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jayb
Dodge Dakota
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11/19/2005
12:51:45
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 Subject: why does my 318 knock?
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my 93 has had this wierd knock for a while. seems like since i changed over to synthetic. when i first switched over, i put in 5w30,like a dumazz, and ran it with that for a while. well, slowly i noticed a faint knocking sound. it still does it, and i think its a lifter knock. i dont lose any oil pressure or anything like that. it only does it at idle. one i give it any gas it goes away instantly. now i run 10w40 synthetic with lucas stab. in it. still get that faint knocking sound at idle. it kinda pisses me off cause i just got this thing like 8 months ago. any how, any ideas, and tips on what to do would be very appreciated. thanks.
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toolfan
GenIII
11/19/2005
13:25:18
| RE: why does my 318 knock?
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lifters tick.
that is not good but i don't know what you could do besides put the correct oil in it.
and some mods to slow it down!
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jayb
Dodge Dakota
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11/19/2005
18:26:35
| RE: why does my 318 knock?
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the correct oil is in it now.
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gen1dak
Dodge Dakota
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11/19/2005
22:43:40
| RE: why does my 318 knock?
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Try 20W50. Just give a little more time to allow for warmup if you're in cold weather. Since the knock lessens with the 10W40, sounds more like rod knock, aka, you got some loose tolerances. Also, since it goes away with throttle (and oil pressure tends to increase as you move up from idle), this would tend to also point to worn bearings. Try the 20W50, or just put in some "motor honey"...that thick STP oil treatment to thicken up the oil. This will help keep oil pressure up to fill in the worn areas of the bearings. If that works, definitely go 20W50 on the next change, and you may still want the STP then too. Worth a shot. 10W30 is fine when the engine is fresh, but loose, you need the thicker stuff.
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jayb
Dodge Dakota
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11/19/2005
23:34:33
| RE: why does my 318 knock?
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right, but if you have a rod bearing loose, you should lose oil pressure.
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daddio
Dodge Dakota
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11/20/2005
10:08:25
| RE: why does my 318 knock?
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jayb,"right, but if you have a rod bearing loose, you should lose oil pressure."
i don't think the drop would be noticeable with just a loose rod bearing. now, with a loose main bearing, yes. an oil pressure drop would be real noticeable. put a mechanical oil press gage to see exactly what's up.
what gen1 stated is a good short term remedy.
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OBIO3
Dodge Dakota
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11/20/2005
13:27:24
| RE: why does my 318 knock?
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I truely see no way you can get a meaningfull answer to your problem > Not enough informastion > How many miles on this engine > What kind of oil was used prior to syn and what weight > Or was the syn your first oil change aftr purchase > If it was, the oil may well have been doctored to cover the knock to faciliate a sale > Now if this was not your first oil change, the problem was not caused by the change > You need to do some better checking > Use a metal rod that you can hold to your ear , better yet a engine stephascope ? spelling, so you can determine if this is a surface knock or coming from deep inside the engine > another thing to try is while idling disconnect one plug at a time > If no change on any plugs you can bet it is not a bearing or ristpin > Even at that this is not a proof positive test but a reasonable assumption > Do all I said and add your answers together for your best guess your going to get > Good luck
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jayb
Dodge Dakota
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11/21/2005
09:44:54
| RE: why does my 318 knock?
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ok a stethascope has been used. its a top end tap. it goes away after 800(or so) rpm's, and oil changed didnt do sh!t. im almost positive its gotta be a lifter tap, but ive never really heard of dodges just doing that. its usually a chevy thing. oil pressure is consistant and doesnt fluxuate abnormally.
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ObieWonDakota
Dodge Dakota
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11/21/2005
10:13:14
| RE: why does my 318 knock?
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Whatever you do, DO NOT, I repeat DO NOT run 20W50 like gen1dak suggested, especially if you are in cold weather.
Ran that in an Aries I used to own (most reliable car I've owned to date) one time. A freak snowstorm hit in Ohio and the temp dropped to below zero (with the windchill). Went out to start the car and it would't turn over because the 20W50 gelled. I needed a ceramic space heater under the oil pan to warm the oil before it would start. I'm not saying running 20W50 is a bad thing, but unless it's in warm weather, I wouldn't reccomend it based on experience.
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jayb
Dodge Dakota
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11/21/2005
11:53:24
| RE: why does my 318 knock?
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im running 15W40 synthetic right now, but im north of seattle, and it rarely gets below 30 unless you hit the mountains where it gets close to 0.
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gen1dak
Dodge Dakota
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11/21/2005
12:13:24
| RE: why does my 318 knock?
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As stated, my suggestion was aimed at loose bearing clearances. If it's lifter "tap" thicker oil won't help. Any make, running hydraulic lifters can have lifter tap. It's probably just a little gummed up since it goes away after rpm increases. A good cleaner like Seafoam would help. Marvel Mystery Oil is also good for this, and it improves the oil viscosity index in the process....just in case you have a "freak snowstorm". I have also has an Aries, and have had 20W50 in it when temps dropped near zero WITHOUT windchill (it does happen on rare occasions down south), and the car still turned over. Blame a weak battery or starter, not the oil.
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ObieWonDakota
Dodge Dakota
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11/21/2005
13:13:01
| RE: why does my 318 knock?
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My post wasn't intended to bad mouth you gen1dak. Didn't know where you lived so I was just stating my experience. Wasn't a faulty battery or starter for me, just the fact the oil jelled. After it was heated, it turned over fine. I noticed I forgot to put the temp when I said with windchill. Should have read -35 with windchill (right next to Lake Erie). It would have been a hell of a lot easier to crawl under there with the heater if it was a Dak versus an Aires :)
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OBIO3
Dodge Dakota
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11/21/2005
19:31:54
| RE: why does my 318 knock?
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Message:
The engine turning with heavy oil in cold temteratures isn't the issue your concerned with > It'the time involved getting that thick oil to cerculate to the bearings and all other moving parts > Hard to visulize just how little room there is to squeez that thick soupy oil through and just think how long it takes to warm it up in that cold temp > Not the engine so much but the oil > 10-30 syn is good all year around > 5-30 is best for the engine in winter in colder climates > Seafoam is a good choice > Autorex is great if done correct as instructed > If the lifter is gummed you will free it > If it colapsed you will gain nothing > If it started this tapping directly after a real hard run/race I'd lean toward colapse > Hard to out guess this >
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gen1dak
Dodge Dakota
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11/21/2005
23:00:20
| RE: why does my 318 knock?
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At that temp, I wouldn't move easily either. :-)
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