Hi there, wow it's been a while since I've posted here, but then I just started trying to do more on my '71 Comet. Anyway, it's got the rebuilt motor and all, with roughly 10,000 miles on it when I noticed this problem. It seems to be pumping oil onto the #4 Plug, obviously causing the car to drive really crappy. To a lesser extent it does on the #5 plug too, but I would say only about 25% of how it does the #4. Anyway, we've done testing, replaced various stuff such as valve cover gaskets, re-torqued the head, and I just got the car back from my mechanic after rebuilding the valve guide seals, and yet after getting the car back I monitored it, and still it's exhibiting the same symptoms. I have to pull the #4 Plug out and clean the crud off of it with a wire brush roughly about once a week)and hope I don't break the plug off, lol). So after talking to my mechanic and explaining the situation, he's telling me the next step is to check the piston rings(he's 100% sure that's where the problem lies). Of course that's a pricey job(quoted $500-$700 total) and i'm just trying to see if there is just something that can be done, to avoid(or at least put off) paying that kind of cash. Especially considering I just rebuilt the motor such a short time ago. The motor itself is the 250 straight six, numbers matching for my '71 Comet. Thanks in advance for any advice I can get here. I do realize I may just have to bite the bullet on the rings but I want to avoid that if at all possible. I also wonder if this will heavily influence my Az emissions test coming up in July.
is the car smoking? you can try a bottle of no smoke or engine restore. problem is that the rings probably didnt seat in that cylinder when it was built. it may have had some slight surface contanimation as well. a cracked piston is also possible. you can ty the no smoke or engine restore but the sad part is eventually it will need to be torn into to know and fix
Thanks for the reply, the car isn't smoking at this time. I do have to add oil about every few weeks or so though.
That's exactly how i found my problem. And you'll fail the emission test. It sound like piston slap in the cylinder. Before to much damage is done yank it out. Pull the bottom end and mic the cylinders. What a supprize. Then you can get it right.
Alright thanks. Dad and I were talking and we figured it wouldn't pass emissions. Well, I know where my money is going for awhile V_V
b-4 you commit to anything, get some zipper baggies and different collor sharpies. tahe lots of pictures so you can remember where everything goes. and shop around on your machine work. get a few local people to tell you there exp with diff shop's. GOOD LUCK!
First thing I would do to it would be a leak down test. In a quiet inviroment you can pinpoint where anything is leaking in each cylinder. That would pinpoint where the problem is When the cylinders heads were repaired were they magnafluxed as well? Edit: LOL Just noticed another AZ guy, we need a sub forum AZ Mavericks/Comets seem to be alot of desert people here. LOL And for local machine shops, standard or duffee around here.
You could install a non fouler on the #4 plug...This will get you by for a bit as far as the driveability problem is concerned but it still wont pass a Tail pipe sniffers examination. Do a leak down test to determine if its bad rings or valve guides/seals.( I know you said you had them done) Its possible the cyl bore is cone shaped (tapered) This will affect ring sealing. Were the bores checked for taper before rebuilding??? Were they honed to break the glaze and replace the crosshatch so the new rings would seal??? Were the rings installed on the piston properly. IE: facing in the right direction (they do have a top and bottom) Gaps staggered properly to prevent excessive blow by. If you reused the original pistons...Were the skirts good on em??? Were the ring lands properly cleaned and checked for tolerance??? They do wear from the movement of the rings working against them... Just a few things to consider...Do a proper leakdown test...It will give you needed info, good luck!!!
there is a spark plug on the market that fires in oil. I used one on an old chevy that used to foul quite often...same symptoms you described. Not the cure but it prevents you from having to pull the plug and clean it all the time... worked for me. also, you may be able to find a decent 6 cyl engine for the same cost as repairing yours...guys on this forum are often pulling the 6 cylinders out and replacing them with V8's.. just a thought here is the plug http://www.autobarn.net/smartplug.html can probably find it locally ... good luck
