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| Engine Knock - Engine Setting Related? https://slantsix.org/forum/viewtopic.php?t=52039 |
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| Author: | ILMopars [ Sat May 11, 2013 7:55 pm ] |
| Post subject: | Engine Knock - Engine Setting Related? |
When I first bought my car it ran quiet, smooth and problem free as far as basic mechanical operation. It was at 650 RPM in N with high beams on, 1700 RPM fast idle, and TDC for timing. Now it is all screwed up, was, rather, now I am fixing it. Idle was at 850-900 RPM, fast idle was over 2000 RPM and timing was after TDC more than 2 degrees. Since the engine settings were messed with by someone else at a shop that shall remain nameless, the engine has developed a bad knock at idle that matches RPM. Is it possible that the incorrect settings have lead to this knock? |
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| Author: | ceej [ Sat May 11, 2013 9:22 pm ] |
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If that was the only change, yes. Moving the timing to after TDC is a problem. Have you verified your timing mark? Most slants like a lot of timing. Have you done anything to increase compression, or have you installed a different intake part, Cam, intake, carb and or exhaust? Is it stock? CJ |
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| Author: | ILMopars [ Sat May 11, 2013 9:47 pm ] |
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The mark is good. The engine is 100% stock, has been one piece since 1970. |
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| Author: | ceej [ Sat May 11, 2013 9:54 pm ] |
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Is the knock timing related? Have you checked the timing chain for wear? Pull all the plugs. Turn the ignition off, then pull the battery cables. Pull the cap, and look at the rotor. Rotate the engine in one direction, then reverse the rotation. Mark the crank pulley. How many degrees do you have to rotate the engine in crank degrees to make the rotor turn? CJ |
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| Author: | ILMopars [ Sat May 11, 2013 10:11 pm ] |
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Knock sound metallic in nature, not timing (I'm pretty sure) related, engine seems fine at idle. |
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| Author: | ceej [ Sun May 12, 2013 4:36 am ] |
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Oh. That kind of knock. No. Settings of that sort aren't likely the problem. Stop driving it and get some information. What is your oil pressure? Your going to need a gauge. Did the engine get revved up abnormally high at some point? Clean the oil pump bypass and shuttle, make sure it isn't sticking. Find out exactly what oil pressure you have. You may be listening to a rod. CJ |
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| Author: | slantsik [ Sun May 12, 2013 5:50 am ] |
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Quote: You may be listening to a rod.
To test this ,pull a spark plug lead off each cylinder, one at a time with the engine running. use long well insulated pliers ,or take the risk of getting belted with 10,000 volts.you can turn the engine off ,pull a lead then start again if you like.If the knock reduces you have found the offending rod/big end bearing. Main bearings are a bit harder to check. oil gauge is good for this one. Other sources of a knock can be : Low oil pressure flex plate bolt loose on auto trans. Very worn camshaft/lifter Broken rings fuel pump loose brackets water pump broken broken valve timing parts(springs etc.) piston slap good luck. Brendan. |
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| Author: | ILMopars [ Sun May 12, 2013 7:02 am ] |
| Post subject: | |
Quote: Quote: You may be listening to a rod.
To test this ,pull a spark plug lead off each cylinder, one at a time with the engine running. use long well insulated pliers ,or take the risk of getting belted with 10,000 volts.you can turn the engine off ,pull a lead then start again if you like.If the knock reduces you have found the offending rod/big end bearing. Main bearings are a bit harder to check. oil gauge is good for this one. Other sources of a knock can be : Low oil pressure - Does have a leaky head gasket and rear main seal, pressure is much higher than it used to be flex plate bolt loose on auto trans. - Could be a possibility Very worn camshaft/lifter - Maybe? Broken rings - Definitely worn fuel pump- New, operating as designed loose brackets - There is only an alternator on the engine, brackets good, and not broken water pump broken- New, operating as designed, engine stays coolbroken valve timing parts(springs etc.) -Checked under valve cover, may be timing set piston slap - Maybe? good luck. Brendan. |
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| Author: | ILMopars [ Sun May 12, 2013 7:08 am ] |
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Quote: Oh. That kind of knock.
Well the engine was set at over 2,000RPM on fast idle, that is abnormal. The bad timing may have bent something or done something.
No. Settings of that sort aren't likely the problem. Stop driving it and get some information. What is your oil pressure? Your going to need a gauge. Did the engine get revved up abnormally high at some point? Clean the oil pump bypass and shuttle, make sure it isn't sticking. Find out exactly what oil pressure you have. You may be listening to a rod. CJ |
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| Author: | ceej [ Sun May 12, 2013 10:03 am ] |
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If you think so. But no. CJ |
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| Author: | ILMopars [ Sun May 12, 2013 10:53 am ] |
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My thought is that if the engine is cold the max safe engine RPM was about 1700 RPM and that if it is set higher, on a totally stock engine then it can stretch, bend, gouge, scrape or something because it is too much stress for a cold engine to handle? Idk, again, just a thought, then again she does have over 71,000 and that is about 140,000 if it were a modern car. Food for thought I guess then it's just tired, but the guy who worked on the car made a comment the conversation went something like: Me: I hope it can go at least 100,000 before it needs a rebuild, I'll pull it apart and restore it. Mike: You'd be luck if it reached 70,000! Hmmm! Sabotage? Did he take advantage of my ignorance? Maybe? |
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| Author: | ceej [ Sun May 12, 2013 10:58 am ] |
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Have you checked the oil pressure yet? You have a 43 year old car. Mileage is peripheral to how long it's going to last. The light on the dash doesn't indicate adequate oil pressure. It just tells you it's not zero. CJ |
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| Author: | DusterIdiot [ Sun May 12, 2013 11:09 am ] |
| Post subject: | x2 |
Quote: Mileage is peripheral to how long it's going to last. The light on the dash doesn't indicate adequate oil pressure. It just tells you it's not zero.
Yeah I'd be looking at an oil gauge to see where it's at, if you get drain back while the car sits overnight and it doesn't get oil pressure up soon after starting, it's not going to like it. If the oil pump is out of tolerance it might have pressure but not a lot (dash light comes on at something like 7 psi, so if you have 20 psi of oil pressure you'll get no light and the engine is not going to like you on the highway).You can also get knock if you are a quart or 2 low daily driving it...checking the dip stick should be a semi-daily ritual. -D.Idiot |
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| Author: | ILMopars [ Sun May 12, 2013 5:45 pm ] |
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CJ, DI, well your both right. I will get an oil pressure gauge and check it out, btw where can I tap into the oiling system to get a good reading? The Dart is going into retirement this July anyways. She will be restored back to factory specs, and will become a family cruiser. I want to have a car that my kids (when I an older) will enjoy, and cherish from a time in Detroit they could only imagine about while I dream about... |
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| Author: | ceej [ Sun May 12, 2013 5:53 pm ] |
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You can tap in at the pressure switch location on the oil pump, just below the oil filter. I removed the switch from my engine and run a sending unit for a high end electric gauge set. The mechanical gauges work, but if the tube to the gauge is damaged, you can blow oil all over the place, including inside the car. CJ |
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