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| Not good..... https://slantsix.org/forum/viewtopic.php?t=29978 |
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| Author: | Eric W [ Sat Jul 12, 2008 11:41 pm ] |
| Post subject: | Not good..... |
Well, after replacing the head last weekend and enjoying the car running great, I have a new problem. Burning oil. Major. Like, two quarts low in two days bad. I drove to work today and traffic was light, so I could see what was going on behind me. OK, here it goes. At idle, no smoke. Driving around town, normal city speeds and maintaining steady speed on freeway, don't notice anything. Decelerating or accelerating hard, smoke city. I replaced the valve guide seals when I lapped the valves, though the ones I used (Felpro) on the intake did not fit over the valve guides like the original (and still good) ones did (I did save them for some reason). They moved on the valve stem rather than stay put. My first mistake? I also cleaned the ridges on top of the cylinders, and scraped the carbon off the top of the pistons. I then vacuumed out the cylinders and used a piece of shim stock to make sure nothing got left around the top ring. I haven't done a compression test yet, nor have I checked the spark plugs yet. I'll do that tomorrow. Could the new head with its new found compression, have overwhelmed the rings? Other than this, the engine runs great and dosn't miss a beat. Runs normal operating temp, no noises, etc. |
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| Author: | THOR [ Sun Jul 13, 2008 3:14 am ] |
| Post subject: | |
I assume that all of this was done with the engine in the car. Does it smoke upon startup after sitting for a few minutes? How far down did you go with the ridge scraper? Do you have a measurement of how much you removed from the cylinders? My suspicion is that there is an issue with the rings. ~THOR~ |
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| Author: | SlantSixDan [ Sun Jul 13, 2008 5:03 am ] |
| Post subject: | |
Oh, dear.  Yep, sometimes the increased cylinder vacuum and pressure created by putting a nice fresh head atop an old engine will finish off rings that were marginal (and were doing OK with the relatively low suction and pressure with the worn head). You're pulling oil up past the rings. Time to contemplate lower-end options.
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| Author: | Charrlie_S [ Sun Jul 13, 2008 5:20 am ] |
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Quote: Oh, dear.
I don't totally agree with that assesment. Usually the rings would have to be bad enough to be passing some oil, before doing the head. I am more inclined to think "trash" got in the ring grooves, from cutting the ridge, or the ridge was cut too far down. I would never cut the ridge, unless I were pulling the pistons. But I do agree it is time for more work.
Yep, sometimes the increased cylinder vacuum and pressure created by putting a nice fresh head atop an old engine will finish off rings that were marginal (and were doing OK with the relatively low suction and pressure with the worn head). You're pulling oil up past the rings. Time to contemplate lower-end options. |
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| Author: | SlantSixDan [ Sun Jul 13, 2008 5:25 am ] |
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Quote: Usually the rings would have to be bad enough to be passing some oil, before doing the head.
They probably were. A surprisingly large amount of oil can be coming past the rings without it being very noticeable from the driver's seat or on the spark plugs, and if I recall correctly (Eric?) this is a high-miles engine.I agree with you that cutting the ridge without removing the pistons wasn't a good idea, but I'm not sure where your line of thought is going when you say the ridge might've been cut too far down...the ridge is where the rings don't reach, so even if it were significantly larger in diameter than the rest of the cylinder, it shouldn't make a difference. |
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| Author: | dakight [ Sun Jul 13, 2008 5:46 am ] |
| Post subject: | |
It can put a slight taper at the top of the cylinder, at the very upper reach of the ring travel. It would be almost impossible to cut only the ridge without extending a small distance below the ridge. Also, the cut area will not be as smooth as the original worn area as the tool tends to chatter a little. All in all, it's a bad idea to cut the ridge unless you're planning to hone the cylinders and install new rings and bearings. |
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| Author: | Aggressive Ted [ Sun Jul 13, 2008 8:49 am ] |
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Eric, I would get the correct valve guide seals and install them and then run some Rislone to clean up your rings for a week or so, then do a compression test. Hopefully the oil ring will clean up and start sealing again. I have done this on worse engines than yours and brought them back to life to were the oil consumption would stop. It should buy you some time, but ultimately you will need to do a rebuild. Two quarts would indicate that the oil ring is plugged full of carbon deposits........That needs to get cleaned out! Since your using oil it wouldn't hurt to dump in a quart of Rislone. You may need to dump the oil at 500 miles or less. It will get pretty black. Rislone is allot like Drano, it unclogs that oil ring and any other accumulations. What kind of oil do you use? |
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| Author: | Joshie225 [ Sun Jul 13, 2008 9:41 am ] |
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The way I read it Eric cleaned the carbon from the top of the bores, but did not cut any metal. The umbrella seals that float on the valve stem work fine, but if the guides are worn they will still pass oil. Were the valve guides checked for wear? I would do the compression test and also pull the manifolds and see if the intake or exhaust ports are wet with oil. My 43k mile 225 needs valve stem seals bad enough the intake ports are shiny with oil. My engine burned about a quart every 300 miles or so. If the exhaust valve guides are really bad you can pass oil through them too. Smoke under deceleration can be intake guides or rings. Smoke under heavy acceleration can be rings or exhaust valve guides. |
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| Author: | slantzilla [ Sun Jul 13, 2008 9:42 am ] |
| Post subject: | |
General rule of thumb is smoke on acceleration is rings, deceleration is valve guides. 
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| Author: | SlantSixDan [ Sun Jul 13, 2008 10:14 am ] |
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I wouldn't be too hopeful that any kind of a flush/clean action will handle this problem, which I think is mechanical in nature (wear). Nevertheless, it wouldn't hurt anything to have a bowl of soup. |
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| Author: | Eric W [ Sun Jul 13, 2008 10:43 am ] |
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Thanks for conferming my suspisions. I only removed the carbon on top of the cylinders. I'm tired of messing with it, time to sell. |
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| Author: | SlantSixDan [ Sun Jul 13, 2008 11:01 am ] |
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!,! For real? You're selling? |
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| Author: | Eric W [ Sun Jul 13, 2008 11:17 am ] |
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I don't have the space or time to rebuild a spare engine, nor do I know anyone around here who does. And good luck finding somebody to help put it in. Plus, its my only car. I put 30K miles a year on it, so I knew it would happen eventualy. I'm just tired of messing with it.....if its not one thing its another! |
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| Author: | SlantSixDan [ Sun Jul 13, 2008 12:43 pm ] |
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That's a shame. Sorry to read it. I hope this doesn't mean we won't see you around here... |
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| Author: | steponmebbbboom [ Sun Jul 13, 2008 12:58 pm ] |
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Why dont you just do what i did and buy a spare engine off craigslist for $100?! harbor freight folding shop crane for what, another $150, couple 4x4 crib blocks under the front wheels, a $20 bottle jack under the trans and you can replace that engine YOURSELF in one day. I did it, so can you. |
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