Escortn Posted September 24, 2012 Share Posted September 24, 2012 Just took my car down to taupo from dorkland for the weekend, mk3 cortina 2lt pinto. Had a full sump before I left then when I got to the track the oil light was flashing around corners, check the dipstick and its all gone. Oil was around the spark plugs and around the thread and you could see that oil had been spitting out through the filler cap. I know it's not the head or the gasket because I just had the head recod, stem seals and every other seal replaced and new headgasket. Also checked the plugs the next day because it started running on 3 and all where fine exept cyl4 was black and seemed to have all this build up on it (fresh spark plugs 2 btw) Anyone have any theories or should I be getting ready to pull it apart? Cheers. Quote Link to comment Share on other sites More sharing options...
QCADTA Posted September 24, 2012 Share Posted September 24, 2012 do a compression test. First as normal, then pour a little oil down ya plug hole and test again, if it improves ya compression significantly time to fire some rings at it. Quote Link to comment Share on other sites More sharing options...
SOHC Posted September 24, 2012 Share Posted September 24, 2012 Sometimes if your engine has high miles it will have a ridge on the bore, when you give it a good trashing the rings will snag on it and brake Quote Link to comment Share on other sites More sharing options...
Dell'orto Posted September 24, 2012 Share Posted September 24, 2012 If its puffing out the cap/breather, then yep you've got some reasonable blowby happening. You should see a cloud of blue smoke when you boot it though Quote Link to comment Share on other sites More sharing options...
Escortn Posted September 25, 2012 Author Share Posted September 25, 2012 Cheers for the feedback. Did a comp test and it goes like this cyl1 140, cyl2 145, cyl3 140, cyl4 135. I put a bit of oil in cyl4 and it raised it to 145. Was all done when engine was cold if this changes anything. Was told by a m8 driving behind me that it only blew oil smoke as soon as I backed off after booting it. Cyl 4s spark plug (which I replaced yesterday) had all this black build up all over when I took it out to. Ideas? Quote Link to comment Share on other sites More sharing options...
Unclejake Posted September 25, 2012 Share Posted September 25, 2012 Depending on exactly how you did the comp test: That is a worn engine, but a pretty evenly worn one. You may get away with just a refresh of the ignition system for a while. A worn engine needs a good spark to operate, but that will not reduce your oil consumption. WRT the smoke only on over-run: that points strongly to valve guide wear or valve stem seals being rooted. Quote Link to comment Share on other sites More sharing options...
Unclejake Posted September 25, 2012 Share Posted September 25, 2012 ............Also checked the plugs the next day because it started running on 3 and all where fine exept cyl4 was black and seemed to have all this build up on it (fresh spark plugs 2 btw). What plugs are you using? You may want to go up in heat range (i.e. fit a plug that runs hotter and is more able to burn away oil) Quote Link to comment Share on other sites More sharing options...
Escortn Posted September 25, 2012 Author Share Posted September 25, 2012 Did the test cold and without throttle open also. I just had the valve stem seals replaced and some machining around the valves so they are seated properly so I'm hoping its not the head. It had ap5fs plugs in it before the head work then I put 7s in and now the most recent are 5s again. Checked the oil also and it's lost a lot on the way back from taupo, I think some of that is part of an oil leak but the leak is definitely not that bad. Cheers Quote Link to comment Share on other sites More sharing options...
durty Posted September 25, 2012 Share Posted September 25, 2012 Need kk's guide to compression tests Paging kk Quote Link to comment Share on other sites More sharing options...
Unclejake Posted September 25, 2012 Share Posted September 25, 2012 NGK do the heat range the opposite of Champion plug - so an NGK 7 will run colder than a 5 (but you probably know that). The engine should run OK @ 135psi. I would hate for you to re-build it if it was just a weak ignition set-up and an oil leak somewhere. Quote Link to comment Share on other sites More sharing options...
Yowzer Posted September 25, 2012 Share Posted September 25, 2012 To get an accurate compression reading, the engine needs to be at operating temperature, and performed with throttle wide open. Crank till the needle goes no higher (should only take a few cranks to get there). Quote Link to comment Share on other sites More sharing options...
Unclejake Posted September 25, 2012 Share Posted September 25, 2012 I just had the valve stem seals replaced and some machining around the valves so they are seated properly so I'm hoping its not the head. The seating of the valve head onto the valve seat has little to do with oil burn on over-run. When you cruise down a long hill with the throttle closed, the combustion chambers are operating under a lot of vacuum. As the piston decsends after each stroke it will suck air and oil down through the gap between the valve stem and the valve guides. The stem seals constrict that pathway, but if the guides are really worn there is nothing the seal can do about it. When you get to the bottom of the hill and plant your foot back on the throttle there will be a huge plume of blue smoke...... but as you keep driving along the flat it will go away. I am not saying this is your problem, but from what your mate saw it should be checked out Good luck mate. It is hard to kill a Pinto!@! Quote Link to comment Share on other sites More sharing options...
sholdowa Posted September 25, 2012 Share Posted September 25, 2012 Every pinto I've had that suddenly starts throwing oil out like this needed a rebuild... and that it more than one lol. However, it could easily be the gasket if you've just rebuilt it. Quote Link to comment Share on other sites More sharing options...
Escortn Posted September 25, 2012 Author Share Posted September 25, 2012 Every pinto I've had that suddenly starts throwing oil out like this needed a rebuild... and that it more than one lol.However, it could easily be the gasket if you've just rebuilt it. Motor rebuild or head? Could it be the head gasket if its just been replaced? Quote Link to comment Share on other sites More sharing options...
sholdowa Posted September 29, 2012 Share Posted September 29, 2012 yup that's what I meant. If the head's been off, it may just have been a problem with the gasket, or torquing the head down. Quote Link to comment Share on other sites More sharing options...
cubastreet Posted September 29, 2012 Share Posted September 29, 2012 Some head gaskets need to be retorqued, don't know if it's just old ones but when I rebuilt a crossflow engine the gasket kit said to retorque after 500 miles or so. Never had to because someone stole the van before I'd even refitted the carb. Could also be PCV valve stuck causing oil to be squirted into your intake. Check and see if your air filter is full of oil / check the PCV is ok. Quote Link to comment Share on other sites More sharing options...
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