Quantcast
Jump to content


Compression test

ricksrb

By ricksrb
in Joyner UTV SxS Forum

 Share

Recommended Posts

ricksrb Mentor

ricksrb

Posted
Posted

Decided to run a compression test and got some disappointing results.

#1 - 162

#2 - 160

#3 - 122

#4 - 120

look like i need rings? i do have some blow by but not sure if what i am getting is abnormal or excessive.

Guest Lenny

Guest Lenny

Posted
Posted

You can probably get buy for a while. From what I have seen others post about compression, it seems that when it gets down to about 95 is when they want to quit running or run and start poorly. You probably need to start to look for a gap in y our life in which you pull your engine. If you get underneath it and tear out the frame member that keeps you from getting the oil pan off like I have, then you can rering it without pulling the engine. Replace the frame member with a goog tough bolt in member, Since I did mine, I have had my pan off several times and once its done your glad you did it for ever more. The last time I pulled my transmisson, I also did so without pulling the engine. Just slid the engine back about 3". Saved a lot of time. What oil do you run.

Lenny

ricksrb Mentor

ricksrb

Posted
  • Author
Posted

so it does sound like the rings to you? i did a search earlier and read about you doing that to the cross member. So i guess i can order the all i need from JMC right? I have been running mobile 1 oil.

dedub Collaborator

dedub

Posted
Posted

so it does sound like the rings to you? i did a search earlier and read about you doing that to the cross member. So i guess i can order the all i need from JMC right? I have been running mobile 1 oil.

didn't silverbullet work on your motor not to long ago?
rocmoc Grand Master

rocmoc

Posted
Posted

Could also because of bad valves or valve guides seals. Also could be a head gasket starting to leak between two adjacent cylinders. After this the really bad stuff that rarely happens. Won't really know until you tear it down.

rocmoc n AZ/Mexico

goindeep Enthusiast

goindeep

Posted
Posted

there are ways to test all of that and pin point exactly where you are losing pressure from. dont just tare the motor down and re ring it. that could be a costly mistake! i had low compression on one cylinder and it ended up being a bad valve...

Josh

No Limitz

ricksrb Mentor

ricksrb

Posted
  • Author
Posted

I have checked for air bubbles in the radiator but was not any, that was one way i was told to check for a head gasket leak. I will be doing more testing soon but want to get by until end of season before i tear into it.

ricksrb Mentor

ricksrb

Posted
  • Author
Posted

Okay, a bit puzzled now. I did a leak down test last night. I found that on #3 i have air coming from exhaust and nowhere else so that tells me exhaust valve. On #4 which on compression test showed 120 lbs same as #3 i could not hear any air coming out anywhere. I checked exhaaust, intake, oil fill on valve cover, and radiator for bubbles. In fact pressure was building up so much it started leaking air from fitting going into spark plug hole. Just to make sure i repeated 4 times with same results. Any thoughts?

Guest Lenny

Guest Lenny

Posted
Posted

Are you doing the leak down test with the exhaust manifold removed. The intake should be treated the same so you can positively issolate each port. Sounds like valves will need to be worked based on #3. The complication with doing valves is the shims. You may be able to have your valve guy cut the valve stem the same amount he seats the valves farther in. Other wise you will have to have the shims replaced, correct replacements could be difficult to find, or regrind their thickness. When I put in the torque cam,I reground the thickness on mine. I was able to use some of the original shims because they were either rtight or needed to go thinner. On the rest, I used standard 25mm shims that were thick enough to grind to size. Having the machine shop make a custom collet to hold the shims in the lathe is real simple. A surface grinder with a magnetic chuck would work too. You could redo the valves and put the head back on, run it a bit to seat the valves and recheck the compression. If you have to tear it down, taking the head badk off and putting it back on is not too bad now that your valve shims are set to go. Just be sure to keep track of what went where. Still havn't found pictures for the under engine frame change but will. Going out of town for the weekend. Leaving about noon today so I'll do it when I get back.

Lenny

goindeep Enthusiast

goindeep

Posted
Posted

one when you did the compression test did you make sure the compression gauge fitting was tight on all four holes? the smallest leak can give you major different readings... second when u pressure tested number 3 was the piston at TDC? the exhaust valve may have been open... on a compression test all cylinders should be within 10% of each other

Josh

No Limitz

Guest Lenny

Guest Lenny

Posted
Posted

Goingdeep. are you doing your compression test turning the engine manually to TDC? When I do mine, I crank the engine over with the starter and let it pump up the gauge. For those that arn't familuar with a compression tester, thsy have a valve stem type check valve in them so they can be pumped up and will hold the pressure. With a leak down test, you of course would turn it manually to TDC or close to it.

Lenny

nocturnalsixer Rising Star

nocturnalsixer

Posted
Posted

Also with compression test i was taught to always have the throttle body wide open (pedal to the metal) that way you are allowing equal amount of air into each cylinder but that's with the engine not taken apart at all

Sent from my DROID RAZR using Tapatalk 2

ricksrb Mentor

ricksrb

Posted
  • Author
Posted

try and answer all at once.

Lenny,

No it was with exhaust manifold on. I hate the thought of messing with the shims from all i have heard from you guys.

goindeep,

yes i made sure it was tight. I did compression test on all cylinders two or three times. On the leak down test i made sure it was at tdc each time i did it.

nocturnalsixer,

yes, i also made sure throttle was wide open.

whats puzzleing me is the #4 now.

ERV JR Collaborator

ERV JR

Posted
Posted

did you try a wet compression test or just a dry ? BTW if you ane not sure what a wet is I will explain. First off are you disconnecting the fuel pump relay ? If you leave it in the injectors can wash the cylinder down.

