P300 on vortec v6 why

10

Asked by Jul 27, 2014 at 02:17 PM about the 1997 GMC Sierra 1500 C1500 SL Extended Cab SB

Question type: General

I have a 1997 GMC 1500 with a 4.3 Vortec
v6 it has a p 300 random multiple cylinder
misfire code I have change distributor cap
rotor button and distributor and plugs and
wires cam sensor crank sensor and iCM
also did intake manifold gas.ket set
complete what else is causing it

6 Answers

61,445

Warped valve,check compression on all cylinder,s,one is leaking down,got same 4.3 in my silverado,went threw same as you ,replaced all,and found valve warped.

10

But it's only got 42000 on moter and it would only show one cylinder misfire if it was a valve correct

61,445

Not really,mine had 3 warped valve,s on different cylinder,s,being warped cause them to seat and sometime,s not,causing my random misfire on different cylinder,s.But that said check compression to rule me out.

10

How long did u let it set each cylinder to check the leak down

61,445

You will know within a few minute,s pressure want hold.

10

Ok

Your Answer

Add photo

Related Questions

  • Engine Skipping rough idle, loss of power 11 answers

    1996 GMC Z71 this happen all at once engine is misfiring, rough idle, loss of power, will start right up, check plugs,/replaced wth is going on with it ,also check MAP sensor and clean it check all ...

    1996 GMC Sierra 1500 C1500 SLE Extended Cab SB

    -

    General

  • Why is my service brake system light on 1 answer

    I have a 2003 gmc Sierra 1500 4x4 I got stuck and put the truck in 4 wheel drive to get out then put it in drive and moved, then it wouldn't move at all saying my service brake system and brake li...

    2003 GMC Sierra 1500 SLE 4WD Extended Cab LB

    -

    General

  • Truck not starting

    My truck will not start and I just replaced my battery yesterday, why is this happening?

    1998 GMC Sierra 1500 C1500 SL Standard Cab LB

    -

    General

  • why won't my 1998 gmc sierra go into reverse? 2 answers

    It goes forward, but stays in first gear. It is a automatic.

    1998 GMC Sierra 1500 C1500 SL Extended Cab LB

    -

    General

  • Looking for input on a V8 swap, stock heads or Vortec? 6 answers

    Hi, I own a 91 GMC Sierra 4WD Standard Cab Stepside with a 4.3 litre V6 and 5 speed transmission. I've put a lot of work into her already, as I do bodywork for a living. I plan on doing a V8 swap this...

    1991 GMC Sierra 1500 K1500 4WD Standard Cab Stepside SB

    -

    Car Customization

Sierra 1500

Looking for a Used Sierra 1500 in your area?

CarGurus has 62,274 nationwide Sierra 1500 listings starting at $1,395.

ZIP:

Search GMC Sierra 1500 Questions

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 4,820
#2 John Saffrahn
John Saffrahn
Reputation 3,390
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 2,970
View All

Related Models For Sale

Used Ford F-150
2,702 Great Deals out of 211,804 listings starting at $1,000
Used Dodge Ram 1500
530 Great Deals out of 12,828 listings starting at $1,995
Used Toyota Tacoma
620 Great Deals out of 35,105 listings starting at $2,155
Used GMC Yukon
520 Great Deals out of 17,125 listings starting at $1,799
Used Chevrolet Tahoe
778 Great Deals out of 28,448 listings starting at $1,500
Used Chevrolet Camaro
282 Great Deals out of 38,302 listings starting at $1,250

Used Cars For Sale

2017 GMC Sierra 1500 For Sale
23 Great Deals out of 35,677 listings starting at $23,699
2016 GMC Sierra 1500 For Sale
53 Great Deals out of 3,970 listings starting at $18,219
2015 GMC Sierra 1500 For Sale
120 Great Deals out of 4,043 listings starting at $14,988
2014 GMC Sierra 1500 For Sale
151 Great Deals out of 4,387 listings starting at $14,495
2013 GMC Sierra 1500 For Sale
89 Great Deals out of 2,375 listings starting at $9,988