The Nissan Path

As title states but it only happens when the truck has been driving for a while and then you come to a stop. Once at a stop and the engine is at idle with the a/c on there is such a drop in rpm's when the compressor cuts on that it causes the engine to knock and almost shake and vibrate the truck, almost violently.

It just started this, worries me of course. Any suggestions? Be back later this afternoon...

Mine gets pretty lumpy, especially when the compressor is working hard on a hot day. It's not abnormal...

Thanks Ship, mine was not as bad today when we took the 3 year old through the drive through at Wendys. Actually it never made a rumble at all.

Who knows, i was just thinking maybe it was like an idle air sensor or a knock sensor or something like that failing.

You might want to check the serpentine tensioner.

smj999smj wrote:You might want to check the serpentine tensioner.

Tensioner and belt replaced with Nissan OEM parts about 500 miles ago...

Air blows cold as it possibly could, actually the coldest air conditioner i have ever felt but what about the compressor going bad?

It's possible. If you can duplicate the noise, a mechanic's stethoscope can be used to try and pinpoint the source of the noise.

smj999smj wrote:It's possible. If you can duplicate the noise, a mechanic's stethoscope can be used to try and pinpoint the source of the noise.

If you don't have a mechanic's stethoscope, you can use a screw driver. The noise will travel up the blade of the screw driver.

Think i have figured it out, the exhaust, (somewhere) is giving me this fierce vibration. Will look under the Path son to se if anything looks loos and then maybe add some exhaust weights here and there...

Any other suggestions...

Bumping for more suggestions, when this does hapen the RPM's do drop a hair, i mean like 50 or so but not enough to be abnormal. What could it be. Still need to look at the exhaust piping as i fell it's whats rattling...

Happens with me as well, seems to me normal. Actually when mine cycles my voltage gauge drops a little.

Check your engine mounts too...

Same thing happens to me. When the a/c kicks on, you can tell. It seems its a strain on the engine even the battery gauge moves. I was thinking mounts too.