Should an engine get quieter or noiser as it warms up?
Tappet clearances close up, so it should get quiter in this
respect, but oil gets thinner, which might allow more movement
between surfaces (tappets / guides for example).
My engine is mechanically extremely quiet when cold, but I get
tappet noise when hot…the hotter it gets the louder it becomes.
I’ve found the opposite to be true of a couple of modern cars I’ve
had (Rover and Honda for example, neither with hydraulic tappets).
Apart from the noise, the engine has good & even compressions and
does not smoke at all. It feels very strong in fact.
Any thoughts? Is oil viscosity critical to engine noise?
In reply to a message from Dr.G sent Thu 22 Apr 2004:
Garth,
Holes grow with heat, oil gets thinner, noise gets louder in valve
trains. Lifter buckets are especially prone to rock and tap a bit.
A mcy. manufacturer I worked for had a problem with tappet (bucket)
head noise when hot. Result of lean fuel mixture (damn emission
requirements). Gave us these infintesimally small incremental sizes
of tappets. As it turned out, tedious measurement wasn’t neccesary.
Just put the biggest one in that would fit (w/o a hammer!)
‘‘Noise is not a warrantiable defect’’. Wonder where I got that?
Dave–
David Ahlers
Skaneateles, NY, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Dr.G sent Thu 22 Apr 2004:
Garth,
That seems to be the norm on these engines. Other than a
little piston slap, mine is very quiet when cold, then gets noisier
as it warms up. This has been true for every XK I’ve worked on.–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Dr.G sent Thu 22 Apr 2004:
Garth-
yes, I spent a while in close proximity to mine tuning it (well,
failing to tune it) and could hear mechanical noises much more
clearly when it was hot.
Even had a little fun trying to identify the different sources.
Sad, really.–
The original message included these comments:
My engine is mechanically extremely quiet when cold, but I get
tappet noise when hot…the hotter it gets the louder it becomes.
I’ve found the opposite to be true of a couple of modern cars I’ve
–
Joe Hardy - '63 3.8 OTS in the UK
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Dr.G sent Thu 22 Apr 2004:
Garth,
I had a similar problem with mine. #3 intake valve made a racket
when the engine was warm. I inspected everything on that valve
assembly, with a microscope, literally. Could not find anything
wrong. In 69 when they made my car they were having a lot of
trouble with valve noise and changed the cam profile quite a few
times. I bought a newer XJ6 head and used that intake cam. The
noise level decreased a little. I changed the tappet (bucket) out
and the noise went away. There was about .0001’’, maybe .0002’’
difference in the diameters.
Mic the buckets and see if there is a small one. BTW, I found that
new buckets available from the usuals are about .019’’ thicker than
the originals. So you will need a new shim. If the old one is on
the thin side, you have a problem.
Anyway, after countless hours in the engine compartment, that is my
success story with valve noise.
Dave Christensen
69 OTS–
davchr
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from davchr sent Thu 22 Apr 2004:
Dave,
Yep, I put all new tappets in when I rebuilt the head…I didn’t
want to disturb the tappet guides though, so chances are they are a
bit worn.
I sometimes get an intermittent louder tapping noise when warming
up. I believe this could be a tappet not rotating properly.
It’s not really a big deal, but with such an otherwise smooth and
relaxing car / engine its kind of disappointing to hear so much
tappet noise when hot.
Has anyone experimented with oils to try to reduce noise? I’m using
cheap 20W50 at the moment.
Regards,
Garth.–
The original message included these comments:
Mic the buckets and see if there is a small one. BTW, I found that
new buckets available from the usuals are about .019’’ thicker than
the originals. So you will need a new shim. If the old one is on
the thin side, you have a problem.
In reply to a message from Dr.G sent Thu 22 Apr 2004:
Garth,
FWIW - I’ve never found the type of oil to make any significant
difference in the tappet noise, and I’ve tried everything from 5W
synthetic to 30W dino-juice. Now the new head gasket, that made
a big difference. Go figure…–
The original message included these comments:
Has anyone experimented with oils to try to reduce noise? I’m using
cheap 20W50 at the moment.
Regards,
Garth.
–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Dr.G sent Thu 22 Apr 2004:
Garth,
You mean you didn’t bore each tappet guide out to a thin OD &
chisel out the remainder, bore the head, heat and insert the new
guide, measure the tappet and hone to .0008’’?
(me either!)
I’d bet if you can figure out which one is tapping a slightly
larger od tappet might do it. Trouble is a manufacturer has to
undersize replacements so ‘‘one size fits all’’.–
David Ahlers
Skaneateles, NY, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from David Ahlers sent Thu 22 Apr 2004:
David,
Actually…no I didn’t. I was going to, but then I thought ‘‘lifes
too short (and expensive)’’. The other thing was that someone told
me that the new guides may work loose.
Ray,
Your recent comment regarding the difference in idle quality and engine sound with the new head gasket brought back memories. I used to work on small block Chevys and the high compression engines had a noticably ‘harsher’ idle than similar low compression engines.
Larry
Larry,
That doesn’t surprise me, but what does surprise me in this
case is that a mere 1 point difference in compression could improve
the idle, and the sound of the engine, so profoundly.–
The original message included these comments:
Ray,
Your recent comment regarding the difference in idle quality and engine sound with the new head gasket brought back memories. I used to work on small block Chevys and the high compression engines had a noticably ‘harsher’ idle than similar low compression engines.
Larry
–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
I pulled out my tach generator last night to find out why the unit went
dead last week, and it was no big surprise that the new unit I installed
a couple thousand miles ago has already failed in the same way my old
one did. The bushing has been pushed back into the unit which
disengaged the drive shaft.
