low compression

  1. Newbie Joined: Jun 2012 Posts: 8
    #1
    hi ppl just wanted a second opinoin on something bassically i have a 106 gti qs conversion an well when starting car it idles a lil ruff and at times loses alot its power iv been lead to beleave tht this could be 1 of many such as a valves is broke and compresion ring done a compresion test at a mates garage an 1&4 were about 150 and 2&3 are below 50 any help much appriceated thanks SL1M
  2. Regular Poster Joined: Jun 2012 Hastings Posts: 437 1998 1.3 ford escort 1999 1.5d citroen saxo
    #2
    Id check the alternator, make sure its charging your battery as it should and giving enough power to your battery to start the car up with. try also cleaning the idle valves. Sometimes the can get blocked. you jsut need to take the valve off and give it a good clean with either wd.40 or some valve cleaner with a cloth. Pot it back together again and hope for the best
  3. Established Member Joined: Mar 2011 Birmingham Posts: 2148 Rover BRM, Rover 800 Coupe, Mk6 golf.
    #3
    As far as i know, the alternator wouldnt cause low compression, I dont see how it would?
    Obvious things that spring to mind would be head gasket/ piston rings... Any gunk in the oil/coolant and does the car smoke at all?
  4. Established Member Joined: Sep 2010 loughborough Posts: 2229 1988 ford fiesta mk2 1.4- 2001 black saxo furio (d
    #4
    sounds like it's got a sticking valve and or headgasket has blown between 2&3.

    do a wet test also. (pour a little oil in to the bores through the sparkplug hole) if the compression increases then the rings are fubar. but haynes says that ideal compression if around 10 bar (what ever that is in psi). i've recently just done (yesterday) my 1.4 8v compression on 136.5k and it was neigh on 200psi on all cylinders iirc no2 were 175psi (have recently done headgasket but no skim. ) but all within 10% of each other.
  5. Newbie Joined: Jun 2012 Posts: 8
    #5
    Quote:
    Originally Posted by f13sta View Post
    sounds like it's got a sticking valve and or headgasket has blown between 2&3.

    do a wet test also. (pour a little oil in to the bores through the sparkplug hole) if the compression increases then the rings are fubar. but haynes says that ideal compression if around 10 bar (what ever that is in psi). i've recently just done (yesterday) my 1.4 8v compression on 136.5k and it was neigh on 200psi on all cylinders iirc no2 were 175psi (have recently done headgasket but no skim. ) but all within 10% of each other.
    anyone selling an engine loool