97 Suburban Vibration

[Jeff V]

I have a 1997 suburban 5.7, at speeds over 55 when climbing a hill I get a vibration, somtimes it will set a code but most time not. After reading many posts I know this is not a uncommon problem, the solution seems to be elusive. Let me list the repairs I have made over the past year hopfully someone will pass me the magic bullit to finally fix this thing. Egr valve, Intake manifold gaskets, plugs, cap, rotor, wires, 4 O2 sensors, fuel pump not to sure about the filter, it was done at the dealership so I assume so. New spider injector ass'y w/regulator, rebuilt tranny,new U joints I think thats it for the engine. I have also changed the steering box and pump with variable assist thing on the back. The steering is still very hard in tight spots. Is there a vehicle speed sensor that could be affecting both steering and vibration?? I have read about carbon build up? Reflashing the computer?? I am really at a loss please help! FYI. All parts used were AC delco, either dealer installed or ASE approved tech installed. One last point the code I get are the occasional p0300, or p0305. Once each in the last year, and an ever present p0430. I am waiting to get the miss and vibration cleared before I change the cats.

[Jeff V]

Any input on above subject greatly appreciated.

[Fireplug]

What do you mean by a vibration??
Do you mean an engine miss??
Does it only happen going up hills?
Where do you feel the vibration? On the floor , steering wheel, on the seat(on your but) I need to get this info.
What code is set??
If the fuel pressure drops even 3 pounds you will get a engine miss.
To do an easy check remove the fuel filter and see if you can blow in it with out ant blockage if thes is resistance its a bad filter and install a new one.
Let me know if that helps

[Jeff V]

The whole truck shakes, as I said in original post i get a p0300 or p0305 only sometime. Since last post I had computer re flashed with no improvement. After reading some of the previous posts I'm thinking valve job. I'm told GM improved the heads for this engine and do not offer remaned heads. Could this be proof GM knows of this trouble and want to get these heads off the street??

[slowdawg]

is this an engine miss or is it a trany shake. is it at all speeds over 55.

[Jeff V]

Well thats a tough question. Most of the time it would set a code,
p0300.but latly it just shakes. I added Techron to the fuel, changed the fuel filter and put a quart of Marvel Mystry oil to the crank case all this seems to have helped. I will see this weekend as the truck takes a 500 mile run. I will post back after the weekend. Thanks for the interest.

[Houston54]

I am having the same problem with my 99 burb. Another thread here talks about the same problem but does not identify a positive solution.

A code was stored that identified a miss-fire in the #7 cylinder so the truck is at the mechanics today to pin point a solution.

I do not think it is plugs or wires. Some else said it could be the camshaft positioning sensor. Did not even know there was one myself.

I will post another reply to identify what my mech finds out.

[ocjmakaveli]

possible solution here check this out

http://forums.vmag.com/suvsuburban05...ages/1602.html

OR

http://www.atcdg.com/TechBulletins/bull_152.htm

[Alice]

Eeeeks! Girl here who loves her suburbanator, 1995 turbo desiel 4X4. Husband hates it, hates it's transmission, hates it's costly engine. That vibration is apparent in my case also. Always showing up at 90-100 kms, but will go away if you speed. Husband fixed the transmission once already with heavy duty parts. He has been test driving it lately because of another problem, and I'm hearing it about that vibration again. I candy coated it with the thoughts that my tires are wearing. He wants to get rid of it, says it's only a matter of time and he's not willing to put any more money into her. Of course we'd be looking into another suburban. Apparently the safest thing on the road and more than enough power to get the kids to school. Like some of the guys I see here, he likes the older ones. I aint gonna go for that, if I must trade, I'm going newer. Not newest, since I've already experienced that deal with this one, but newer. When did the body style change? Did Chev do any other improvments before that? Where are all the desiels and why do I feel they are rare? Husband wants to go gas engine. Iam I an idiot wanting to hang on to this truck just because I kept it looking good? What should I be shopping for?