mark105 Posted February 9, 2010 Share Posted February 9, 2010 i have a bit of a problem in that i cannot explain how i got a compression test of 0 on my freshly rebuilt engine and would very much like to find the cause before i spend another $100 on a wasted head gaskit. i had my engine fully rebuilt, put it all together correctly and had an issue with no 1 didnt seem to be firing at all as all i had was unburnt fuel in there and the spark plug was as clean as a whistle so i went over everything electrical, from replacement 2nd hand coils, to new plugs, tested all the looms, injectors tested and cleaned, pulled everything out of the engine and tested it was all firing by manually turning the CAS, replaced the AFM all to no avail. Then i put a compression tester in no 1. 0 compression. this is weird, so air came the compressed air, leaking out no 1 inlet valves, so out came the cams, this some what slowed down the air leak but it was still there, so off came the head and back to the engine builders it went, 3 hours later and the head fully disassembled and reassembled and leak tested nothing wrong with it. engine builder did say no 1 had some shit under the inlet valve but there still would have been way more than 0 compression there and would have easily burnt out after been run in. He also commented that i still must have no spark as even though the inlet valves were leaking it still should have burnt something but that is another issue all together and im now suspecting my ECU is faulty and not firing the ignition under load but thats not the issue i need solving. My issue im stuck with is where my 0 psi compression came from as i dont want to put the head back on only to have the same problem even though i have been told everything is fine. So what im stuck at is can a hydraulic lifter hold a valve open some how? My hydraulic lifters have never ticked. The thing my engine builder suggested was maybe my oil is to thick and not draining from them as i have 15W-50 penrite semi synth in there from appco but suggested i should be running something like 5W-30 stuff. Does any one have any theory's? or had something similar happen as this has both me and my engine builder stumped. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2010 Share Posted February 9, 2010 Is it definitely only one cylinder? Have you performed a cylinder leakdown test? Do this and find out which valve it is coming from. Next remove that side cam and determine if it is before or after the cam (if it is actually in the valvetrain) Quote Link to comment Share on other sites More sharing options...
mark105 Posted February 9, 2010 Author Share Posted February 9, 2010 if by leak down test you mean put cylinder at tdc and blast compressed air into see where it leaks then yes i did this. first i did it on no 1, no 1 leaked out inlet valves so tested no 2 and this was fine, so i pulled the cams out, tested no 1, leaked a little less but still leaked out inlet valves and then tested all the rest and they were fine no leaks. so i took head off and sent back to engine builders like i said in my first post they have fully gone over it and said no 1 leaked a little because of shit under it but not enough to be a problem and that my head is fine. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2010 Share Posted February 9, 2010 Oh you have the head off- disregard what I said.. Try this - Fit sparkplugs Remove cams Turn head upside down and place blocks under the head so it is not resting on the valves Fill all combustion chambers with kerosene or diesel Wait till you see fluid leaking out of one of the inlet/exhaust ports If it is not leaking, it would likely be one of 2 things - seized lifter or rings not sealing Sounds dumb, but has he put rings on all the pistons? How hard is it to swap lifters with the head installed? Alternatively you could assemble and perform another compression check - if problem is still there, swap the lifters from that cylinder with another cylinder and reassemble and compression check again and see if the fault has moved with the lifters.. Quote Link to comment Share on other sites More sharing options...
mikuni Posted February 9, 2010 Share Posted February 9, 2010 I can't help with too much of this but if there was fuel and no spark on cylinder 1 it could have had bore wash resulting in very low compression on that cylinder alone. There may have also been a small problem with a lifter on number 1 too and this could have thrown you off the scent perhaps? In saying that, I wouldn't have thought that would drop the compression to none? Quote Link to comment Share on other sites More sharing options...
bubblegoose Posted February 9, 2010 Share Posted February 9, 2010 drop head back on with old headgasket and some goop do test again test + good = fit new gasket test + bad = cry worth checking one more time, for the time it takes to bolt a head down anyway Quote Link to comment Share on other sites More sharing options...
