300td at altitude
 

Hello,

I have a 1987 300TD in Mexico at 7,000 ft. elevation. I have noticed a drop in performance and sluggishness. I added diesel fuel additive and it helped somewhat but not 100% improvement. Any ideas of other things I could do?

All engines, including turbocharged engines loose output at altitude. It is usually more noticeable on naturally aspirated engines, but turbos suffer too unless they are designed to maintain a fixed level of absolute manifold pressure; however, they are usually set up to limit boost to a specified gage pressure (pressure relative to the surrounding ambient pressure) , which means absolute manifold pressure will go down with altitude.

High temperatures prevalent at high altitude in tropical areas further contributes to a lowering of inlet air density, so it's a double whammy.



Duke

Duke, thanks for the information. I'm glad this is pretty normal and not anything to worry too much about. John

Also stay ahead of your air filter. Every bit of air is important at that elevation. Engines work quite hard over 5,000 feet.

Haasman

It is a good time to check those fuel filters as well.


Darrell

You probably want to post this question over on the diesel forum. I don't know about the 87, but the 85 and olders had a boost sensor controlled via a plastic line that could get plugged lowering boost and effecting performance. You may have a similar problem. I don't notice a big change in 85td performance from sea level to mile high unlike the NA.

Are you saying that you have seen a decline in performance when going from sea level to 7000' or if there has been a degredation in performance while at 7000'?

thanks all for the information. I noticed the degredation mostly once here at 7,000 ft but since we were mostly cruising on the highway it's difficult to tell. I have spare fuel filters and will definitely check those and the air filter as well. John