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2004 Neon Shakes

I have a 2004 Dodge Neon that I’ve been troubleshoot for awhile now and can’t figure it out. My engine shakes pretty badly and found I had some broken engine mounts on my passenger side. I’ve replaced them and calibrated my struts but the problem persists. I appreciate any advice.

It’s a standard modle with 97,000+ miles

what does “calibrated my struts” mean?

Is the check engine light on?
If it is, please post fault codes
Any obvious vacuum leaks at idle?

Severe service replace spark plugs every 30K

normal service replace spark plugs every 60K

I just looked up your owner’s manual online.

You’re not still on the original plugs, are you?

Yes, I replaced my spark plugs in December, it was the second time I replaced the spark plugs since I owned the car.

I just adjusted the struts to see if that was causing the problem.

No, the engine check light is not on, nor are any other warning light indicators on.

Can you explain what “adjusted struts” is supposed to mean?

Are you talking macpherson struts for the suspension?

As far as I know, struts get replaced, not adjusted.

I’m not sure what the suspension has to do with a vibration at idle.

I feel as if I’m misunderstanding something you said.

The engine mounts. You have to measure them carefully when installing, thus “calibrate”

How about the normal stuff, like plug wires? You can also measure the coil with an ohm meter. Is it shaking during idle? IAC or MAP could need cleaning. I would suspect the temp sensor would throw a code.

I replaced the plug wires the last time I changed plugs, and I did check them again while searching this problem out. It is shaking when idle. I’ll check the IAC (don’t know what MAP stands for though).

I have a question about those engine mounts. Each one on the port side of the car (upper and lower) has a tab bolted to them. I’m trying to figure out what that tab is for or what function it serves.

@Trulyevilbob thanks for the info

For your information engine mounts are called engine mounts

Nearly all people think of MacPherson suspension struts when they hear the word struts

Using the wrong terminology could lead to a misdiagnosis and an angry customer down the road.

Do you have some kind of a shop manual? That might help you with those “tabs”

Yes, haynes manual but either it doesn’t say or I can’t find it in there.

I would also change the O2 sensors if this hasn’t been done. I replaced them for good measure on one of my vehicles when it was running poorly and was amazed at the difference it made in power, performance, and fuel economy. I had a rough, crappy idle like you too and there was never a check engine light. I understand the O2 sensor must be really out of tolerance to throw a code.

Definitely check all the normal tune-up type stuff like plugs, wires, coil or coil packs, cap/rotor (may not have them depending on year), as well as vacuum lines. Spray starter fluid or carb cleaner around the engine bay with it running and see if the engine runs differently. If there is no change, it is likely not a vacuum leak.

MAF/MAS is located in the plastic intake plenum. 2 screws and spray it with cleaner that is safe for sensors. It should be silver colored. Mine was brown and I cleaned it and it idles smooth now.