300D turbo slowing down!!
 

love my 300D turbo, 82' 225k miles. lately, it's been slowing down on the highway, can't get past 65mph, when i first get on the highway, it feels a lot stronger, pulling to 75-80, but starts slowing after prolonged driving. could the presure in the turbo be dropping? other than the basics, i am not very knowledgeable about the mechanics of engines (diesels especially), so any help would be appreciated.
second,can anyone please inform me of the routine maintenance needed for diesels? usually just changed the oil, so far nothing has broken down, but i feel i haven't kept up with things.
lastly, my trans slips trying to get into 4th when first driving after a long rest. can a trans service take care of this or is it time to rebuild??? thanks a bunch for any and all suggestions.

I have several recommendations. 1st, your 300D turbo should be faster than a striped a$$ ape on the highway. Mine will run to 120mph and maintain it effortlessly. You have some problems to take care of.

Some other maintence items worth checking out:

Valve adjustment (I go over the valves every 20,000 miles)
This could cause a loss of power and in severe cases burnt valves.

Regular transmission fluid&filter changes.
This can help prolong life by keeping clutch material out and keeping everything clean and fresh. If this hasnt been done regularly, be VERY careful. Transmission seals tend to "adapt" to the chemisty of the fluid and when new fluid is introduced the seals will just fall apart. If your transmission hasnt had regular services, this isnt the time to start.


Now on to your main problem. maintaining speed. It is possible you have a turbo problem. The wastegate may be either stuck open or weak. You also need to check out the boost fuel adjustment aneroid commonly referred to as the alda. this could be clogged from years of EGR soot and CCV oil vapor. Youll need a competent shop to perform more advanced checks.

Where are you located? Let me know, I know some guys who are very good all over the country.

I would change both "underhood" fuel filters first.

Sometimes we concentrate on the big stuff and forget the simplest little items. Fuel filters are a big must that I forgot! :)

car54,
After reading the original post, I think maybe you could help me.
I am looking for a good, knowledgable about the car kinda garage or mechanic in the Philly Pa area.
Thanks!

You also might be a candidate for a poorly vented tank.

After a highway run in which the car loses power, pull off, cut the engine, jump out and open the fuel tank cap. If you hear an inrush of air - you've got a vent problem.

Not all that likely, but I mention it as a cheap test.

Ken300D

car54,
thanks for the detailed response. i'm in the los angeles and san diego area of california. now i know that there's something wrong if your turbo hits 120mph. i just thought that mine was getting a little old. please reply back if you know anyone around here or have any other ideas. about how much would it cost to replace the trans seal you were talking about?

aah. Your out on the west. I dont know anyone out there. closest is Layton, Utah. sorry.

Follow the recommendations of others here as to the fuel tank, fuel filters, ect.

As for the transmission, its not a single seal, its a dozen or so inside, no simple replacement. I would first take care of your sick engine, then when thats solved, focus on maintence of the transmission

You can tell alot by the color of the fluid on the dipstick. with the engine warm and idling in neutral, check the fluid on the dipstick. check it for color and appearance. sniff the dipstick. compare all these properties to the color and smell of new ATF. If the transmission fluid is brown, smells burnt, or has alot of shiny particles in it, you need help. If it is just slightly darker than new ATF and smells the same or very close, your fine. If its clean in the transmission, I'd feel safe just changing the fluid in the pan and the filter. If the transmission stuff is dirty, i'd just leave it alone. If its pretty clean, your probably safe doing a fluid and filter change.

Good luck fixing your car!

If changing fuel filters dosen't do the trick, it could be growth in the fuel tank. Perhaps you could try to open it up by disconnecting the fuel line, take off the fuel cap and blow compressed air into the tank. Do a search on this topic.

also it could be the strainer in the bottom of the tank is cloged up. above the differential where the fuel line comes out of the fuel tank.it is a very big nut like 38mm or something

Mr. MB Motors in Tarzana sounds like a good place to start for you. Good luck. They are well thought of.