Valve ticking, but not a valve?

jmcjunkin · 08-11-2004, 09:45 PM

Any ideas? I am pulling my hair out with this nagging little noise.

My 3.0 sounds great and with no valve noise when cold, but develops a definite ticking when warm. It absolutely drives me crazy, sounds just like a valve out of adjustment. It has been doing this for 2 years. Engine runs perfectly. But the sound is driving me nuts!

I have adjusted and re-adjusted valves, and the ticking will not go away. Could it be elephant's foot? If so, how hard is that to address?

Would running a different weight oil make a difference? Other ideas?

Thanks in advance.

Jamie

Gordo2 · Gordo2's Garage

A few thoughts:

Small exhaust leak.

If under accelleration: head leak (broken stud).

If you only hear it with the hood up standing next to the engine: spark jumping (bad plug wires).

Good luck,
Gordo

Alan Cottrill · Alan Cottrill's Garage

I had the same problem...turns out it was my guides. Before I pulled the engine I pulled the rockers and changed the elephant's foot. the new ones were looser than my old ones. no help there.

try using something like Lucas oil conditioner...something real thick...but not too much, if the oil gets too thick you could run into a little oil starvation on cold starts. if it quiets down with thicker oil it could be the guides.

I went to a thicker oil and it helped the noise some. but eventally I had to break down and rebuild.

jmcjunkin · 08-11-2004, 10:32 PM

Thanks - I will try the oil conditioner. A cheaper way to go. The engine was completely rebuilt (though not by me) 10k miles ago, so I am hoping the guides are ok. If it is the elephant's foot, it that an easy job to change?

toolman · toolman's Garage

I have the same problem, I think the oil additive is a band aid. I wish someone else would chime in and offer some reasons for this.

RoninLB · 08-12-2004, 05:12 AM

Quote:

Originally posted by jmcjunkin

I have adjusted and re-adjusted valves, and the ticking will not go away. Could it be elephant's foot? If so, how hard is that to address?

were the feet machined clean at the reblild? were the rocker shafts spec'd? were the rockers re-bushed?

removing the rocker is brainless, although some simple technique is involved.

toolman · toolman's Garage

Could one replace the rockers and shafts with out removing the engine? Would they "bed in" to the cam OK?

RoninLB · 08-12-2004, 05:48 AM

Quote:

Originally posted by toolman

Could one replace the rockers and shafts with out removing the engine?

Would they "bed in" to the cam OK?

Yes

if the feet are not machined I was told to keep exact order and replacement of them so it's realigned with the cam lobes.

new feet = no prob on a good used cam lobe afaik.

RoninLB · 08-12-2004, 05:55 AM

Quote:

Originally posted by toolman

, I think the oil additive is a band aid.

it depends on the situation.

worn valve guides are a different situation than worn feet. A heavy grade will take up some clearance in the valve to guide fitment. A new valve seal, especially exhaust valve seal, may make the situation livable till machine work comes along. It's worth a shot imo.

toolman · toolman's Garage

I just had the top end rebuilt 3000 miles ago. I didn't have the rockers and shafts mic'd. I never thought of it. I should have had the rsr seals put in at that time because I have a small leak at the end of one of the shafts. I was going to do another valve adjust soon to make sure I did it right and try the torque on the shafts while I was in there. Thanks for the help Ronin!

RoninLB · 08-12-2004, 06:20 AM

Quote:

Originally posted by toolman

I should have had the rsr seals put in at that time because I have a small leak at the end of one of the shafts.

I was going to do another valve adjust soon to make sure I did it right and try the torque on the shafts while I was in there.

the seals are Not a guarantee. Although it can't hurt. I replaced the rocker shaft end steel locks 'cause they've been r7r 2x, so it was WTF.. also the tower hole can become groved afaik causing a re-seal ng. The book spec screw torque is bs imo. I didn't use a torque wrench but had an feel about the thread strength.. so it was torqued fairly tight relative to book #'s. I used a 1/4 rachet and a guesstamate is the finger strength to crack a walnut..
Of course this assumes using the proper nutcracker Tool, you understand.

jmcjunkin · 08-12-2004, 08:32 AM

Thanks Ronin. Any views as to how heavy of a grade you can go to witout risking oil starvation while cold? Oil conditioner or heavier grade?

I don't know which I am hoping for -- worn guide or foot. I guess foot.

RoninLB · 08-12-2004, 10:50 AM

Quote:

Originally posted by jmcjunkin

Any views as to how heavy of a grade you can go to witout risking oil starvation while cold?

I don't know which I am hoping for -- worn guide or foot. I guess foot.

your in sunny Calif so I assume 40deg is cold. On a routine car I'd run straight 40w or straight 50w down to 35deg.

But, maybe you should get an opinion from somebody who knows the 911 oil circuit better than me before you go this path.
Straight 40w is definately ok for 40deg ambiant.. not sure about 50w at 35deg, even with worn bearings in the 911.

Paulporsche · 08-12-2004, 02:59 PM

JMCJUNKIN,

Have you tried to isolate or otherwise locate the source of the ticking with a stethescope or a stick? Like Gordo, I think you should look into exhaust or head stud leaks. Also, how about a bearing noise from something like the alternator or fan?

sammyg2 · 08-12-2004, 04:01 PM

It's official, RoninLB is the acronym king

RoninLB · 08-12-2004, 04:25 PM

Quote:

Originally posted by sammyg2

It's official, RoninLB is the acronym king

jmcjunkin · 08-12-2004, 04:50 PM

How do I isolate the noise with a stick? Haven't heard that one.

Jamie

toolman · toolman's Garage

You hold the stick (I like to use a long screwdriver) up to your ear, and put the tip on the area you would like to listen to. A piece of plastic tube work well too.

blackbird225 · blackbird225's Garage

I can tell you right now that I have this very tick on my 70T. It has driven me bananas. Its like a magnet for the ear. After tons of searching and posting and asking, begging etc, I have gathered that it is most certainly a bad cam lobe/rocker face combo. Before you say " i dunno" I tried a nutty test that cleared it all up for me. I bought a $10 automotive stethescope. Then I found the tick was coming from the #1 or #2. I pulled all 4 rockers from those cylinders and found nothing that jumped out until I hit #2's exhaust. It had much more damage. But JWW said it may be an oil squirter clog at that area that starved just that rocker/lobe combo. So to test I assembled the rockers again, but left out the one with lots of damage. I started it up, put the stethescope to the fan shroud screws and let it run for 60 seconds. The sound disappeared. GONE.... I thought a new rocker would do it, $40 later from PP and the sound quieted a little. 100 miles later, its back with a vengeance. Its the combination of the two. Its got to be. I plan to replace the cams and have the rocker refaced in Cal. If you remove the engine tin, you can easily pull the rockahs, only if they were installed right in the first place. Also, a good opportunity to go with the RSR seals. I have one single rocker with the seals!
What say ye?

Michael

blackbird225 · blackbird225's Garage

Don't skimp with a stick. The real thing is like $7.99 at AutoZone or PepBoys or Sears. It wont cunduct electricity, and it fits in BOTH ears, blocking out other noises. When was the last time your doctor put a dowel to your back and asked you to breathe deeply? The screwdriver works nice, but I don't like to stick my torso in there with the fan spinning. The real deal gives you the best results and its purpose built....

Michael