Try a wet test, jake a cap full of oil,or the old oil cans with the pump and tip and squirt a few shots of oil and then spin it over with the gauge in it. Th oil will seal up the rings.

Also a compression test should be done at operating temp due to expansion, mind you I have done them cold also. You could warm it up then recheck it

ricksrb Mentor

ricksrb

Posted
  • Author
Posted

So what happened any way how did u loose compression how many miles

if it was thr rings i would say because back at the start of April i noticed a hose clamp had come off the hose at the throttle body and there was dust in my intake. But with the leak down test it appears to ba an exhaust valve and not sure how that happened. I only have about 1700 miles on it.

charlie Experienced

charlie

Posted
Posted

Well u can't speak for the troopers but I wrk on subarus all day and Thursday I had one come in with misfire shirt story did all my tests found broken valve guide in exhaust and burnt valve the fuel out there these days and poor maintenance is reaking havoc on these engines

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Similar Topics

    • redDance
      “Fake” Beadlock Rings
      By redDance
      Does anyone know where to get beadlock rings that can be welded or mechanically fastened to stock uforce 1000 rims.  Totally for cosmetic purposes 
    • Hunterman22
      2021 Hisun Axis 500 No Start - Need Help Please
      By Hunterman22
      2021 Hisun Axis 500 UTV (From Lowes)
      Will NOT START
      MY apologies if this is to much info just wanted to give yal the most information possible for help.
      I'm a so called diyer. An Electrician by trade 21yrs. I got my S×S from my last job. The contractor purchased this S×S for this specific job brand new, from Lowes. They used it for hauling materials, tools, & a little bit of anything you can think of on an Industrial type job site. 
      I remember getting on the SxS one time & pushed the gas petal all the way to the floor & SxS had very little power. 
      So anyway ,when the job finished up back mid July this year (7/2024) , I asked the contractor what they was going to do with it. I was told to take it. Otherwise it would go to the contractors yard (storage yard) & most likely rust away. 
      Took it home washed it , it had a heavy coat of dust on it & in it dust was every where. My helper & I had to push it on the trailer to get it home.  After washing it throughly I let it sit & dry out for a good day and half, maybe 2 days. Before trying to start it. NO START. Will turn over & try to start but thats it. 
      So here's what I've purchased & installed. New Air Filter, new spark plug, new air idle control valve (AICV), new throttle position sensor, new throttle body, new oxygen sensor, new digital dash speedometer/fuel gauge/clock. 
      Also drained the old oil & gas & replaced with new oil & 93oct. gas. I should probably mention that I've changed the AICV twice. The 1st time I changed the AICV I was able to get the SxS started & let idle for at least 10-15min. Drove out of the garage, with very little power,  turned it around & barely got it back in the garage.That was the one & only time I've been able to start the SxS. I've also cleaned the Throttle Body and & intake with TB cleaner.  So after that the AICV was  making weird noise so I pulled it out & tried cleaning it, pretty sure I messed it up. So I purchased a Throttle Body that came with new AICV & TPS. Still NO START.  I've checked the fuel pump & the fuel injector.  I took the injector off still hooked up to wiring & turned the key over, the injector sprayed a lot of gas out kinda the size of a volleyball. I've also checked the clearance gap on the intake & exhaust valve. But today 11/2/2024 I'm going recheck spark plug gap & the valve gaps. And alot of other checking. Would the driver side seat belt have anything to do with it not starting?? I know the driver side seat belt has to be in gauged for full throttle "going fast". Thing is the drv. side seat belt will latch but feels like might be messed up inside of it. Tired opening it up but to no avail.  I've never had a S×S or 4wheeler so I was really excited when I got the S×S,not so much anymore.  I work on & fix my own vehicles usually no problems.  But this SxS is kicking my ass.
      So if possible & someone could help me with some ideas or tell me what Im doing wrong or did wrong, I would greatly appreciate it.  Thank you for reading thus far.
       
       
    • Clayton Walker
      Im New here but just got my Uforce Fitted for Hunting Season
      By Clayton Walker
    • Kingfish
      Now that I have done the LI-Ion batt conversion, I need to do something about the suspension
      By Kingfish
      The conversion took about 350lbs. off the vehicle.  It never rode great, but now I feel every  crack in the road.  I have backed off spring compression nut to the point just under where they would move around if suspension was at full extension, but it is still very stiff.  I would like to put some softer coilover springs on it, but I have no idea what the spring rate is with the original springs so I would just be guessing on what to order.  Does anyone have the data for the original spring compression rate?  I am willing to give up a little ground clearance for a softer ride. Right now when sitting still the rear suspension is at or near full extension and the rear tires have several degrees of camber which will cause uneven wear if allowed to continue in this state.
    • Ridge Runner
      2019 Coleman 550 Outfitter, need help accessing tail gate latch screws
      By Ridge Runner
      Hi
      i have a 2019 Coleman 550 Outfitter.  The tail gate has a pin on each side, that snaps into latch blocks that are mounted on the inside of the tail gate opening.  There are two M6x16 pan head screws(bolts?) that hold the latch blocks in place.  The screws enter from inside the bed body, and I can’t figure out how to access them.  This is right by the tail light assemblies.  I tried taking a pan head screw out of the fender lip, but found out there is not a nut firmly inplace, to hold the pan head screw in.  Bottom line I’m making it worse.  
      coleman was no help.  If I could figure out how they attached the tail light, then maybe I could put the latch screws in through the tail light hole.  Any ideas?
       
      thanks
      Ridgerunner

UTV FORUMS

MORE SECTIONS

FOLLOW US ON

GET IN TOUCH

  • Automotive Webmaster
×
×
  • Create New...