Car vibrating - terribly at highway speeds

[emilfred]

Hi ,

I have a 2001 Honda Accord EX 4DR sedan, 4 cyl.
I been having this problem with this vibration at above 50mph - the whole car literally starts vibrating and when i'm going uphill its pretty worse .... and it happens only at above 50mph and in 5th gear....

When i asked the prev owner (a frnd of mine) he laughed and said it was tyre rotation problem.
Then at 90K miles service i asked the dealership to look into it and they told me the same and did a tyre rotation and balancing ...
The problem still persists ....
Now at the 93K oil change i asked them again and they are telling me that it is a problem with the front axles being worn out ....

I'm a little bit confused on how they 'found' this out the second time...
Also i'm not really sure if they are just sayin this to get some money out of me....

If anyone had similar experience or knows something about this ... pls help me out ...
Thanks
Emil

[EyesofFreedom]

I can be several things...

A broken chord or belt on a tire...

A loose or damaged ball joint...

Severe alignment issues...

Frame has been comprimised from a wreck...

CV Axles can cause an up down bouncing vibration...

[06RSXSiVTEC]

I had the same problem in my 94 Prelude. When I looked into it I noticed that my CV Axles were worn pretty bad. That is what I would look into first on your car.

[EFR]

take your car back to the dealer and ask for a phase match and balance. if the vibration is only at certain speeds it is a tire problem and not the other things listed above. if the vibration happens at all speeds then it could be anything listed above. phase matching measures the heavy spot of the rim and tire. you match the heavy spot of the tire with the light spot of the wheel, usualy where the valve stem is. if you if have a car, not truck or suv, any tire with more than 20 pounds of road force will cause a vibration to start around highway speeds. if you have a tire with high road force and do not want to replace it have it put on the right rear, pasenger side. that is the furthest away from the drive and you will not feel it as bad.

[BradRedman]

not sure if the issue is cured, but another thing this could be is a flat spot on the tire

[1BadBoy]

I have something that I would describe as similar. But with some distinct differences. About 15 months ago or so I noticed a very pronounced "miss" (at least that's what I thought at the time) while going up a hill. However, it would come and go - mostly go. Lately, for the last couple of months, it has gotten so that it occurs much more often than not.

The strange thing I realized today, after doing a complete tuneup, including timing and measuring the compression on all cylinders, and then having the fuel injectors cleaned last week, is that the "miss" seems to increase in rhythm as the car speed increases. It made me wonder tonight if it could be something mechanical. Such as possibly the drive shafts or something in the engine/transmission area. The car runs smooth at idle and when going down the road at a steady speed - at least if not accelerating. But if I start to press the gas or have to climb a hill, the "miss" gets noticeable. It can get really bad if the hill is big enough.

Does anyone have any thoughts about what could cause this?

[BradRedman]

from the sound of that it seems as if youa re getting to much fuel somewhere on the fuel curve. Do you have any modifications at all on your computer? also it could possibly be a sensor going bad such as an o2 or perhaps a maf which if they are going bad and not bad yet that could be the problem.... on the intake side pull off all sensors and do a thorough cleaning of them and see if that changes anything

[EyesofFreedom]

You are on the right track...it is a fuel issue. When you place the motor under strain...acceleration or hill climing...it stumbles like it doesnt want to take the fuel. You said you had a complete tune up. I am guessing the plugs were changed...have you checked for faulty plug wires and the output of the coil(s)?

[1BadBoy]

Thanks for the quick responses. I did do a complete tune-up including the following items:

> Plugs (Bosch Plus-4; I know, many don't like these plugs :-)
> Plug wires
> Cap
> Rotor
> Fuel Filter
> Fuel Injectors cleaned (not replaced)

I even performed a compression test. Highest pressure was 138lbs with the lowest at 126lbs. The 2 in the middle were at 130lbs and 134lbs. None were too far off and all within what appears to be an acceptable range.

I bought the car new, and have not made any modifications beyond stock part replacements. I have only done maintenance items as needed. I am not sure where the sensors are to which you are referring. Are there any photos online somewhere?

I will be ordering a new coil and igniter this week. I need to pull the current igniter off to ensure I get the correct part as directed by the local Honda dealerships.

If it's a fuel issue, do you have any suggestions as to what I should look for?

The manual says to perform a fuel "pressure" test, though I would need to pickup a fuel pressure gauge. But on the 1990 Accord EX, the fuel rail has a screw that is easily accessed which can be removed to attach the pressure gauge.

Is there any other item related to the fuel system that I could/should be looking at?

Thanks,
Dave

[EyesofFreedom]

the only other things in the system would be the fuel pressure regulator and the air flow sensor...