Has anyone found a reliable way to secure these so that this doesn’t
happen? I can’t understand why they didn’t leave a small collar on the
end of the bushing so that it could only be inserted to a certain depth.
It’s probably made of sintered bronze, so I suppose it wouldn’t be
possible to braze little collar onto it eh?
In reply to a message from Eric MaLossi sent Thu 22 Apr 2004:
Hi,
I repair these regularly.
After you pull the center tab back out with it’s bronze bushing,
drill a tiny hole through the white metal casing and into the
bronze bush (about 1/8’’ from the end and barely into the bronze).
The drill should be the same size as the solid ‘‘nail’’ of a standard
1/8’’ ALUMINUM pop rivet. The drill is around 3/32’’ diameter, but
you better measure it. Snip off about 3/16’’ of the pop rivet shaft
and tap it into the hole, securing the bronze in place. If the pin
is a little longer than the hole depth, it will peen over and
secure itself in place. Any excess can be filed away and being
aluminum, will distort before the other metals. Use only an
aluminum pin, steel won’t peen over.
The bronze bush is now secured by the pin.
Put your tongue on the 2 connectors and spin the rotor with your
fingers. If you feel a mild tingle, you’ve got a working gen.
again. Or you could hook it up to a voltmeter if you don’t know who
it’s been dating lately .
Phil.–
The original message included these comments:
I pulled out my tach generator last night to find out why the unit went
dead last week, and it was no big surprise that the new unit I installed
a couple thousand miles ago has already failed in the same way my old
one did. The bushing has been pushed back into the unit which
disengaged the drive shaft.
Has anyone found a reliable way to secure these so that this doesn’t
happen? I can’t understand why they didn’t leave a small collar on the
–
PhilW
Virginville, Pa., United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from PhilW sent Fri 23 Apr 2004:
Nice fix, Phil! THAT’S one I never knew before! Off to see if
Tweet’s needs doing!–
The original message included these comments:
After you pull the center tab back out with it’s bronze bushing,
drill a tiny hole through the white metal casing and into the
bronze bush (about 1/8’’ from the end and barely into the bronze).
The drill should be the same size as the solid ‘‘nail’’ of a standard
1/8’’ ALUMINUM pop rivet. The drill is around 3/32’’ diameter, but
you better measure it. Snip off about 3/16’’ of the pop rivet shaft
and tap it into the hole, securing the bronze in place. If the pin
is a little longer than the hole depth, it will peen over and
secure itself in place. Any excess can be filed away and being
aluminum, will distort before the other metals. Use only an
aluminum pin, steel won’t peen over.
–
Paul Wigton, 1963 FHC, called Tweety!
Brighton, CO, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
In reply to a message from Ray Livingston sent Thu 22 Apr 2004:
You need to burette the engine really Ray before you can be certain
of that 1 point change. There may be more surprises in store!
But then in any case, a one point change from ‘OK’ to ‘OK-but-
different’ is going to be less noticeable I expect than a one point
change that brings a ‘Not-OK’ engine back into the normal range.–
Peter Crespin 94 X300 Daimler / 66 2+2 ‘E’
Buxton, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
Phil,
I had considered doing something like this, but was concerned that if
the pin worked loose it would end in the drive train. It sounds like
you’ve had success with it though, so perhaps I’m just being a worry
wart.
You say that you “pull” the thing back into the correct position. The
last time this happened to me, I ended up having to take the back off
and then push it back into place which was a real pain. How does one go
about pulling it out?
Eric,
I knurled the heck out of mine and so far so good. If it does fail someone here said that they had drilled and tapped a hole for a set screw, that seems like a permanent fix.
pauls 67ots
I pulled out my tach generator last night to find out why the unit went
dead last week, and it was no big surprise that the new unit I installed
a couple thousand miles ago has already failed in the same way my old
one did. The bushing has been pushed back into the unit which
disengaged the drive shaft.
Has anyone found a reliable way to secure these so that this doesn’t
happen? I can’t understand why they didn’t leave a small collar on the
end of the bushing so that it could only be inserted to a certain depth.
It’s probably made of sintered bronze, so I suppose it wouldn’t be
possible to braze little collar onto it eh?
In reply to a message from Peter Crespin sent Fri 23 Apr 2004:
Peter,
Not sure what you’re getting at here. I certainly do not need
to ‘‘burette’’ to know precisely how much it dropped. I now all the
pertinent measurements to high accuracy already. It dropped from
9.91:1 down to 8.91:1, give or take perhaps 0.01:1.–
The original message included these comments:
You need to burette the engine really Ray before you can be certain
of that 1 point change. There may be more surprises in store!
Peter Crespin 94 X300 Daimler / 66 2+2 ‘E’
–
Ray Livingston - '64 OTS Santa Cruz, CA
Santa Cruz, CA, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
i have the same behavior.
i asume i have some waer onr bearings etc. when could the oil is masive &
heavy viscous. when warm, the oil gets thiner, so less sound reduction
Wilko Pels
71 ots Amsterdam
At 14:55 22-4-2004, you wrote:
All,
A simple question…
Should an engine get quieter or noiser as it warms up?
Tappet clearances close up, so it should get quiter in this
respect, but oil gets thinner, which might allow more movement
between surfaces (tappets / guides for example).
My engine is mechanically extremely quiet when cold, but I get
tappet noise when hot…the hotter it gets the louder it becomes.
I’ve found the opposite to be true of a couple of modern cars I’ve
had (Rover and Honda for example, neither with hydraulic tappets).
Apart from the noise, the engine has good & even compressions and
does not smoke at all. It feels very strong in fact.
Any thoughts? Is oil viscosity critical to engine noise?
.