Matt306 Posted October 7, 2017 Share Posted October 7, 2017 My little four pot (which i will swap out for a six cylinder sometime next year/year after/maybe year after that) seems to have developed a little lack of power.I have done the tappets to get a little stiff pull on the tappets when feeding in 10thou feeler and pulling back. I did a cold pressure test and got 150/90/150/150 psi on the pistons. I know its meant to be done warm so went for a drive and run again and the offending chamber has now risen to 100 psi. Not noticing any coolant leak but would like to sort the problem. Most obvious is remove the head and have a look but is there anything i can look at prior to that Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted October 7, 2017 Share Posted October 7, 2017 the 150 psi is probably about right for the engine.Do a wet compression test next. That is, put a tablespoonful of oil in each cylinder and repeat the test. This oil provides additional ring sealing and helps determine whether you have a ring/bore issue or valve seating issue. If it's a ring leak, adding the oil will give a bigger improvement than a valve issue.Hopefully it's a poorly seating valve and fairly easy and cheap to resolve.Leak down test is another option but involves slightly more elaborate equipment.Nick Quote Link to comment Share on other sites More sharing options...
RedRooster Posted October 7, 2017 Share Posted October 7, 2017 Check your water for oil & check your oil for water, if you can find some one with a block leak tester try that. Quote Link to comment Share on other sites More sharing options...
RedRooster Posted October 7, 2017 Share Posted October 7, 2017 Check your water for oil & check your oil for water, if you can find some one with a block leak tester try that. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 7, 2017 Author Share Posted October 7, 2017 I'll stick some transmission oil down piston two and try that. I had the sump off and the checked the rad, no sign of fluids being in the wrong place. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted October 7, 2017 Share Posted October 7, 2017 Most likely the exhaust valve seat IMO. That much compression missing going into the water jacket would cause a header tank like a jacuzzi and water everywhere.....Nick Quote Link to comment Share on other sites More sharing options...
TedTaylor Posted October 8, 2017 Share Posted October 8, 2017 Quoted from RedRooster If you can find some one with a block leak tester try that. Yep in the Forest of DeanNot used it for 20 years and not sure about the fluid but could check that - it is only universal indicator liquid to test for pH (acidity/alkalinity)MUT Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 8, 2017 Author Share Posted October 8, 2017 Cheers all.But some ep90 down the bored and all the compressions rose. From 150 to 250 or over on 1,3 and 4. Number 2 went up from 90 to 150 so a smaller rise so I am thinking valve stuck. I had the stems and new valves about 4000 miles ago . I guess it's head off time to grind in valve or is there an easier way. Or is my thinking to cock? Quote Link to comment Share on other sites More sharing options...
JohnD Posted October 8, 2017 Share Posted October 8, 2017 Thats misinterpreting the results.Any rise = no valve problemOnly if the pressure does not rise can you diagnose a stuck or damaged valve. The first will be obvious, running the engine with the valve cover off.The reason why compression down on 2 isnt obvious. Your numbers are so high compared to those usually got that I suspect a very sensitive gauge, so the absolute pressure in 2 may be so low as to suspect faulty piston or rings.John Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 8, 2017 Author Share Posted October 8, 2017 Either way it's head off time I guess? Going to up load a video to YouTube with her running see if u hear what I hear. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 8, 2017 Author Share Posted October 8, 2017 Here's the you tube video.https://youtu.be/zJaOxvrWlzw Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 8, 2017 Author Share Posted October 8, 2017 Couple more... Looking at the white smoke I am erring too piston ring. Which is blooming annoying as I only took the sump off two weeks ago.https://youtu.be/8oKBVI5rjOUhttps://youtu.be/Wk-AaGNxrJ8 Quote Link to comment Share on other sites More sharing options...
poppyman Posted October 8, 2017 Share Posted October 8, 2017 Sadly it does look like oil smoke Quote Link to comment Share on other sites More sharing options...
daver clasper Posted October 8, 2017 Share Posted October 8, 2017 HiAre compression dry/wet tests a fool proof way of diagnosing ring/piston/bore or head wear or a good starting point, please.Thanks, Dave Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted October 8, 2017 Share Posted October 8, 2017 Good starting point.Nick Quote Link to comment Share on other sites More sharing options...
