[kaspotz]

I have a 1984 300TD with roughly 400k miles on it that I purchased two years ago. I've probably only put on about 10k more miles during that time. It's always started a little rough after sitting for a while (engine feels like it's "kicking", there's a little bit of smoke) but lately it has been much worse. The past few weeks it has taken much longer to warm up before idling properly. This happened after I took it on a 120-mile round trip for the weekend. I'm planning on changing the fuel filters and doing an oil change soon (I do this once every 4 months) but in the past this has never done anything to help with the rough starts. Does anyone have an idea of what else I could do to curb this issue?

One other side note that I find weird, I live in Washington and the winter hasn't been that bad. Most mornings are around 40 degrees and the car will start up decently well when I leave for work around 8am. But when I get off work at around 5 the initial start is much worse (car takes about twice as long to get warmed up). Why would it be a harder start when it isn't as cold out? The drive to work is only 4 miles round trip and that is the main driving the car gets every week.

 

[dkr]

Try doing two or three runs of the glow plugs and see if it starts up any better.

Dkr.

 

[dependable]

White smoke is usually unburnt diesel or coolant in combustion chamber. How is anti freeze level? Does smoke smell sweet, or just like diesel.

Maybe test glow plugs to see if all are working. Once one goes bad, the others go in succession, making motor progressively harder to start.

 

[300Dman]

I go along with dependable.

What does the Smoke smell like?

Bad headgasket signs are a Upper Radiator Hose that remains inflated/hard after the Engine has sat and cooled off. Bubbles in the Coolant Recovery Tank when the Engine is running. Oil in the Coolant Tank.

Do a quick check of your timing Chain Stretch by removing the Valve Cover and lining centering the Mark on the back of the Camshafttear with the one on the first Camshaft Bearing Tower and take a look at what the pointer is pointing to.

You did not say if you have ever done a valve adjustment on the Engine.

Air leaks on the suction side of the Fuel System can cause white smoke

Worn out Injector Nozzles and or low Pop/opening pressure on the Injectors can cause the Fuel not to atomize well and not burn creating white diesel smelling smoke.

Late Fuel Injection Pump timing. (That happend to me on another Diesel when I instlled the Pump with the timing too late. Large pure white coulds of atomized diesel fuel out of the Exhaust.)

In short poor compression (that includes the Head Gasket), worn Injectors, out of time, air leak and or Valves need adjusting.

By about 150K or less the Original Injector nozzles should have been worn out.

It might be you could pull the Injectors and heat shields and look down inside the Precombustion chambers and see if there is anything you can see. Mainly you are looking for differences in the Carbon Buildup to see if all the Cylinders are functioning the same.

It is cheap to replace the 2 sections of Fuel Inlet Hose with 5/16" ID Fuel Hose you can get from a regular Auto part store as it is also rated for Diesel Fuel as well as gasoline

 

[xlimodriver]

White smoke = Condensation, Warm air from exhaust hittng cold air.

Started my W126 up earlier this week to get the juices flowing.