engine suddenly only works on 5 cyl

Asked by Jul 15, 2016 at 03:46 PM about the 1990 Ford F-150 XLT Lariat LB

Question type: Maintenance & Repair

My truck was running rough on
excelleration at times. Then suddenly on 5
cyl instead of 6. Friend said he did
compression test then no compression on
#1 cylinder.  Said it might have a bent valve.
Could that be so? Lariat but unsure SB or LB

1 Answer

5,035

If there's no compression, try squirting about a spoonful of engine oil in the spark plug hole and recheck compression, if still no compression, u have a bad valve, if compression goes up with oil, u have a bad ring or cylinder

Your Answer

Add photo

Related Questions

  • engine suddenly only works on 5 cyl 2 answers

    My truck was running rough on excelleration at times. Then suddenly on 5 cyl instead of 6. Friend said he did compression test then no compression on #1 cylinder. Said it might have a bent valve....

    1990 Ford F-150 XLT Lariat LB

    -

    Maintenance & Repair

  • 5.0L. WHAT IS THE FIRING ORDER AND DOES THE DISTRIBUTOR ROTATE CCW OR CW,AND #1 CYL. LOCATION 2 answers

    1989 Ford F-150

    -

    Maintenance & Repair

  • I have 92 ford f150 6 cylinder/spark plug order 2 answers

    i have 92 ford f150 6 cylinder gave it a tune-up i got the plugs in wrong order on distributor and spark plugs how can i get them in order. how do i know where 1 cyl. is from front of motor. what is ...

    1992 Ford F-150 STD Stepside SB

    -

    Maintenance & Repair

  • 1988 F150 4x4 ,6 Cyl 5 Spd, vehicle will not start 1 answer

    A few days ago the stater had a run on issue , we took the neg wire off battery for a few minutes then put it back on . The truck started okay but the steering column was smoking a little. Now today...

    1988 Ford F-150 S Standard Cab 4WD LB

    -

    Maintenance & Repair

  • 2001 6-cyl F-150 towing 25 answers

    My father just told me he wants to give me his F-150 6 cyl (2001 model) pickup this summer. I have two horses and am wondering if this truck could haul a 2-horse trailer. I don't yet own a trailer (...

    2001 Ford F-150

    -

    General

Search Ford F-150 Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

Ford F-150 Experts

#1 OJ
OJ
Reputation 6,720
#2 dandyoun
dandyoun
Reputation 4,130
#3 tennisshoes
tennisshoes
Reputation 2,470
View All

Related Models For Sale

Used GMC Sierra 1500
992 Great Deals out of 60,344 listings starting at $1,299
Used Ford F-250
558 listings starting at $1,342
Used Ford Mustang
541 Great Deals out of 43,035 listings starting at $1,699
Used Ford Explorer
1,093 Great Deals out of 72,153 listings starting at $1,000
Used Ford Ranger
203 Great Deals out of 6,785 listings starting at $1,595
Used Jeep Wrangler
518 Great Deals out of 18,484 listings starting at $2,500

Used Cars For Sale

2017 Ford F-150 For Sale
5 Great Deals out of 83,537 listings starting at $17,710
2016 Ford F-150 For Sale
185 Great Deals out of 56,813 listings starting at $4,922
2015 Ford F-150 For Sale
215 Great Deals out of 7,553 listings starting at $18,296
2014 Ford F-150 For Sale
501 Great Deals out of 11,523 listings starting at $11,479
2013 Ford F-150 For Sale
680 Great Deals out of 14,068 listings starting at $8,450