Tapping noise from valve cover

[Empty3]

Okay,

Routine maintenance (tranny, oil, grease etc.) and I just notice a tapping
noise from passenger side (under valve cover) on my 90' Coupe (L98 engine).
What the worse it could be and, optimistically, what could it be?

Empty3

[Charlie]

Most likely it is one of the push rods for the valve lifters. What usually happens is that an end will get flattened or the rod will get bent causing slack in the stroke. That's the tapping noise. The rods are cheap, just figure out which one it is and replace it. You don't have to replace them all. Chevy's have done this for years. The only other part you will need is a new valve cover gasket. I keep a few of them around in my tool box. The only difficulty is getting to the valve cover, the rest is simple.

--
Charlie
!993 Corvette Convertible
"Empty3" > wrote in message ...
Okay,

Routine maintenance (tranny, oil, grease etc.) and I just notice a tapping
noise from passenger side (under valve cover) on my 90' Coupe (L98 engine).
What the worse it could be and, optimistically, what could it be?

Empty3




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.737 / Virus Database: 491 - Release Date: 8/12/2004

[Empty3]

Charlie,

Thanks, I suspected something with the lifters and anticipated worse things.

Empty3
"Charlie" > wrote in message ...
Most likely it is one of the push rods for the valve lifters. What usually happens is that an end will get flattened or the rod will get bent causing slack in the stroke. That's the tapping noise. The rods are cheap, just figure out which one it is and replace it. You don't have to replace them all. Chevy's have done this for years. The only other part you will need is a new valve cover gasket. I keep a few of them around in my tool box. The only difficulty is getting to the valve cover, the rest is simple.

--
Charlie
!993 Corvette Convertible
"Empty3" > wrote in message ...
Okay,

Routine maintenance (tranny, oil, grease etc.) and I just notice a tapping
noise from passenger side (under valve cover) on my 90' Coupe (L98 engine).
What the worse it could be and, optimistically, what could it be?

Empty3




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.737 / Virus Database: 491 - Release Date: 8/12/2004

[Dad]

> "Empty3" > wrote in message
...
>Charlie,

>Thanks, I suspected something with the lifters and anticipated worse
things.

>Empty3

Don't overlook the injectors.

--
Dad
04 C5 CE Z51
72 Shark Black/Black/4spd

[Charlie]

Where in Houston are you? I'm up off FM 1960 &SH 249.

--
Charlie
!993 Corvette Convertible
"Empty3" > wrote in message ...
Charlie,

Thanks, I suspected something with the lifters and anticipated worse things.

Empty3
"Charlie" > wrote in message ...
Most likely it is one of the push rods for the valve lifters. What usually happens is that an end will get flattened or the rod will get bent causing slack in the stroke. That's the tapping noise. The rods are cheap, just figure out which one it is and replace it. You don't have to replace them all. Chevy's have done this for years. The only other part you will need is a new valve cover gasket. I keep a few of them around in my tool box. The only difficulty is getting to the valve cover, the rest is simple.

--
Charlie
!993 Corvette Convertible
"Empty3" > wrote in message ...
Okay,

Routine maintenance (tranny, oil, grease etc.) and I just notice a tapping
noise from passenger side (under valve cover) on my 90' Coupe (L98 engine).
What the worse it could be and, optimistically, what could it be?

Empty3




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.737 / Virus Database: 491 - Release Date: 8/12/2004

[Marty]

>"Empty3" > wrote in message
...
>Charlie,

>Thanks, I suspected something with the lifters and >anticipated worse
things.

>Empty3

It could still be.
Use a stethascope to assure it is coming from the valve cover and not an
exhaust leak,it can sound very much like a bad lifter.
If it is inside the valve cover, remove it and fire it up. Isolate which
valve it is using the scope, then determine if it is the pushrod &
rocker,the lifter or a flattened cam lobe. The rocker stud or nut may be the
culprit also.
A damaged pushrod/rocker and valve stem may only be a symptom.

Marty
84 L83
63 194 Tempest Conv.

