I'm trying to sell my CRD and analyzing everything that could be a possible turnoff during a test drive. Something that mine has always done since owning it is when the blower is on, whether its the heater or the A/C every couple of minutes the engine kind of shudders. I thought it was from when the a/c compressor was kicking on and off, but it does it even when the a/c button is off. It's not an RPM jump, it's just a strong momentary "shake" or "shudder" of the whole vehicle. Almost like a surge is going through the system. However if I turn off the blower, it completely goes away. I can only feel it at idle.

Any ideas?

Here's a link that hopefully answers your question.
This should also confirm your initial suspicions as to the source of the "shutter" (and how to verify that hypothesis).

viewtopic.php?p=57801#p57801


There have been many threads in past years about this, but this one was easy for me to find because I was involved in it. .

Hope this helps.....

Yes, it's the A/C compressor that does this. Mine does the same, as I suspect most do. It's normally very subtle but can, however, be quite noticeable when cruising at the lower end of the 5th gear range. Like CHessMaster points out A/C off doesn't necessarily mean that the compressor is off.

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