Engine Light, Vibration, and a thump or bump at 65.

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DEVLISH
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I have a 1996 Chevy Astro AWD Cargo Van with the v6 and an automatic transmission. It has 154,000 miles on it. I just bought it about 3 months ago. I am planning a brake job next month. I just put 4 new tires on. I found out it has 8 inch custom rims. There was a horrible noise when I turn the wheel too far, mostly in reverse. That seems to be gone since I put on a slightly narrower tire. The ABS light has been on since I bought it and I am getting maintainence caught up as soon as I can. (Brakes right after the 1st) It also needs the 150,000 mile cooling fluid change.

Now I have a new problem and I am not sure what is wrong. When I drive it I get a vibration that rattles all the doors and windows. No noises what so ever. I think the engine seems too pause or hesitate with the vibration, but that may be my imagination.

This started on the freeway at 65mph. It felt like a thump on the gas pedal or perhaps like what if feels like when coming down from a hitting a big rock minus the other parts of hitting a rock. Then a few miles down the road it did it again. After that the vibration started at over 50mph. I limped the van home.

The vibration lasts for maybe a minute. Seems like forever but I'm pretty sure its just a few seconds. I don't hear or feel a shft. Not grinding noises, nothing. Now I can't go 10 blocks without that vibration and I occasionally get the thump too. I would really like some idea of what the problem could be before I go take this into the dealer for repair and fluid change.

Also the service engine soon light is coming on and going away, coming on and staying lit for couple start ups then going away again.

Is this all one problem or perhaps 2 or 3 and what could they be? HELP!!!
Nov 29, 2007 at 10:50 AM
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2CARPRO JACK
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If the vibration is an engine misfire then it will set the light. Does it start ok? When it is vibrating, does the steering wheel move or saw back and forth? Wheels tight? Those vans went through idler arms fairly quick. Have the front end inspected, at that mileage, it could very well need a fair amount of work. The check engine light and ABS light, take it to Autozone and have them scan it , they do it for free. Get back with the codes, and we can go from there.
Dec 1, 2007 at 12:25 AM
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DEVLISH
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The steering wheel is neutral. No sawing, no pull, nothing. I can not hear any misfire, and the van starts every time.

I feel the vibration through my seat and foot. I can hear the doors and windows rattle it is so strong.

I'll get to an autozone ASAP.

I have noticed the idle is sounding pretty sick, kind of like something is slipping the last two trips around town since I posted here.

I had the front end inspected at Les Schwab and they replaced the tie rods ends a month ago. Les Schwab just put on 4 new tires including mount and balance. I'll run it up and have them check that everything is tight.

Thank you very much!! I really appreciate the help!
Dec 1, 2007 at 4:29 AM
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DEVLISH
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I guess I was wrong. I am not hearing a misfire but the codes came up as P0340 and P0300. I am scheduling a tune up and having them look at the cam sensor and the timing chain, serpentine belt, or what ever mechanism is used to time the astro. Any thing else I should be aware of?

The timing is finally now off enough to tell it while driving. I'm sure its a tune up or timing issue now. I'm hoping nothing else is wrong.

Thank you for all the help.
Dec 8, 2007 at 11:55 AM
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