I've got a shaky ride...

[whimperingcat]

I have a 98 Explorer. My check engine light came on and was still driving fine so I didn't go to Auto Zone to get it diagnosed until the next day. When I started it up to leave it was shaking insanely bad. As I was driving I couldn't go over 30 or it would shake even worse. Auto Zone told me it was the mass air flow sensor. Bought the part, put it on, but it made no difference. I'm afraid to drive it any more in fear of the shaking damaging the engine. I'm a freelance photographer and I need the Explorer to haul all my gear, so any help with this will be greatly appreciated! THANKS!!!

 

[MonsterTruck460]

Is the shaking coming from the motor? i.e. firing on all cylinders?

 

[whimperingcat]

Yes, it shakes while idle too, just nowhere near as bad as when I start driving.

 

[whimperingcat]

Before this started it was a very smooth ride, no problems at all.

 

[MonsterTruck460]

has it had a tune-up lately? Plugs and wires?

 

[whimperingcat]

I planned on doing that next month. I've had a car in the past that had an oil leak that caused my spark plugs to foul out every few months, but it never shook like this. I don't even really know what to compare it to. It's just really bad. lol

 

[yavapaires]

Check the coolant level? Not just the reservoir, but the radiator too. You could be getting coolant in at least one cylinder, causing a miss. That could cause a plug to misfire. What codes didthey giveyou?

 

[whimperingcat]

They didn't give me the codes, they just said the only code showing was the mass air flow sensor. Do you think a bad plug would cause the car to shake? Its a pretty violent shake... kinda like driving over a really rough terrain but it feels like the engine is being shook to death. lol

 

[emac2001]

i would do a full tune. could be wires/plugs, maybe even a fuel system problem.

 

[gavin]

They didn't give me the codes, they just said the only code showing was the mass air flow sensor. Do you think a bad plug would cause the car to shake? Its a pretty violent shake... kinda like driving over a really rough terrain but it feels like the engine is being shook to death. lol

never trust what a retail employee tells you.
this is why most of those auto parts stores will no longer scan vehicles for free; because they tell the customer "what's wrong" when it's incorrect.

is your CEL blinking, or on solid?
If it's a constant mis-fire, the CEL would blink (at least, in my experience the CEL blinks when a cyclinder is mis-firing)

otherwise, we would need to know what the code is to even begin to think of what it could be.

Trying to troublehoot with no more info than you've provided is like shooting in the dark.

FWIW, when I had a spark plug blow out on me (ceramic blew out of the metal part), it was a rough shake that got worse with higher RPMs.
lots of funny looks driving through town with 1 cylinder missing a spark plug

 

[sport97]

Check all the plugs and wires to be sure they are all hooked up and in. Go back and get the actual code. Having the code will assist you in looking it up/ us with diagnosing it.

If it's a constant mis-fire, the CEL would blink (at least, in my experience the CEL blinks when a cyclinder is mis-firing)

My parent's olds bravada has pretty low compression on the number 1 cylinder, and 75% of the time we have a CEL, its for a misfire and it does not blink, so this must not always be the case. It runs like trash at idle but smooths out when running, although you can tell its wayyy down on power.

 

[gavin]

Check all the plugs and wires to be sure they are all hooked up and in. Go back and get the actual code. Having the code will assist you in looking it up/ us with diagnosing it.



My parent's olds bravada has pretty low compression on the number 1 cylinder, and 75% of the time we have a CEL, its for a misfire and it does not blink, so this must not always be the case. It runs like trash at idle but smooths out when running, although you can tell its wayyy down on power.

interesting.
my parent's 2000 Chevy Blazer, when it was mis-firing really bad, would have a blinking CEL with the mis-fire, also. Even my sister's 2001 Silverado did the same thing.
Must be more to it, then... but I do know a blinking CEL is related to a mis-fire, apparently under a certain condition.

 

[whimperingcat]

Sorry it's taken me so long to get back to you guys. My car is still shaking, but I have a much better idea of what's going on. Based on a hunch from a friend, I replaced the coil pack. This hasn't eliminated the shake entirely, but it made a dramatic difference. I can speed up without hesitation. The problem now is that once I get up to speed (about 45mph) it begins to shake again. I do have new plugs and wires that I'm about to put in and I'm hoping that this will repair the problem (based on what you all have said here, I'm thinking it will). I drove it after I replaced the coil pack and I went about 3 miles before I came up on a hill (I live in TN), and when I started up it the shaking got worse and the CEL started flashing, which prompted me to turn around, which caused the flashing to stop and the light to go back to being steady. Then it drove just fine the whole way home... no shaking at all even after I got up to 55mph. I went ahead and parked it again though because I'm just too paranoid about messing it up. Repairing it has been a real dance with time and money. Again, thank you everyone for your help.