[Charlie]

Your 63 Tempest. Transaxle? I had one years ago, it had the 326 V8 in it. Fun car. Shifter was a lever on the dash.

--
Charlie
!993 Corvette Convertible
"Marty" > wrote in message ...

>"Empty3" > wrote in message
...
>Charlie,

>Thanks, I suspected something with the lifters and >anticipated worse
things.

>Empty3

It could still be.
Use a stethascope to assure it is coming from the valve cover and not an
exhaust leak,it can sound very much like a bad lifter.
If it is inside the valve cover, remove it and fire it up. Isolate which
valve it is using the scope, then determine if it is the pushrod &
rocker,the lifter or a flattened cam lobe. The rocker stud or nut may be the
culprit also.
A damaged pushrod/rocker and valve stem may only be a symptom.

Marty
84 L83
63 194 Tempest Conv.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.737 / Virus Database: 491 - Release Date: 8/12/2004

[Marty]

Yup,has the transaxle. Very difficult to get parts for the car.
Mine has the slant 4 banger. Not a comfy driver but it looks great and turns heads on cruise nites ;-)
It would drive great if I could just get the time to overhaul the suspension/steering...sigh....perpetually poor & out of time ;-(

Marty
84 L83
63 194 Tempest Conv.

"Charlie" > wrote in message ...
Your 63 Tempest. Transaxle? I had one years ago, it had the 326 V8 in it. Fun car. Shifter was a lever on the dash.

--
Charlie
!993 Corvette Convertible
"Marty" > wrote in message ...

>"Empty3" > wrote in message
...
>Charlie,

>Thanks, I suspected something with the lifters and >anticipated worse
things.

>Empty3

It could still be.
Use a stethascope to assure it is coming from the valve cover and not an
exhaust leak,it can sound very much like a bad lifter.
If it is inside the valve cover, remove it and fire it up. Isolate which
valve it is using the scope, then determine if it is the pushrod &
rocker,the lifter or a flattened cam lobe. The rocker stud or nut may be the
culprit also.
A damaged pushrod/rocker and valve stem may only be a symptom.

Marty
84 L83
63 194 Tempest Conv.




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.737 / Virus Database: 491 - Release Date: 8/12/2004

[warthog]

"Empty3" > wrote in message
...
> Okay,
>
> Routine maintenance (tranny, oil, grease etc.) and I just notice a tapping
> noise from passenger side (under valve cover) on my 90' Coupe (L98
engine).
> What the worse it could be and, optimistically, what could it be?
>
> Empty3
>
>
> There are several things it could be if it isn't a noisy exhaust port.
The most common one is a bent pushrod. I had a tappet break once and it will
cause the noise.
A collapsed lifter will do it as will a flattened camshaft lobe.Very
rarely will a stud pull loose unless you're racing . I just bought a super
nice 67 chevy c-10 pickup with the very same problem and it turned out to be
a flattened cam lobe. I hope you aren't as unlucky. Let us know what you
find out.

Warthog---------------JP- 8 lights my fire.
74 C3 convertible
67 chevy c-10
65 Harley Sportster

[Marty]

The 62' & 63' Tempest/LeMans were creatures of their own. They were the product of John Delorean who was forced by Pontiac to produce a muscle car. The ropeshaft/transaxle wasn't up to the HP so it was abandoned for the 64' GTO.

Delorean later moved to Chevrolet, I wonder where Chevy got the idea for the C6 driveline..;~)

Marty
84 L83
63 194 Tempest Conv.

"Charlie" > wrote in message ...
I sure wish I would have kept that car. Actually, I wish I would have kept quite a few of my old cars. Mine was two tone green, but it wasn't a convertible. For parts, doesn't the Buick use most the same parts except for the transaxle?

--
Charlie
!993 Corvette Convertible
"Marty" > wrote in message ...
Yup,has the transaxle. Very difficult to get parts for the car.
Mine has the slant 4 banger. Not a comfy driver but it looks great and turns heads on cruise nites ;-)
It would drive great if I could just get the time to overhaul the suspension/steering...sigh....perpetually poor & out of time ;-(

Marty
84 L83
63 194 Tempest Conv.

