1998 GMC 1500 Misfire
5

Asked by LocoSmith Aug 17, 2017 at 04:37 PM about the 1998 GMC Sierra 1500

Question type: Maintenance & Repair

After taking a 3 hour round trip in June, my truck began to misfire on the way
home, so I had to keep it revved to keep it started.  Initially, we did a full tune
up (spark plugs, plug wires, cap, rotor, oil, antifreeze, etc.)  This didn't fix the
problem and it turned out to be a cylinder 7 misfire.  The head was removed
and reviewed and no cracks were noticed.  It was put back together and ran
smooth until a couple weeks ago when it started misfiring heavily on the first
drive each morning.  It didn't seem to do it as much after that first drive each
day.  We replaced the plug wires and spark plugs thinking it may be defected
parts.  Nonetheless, it was not.  Cylinder 7 continues to misfire based on the
spark plug residue.  Please give me any and all recommendations.

2 Answers
22,300

Guru9FSV8 answered 6 years ago

Gasket not sealed in the area of #7. When heats up it seals. Look this up on these gm products. Manifold gasket?

2 people found this helpful.
Mark helpful

GuruC9VVG answered 5 years ago

The gaskets are fine. No compression problems - plugs are new & good. The engine runs great - just the damn misfire problem.

Mark helpful

Your Answer:

Related Questions

  • 1998 GMC 1500 Misfire 2 Answers

    After taking a 3 hour round trip in June, my truck began to misfire on the way home, so I had to keep it revved to keep it started. Initially, we did a full tune up (spark plugs, plug wires, cap, r...

    1998 GMC Sierra 1500

    -

    Maintenance & Repair

  • misfire on my 1998 GMC pu. 1500 , 5.0 4 Answers

    my truck just all the sudden started running ruff , the code reads random misfire . as I am driving the service engine light flashes . was running fine before

    1998 GMC Sierra 1500 C1500 SLE Extended Cab LB

    -

    Maintenance & Repair

  • 1998 GMC 1500 SLT 1 Answer

    My 1998 GMC 1500 SLT with a 350 engine in it. It was sitting for a while. When I first started driving it it was doing fine until after about 2 hours of drive time. My gauges are all inaccurate. I ...

    1998 GMC Sierra 1500

    -

    Maintenance & Repair

  • 1998 gmc sierra 1500 wont start 1 Answer

    I have a 1998 GMC Sierra 1500 and it will not start. It died on me while I was driving and I had it brought back to my house. I have replaced the fuel filter, the starter and the battery. And I had...

    1998 GMC Sierra 1500 C1500 SLE Extended Cab LB

    -

    Maintenance & Repair

  • 1998 Gmc seirra 1500 starts sometimes. 1 Answer

    My 1998 GMC has been running fine for months. yesterday I parked it for maybe 2 minutes and went to start it again and nothing. It didn't even turn over. the lights the horn and the radio all work fin...

    1998 GMC Sierra 1500 K1500 SL 4WD Extended Cab LB

    -

    Maintenance & Repair

Sierra 1500

Looking for a Used Sierra 1500 in your area?

CarGurus has 7,729 nationwide Sierra 1500 listings starting at $5,500.

Postal Code:

Shortcuts

Search GMC Sierra 1500 Questions

CarGurus Experts

  • #1
    yetilikesbeer
    Reputation
    12,350
  • #2
    dragonflyoffshore
    Reputation
    11,510
  • #3
    John Saffrahn
    Reputation
    11,450
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Chevrolet Silverado 1500
169 Great Deals out of 7,335 listings starting at $6,995
Used Ford F-150
303 Great Deals out of 13,403 listings starting at $3,888
Used Chevrolet Silverado 2500HD
20 Great Deals out of 1,577 listings starting at $8,999
Used Toyota Tacoma
33 Great Deals out of 774 listings starting at $9,975
Used GMC Yukon
13 Great Deals out of 916 listings starting at $6,900
Used Dodge RAM 1500
81 listings starting at $2,000
Used Chevrolet Tahoe
16 Great Deals out of 763 listings starting at $7,499
Used Ford F-250 Super Duty
28 Great Deals out of 732 listings starting at $2,890

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.