mark105 Posted February 9, 2010 Author Share Posted February 9, 2010 Oh you have the head off- disregard what I said..Try this - Fit sparkplugs Remove cams Turn head upside down and place blocks under the head so it is not resting on the valves Fill all combustion chambers with kerosene or diesel Wait till you see fluid leaking out of one of the inlet/exhaust ports did this and inlets leaked, no 1 more than the others but all them did oh so very very very slowerly. Hence why i took it back to the engine builders today and they spent hours going over it and re pressure tested everything and said it is fine. no 1 had some shit on the seat but nothing that wouldnt have burnt out and sealed up once i had run it in (engine hasnt even been run in yet, has done a total of about 10 mins running) this is why im suspecting the lifters but i have no idea how to test them, i guess moving them around would be a good test even though my workshop manual says not to do this. im just worried about putting it all back together and then having to take the head off again wasting another $100 head gaskit again. rings not sealing would result in more than 0 psi surely the only way i can see you would get 0 psi is from valves being open as they are the only thing i can see that would flow enough air. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted February 9, 2010 Share Posted February 9, 2010 I haven't properly read this thread, but 0 compression would have to be as a result of a tight valve lash preventing the valve closing. I knew a guy who rebuilt his engine after a cook up. He has the head shaved,as well as the rest of it. Then he slapped the head back on without resetting the tappets and had no compression. Fail. Quote Link to comment Share on other sites More sharing options...
fuel Posted February 9, 2010 Share Posted February 9, 2010 are you able to get ahold of another set of lifters? Quote Link to comment Share on other sites More sharing options...
fuel Posted February 9, 2010 Share Posted February 9, 2010 I haven't properly read this thread, but 0 compression would have to be as a result of a tight valve lash preventing the valve closing.I knew a guy who rebuilt his engine after a cook up. He has the head shaved,as well as the rest of it. Then he slapped the head back on without resetting the tappets and had no compression. Fail. it has hydraulic lifters Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2010 Share Posted February 9, 2010 OK going totally out there - what if engine builder has epically failed and left the rings off number 1? Also, If the lifter surfaces are all in good nick then there should be no problem with switching them around temporarily.. Quote Link to comment Share on other sites More sharing options...
johnnyfive Posted February 9, 2010 Share Posted February 9, 2010 Is your compression tester known ok, Sealing alright? Stranger things have happened Quote Link to comment Share on other sites More sharing options...
mark105 Posted February 9, 2010 Author Share Posted February 9, 2010 i installed the rings, i know they are there. the lifters have no signs of wear on them and were all measured with in tolerance. tho because of how unloved this engine was before i got it and the amount of caked up old oil before reconditioning im suspecting that maybe a lifter has seized. i guess i will try what bubblegoose said and put head back on with old gaskit and re compression test now the engine builder has gone fully over the head and see if problem is still there, if not i will re-install cams and see if problem arises if so hydro lifter, if not fuck knows what was wrong. philly nah i dont have access to a spare set of lifters unfortunately. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2010 Share Posted February 9, 2010 it misfires on 1 cylinder when running.. compression tester has just confirmed symptoms Quote Link to comment Share on other sites More sharing options...
mark105 Posted February 9, 2010 Author Share Posted February 9, 2010 Is your compression tester known ok, Sealing alright?Stranger things have happened yeh it works, that was first thing i did, put it in no 1, crank, 0 wtf this thing must be broken, put it in no 2, crank shit it works, wtf is wrong with no 1. Quote Link to comment Share on other sites More sharing options...
fuel Posted February 9, 2010 Share Posted February 9, 2010 yeah I would say swap the lifters from number 1 to number 2, and see if number 2 now has no compression. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted February 9, 2010 Share Posted February 9, 2010 In certain circumstances, a lifter can "pump up" and create negative valve clearance so that its valve cannot close. Typically this occurs in the most upper rpm range of an engine, and limits the engine's performance. Lifter pump-up is serious, as there may be interference of the valve with the piston or, burned valves may result. In all cases it is important to follow the manufacturer's recommendations for oil viscosity and quality. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2010 Share Posted February 9, 2010 yeah what you say Yowzer is true but seems highly unlikely for a set of lifters to stay pumped up that have been sitting round for as long as these have. and for pumping up on startup - doesn't seem possible 10-5 can you please take some detailed pics of the head and lifters.. thanks Quote Link to comment Share on other sites More sharing options...
Yowzer Posted February 9, 2010 Share Posted February 9, 2010 Yeah def doesn't seem likely, but thicker oil could be causing some issue. Potentially the lifter is just full of crud, could be blocking it so the thicker oil can not escape as easily Quote Link to comment Share on other sites More sharing options...
fuel Posted February 9, 2010 Share Posted February 9, 2010 yeah what you say Yowzer is true but seems highly unlikely for a set of lifters to stay pumped up that have been sitting round for as long as these have. and for pumping up on startup - doesn't seem possible10-5 can you please take some detailed pics of the head and lifters.. thanks happens all the time with nissan engines bro, especially SR20s. They just don't like thick oil at all. Quote Link to comment Share on other sites More sharing options...
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