[Empty3]

Thanks Marty and Warthog.

You mentioned racing, I don't race, but about a week ago I did floor it on
the highway (no one was in sight).
I'm hoping for a loose stud, but will take a look.




"warthog" <warthog@iamnotaninvalid> wrote in message
...
>
> "Empty3" > wrote in message
> ...
> > Okay,
> >
> > Routine maintenance (tranny, oil, grease etc.) and I just notice a
tapping
> > noise from passenger side (under valve cover) on my 90' Coupe (L98
> engine).
> > What the worse it could be and, optimistically, what could it be?
> >
> > Empty3
> >
> >
> > There are several things it could be if it isn't a noisy exhaust port.
> The most common one is a bent pushrod. I had a tappet break once and it
will
> cause the noise.
> A collapsed lifter will do it as will a flattened camshaft lobe.Very
> rarely will a stud pull loose unless you're racing . I just bought a super
> nice 67 chevy c-10 pickup with the very same problem and it turned out to
be
> a flattened cam lobe. I hope you aren't as unlucky. Let us know what you
> find out.
>
> Warthog---------------JP- 8 lights my fire.
> 74 C3 convertible
> 67 chevy c-10
> 65 Harley Sportster
>
>

[Empty3]

"Marty" > wrote in message
...
>
> >"Empty3" > wrote in message
> ...
> >Charlie,
>
> >Thanks, I suspected something with the lifters and >anticipated worse
> things.
>
> >Empty3
>
> It could still be.
> Use a stethascope to assure it is coming from the valve cover and not an
> exhaust leak,it can sound very much like a bad lifter.

A mechanic friend of mine told me the same thing about the exhaust leak.

> If it is inside the valve cover, remove it and fire it up. Isolate which
> valve it is using the scope, then determine if it is the pushrod &
> rocker,the lifter or a flattened cam lobe. The rocker stud or nut may be
the
> culprit also.
> A damaged pushrod/rocker and valve stem may only be a symptom.
>
> Marty
> 84 L83
> 63 194 Tempest Conv.
>
>
>

[Empty3]

"RicSeyler" > wrote in message
...
> Like Dad said, don't over look a hammering injector!
>
> I've never seen a bent pushrod unless you have had a major
> failure or ingested a bunch of water while the motor was running.....
>
> Collapsed lifter
> Stud pulling out of head
> Rocker nut backed off.

Thanks Ric. It will be two weekends before I even decide to tear into it.

Empty3

[Empty3]

"RicSeyler" > wrote in message ...
If you determine it's inside the valve cover, get a set of rocker arm clips,
to block the stream of oil coming up from the pushrods, and start the motor
with the offending side, valve cover off to isolate which rocker is noisy.
You can get by without the clips, but have a bunch of towels around
the head and fenderwell to catch some of the oil.. It will get a little smokey also :-)

After you find which one is making the noise, sight down the heads of the rocker studs
to see if the offending stud is taller than the rest. You can also just try tightening the rocker nut
a quarter to half a turn and then it fire back up to see if still tapping.... BUT if it's the stud pulling out,
the tapping will return after a couple heat cycles, (the stud will continue to pull out)

I don't think you will find a bend pushrod or a wiped cam lobe. Wiping lobes generally
occurs during break-in, or if the car has been run without oil volume or pressure.

If it turns out to be a nut backed off, then get new rocker nuts from GM..
Or if its a lifter, do them all, and get ALL new rocker nuts.


Ric, thanks. Since I bought the car with the intent of fixing real nice,I'll look into what you describe. I may just upgrade while I'm in therepoking around. Turns out my mechanic friend is willing and eager to assist.Nice weekend project I would think. thanks!

[Tom in Missouri]

Porsche 924 and 944, circa 1978. Front engine, rear transaxle, high polar
moment, used in a sports car.

Of course, the Tempest was supposed to be a sports car and the basic
transaxle was used in many prototype Corvettes.

DeLorean was long gone and a "try-to-forget" memory in Chevrolet when they
were making the C5 and C6 drivelines.

