I have a 92 300d 2.4td it idles rough and brakes hard at times.
there is also alot of oil in the intake tube. could this be a vacume problem?

I'm not very familiar with the 92's 2.4L but it sounds like a combination of problems but I think the one you may need to take care of is a new vacuum pump. Is there any oil in the vacuum hoses? The intake has oil in it from the blowby generated by the motor, the intake manifold has crud in it from the EGR and the previously spoken of oil. Both of these are pretty well normal. Hard braking would be from the lack of vacuum reaching the brake booster, most likely. Check to see how much vacuum the pump is making at idle. On the old 617s it should be in the 17-22" range.

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Jeff M.
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