I have a 2008 tahoe with a v8 flex fuel engine and it started with a hard idle and then the check engine light came on and the service traction and stabilitrak lights also came on. I have tuned up the truck and changed the Throttle body unit. the check engine turned off and so did the other service lights and now when i drive it is ok but at a stop light or while in park it starts to idle hard and the oil pressure drops it has only been 1500 miles since my last oil change. when in park as soon as i pick up the Rpm to above 1500 it appears to be ok. Please help as I am running out of ideas and money.I forgot to mention the check engine light alond with the service message come on again only when the oil pressure drops.

 

Hey leezerrato,

I'm sorry to hear of this concern with your Tahoe. Please feel free to send us a private message referencing your concern if you would like for us to take a further look into this. In the message please include your full contact information, dealership name, VIN, and current mileage in the message. We will be glad to help!

Kristen A.
Chevrolet Customer Care

 

Who changed the throttle body for you? Not totally sure about this, but sounds like the engine is possibly learning the new idle associated with a brand new throttle body. The dealer has a programmer that will take care of this for you. Or the car will eventually learn the new idle itself after driving it for some time, how long you might ask, it will vary drastically, assuming the learning idle is the issue.

When I cleaned the gunk out of my TB, I had idle issues which was to be expected, and I barely touched/moved the throttle plate, and I had idle issues until the car relearned the new idle. Had to drive a few hundred miles before the idle went back to normal. Good luck!

EDIT: sounds like there may more than one issue here.

 

leezerrato Welcome to the forum...
Post the codes if you can... the low oil pressure is probably one of them...that needs to be addressed soon... it could be as simple as a plugged screen or defective sensor or it could be a bigger problem...

I agree with Typerod on the throttle body, it will for sure run differently for a period of time until the TB "learns"

 

Thank you all as for the TB I changed that out with a new one thatstated I did not have to relean and the code that keeps coming out is P0300 which is a multiple misfire as I took it to go threw a more detailed computer scan 2 and 8 have a fail i switched the plugs and wires with new ones and still the same thing, I then switched the coils around and the same cylinders still fail no matter what coils or plugs I put in them. I have been advised may be my Fuel injectors as no other codes are coming out on the diagnostics. What do you guys think ?

 

you might try a compression check so that you know all cylinders are getting about the same compression...
Its possible you have a tank of bad fuel, might try a couple of bottles of fuel additive and fresh gas from a different station....
these are good places to start before throwing money at parts

 

I have visited several mechanics already and only 2 say it may be my fuel injectors as the same 2 cylinders are still showing there is something wrong the cose is for mutiple misfires but the hard idle seems to be a common thing with chevys any real fix that have worked.