it's a water cooled turbo) or the oil in the passages will cope well with that.
It's also an indicator of trouble inside the combustion chamber. Whether that's a stuck/leaky injector, or oil entering and combining with the diesel during the combustion process would be a process of investigation.
I'd agree with your call - 700C (south of the turbo) should be an upper limit. If it reaches that temp, you're either pushing too hard or there's a problem.
On that EGR - the EGR valve is closed at idle, so there should be no difference between blocked/unblocked. Curious that you notice a difference, unless your unblocked EGR is operational when it shouldn't be!
4.8GU
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traditional diesel "experts" will look at these temps and say man that is high or way too high but I can tell you now that is about what they run as a factory setup with NO mods. That is why I mentioned in a thread somewhere that anyone running a chip (any type but some worse than others) without any breathing mods like exhaust intercooler etc are asking for trouble.
As far as I am concerned if a truck runs up to 500 odd egt post turbo stock then there is some lee way to go higher but not much. These d40's definitely run on the edge I reckon and they obviously have made some headway in metal alloys to handle the heat new generation diesels make.
I can see 400 in mine without even trying and it is only a short hill in 6th doing 110km/hr that it will hit 500+. And I don't have any extra fuel going into mine. Unfortunately the only way to really know where the limit is on these particular motors would be to push it till it blows up. I for one am not willing to put my hand up for that task! lol
EDIT: How do you know that is the upper limit of temp woznme? I know the melting point of normal aluminium is around 630c or something but obviously the alloys used in motors these days are far better. Just curious to know if you have some inside info that is all
As far as I am concerned if a truck runs up to 500 odd egt post turbo stock then there is some lee way to go higher but not much. These d40's definitely run on the edge I reckon and they obviously have made some headway in metal alloys to handle the heat new generation diesels make.
I can see 400 in mine without even trying and it is only a short hill in 6th doing 110km/hr that it will hit 500+. And I don't have any extra fuel going into mine. Unfortunately the only way to really know where the limit is on these particular motors would be to push it till it blows up. I for one am not willing to put my hand up for that task! lol
EDIT: How do you know that is the upper limit of temp woznme? I know the melting point of normal aluminium is around 630c or something but obviously the alloys used in motors these days are far better. Just curious to know if you have some inside info that is all
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Thats what is suggested as a safe range for most modern engines by Turbo Logix which pretty much only do monitoring equipment. If they state that figure they must be sure its fine as they'd be pretty open to claims if the stated max 760 limit is not safe. Good enough for me. A few months ago i enguired if they can ship to australia but they never replied. shame because their units look good.
