Not An H3 Prob, Please Help!

[marin8703]

Hey everyone, this isnt about my H3 its about my dad's Chevy Express Cargo Van. He told me to ask you guys about this problem, cauze you have turned out to be a knowledgeble bunch of people.

anyways here it is. the van drives just fine most of the time. Its just once in a while when its been moving and you stop at a red light or something it kina jerks forward slightly. This doesnt happen as you stop but after you have stopped, maybe after 30 seconds, a minute or even more.

The chevy techs at the dealer dont have an answer, and i dont blame them since they cant recreate the problem, it happens very rarely. I have felt it too, so its not just in my dad's head.

Do any of you know what that could be? I and my dad would greatly appreciate any help with this issue. And sorry for posting this on this forum, but I was unable to find a chevy express forum, and i tought you guys would probably know.

Thanks!

[Beastmaster]

Which Engine and transmission?

[marin8703]

the truck is a 2004. The engine is a Vortec 4.3L V6. Im not sure about the transmission, this is what it sais

"1500 and 2500HD Extended Wheelbase: four-speed electronic automatic with overdrive (4L60-E) (for less than 8,600-lb. GVWR1)"
and it also sais this RPO: M30.
heres a link if you wana take a look http://www.chevrolet.com/express/specifications/ and then sellect the transmission tab.

Thanks for any help. The dealer said he doesnt know what it could be, but he is certain its normal. I dont know how he can say its normal if he doesnt know what it is.

We're gona purchase an extended warranty from Gm in the next couple of days, cauze the bumper to bumper will expire in january, and we just want to play it safe for at least 20k -30k more miles.

Thanks for any help you can offer!

[marin8703]

anyone know anything about this?

[fourfourto]

I would start simple.

#1 Clean flap in air intake with fuel injector cleaner(dont use carb cleaner)follow directions on can.(this is a maintanance thing it couldnt hurt)

#2 make sure high idle controll for a/c isnt on all the time.
to check run car turn a/c on look at tach ,rpm's should go up.
turn air off rpm's should go down.
If it does nothing it could be stuck on? Easy to check and couldnt hurt.

#3 check linkage on gas peddle and under hood at throtle body,clean with fuel injection cleaner and Lube with spray couldnt hurt maitanance thing.
Also check your throttle cable at the same time and lube if posible.

#4 Could be trans ? check with a mechanic

#5 lift up battery and slip another van under it

Good luck

[Wisha Haddan H3]

This may be a completely different thing, but in other vehicles with an auto tranny, I've noticed a slight lurch when stopped as the A/C turns off. I guess enough torque is released to briefly overcome the brakes. The 4.3L has a lot of torque ... about 250 ft-lbs, so maybe that's it

[marin8703]

hey thanks guys, ill do some of those maintenance things just in case. Ill check out if it happens in relation to the ac. that might actually be it.

thanks!