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sound familiar? Odd rattle
https://slantsix.org/forum/viewtopic.php?t=38616		 Page 1 of 1
Author:  Dantra [ Wed Jan 13, 2010 5:26 pm ]
Post subject:  sound familiar? Odd rattle
after reading page upon page using the search function, I have decided to ask the forum members here...

I just replaced my very tired 225 with another 225 (low milage) and have finished the fine details of the install... timing 5 btdc, dwell 42, new poits, new vacuum advance etc. Upon the initial test drive I noticed what I would call a rattle, not so much a knock but close maybe. It's not present at an idle or higher rpms, just right about at the shift point of my 3 speed at a cruise. I can replicate it while sitting still as well with a raised rpm..kinda seems to be in the float spot where it's not really idle but not under a pull either.

When I first notced it I wondered if maybe the timing and dwell was off, causing the noise. I played with the timing a little just to see (since I hadn't checked it yet) I found that if I retarded the timing and pulled the advance line and it seemed to reduce the noise. But now I have everything all dialed in and the noise is present at certain rpms.

I'll add this as well...when I first installed the motor, I changed the oil and filter not using the ideal engine oil for a slant I'm sure. On the shelf I had 2 gallons of 15w40 and thought I'd go ahead and use it for the initial flushing of garbage that could possibly have been in the motor rather than waste money buying 5 qts of oil that I was going to dump after an hour of running. I plan to replace that oil with 10w30 this weekend. I use 15w40 ALOT in our high mileage shop vehicles without a problem...but they are chevys. Think it may just be that the slant doesn't like the 15w40 or do I potentially have another problem at hand?
Author:  SlantSixDan [ Wed Jan 13, 2010 5:34 pm ]
Post subject: 
The rattle is probably one or two valves — yes, even if they've been adjusted rather recently — and/or a bit of piston slap. I think I know the sound you mean; it's usually of no real consequence except for the annoyance itself. A careful valve adjustment will likely reduce or eliminate it.

Also, don't know what your ambient temperatures are, but if they're at all wintry (and I suspect they are, you being in Indiana) both 15w40 and 10w30 are too thick for a low-miles engine. Use 5w30 or, better, 0w30.
Author:  Dantra [ Wed Jan 13, 2010 5:52 pm ]
Post subject: 
I've only driven it at full operating temps and that's when I noticed the rattle. This is a toy atm, not a driver yet. As mentioned, I plan to remove the flush oil this weekend and I'll go with the 5w30. I'll run the valves tomorrow...what is it, 10 and 20 ? I don't have any lifter ticking but I'll run them

I hear every little noise since Iam literally sitting right beside the motor

Thanks
Author:  SlantSixDan [ Wed Jan 13, 2010 5:55 pm ]
Post subject: 
Do the valve adjustment correctly (procedure at link)
Author:  Dantra [ Sat Jan 16, 2010 1:31 pm ]
Post subject: 
well I never did get to the valves but I did swap out the oil thursday...it became more evident that it was bearing noise that I was hearing. Kinda what I initially thought but just didn't want to believe it. My wife and I drove it to El Rodeo (one of our favorite eats) lastnight and I was hearing the noise right at the shift poibt or at a slightly raised idle. I take out out today and drive around with the doghouse open (you can do that in an A :D ) and really got to dial in on the noise. I came back home an started pulling plug wires and found that when I pulled #6, the noise would go away almost entirely. So I'm guessing a #6 rod bearing is bad, which is a real shame since I just put this motor in. I guess I'll drop the pan since it's so easy to do in this truck, and have a peek.

Lemme ask this...Is this a common area for the slant? I know that many motors have common area problems ie the 3rd gen Hemi is notorious for breaking rings glands on the #1 piston. Just seems odd since this thing has awesome oil pressure and runs so well otherwise.

My next move is to email the seller and let him know what a pos :x he is for telling me that it ran great, no noise, no smoke. It does run great but it has a noise and a lil' smoke that I can deal with. Shame on me tho, I shoulda pulled the pan and had a look for myself :cry:
Author:  Dantra [ Sat Jan 16, 2010 2:53 pm ]
Post subject: 
Pan is off and rod caps are removed :)

Before pulling the caps, I went through to see if I could feel any play and found good ol' #6 had some slop. I pulled the cap and found a shot bearing but to my surprize the journal didn't look so bad. I also notised that this motor has been rebuilt before since all of the rod caps were stamped/ punched with their positions. I also found the reason for the bad bearing...are you ready? The pan had sandy gritty material in the bottom of it. I have to assume that this motor had been sitting outside, laying on it's side in the mud or something.

I plan to put some rod bearings in, clean it up and see if I can at least get a summer out of it. Maybe build the stock motor up while waiting for this replacement to go south :shock:
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