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Re: TR3 engine knocking, Help .

To: Nickbk@aol.com
Subject: Re: TR3 engine knocking, Help .
From: jibrooks@juno.com (Jack I Brooks)
Date: Tue, 26 Nov 1996 21:26:52 EST
Cc: triumphs@autox.team.net
References: <961126002235_1984706328@emout11.mail.aol.com>
Nick,

Since you have really made my day, I have only one question:  What about
the timing chain?  Any possibility the problem could be there?  I am
going to do the old metal rod or heater hose trick to try to identify
where the noise is coming from.  I'll let y'all know tomorrow.

Jack Brooks
Hillsdale, New Jersey
1960 TR3-A TS69032L

On Tue, 26 Nov 1996 00:22:36 -0500 Nickbk@aol.com writes:
>In a message dated 96-11-24 22:38:31 EST, you write:
>
><<  The TR3 we purchased a
> month ago seem to be developing a loud regular knock at the front of 
>the
> engine, which I am hoping is the big end of number one cylinder, and 
>not
> a crank bearing.   
><snip>
>Help! 
>All you regular TR wrenchers.  It has come on fast, less than 200 
>miles;
> almost sounds like it could be from the water pump, but I feel it is 
>from
> the cylinder #1 area.  Rattles at idle, up to around 4,000 RPM, where 
>it
> seem to go away, maybe.  I was planning on checking out the bearings 
>this
> winter because of low, 15 psi oil pressure when hot.  The cold oil
> pressure is 70 psi, limited by the pressure relief valve.  I took it 
>out
> cleaned it, and later adjusted it to be sure that it was working.  
> 
> If the problem is a crank main bearing, can that be done from 
>underneath
> also like the big ends?  I only discovered this noise today and my
> preliminary reading of the manuals is not clear.
> 
> If anyone has any ideas or things to check out,  I would appreciate 
>your
> guidance.  Also, if anyone has redone the bottom end with the engine 
>in
> the car, I would appreciate your titbits of wisdom.   >>
>                                             
>
>Jack-
>
>It sounds like good news/bad news time...
>The good news is that winter time approaches, the bad news is that 
>you're
>gonna need the time to fix it.
>
>Its definetly difficult to diagnose sounds "over the net", so give 
>these
>ideas a try. 
>
>First, remove the fan belt (new to TR3's ?, you'll love removing it), 
>then
>run the engine and check for the noise. No noise = good news. Noise 
>must be
>coming from water pump, generator or front hub/pulley (check for tin 
>halves
>of pulley bent/cracked). Still have the noise = bad, go to two.
>
>Two, with engine running and noise at maximum sound, remove each plug 
>wire
>one at a time and listen for lessening of noise. Less noise with wire 
>off =
>sorta good. When the plug wire is removed, there is less strain (no 
>fire, no
>expansion of gases and no "push") on the piston, hence less noise. 
>Whichever
>cylinder has the most effect   on the noise, probably has a bad 
>bearing or
>wrist pin. No change in noise level = bad, go to three.
>
>Three, final desperate act, as you probably have bad main bearings, 
>with
>engine running, depress clutch pedal. These motors are not noted for 
>losing
>their thrust washers, however, I have seen more than one of them with 
>the
>washers inserted backwards. Surprisingly, this usually seems to have 
>only a
>small effect on the crank, but the washers just fall apart due to the 
>high
>heat generated on their steel backings. Change in noise here = good as 
>a new
>set of washers may get you down the road. No change in noise  = bad, 
>we're
>back to the main bearings.
>
>Rod bearings and even the thrust washers can be changed from under the 
>car.
>Not a fun job on your back with old oil and grease droppin in your eye 
>at
>some crucial moment, but do-able. YOU can change the main bearings in 
>the
>car, but you're gonna wish you'd have pulled the motor. The center 
>main is
>piece-o-cake, and the rear isn't too bad, but the front one is 
>tougher. The
>front cap has two bolts through the front plate into the face of the 
>bearing
>cap. You can get to these bolts, and you can even get the cap off, but 
>the
>front of the cap mates to the back plate of the front timing cover and 
>there
>is a gasket between them. If your luck isn't perfect (and we know that 
>it
>isn't, or you wouldn't be in this mess), there's no way to replace 
>that
>section of gasket that's gonna tear out with the bearing cap, and its 
>gonna
>leak like the devil. Be sure to use lots of  "gorilla snot" (technical 
>term
>here for 3m or rtv) stuffed up there. 
>                               
>Of coarse all this talk of changing bearings, assumes that the crank 
>is
>perfect and does not need to be turned. (Remember the plastigauge !)
>
>Glad its you, not me...
>         Nick in Nor Cal          
>

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