Hi,
my 2002 4dr 4wd blazer drives fine but when i hit the gas to take over another car and it hits the 4000 rpm the car starts shaking, shivering.
When i let off the gas and the revs go below 4000 all is fine again.
I think it comes from the engine but it can also be the tranny.
It doesn't matter if i'm driving 50 km/h or 130 km/h therefore i think it's in the engine and not the trans.
Does anybody have any idea on where to look at first?
thanks in advance.

 

Have you checked the engine mounts, u-joints, and driveshaft?

 

Try KISS first front tire balance

 

I don't think it's tire balance because it is not speed related. I'll check the engine mounts, thank you.

 

If you put it in a lower gear it still does it at 4 grand?

 

Yes, also in kickdown and in neutral.
I'm thinking, is there a harmonic balancer on the 2002 4.3 vortec engine?
And if so, is it hard to replace?