rmf2

All the scan tool told me was a p0300 random/multiple misfires. I was thinking the same thing. Is there a scanner that would give me more information, or is this a time for me to punt and take it into the dealer?

Yes, I have been assuming it was the intake, I do now own, nor do I know anyone one local with a better scanner than what I can get codes scanned at the parts store.

Listing the changes that were made, over the weekend.

1) removed intake/alternator/exhaust manifolds/ and cylinder heads
2) installed new/rebuilt heads (older style) using fiber head (felpro) head gaskets - torqued down to 22 lbs/ then 90 then 70 degrees in sequence - upper bolts torqued to 22 lbs
3)installed new spark plugs and wires
4)re-installed manifolds to heads with new gm exhaust gaskets
5) re-installed the hoses and alternator
6) re-installed the intake with new GM gaskets (teal colored) - did not torque them down in the correct sequence or to the right lbs since my torque wrench only went down to 10.

Monday (was idling rough) - loosened the intake again and re-torqued to 10lbs in correct sequence. No SES light

Tuesday ran much worse, - major rough idle, SES light on, flashing SES on acceleration - scanned computer at parts store only 2 codes p0300 for both, one was pending.
used carb cleaner and when i sprayed around the intake it would sound like a snaping sound, almost like liquid being pulled through a straw and draing air.

1) Removed the intake completely, noticed I had not cleaned the intake well
2) cleaned the intake, gaskets, and head intake surfaces
3) re-installed gaskets to the intake
4) re-installed intake - setting it straight down on the surfaces
5) torqued all 10 bolts to 44 in/lbs in sequence and then to 89 in/lbs
6) re-connected injectors, MAP, EVAP, coil pack leads, PCV, passenger valve cover hose, knock sensor connector, EVAP hose, fuel line, (everything I had removed)
7) started truck seemed to run smoother, spray carb cleaner around passenger side and was still getting a slight snapping type sound but not nearly as much as before, after a while that even stopped, thought gaskets must have warmed and seated better.

Wednesday, drove to work, didn't notice much of an issue on the way to work 17 miles, no rough idle when at stop lights.

Went to lunch after the truck started to warm it started to idle roughly and and SES light started to flash again during accelerations.

Sorry so long, that is where I am today.

I do have a set of felpro green intake gaskets I could put on, would these be any better? could I have a bad set of intake gaskets from the dealer, and they are just not sealing well?

I am at a loss and any help is appreciated.

bullygoat

Have you checked your plugs and wires? I haven't seen where you said you did and that could cause the problems you're having. Were these heads worked at all? You really can't screw up these intake gaskets unless they aren't on the intake correctly.

rmf2

I checked the wires, to ensure they were installed correctly and tightly. The plugs are new as well as the wires.

I also check to make sure the wires were not hitting on the manifold and burning.

I have not pulled the plugs since I had just installed them.

Removing the wires to check them again will not be all that bad, except for the rear passenger side, since it is pointing towards the firewall and the AC parts that are back there in the way. I know when removing the old wires it was a pain and since I was not concerned about wires being damaged, or the heads, since I was replacing them, I just pulled the wire off by the wire.

Also with a plug wire issue I would think it would register to a specific cylinder, unless i had multiple cylinders not right.

The replacement plugs and wires were both AC-Delco plugs were the 41-110 iridium and the wires 9748hh for the non-delphi coils.

bullygoat

GM vehicles rarely set individual cylinder misfire codes. I think your next step is find someone local with a scanner and buy him a case of beer or take it to the dealer. It's hard to diagnose a misfire when you don't know where it is.

rmf2

Ok thank you, guess it is time to punt and call the dealer.

thank you everyone.

rmf2

One thing I will ask, should I remove the heat shields from the sprak plug wires? I moved them over from the original wires to the new wires. Could these be causing a problem ?

Just thought I would ask

hog

If it still sounds like its sucking starting fluid into the intake while its running, thats your issue right there.

If you dis-assemble again, place a straightedge over 2-3 ports of the intake at a time and check for straightness, heads as well.

Somethings not sealing if you hear fluid being ingested. You can accomplish teh same thing with a stream of acetylene from a torch. You are looking for changes in idle/engine running as you pass the gas/fluid around the intake ports.

peace
Hog

rmf2

Dropped it off at the dealer tonight and the mechanic put a tech 2 on and checked it, it is giving a miss on cylinder 5, and a few on cylinder 4. They are going look at it tomorrow and see if they can tell me what they find.

The heads were checked by the machine shop prior to installation and were straight and true I was told, not issue found in the physical inspection, I was having them checked since they had been shipped to me.

They had been rebuilt but not used.

Lets hope for good news.

Rich

01Blackerado

iTrader: (4)

Is it possible you put the head gasket on upside down!? If you did there will be a small opening that will allow coolant to flow into the piston. If youre positive everything else is good to go then try checking the head gasket placement!

rmf2

I am quite sure they are oriented the correct way, the word front is on the top and pointed towards the front on both sides. I used felpro 9292 pt gaskets since I had 862 heads with the recess to install.

Thank you for the idea.