Truck Shaking At Just Below 1000rpm

strafingmoose · February 21, 2008

Hi there!

So like the title says, my truck shakes when it gets at around 1000rpm (just a notch below). In park, acceleration, deceleration, it'll do it.

What is it? The engine, the tranny ? Any ideas appreciated.

mkoronka · February 21, 2008

Hi there!

So like the title says, my truck shakes when it gets at around 1000rpm (just a notch below). In park, acceleration, deceleration, it'll do it.

What is it? The engine, the tranny ? Any ideas appreciated.

There could be a number of things causing this, a clogged fuel filter, if the fuel system is csfi it could be an injector leaking or mis-firing. there could be vacuum leaks causing this as well. Also a plugged PCV valve, leaking haed gasket, a fault in the electrical wiring, or bad plugs. I would check the vacuum lines first. Then change the fuel filter and air filter if it has been a while. I personally change the fuel filter every year and a lot of crud comes out of it when I do. The PCV valve should rattle when you shake it, If not. Clean it with Carb cleaner and re-install it.

I had a ford that done this and I finally found a cracked vacuum line causing this.

Let me know if any of this helps. My e-mail [email protected]

strafingmoose · February 21, 2008

Well, I had a optimum inspection (at a GM dealer) done on the truck before I bought it and it didn't mention problems with injections or the head gasket.

I'm having all the filters replaced soon, we'll see.

Thanks for your help

mkoronka · February 22, 2008

Well, I had a optimum inspection (at a GM dealer) done on the truck before I bought it and it didn't mention problems with injections or the head gasket.

I'm having all the filters replaced soon, we'll see.

Thanks for your help

I was just checking to see if anyone else had any ideas. I hope that you have a trust worthy GM dealer because the one I have in Bakersfield, CA. Motor City does not do very good maintenance. I should say that they have good technicians when it comes to real engine and transmission work, But, When it comes to doing routine maintenance they let some tech that has no pride in his work and I used to have my GMC jimmy and Pontiac transport serviced there and every time I had to return to have them fix a leak and top off the radiator when it was flushed. They never would get it right and after paying $80 per hour I figured they should fix their mess ups.

I have not let them touch my vehicles since 2001 and they are both in great condition.

I have read that many people have had major problems with GM products. I have must be the exception, because My GM products work great and are a pleasure to drive. I do regular maintenance and do not follow some of those five year recommendations such as coolant changes. I flush and refill every two years regardless. It has served me well over my lifetime and have never had an overheating problem since I started driving in 1977.

I just recalled that in 2001 My GMC Jimmy"s engine would shake and run really rough. Although it showed a trouble code, I had to replace the fuel filter, But, There was a also a problem with the fuel rail that GM repaired under a recall. I do not remember if the two things were related.

Have a nice day and I will check back some other time. M Koronka