Problem with Vibration

Hi there, body vibration is usually a result of a rear end problem, worn suspension, tyres and rims, i would have this inspected first.

mark (mhpautos)

I have a 2003 Kia Optima with a 2.4L engine. I picked up a high frequency engine vibration that can be felt in the hood and right fender at idle and in the steering wheel at all driving speeds. I replaced both belts (no defects noted) and checked all the accessory pulleys & bearings for roughness or play. Everything normal except water pump makes a noise - if you're a deer hunter, it sounds like a doe bleating! No problems with engine temp though. What next?

Water pump noise means the bearing is going out. Replace it soon.

Two person job: With the hood up and one person standing to the side of the vehicle, have the other person put the car in gear while holding the brake firmly and with the parking brake engaged. Person in the driver's seat gives the engine a little throttle. Observe the engine for jumping or movement.

Check the engine for vacuum leaks and verify the proper ignition timing. A good quality fuel injector cleaner might also be a good idea.

Thanks, I was afraid you'd say that. The water pump looks like a pain to change! I'll check the other items also though I haven't noticed any performance or mileage changes.

See image.
2.4L 4-CYLINDER ENGINE -2003 Kia Optima SE
Page 1 of 2
ENGINE COOLANT PUMP
REMOVAL

Drain the coolant and disconnect the radiator outlet hose and engine coolant by-pass hose from the engine coolant pump.
Remove the drive belt and engine coolant pump pulley. Remove the timing belt covers and the timing belt tensioner.
Remove the engine coolant pump mounting bolts and then remove the alternator brace. Remove the engine coolant pump assembly from the cylinder block.


Install the timing belt tensioner and timing belt. Adjust the timing belt tension, and then install the timing belt covers.
Install the engine coolant pump pulley and drive belt, and then adjust the belt tension. Refill the coolant.
7. Run the engine and check for leaks.

I'm feeling a vibration/ rocky sensation from the engine througout the car. It idles perfectly and is not missing. Just a steady rough feeling from the engine

With that many miles, I suspect your engine mounts are worn/broken. Check them, you should have 3 engine and 1 transmission mounts.

Hello, my engine only vibrates when in "drive" when i'm in park, reverse, or neutral there is no vibration. i was wondering what could be the cause of this sort of thing. thank you for your answers.

Hi there, Have you checked the engine mounts, always start looking at the simple things first.

Mark (mhpautos)

I recently had a rear motor mount replacement but not the front. How do i check to see if that's the problem? is buying a new one the only way?

alright so i bought a 2002 Kia Optima 2.4L for cheap cause it was broke, the timing belt broke and all valves got bent, so i installed reman. head and timing belts, everything is timed perfect including balance shaft, got a tune up, oil change, new cmp sensor but still when all back together, starts for ab 3 seconds, vibrates excessively (like a electric toothbrush on steroids) then dies every time even with map sensor, maf sensor or cmp sensor unplugged (1 at a time) im pretty sure its throwin a code, will have it scanned tomoro......any ideas of what i need to check

also when i got the car, the three wires that plug into the cmp (camshaft position) sensor are wired directly, idk what order they need to be in and the engine balancer shaft belt was missing, so either someone already looked took it out of someone left it out a while back, if the shaft was somehow messed up and causing vibration, what would leaving the balance shaft belt off do?

You will have to clear all codes and do a re start and report what fresh codes are set.

The attached diagram shows the wiring circuit. Hope it is helpful.

thank you for the diagram!
is the crankshaft position sensor more important than the camshaft position sensor?

Both are equally important as each has its own own duties.

ok, scanned it, codes p0340 (CMP sensor bank 1) and p0118 (coolant temp high output) were on there twice, which makes since to why both radiator fans come on as soon as its started and the wiring is wrong on the CMP sensor, well i cleared them and started the car and they came back, but just the cmp sensor not working wouldnt make the motor vibrate so bad that the engine basicly knows to shut off, when it starts for the 3 seconds i can gas it to get the rpms up to ab 4k before it shuts off again

does anyone know what order the wires to the CMP sensor need to be in from top to bottom, theres a black ground wire, a black signal wire with a few dashes on it, and a pinkish hot wire

ive done some research and now im pretty sure its the front balance shaft that is drivin off the oil pump pulley, it can be 180 degrees off and still register as being in time

The faulty CMP would cause difficult starting and erratic idling and stalling.

The above wiring diagram shows the order of the CMP wires.

ok but even leaving all the wires unplugged from the CMP sensor, the car starts and does the same thing

thanks for the diagram again

That is akin to having a faulty CMP which would cause stalling after 3 seconds.

lol ok well thank you for all your information, i have learned alot

ok so i timed the car myself and it starts and runs/sounds awesome and smoothly so the other guy got the front balance shaft 180 degrees out of time but it still dies after a few seconds, i gues il replace the CKP sensor next since the CMP sensor is new and i wired it as the diagrams say to

Is the Check Engine Light indicating?

yes still for the CMP sensor code, the ECT sensor code is gone because i found that i had forgot to plug the ECT sensor in when replacing the head, also the fuel pump didnt seem to be working recently, i found that theres no power at the connector for the pump, only for the fuel level sensor, the relay clicks once and hums for a few seconds when key is turned on, i can jumper a wire at the relay connection and get power to the pump

im not really woried about the fuel pump relay right now, i think mayb that system will work when i get the CKP sensor but if not, il go from there, im goin to be running out of things to replace haha

The fuel pump would only work for a few seconds when ignition is turned on and fuel pump would not get constant unless the engine is running or while craking.

If the code is still for the CMP, you have not resolved the problem of the sensor yet. It could be the wirings or a faulty CMP/PCM.

well would the CKP sensor throw the same code mayb, ive heard of that, and i know but it doesnt even prime the fuel pump

Priming of the fuel pump is not done by the sensors. The ECU controls that.

ya but if the ECU knows theres a posistioning or ignition problem, mayb it would cut off the fuel, im just tryin to learn lol

For initial priming the ECU does not rely on any sensors. It is triggerred by power supply. Only when cranking or engine is started does the sensors come into play.

ok so the fuel pump wont prime but will turn on when the engine is cranking and running for the 3-4 seconds and i replaced the crankshaft pos sensor today and nothing changed.....stupid Kias

You need to resolve the problem of the CMP troule codes first. It could be the wirings or a faulty ECU.

omg omg, the car runs! i took the new cmp sensor out and was checking ohms on it and got nothing and i had the old one to test also and noticed on the old one, there was resistance between the 2 outer prongs so i put it in and tried different combinations of the wiring and found the rite one, red wire top, ground wire middle, and signal wire bottom. I bought a BAD new sensor, thank you for all your help KHLow

You're welcome. Glad to know you have fixed the problem.

Have a nice day.

well when driving the car, the power would cut in and out, the next day it got much worse, cruising down the highway, it would cut out then completely stall so i would coast to a stop then try to start it a few times until it started and ran fine and would happen about every 2 miles, i cleaned the maf sensor with the maf cleaner and completely fixed the problem.... i hope this whole form helps kia owners haha

nvm the same problems happen after something is getting too hot i guess, after driving the car at operating temp for a while, the symptoms start and get worse

Is the MIL still coming on and same trouble codes?

If not, check the Engine Coolant Temperature sensor.