RedRooster Posted October 8, 2017 Share Posted October 8, 2017 Leak down test if you have a compressor would be another thing.Also check the torque of the head bolts, may give you an idea if they are loose.To be honest its only going to take a couple of hours to get the head off & you probably need to do that anyway so just get on with it. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 8, 2017 Author Share Posted October 8, 2017 Quoted from RedRooster Leak down test if you have a compressor would be another thing.Also check the torque of the head bolts, may give you an idea if they are loose.To be honest its only going to take a couple of hours to get the head off & you probably need to do that anyway so just get on with it. You aren't wrong in getting on with it, I was in the garage and the head is now off.I put photos in this folder;https://photos.app.goo.gl/ekn5ny4gBDwi2skg1Head offhttps://photos.app.goo.gl/mN2SAaQJuGeDF2702 https://photos.app.goo.gl/LH9t.....gl/vzqfFQ6DBQHLugTh2Underside of head note the two lighter coloured valves ???https://photos.app.goo.gl/l26ZznD72q8MLsAK2 I think there is thick black soot from the EP90 oil i tipped down the bores earlier. There is a slight browning on the edge of number two . Sign of a leak? The top of the piston has a lip from the piston wear. Anyway thoughts, before i take the sump off for the second time in as many months! Quote Link to comment Share on other sites More sharing options...
RobPearce Posted October 8, 2017 Share Posted October 8, 2017 The lighter coloured valves is fairly normal - exhaust valves tend to be less black because they run hotter, and the inner cylinders run hotter than the outers. The brownish patches on the no. 2 piston are a little odd. If you do take the pistons out, I wouldn't be surprised to find ring faults lined up with them. On the other hand, I'd not be surprised if you didn't find anything. Quote Link to comment Share on other sites More sharing options...
poppyman Posted October 8, 2017 Share Posted October 8, 2017 Looking at the lighter shade and loss of carbon on no2 cyl, suggests to me head gasket failure in its very early stages Anyone else think that??Surely there would be marks on the bore if it was a ring? Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 8, 2017 Author Share Posted October 8, 2017 No bore marks. Quote Link to comment Share on other sites More sharing options...
poppyman Posted October 9, 2017 Share Posted October 9, 2017 Personally i would change the head gasket first, as the low compression should not really make a lot of differance in power loss Like someone else said you can take the piston out and not find anything One test my old gaffer used to do to check rings, is to get all the pistons level with each other and then put a measured amount of engine oil in each bore and see which one drained out first It is a bit time consuming, but i guess its not your daily driver Good pics by the way Cheers, tony. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 9, 2017 Author Share Posted October 9, 2017 Thanks for the reply. I didn't notice any issues with gasket and head was skimmed a while ago with no over heating issues since. I haven't noticed oil in water or vice versa.Could probably do with a rebore though. I'll do the oil measure. I've never had pistons out so rings could be shot. Quote Link to comment Share on other sites More sharing options...
poppyman Posted October 9, 2017 Share Posted October 9, 2017 If you go down the route of taking the pistons out? I would measure the bores as you might not need a rebore and just get away with new rings Also you might just have a "stuck" ring if it has been stood for a while in the past?It would be interesting to see the pistons if and when they come out Cheers, Tony. Quote Link to comment Share on other sites More sharing options...
Matt306 Posted October 9, 2017 Author Share Posted October 9, 2017 I tested compression before the RBRR last year can all four pistons we around the 150 mark. I don't know when the pistons we last out though. For that matter I don't know if 150 psi is good or bad on the others. Quote Link to comment Share on other sites More sharing options...
poppyman Posted October 9, 2017 Share Posted October 9, 2017 Around the 150 mark is about right, giving the fact you have done the rbrr, i would now suspect an exhaust valve. so i would now take the valves out and see what they are like, as even using an additive the valves still run hotter on long runs at highish continuess speeds.The smoke on the video is not excessive by any means.Keep us posted Cheers, Tony. Quote Link to comment Share on other sites More sharing options...
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