2003 Silverado Shake Or Shutter

dakotaSioux · June 4, 2011

2003 Silverado Z71 4x4

80k Miles

My brother-in-law (mechanic) sold this truck to me a couple months ago and it has ran nice during that time. He did a big tune up before giving em the truck including tranny flush and whatever else in included in 100k maintenance. Anyway... truck shakes a tiny bit at idle. When you put it in drive it you can noticeably feel it shake. It does seem to smooth the faster you go. I hooked my scanner up and received 4 codes. The service engine light is on.

p0300

p0449

p0455

p0300

So far I have only cleaned the throttle body. Not sure where to go from here. Advice would be appreciated, after googling all afternoon I'm under the impression it could be a host of things including spark plugs (brother put in brand new ones before he gave it to me) MAF sensor (which I think cleaning this might be my next step).

Update: I disconnected the MAF sensor and it seems to run a bit better once moving (could be my imagination) but still shakes as soon as its put into gear.

Any ideas?

desrtrat · June 5, 2011

you need to fix the evap codes first, and see if the idle improves.

hockeypro1411 · June 5, 2011

Cleaning the MAF is a cheap and easy way to start troubleshooting. Next you can pull the plug wires off of each coil to check for spark. Both easy and low/no cost.

dakotaSioux · June 5, 2011

Cleaning the MAF is a cheap and easy way to start troubleshooting. Next you can pull the plug wires off of each coil to check for spark. Both easy and low/no cost.

I will try this in the morning, thanks.

dakotaSioux · June 5, 2011

I hooked my scanner up again this morning for giggles and now I'm only getting

p0300 Misfire

p0449 Fuel Evap Solenoid

I also have 2 gas/moisture leaks at the seals coming from the ends of the cat converter. I assume this means the mixture is too rich which could be why my exhaust smells quite potent. I now think the o2 sensors need to be changed.

Bob D · June 5, 2011

p0300 (random misfire) could be many things.

Did the 100k tuneup include wires, distributor cap, rotor?

I wouldn't worry too much about the p0449 code until other issue is resolved.

It should not affect driveability.

hockeypro1411 · June 5, 2011

p0300 (random misfire) could be many things.
Did the 100k tuneup include wires, distributor cap, rotor?

I wouldn't worry too much about the p0449 code until other issue is resolved.

It should not affect driveability.

I do believe the only motor that still had a distributor in 2003 was the 4.3l V6. I guess I assumed it was a 4.8 or 5.3.

But yes, a dead cylinder will cause the exhaust to smell really rich.

Bob D · June 5, 2011

..I do believe the only motor that still had a distributor in 2003 was the 4.3l V6...

I think dizzies were on all V8s through '06.

Do correct me if mistaken.

txab · June 6, 2011

..I do believe the only motor that still had a distributor in 2003 was the 4.3l V6...

I think dizzies were on all V8s through '06.

Do correct me if mistaken.

You are mistaken. Switch was earlier than '06

dakotaSioux · June 6, 2011

I checked MAF sensor and it was fine. I took it into a local shop since I hurt my back and was beginning to get frustrated. The culprit? E3 spark plugs. Shop owner said he's seen this quite a few times and that a lot of the big block engines do not like the E3 and to use only the OEM plugs Ac Delco Platinums is what he recommended. He only charged me $60 which was great. He switched one plug out for me and replaced it with an OEM and it's running like a champ. I'll be going to purchase the rest in a few minutes. I don't feel too bad about replacing the O2 sensors since it was a good learning experience. I notified my brother in law and he was surprised to hear about this problem. The shop owner also checked the p0449 code and verified it was the solenoid evap so that will be my next project in the coming weeks. Thanks for all the help, appreciated. The shop is South Point Auto Repair in Fargo, ND. Hard to find good honest service but these guys are top notch.

hockeypro1411 · June 7, 2011

..I do believe the only motor that still had a distributor in 2003 was the 4.3l V6...

I think dizzies were on all V8s through '06.

Do correct me if mistaken.

The switch was MUCH earlier than 2006. Had to be at least pre-2001 because I know of more than a few 2001 5.3's with individual coil packs. I'll have to look into exactly when the switch was made..