Bimmerfest BMW banner

1 - 11 of 11 Posts

·
Registered
Joined
·
135 Posts
Discussion Starter #1
Team, what are your exhaust gas temperatures?

I only recently added EGT to my live graphing (obd2 phone app) and don't have sufficient data yet. My vehicle is a 2012 x5d with 137k kms on mostly (80%+) hwy, and flat/level roads, no hills.

This week, i am sure i saw EGT around 320C for a couple of days while cruising at 140 kmh (87 mph) on a flat hwy. My drive to work is 20 min hwy speeds. Ive seen lower EGT at lower travel speeds (duh). Upon engine start in the morning, with ambient air and coolant near 0C mark, the EGT starts at 50+C, seems to be consistent.

Yesterday, i felt rebelious and did 165 kmh (100 mph) for a short time and noticed EGT climbing and staying above the 600C (1100F) mark. Dropped later when i got home. No concerns for me at this point as this should be attributed to a higher flow of hot combusted exhaust.

So this morning, i was keeping an eye on the EGT readings and once coolant was in NOT (75C min, 85-89C is optimal), i saw the EGT go above 600C. And stayed there for a good 10-15 min. Was dropping to under 300C when i got to work's parking lot and had to turn off car. (My water pump and thermostat were replaced last month and i was already logging coolant temp and can confirm that it's stable and within range. No issues on engine temps. So regen should be occurring regularly based on coolant temp condition.)

My phone app is not Carly (will be installing torqur pro soon) so i have no data on regen counts and soot mass. Waiting for my cable for ista and hopefully i can get more answers there.

Question for u: was this a regeneration cycle temps i caught? Like i said, i only started logging EGT recently and don't have enough experience with it. I'm not concerned but wanted to hear what your experience and advice with EGT is.

Thanks very much.

-----
Here is what i was able to find using the forum search and google.

Generic:
-"The exhaust gas temperature (EGT) pyrometer can be one of the most important gauges on a turbo-diesel-powered vehicle. It can warn the driver of situations that are potentially damaging to the engine, and it can also be used as a guide for optimizing fuel economy."
-"Excessive EGTs are due to a rich air/fuel mixture, which can be caused by too much fuel."

Bmw specific
Service bulletin SI B18 03 10
-"During normal driving, there is a continuous regeneration of the diesel particulate filter that takes place at exhaust-gas temperatures between 280 and 350° C (slower oxidation process). The soot particles can only be burned off when the required exhaust-gas temperature has been reached."
-"The DDE initiates the regeneration process by decreasing incoming air by the* throttle valve, and one or two post injections are executed. This heats the exhaust-gas temperature to approx. 600C."
-https://www.bimmerfest.com/forums/showthread.php?t=1262934, Post #31
"I have seen EGT before catalyst temps around 620°C during active regen, successful regen count then goes up by one . . . I have also seen EGT before catalyst temps of about 350°C - which I assumed was a passive regen, regen count did not go up."
-https://www.bimmerfest.com/forums/showthread.php?t=917033, post #109
"Temps were running around 300´C (250-350´C while cruising, and up to 480´C uphill), and 600-630`C when regenerating."
-https://www.e90post.com/forums/showthread.php?t=1384860&highlight=Egt
"600+ degree [C] EGT. The car will operate in vacuum during a regen [...] over 75 degrees on the coolant too."
----- Screenshot_20181220-080038.jpeg
 

·
Registered
Joined
·
283 Posts
The 600C you saw this morning was likely due to a DPF regen. You also have to take into account of the pyro's(thermocouple) location, pre-turbo or post turbo. Pre turbo numbers are generally 100-300F hotter than post turbo depending on the load and turbo efficiency.

Although it varies from engine to engine, 1,100F(600C) is not that hot for a diesel if the pyro is pre-turbo. My Cummins will get there within seconds of going wide open throttle depending on which tune I have loaded. I set my CTS2 monitor to alert me when my EGT's get to 1,400F so i will know when to back off the throttle.
 

·
Registered
Joined
·
830 Posts
The 600° C was a DPF regeneration. I've been loosely monitoring my EGTs for over 2 years, and I usually see 250° to 350° C during normal driving, with over 500° C for 15 minutes or so about once every tank of fuel. For what it's worth, when a DPF regeneration is occurring, the EGT will even stay around 500° even if I'm idling at a traffic light.
 

·
Registered
Joined
·
451 Posts
I monitor my 328d DPF's temps and typically it's in the 400-500F (204-260C) range at light load, 700-800F (371-427C) range constant throttle (cruising) and 1100-1300F (593-704C) range during regen.
 

·
Registered
Joined
·
135 Posts
Discussion Starter #5
Ok thanks for sharing yr experience and knowledge, fellas. Good to know my EGTs are in normal operating range, as expected.
 

·
Registered
Joined
·
135 Posts
Discussion Starter #6
Update: got JR stage 2 tune. EGT didn't seem to change. 260-320C when on hwy cruising at 140 kmh. Will continue logging EGT
 

·
Registered
Joined
·
135 Posts
Discussion Starter #10
Finally another DPF regeneration cycle. Hadn't caught one in a while as local ambient temperature here dropped to -20C and thermostat couldn't warm up car and keep it there sufficiently long to complete the burn process.
Today it got a bit better with air temp at -6C and thermo finally got coolant to 89C (was max 84 at hwy speeds last couple of weeks) and i saw the EGT shoot up near 600C for DPF regeneration. Stayed on highway extra. Screenshot_20190201-155150.jpeg
 

·
Registered
Joined
·
135 Posts
Discussion Starter #11
My EGT (sensor1) got to near 400C, with the engine below 70C and speed under 70 kmh. Car was barely driven a few kms till i saw this and no hard acceleration.

I do know it wanted to do a regen yesterday, only after 30 kms on the highway and as soon as i took the exit ramp... So regen never finished.

Was it trying to raise egt to complete the regen? I cant seem to force a burn cycle via torque pro (carly can, however i don't have it)
 
1 - 11 of 11 Posts
Top