2L-T EGTs - how hot is too hot and how to reduce temps (1 Viewer)

[richmason]

Thanks to the excellent feedback from the forum, I have my EGT probe placed such that it actually reads and the results are disturbing. I went from never over 900 or so to 1450 under acceleration and holding 60-65 mph on my first test drive. New turbo is putting out around 10-12 psi. I always drove my TD VW Westfalia to keep EGTS at 1100 or lower if I remember correctly. Seems like I've been running this truck a lot harder than I should have been for the past few years and I think I finally understand what is causing my overheating problem at highway speeds and on long hills. My question is what EGTs should I be aiming for and how to get the temps down. Should I start by turning down the boost and/or fuel or should an air-to-air intercooler be sufficient to get things back to safer numbers? Exhaust has been brought up to 2.5" already.

Thanks for any and all advice!

 

[GTSSportCoupe]

That does hotter than I'd like for my motor. An intercooler would help a lot, but some tuning to your motor will help also. More boost without an increase in fuel would help.. Or leave the boost where it is and lower the fuel. You'll have to learn how to adjust your boost compensator. Probably turning up the spring tension would be the way to go (increases resistance to fuel pin). Leave the fuel screw in the factory position. Only work with the boost comp.

 

[richmason]

Thanks for the suggestions. I shortened the wastegate actuator a bit, raising the boost and lowering the egts. First adjustment gave me over 20 psi and max egts of 1050 so further adjustment is needed to dial it in. What are thoughts on max egts measured pre-turbo for these engines? 1250 for short bursts 1100 for extended runs or can I go hotter without damage?
Cheers,
Rich

 

[FJBen]

1100 all day long on diesels. That said, being a 2lt and it’s already hot, I would turn fuel down, and 20psi on a factory turbo is blowing hot air without an inter cooler.
get the cooking system, fan and everything in order ASAP and don’t be surprised if the head crack soon. Heat is the enemy on these.

 

[richmason]

Good advice all around. Chasing the overheating I did everything in cooling system including blue fan clutch mod with no success. Inter cooler and waterless coolant are all that’s left. I turned the actuator back out a turn and that brought the boost and temps into area where I can avoid extremes if I’m watching the gauges. Now I need a longer highway trip to see how the overall cooling situation is. Thanks again.

 

[FJBen]

I didn’t see it mentioned, but when you say you overhauled the cooling, did you Cleanout the radiator or replace it?

 

[richmason]

I replaced it with a new unit from Euro 4x4 in France. Took a longer drive today and it looks like my current waste gate setting gives me a max of 1200 and boost around 15 under full throttle. With that setting I feel like I have a little less power than with the previous turbo, which maxed out at 12 psi, but not much. Since the EGT probe was improperly installed, I don't have a baseline EGT for the previous turbo but since it would overheat before as it heat soaked and current setup seems to stay below half on the water temp gauge, I would guess that the EGTs were higher. Next step will be to reduce the fuel as suggested with the boost compensator until I can put an intercooler on it. Thanks again.

 

[SNLC]

I would keep EGTS at about 250-350 at idle and max of 1200. For sustained temps, 950 is where I like the top end.

To much fuel and it will be at 450+ at idle and go way over 1200 under load.

Cooling system, intercooler and proper tune can all help keep them under control. I have also had great results with ceramic coating and oil coolers. Also more air in and out can help too. Meaning more boost and correct size exhaust.

Cheers

 

[richmason]

After years of struggling with overheating, I am cautiously declaring victory after rotating the boost compensator diaphragm 90 degrees clockwise and thus reducing the fuel supplied along the boost curve. I can run uphill in 5th gear with the pedal on the floor, boost at 12 psi and EGT just below 1250 for miles now with the temp needle just below halfway. Before, there were trips I couldn't take because there was no way to keep the temp needle from climbing on long steep hills no matter how slowly I tried to go. This was even after installing a snorkel, replacing the radiator, modifying the fan clutch, increasing the exhaust to 2.5 inches, and replacing the turbo. Once it really heats up outside, I may need to drop the fuel a bit more but by then I hope to have an intercooler, which will hopefully compensate. Thanks to everyone on the board who provided advice along the way. This was always a frustrating issue because I didn't want to make modifications to the truck trying to go faster. Rather, I was always chasing an overheating issue that emerged once I moved the truck to the US from Liberia and started driving at higher speeds to keep up with traffic, on hillier terrain, and in warmer temperatures. The only modification to the fuel system was a pump rebuild by a local diesel shop to fix leaks, which may have actually made the overfueling worse. Without an accurate EGT gauge, I had no way of knowing. Now on the no-start when hot issue and popping out of first gear! Happy New Year!

 

[GTSSportCoupe]

Increasing the spring resistance to the pin movement is another way to reduce fuel too. This would allow you to run higher boost without more pin movement. (ie. more air, but not more fuel).

Glad you figured it out.

 

[richmason]

How is that adjustment made? With shims under or on top of the spring or with different springs? Is there a procedure you can outline/link to for this adjustment? Cheers, Rich

 

[GTSSportCoupe]

How is that adjustment made? With shims under or on top of the spring or with different springs? Is there a procedure you can outline/link to for this adjustment? Cheers, Rich

Check the manual. In the 1HDT diesels there is a 'starwheel' that sits under the spring (which resists pin movement). Turning this wheel in one direction pre-loads the spring more (less fuel), turning the other direction un loads the spring (more fuel).

That said I think the 2LT might be more complicated. I think it has two springs. Check the repair manual. It will explain how to adjust this in the fuel pump section.

 

[DieselMechanicN]

You shouldn't be adjusting your wastegate to tamper with the boost, the boost pressure has to be set by the spring rating in the wastegate itself or by a boost tap. By messing around with the lever you're going to cause all sorts of dramas. If you want to set it properly, take the arm off the turbo, wind it untill slips onto the wastegate (turbo end) in the fully closed position then remove it again. Wind in 1/2 a turn to a full turn so you have to pull the arm out with force to fit back over the turbo end and that's your proper adjustment. This means the spring is forcing the wastegate closed untill the compressor housing signals it's at it's spring operating pressure, which is the correct operation.

 

[richmason]

Got it. Thank you.

 

[richmason]

Edited to remove my previously posted comment. Not sure how to just delete the post.