Engine trembling at red lights, highbeams/defroster works on and off

[sbouillot]

Good morning all,
First post here.
I just got a 2008 Mazda 3 with 73k on it from a private seller.

A few issues I've noticed in the last days I have had it.

When at a red light, my vehicle kind of shudders/feels like air is entering the system? Starts after 5 seconds and then shudders for 3 seconds .. and again until I go. RPMS do not move at this point whilst it is doing this (Had on 02 gone on another car,it was a similar feeling)

Also, I noticed, sometimes my high beams work, some times they do not along with my rear defroster...I run the vehicle, drive it to work.. turn it off and on again and then these seem to work...

Any idea what these issues could be?


Thanks..

[morganc]

I'd start by going through and checking all of your fuses and battery connections for signs of corrosion. Clean anything that needs it.

[JonsMazda]

Try cleaning the throttlebody, CAI and MAF Sensors. Check all connectors for loose connections. Try doing an ECU restart by pulling battery connectors.

[dont_panic]

With regard to the shuddering at stoplights, have a look at the passenger side motor mount. When this goes, it usually presents itself as vibration at stoplights. You might see oil that's leaked out of the mount.
I just got an 08 with the same issue - changed the mount and no more vibration.