Ticking noise from gearbox.

[89TargaPaul]

Hi.

I have a 1989 targa with about 180 000 kms on it. Believed to be all original. This past summer I noticed a ticking noise (sounds the same as a stuck lifter) when hot and at idle. The noise is not there when the car is first started and cold. Clutch in or out makes no difference. Strangely it seems louder the hotter the outside air temp is.

Gearbox oil was changed after first hearing the noise. The oil was fairly dirty and magnetic pickup had a lot of crud stuck to it. The oil change made little to no difference.

It shifts nice. The clutch feels good.

Anyone experience anything similar?

I'm guessing I have a bearing going bad??

[89TargaPaul]

[porsche930dude]

your post doesnt really make sense. by your description it sounds like an engine problem. Is it doing it only when rolling when hot? How about engine on or off coasting. under load or not?

[flat6pilot]

Does the tick inc/dec with speed or engine RPM? Not sure what the relationship the gearbox has to do with any of this unless it sounds different in different gears.

[89TargaPaul]

Originally Posted by porsche930dude

your post doesnt really make sense. by your description it sounds like an engine problem. Is it doing it only when rolling when hot? How about engine on or off coasting. under load or not?

The ticking noise is coming from the gearbox.

I can only hear it at idle.

When hot.

[89TargaPaul]

Originally Posted by flat6pilot

Does the tick inc/dec with speed or engine RPM? Not sure what the relationship the gearbox has to do with any of this unless it sounds different in different gears.

It doesn't change with engine RPM increase.

[fanaudical]

That is a bit of a puzzler. I'm having a bit of trouble understanding how this could be.

Does the ticking noise speed up with engine RPM? Or is the frequency of the ticking noise consistent as engine speed changes?

[dannobee]

If you push in the clutch at idle with the trans in 1st gear and the car not moving, nothing in the transmission is turning.

What makes you think it's the trans?

[mikedsilva]

Originally Posted by 89TargaPaul

Hi.

Clutch in or out makes no difference.

Can't see it being a gearbox problem. Maybe a throwout bearing but that would make a difference between clutch in and out.

I think you have a noisy rocker and the sound is bouncing off something else, appearing to eminate from the gearbox.


Gearboxes can start to make a bit of noise at idle, in neutral, with the clutch engaged... as the box oil warms and things, sometimes there is a little gear lash you might hear..

But according to your testing, this is not the issue.

[Tea Tray]

Clicking only when hot and at idle, gets more noticeable when hotter.
Doesn’t sound rpm dependent. (This puzzles me a bit, does the clicking go away with rpm increase, or can you no longer hear it?)
Clutch in/out doesn’t change noise.

My first thought is to use the “screwdriver to the ear” diagnosis where you use any long metal/hard plastic object placed on the noisy place and the the other end on the bony thing at the front of your ear opening.

My ‘87 G50 trans does make “some noise” when hot on the lift and after 26,000 miles (136k total) it’s still the same.

Is some ancillary bracket, heat shield, throttle linkage, etc tricking you?
You can try some crazy things like unplugging, shaking your heater blower or making sure your air box isn’t half full of acorns, etc.

I’m guessing the noise isn’t only with the car on a lift and a bad CV joint isn’t the culprit.

[Dpmulvan]

Ticking noise when hot first place I would look would be cam chain housings. Then rockers

[89TargaPaul]

Originally Posted by fanaudical

That is a bit of a puzzler. I'm having a bit of trouble understanding how this could be.

Does the ticking noise speed up with engine RPM? Or is the frequency of the ticking noise consistent as engine speed changes?

The noise sounds the same regardless of engine speed.

[89TargaPaul]

Originally Posted by dannobee

If you push in the clutch at idle with the trans in 1st gear and the car not moving, nothing in the transmission is turning.

What makes you think it's the trans?

Got the car good and hot. Put it up on a lift. Went all over it with a rubber hose held to the ear. Both myself and a tech. Engine at idle. We even left it in first gear with wheels turning one time.

No strange noise from the engine or exhaust. Just a steady tap,tap,tap......from what seems to be inside the gearbox.

[89TargaPaul]

Originally Posted by mikedsilva

Can't see it being a gearbox problem. Maybe a throwout bearing but that would make a difference between clutch in and out.

I think you have a noisy rocker and the sound is bouncing off something else, appearing to eminate from the gearbox.


Gearboxes can start to make a bit of noise at idle, in neutral, with the clutch engaged... as the box oil warms and things, sometimes there is a little gear lash you might hear..

But according to your testing, this is not the issue.

I have no clue......just guessing!

We adjusted valves and checking for "walking". Engine sounds really good.....smooth ect.

[89TargaPaul]

Originally Posted by Tea Tray

Clicking only when hot and at idle, gets more noticeable when hotter.
Doesn’t sound rpm dependent. (This puzzles me a bit, does the clicking go away with rpm increase, or can you no longer hear it?)
Clutch in/out doesn’t change noise.

My first thought is to use the “screwdriver to the ear” diagnosis where you use any long metal/hard plastic object placed on the noisy place and the the other end on the bony thing at the front of your ear opening.

My ‘87 G50 trans does make “some noise” when hot on the lift and after 26,000 miles (136k total) it’s still the same.

Is some ancillary bracket, heat shield, throttle linkage, etc tricking you?
You can try some crazy things like unplugging, shaking your heater blower or making sure your air box isn’t half full of acorns, etc.

I’m guessing the noise isn’t only with the car on a lift and a bad CV joint isn’t the culprit.

Its a strange issue. I've only owned the car for 4 years and have never had any experience with the engine/gearbox out (I guess until soon!),but one person has suggested that if the clutch is worn out it can make strange noises. If its the original clutch with 180 000 kms on it I guess it must be time anyways?

[hcoles]

Try taking the trans. cover off (inside just behind seats) and grabbing on to the shift rod and see if the noise is changed.

[Dpmulvan]

Take your cell phone out there and record it and post it.

[89TargaPaul]

Originally Posted by hcoles

Try taking the trans. cover off (inside just behind seats) and grabbing on to the shift rod and see if the noise is changed.

Thank you. I never thought to have a poke around in there.

[89TargaPaul]

Originally Posted by Dpmulvan

Take your cell phone out there and record it and post it.

I have around 6 more weeks of snow/ice and tons of salt being dumped on the roads before I can drive it and get it good and hot again.

If you've ever heard a V8 with a stuck engine lifter.......it sounds very similar.

[89TargaPaul]

-10 C with a slight dusting of snow.