1990 1500

Discussion in 'GM Powertrain' started by steps350, Jan 5, 2011.

  1. steps350

    steps350 New Member

    Hey all Just wanted to say Hi , Iam new here my name is Corey, and i live in lethbridge alberta. I just bought a 1990 gmc 1500 4x4 for $750. it runs and drives . Iam just wondering the exhuast is cut off right after the cats and upon cold starts there seems to be a ticking noise coming from the exhuast , once it warms up the ticking gets quieter, I lisened in the engine bay and by the exhuast and iam pretty sure its coming from the exhuast, could cutting it off right after the cats make this noise?
    thanks all in advance
  2. dualdj1

    dualdj1 Rockstar 100 Posts

    could just be lifters ticking. Have you changed oil since you got it? might want to run some system treatment/cleaner though it.
  3. steps350

    steps350 New Member

    ya I just did a whole tune up last night iam goin to check the timming today there seems to be a miss at idle
  4. ejohnson03

    ejohnson03 Epic Member 5+ Years 1000 Posts

    If the Header or Collector gaskets are lstarting to leak, you will also hear some ticking.

    Gaskets are cheap, just replace them and rule out that as an issue.
    1 person likes this.
  5. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Welcome to the club, Corey.
  6. stephan

    stephan Rockstar 4 Years 5000 Posts

    Hey Cory, welcome to the club. X2 on EJs exhaust gaskets repl. since you're hearing the ticking noise at the exhaust
  7. steps350

    steps350 New Member

    hey guys thanks for the info and I love the site, yea long story short I bought the truck off of a farmer that I dont think has ever done any tune ups on the truck, the plugs where beyond fouled same at the dis cap and rotor so iam in the middle of trrying to get it all tuned up, it just seems low on power like when its idling and when you step on it , it seems dosnt seem to be hitting on all the cylinders i have timed it , any suggestions?
  8. stephan

    stephan Rockstar 4 Years 5000 Posts

    Since you don't know any of the maintenance history on this rig, I would warm the engine up to operating temp, pull the plugs & do a compression check. Even better would be to do a leak down test if you know somebody you could borrow the guages from. You mentioned fouled plugs. Were they wet fouled? If so, with oil or gas? Your miss could be plug wires if you haven't replaced them yet, but you need to find out if the rings & valves are sound on all 8 cyls. first.
  9. steps350

    steps350 New Member

    yea on # 8 cylinder I pulled the new plug and it was a little wet with what looked like a little oil so thats kinda got me worried, the engine only has about 160xxx kms on it but thats all I got left is to do the wires
  10. stephan

    stephan Rockstar 4 Years 5000 Posts

    ok, a little oil on one plug isn't so bad. You might try putting a 1 step hotter plug in that cyl to keep it burned off, but I would definitely do at least a compression check. Since you got it from a farmer, he might have started it 10-20 times a day to stock feed etc & it may have never gotten warmed up or ever seen the roads. He might have used it exclusively in the fields.
    1 person likes this.

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