And I think you have it wrong, I think DeLorean forced Pontiac to build the
muscle car. Pontiac was in the spot much of GM has been lately, a old
people's car. The Tempest and then the GTO were the spark to fire up a
younger clientele. However, as many back then have said, you had to be a
rather well-off young person to afford a GTO.



"Marty" > wrote in message
...
The 62' & 63' Tempest/LeMans were creatures of their own. They were the
product of John Delorean who was forced by Pontiac to produce a muscle car.
The ropeshaft/transaxle wasn't up to the HP so it was abandoned for the 64'
GTO.

Delorean later moved to Chevrolet, I wonder where Chevy got the idea for the
C6 driveline..;~)

Marty
84 L83
63 194 Tempest Conv.

"Charlie" > wrote in message
...
I sure wish I would have kept that car. Actually, I wish I would have
kept quite a few of my old cars. Mine was two tone green, but it wasn't a
convertible. For parts, doesn't the Buick use most the same parts except
for the transaxle?

--
Charlie
!993 Corvette Convertible
"Marty" > wrote in message
...
Yup,has the transaxle. Very difficult to get parts for the car.
Mine has the slant 4 banger. Not a comfy driver but it looks great and
turns heads on cruise nites ;-)
It would drive great if I could just get the time to overhaul the
suspension/steering...sigh....perpetually poor & out of time ;-(

Marty
84 L83
63 194 Tempest Conv.

[Marty]

Tom,
Your correct, the forced thing was to go to the Chevy Division. Not sure why
the transaxle never made it to production in the Vette back then. Production
costs maybe? Surely couldn't have been any worse in handling.
IIRC the Tempest suffered from handling problems with the x-axle as well as
noise from the ropeshaft turning at engine speeds. Mine howls pretty good at
idle.

Marty "in Missouri" ;-)


"Tom in Missouri" > wrote in message
ink.net...
> Porsche 924 and 944, circa 1978. Front engine, rear transaxle, high polar
> moment, used in a sports car.
>
> Of course, the Tempest was supposed to be a sports car and the basic
> transaxle was used in many prototype Corvettes.
>
> DeLorean was long gone and a "try-to-forget" memory in Chevrolet when they
> were making the C5 and C6 drivelines.
>
> And I think you have it wrong, I think DeLorean forced Pontiac to build
the
> muscle car. Pontiac was in the spot much of GM has been lately, a old
> people's car. The Tempest and then the GTO were the spark to fire up a
> younger clientele. However, as many back then have said, you had to be a
> rather well-off young person to afford a GTO.
>
>
>
> "Marty" > wrote in message
> ...
> The 62' & 63' Tempest/LeMans were creatures of their own. They were the
> product of John Delorean who was forced by Pontiac to produce a muscle
car.
> The ropeshaft/transaxle wasn't up to the HP so it was abandoned for the
64'
> GTO.
>
> Delorean later moved to Chevrolet, I wonder where Chevy got the idea for
the
> C6 driveline..;~)
>
> Marty
> 84 L83
> 63 194 Tempest Conv.
>
> "Charlie" > wrote in message
> ...
> I sure wish I would have kept that car. Actually, I wish I would have
> kept quite a few of my old cars. Mine was two tone green, but it wasn't a
> convertible. For parts, doesn't the Buick use most the same parts except
> for the transaxle?
>
> --
> Charlie
> !993 Corvette Convertible
> "Marty" > wrote in message
> ...
> Yup,has the transaxle. Very difficult to get parts for the car.
> Mine has the slant 4 banger. Not a comfy driver but it looks great and
> turns heads on cruise nites ;-)
> It would drive great if I could just get the time to overhaul the
> suspension/steering...sigh....perpetually poor & out of time ;-(
>
> Marty
> 84 L83
> 63 194 Tempest Conv.
>

[bd_juju@hotmail.com]

[Tempest w/ropeshaft]

> Mine howls pretty good at idle.

My Porsche 928's torque tube howls pretty well, too...

So, I'm assuming that GM worked the bugs out & you get 200k out of a
C5's torque tube??
What's the failure mode on them? Any 'been-there-broke-that'?

cds