EGTs too high after mods...what now?

[DrHarry]

Hi guys. My 2008 CRD 3L is running EGTs of 600 when I am cruising at 100km/h towing a medium size trailer on the flat. With a head wind or on any slight incline, they want to head towards 700!

Around town temps are 200-300.

Boost with my adjustable valve sitting around 13 max.

Current mods include EGT block, 2.5" mandrel exhaust and diesel gas. I think the EGT block has made the biggest difference to this problem.

I know these temps are not really safe but at present the vehicle is useless as when I cross the Nullarbor or head to the hills I am very limited by the temps.

Is there a fundamental problem with my motor, or have the mods caused this and now I need to do more e.g. intercooler :-(

Thanks
Harry

[big_fletch]

Hi guys. My 2008 CRD 3L is running EGTs of 600 when I am cruising at 100km/h towing a medium size trailer on the flat. With a head wind or on any slight incline, they want to head towards 700!

Around town temps are 200-300.

Boost with my adjustable valve sitting around 13 max.

Current mods include EGT block, 2.5" mandrel exhaust and diesel gas. I think the EGT block has made the biggest difference to this problem.

I know these temps are not really safe but at present the vehicle is useless as when I cross the Nullarbor or head to the hills I am very limited by the temps.

Is there a fundamental problem with my motor, or have the mods caused this and now I need to do more e.g. intercooler :-(

Thanks
Harry

G'day mate,

Personally i think that your peak boost is set a little low and about 15-16psi would be better.. Temps around town will stay the same however Highway temps should sit more around the 400 odd with the trailer.. Mine is a DI (not a CRD) and on the highway with no load my boost sits about 10-12 psi with temps about 270-300deg.. Maybe try this and see if it helps with your temps?

Fletcha

[patch697]

You can go higher in your boost (15/16 psi is quite safe) & this should see a good reduction in your EGT's

[DrHarry]

Thanks for that. Temps are definitely a little better with a bit more boost and I will push it up a bit. But previous experience tells me this will only lower the temps a smidge.

I will report back when I have tried that.

Harry

[patch697]

Thanks for that. Temps are definitely a little better with a bit more boost and I will push it up a bit. But previous experience tells me this will only lower the temps a smidge.

I will report back when I have tried that.

Harry


That sounds a bit strange, I've seen a 4pound increase in boost pressure bring a EGT down by 100 to 150 degree under load.

[Ben-e-boy]

gday


are you towing in 5th gear?? and have you had a dyno tune since modding it??

benny

[big_fletch]

That sounds a bit strange, I've seen a 4pound increase in boost pressure bring a EGT down by 100 to 150 degree under load.

Yer ill second that, i saw about 400deg running about 8psi on highway at 100km/h.. Screwed boost up to 10-12 and temps dropped to about 270deg while still keeping fuel economy quite good

[DrHarry]

I tow in 5th on the flat or down hill. Change to 4th if any hint of struggle/hill/headwind which does help keep the EGT at 600-620. But basically whatever I do I am struggling to get past 100-110km/h without passing 600 degrees.

No dyno tune ever done...what would they actually adjust when they do that? Adelaide seems a little short of places to get it done close to the city.

Thanks for your help with this guys...

Harry

[DrHarry]

OK it seems you guys were right. I screwed my ASE boost controller right in and still couldn't get the boost past 13 (subsequently I have taken it apart and it is a bit oiled up so may be something was sticking). So I removed it altogether and plugged back the OME servo thingy. Unfortunately this allows the turbo to over boost quickly to 18, and 22 if I really give it some stick going up the freeway out of Adelaide.

HOWEVER, the EGTs are never passing 500.

So, back to my original problem of over boosting *sigh*. I assume some over boost is not as bad for the motor as the high EGTs? Maybe I need a "proper" Dawes valve.

Harry

[bigG]

Dr Harry
The CRD ECU controls the issue of boosting mine never goes over 15psi and yes egt temp in a crd are higer than the Di model, don't worry about hitting 600 to 650 as I get these temps when I giving mine a hit on hills of into strong headwinds. The issue with high temps are if they stay high. Just hitting 600 for a short time is no problem at all, if it does not go down as quickly as you back off then you have a problem

regards

[pearcey]

G,day Dr Harry.
You could try Detrac Diesel at 8 Quinlan Ave StMarys.Phone 82776299
These guys are very good by all reports, and have all the equiptment. They are also like Patrols.
Hope this is some help.
Pearcey

[fat paddy]

So is everybody talking in degrees Fahrenheit or Celsius here?
I just fitted an EGT meter and a boost meter. These things are a driving hazzard as they are so interesting to watch. I am amazed how quickly the temp changes due to driver imput and terrain input.
What is the maxium safe operating EGT post turbo? I range between 400 and 700 degrees F and it settles to about 600 at 110Km/h.
The boost sits in the low teens at cruising speed but I can easily pop it up to 20 plus with a heavy right foot before the engine control detects the over boost and drops it instantly back to 10ish.
Engine mods are a D-Tronic, a catch can and a regularly cleaned AFM.

[YNOT]

We're talking celsius. The safe maximum for post turbo temperatures is 500C with short bursts to 550C OK. Not sure what that is in fahrenheit.
20 Psi is too high for a standard turbo. Assuming you have a ZD30 you should be able to hold 16-17 Psi constantly under load with proper boost control, which should keep your EGT's to safe levels.

Tony

[fat paddy]

Hi Tony,
Thanks for the quick reply.
The boost only gets to above 20 psi momentarily then heads south again.
Is a Dawes valve meant to sort this problem?
BTW 500 degrees C equals 932 degrees F, my EGT 2 inches after the turbo has not even approahed this. 550 degrees C equals 1022 degrees F.....that is some serious heat.
Cheers,
FP

[YNOT]

Boost on the ZD30 is controlled by the computer. A dawes valve can be fitted a number of ways, one way it stops boost spikes but leaves the computer in charge, the other way when used in conjunction with a needle valve is full manual boost control.

If you think those temperatures are hot add 100C for pre turbo temps!

Tony

[boots]

Question / clarification ? zd30 turbo max boost can be adjusted by the actuator stop screw , as to limit max boost ?

[Skull]

I am not familliar with your ASE controller. Had a quick read around other forums but not much on it. Do you have this taking the CPU control solinoid out of the equation or controlling the spool rate?