When I First crank up my 84 300D it is much louder than it should be and very low on power After a few min the engine sounds normal and i have plenty of power. Could it be that my oil pump is bad?

nope its a diesel, this is normal. Completely normal. When it starts the pinging and clattering should be more pronounced and it should have very little power until it is warm. Its just related to the engine being cold and the diesel fuel burning differently in a cold engine

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1981 300SD 512k OM603

Yes, normal for a cold engine.

The reason I ask is that I have an 83 SD that does not do it. I tis never loud and never slow. Same motor what could be the difference?

Spammers, what a waste of life.

so whats the deal with spammers, is it all computer generated? Or is it some douche in russia that gets payed for it? I just cant see the latter actually working

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1981 300SD 512k OM603

Try pouring some Diesel Kleen in the tank for a few tankfuls. The stuff really works. In theory, it costs less than the value of the gain. They say it increases your fuel economy more than the cost of the product. It might raise it 1-3% perhaps, they say up to 6 or 8%, I think.

But if you use it for a few tanks, it will clean out your injectors and quiet it down a bit. Also, temperature changes will make your car sound different. I noticed mine was making more noise when we went from winter into slightly warmer weather for a while. Now that the weather's completely changed here in Atlanta, the engine sounds normal again.

jeff 1991 300d

This is one of the things that I think causes the problem (stock nozzles). On my car and a set of injector I pulled of another car I found that the tiny central drilled hole in the injector pintels were completely plugged with carbon. My understanding is that they are there to give pre-injection of some fuel at idle. I also think ounce they are plugged dumping some chemical into the tank won't help. You could pull one injector and take a look but use a magnifying glass.

Here is a pdf on cleaning the injectors:
http://www.pauldrayton.com/uploadfiles/merc/Service/W123/w123CD2/Program/Engine/617/07_1-137.pdf
Other differances between your 2 cars could be IP timing, timing chain, milage and other normal tune-up type stuff.

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84 300D, 82 Volvo 244Gl Diesel