Funny engine noise

[sib8292]

Not funny ha ha.

A tinkling or metallic sound on tickover, disappears at higher revs.

I've an idea that stretched cylinder head bolts can happen and can lead to this effect due to head gasket blowing?

Any views?

 

[AirCooledExcellence]

Hi Sib,

Does your car have updated chain tensioners? If not it may be tensioner failure, does it sound like a chain being pulled over a dustbin lid? If so, don't drive it anymore, get it checked out ASAP as terminal engine damage could occur!

Cheers,

Tim.

 

[sib8292]

Ah well theres a question. When I bought the car over 10 years ago it was something which I did not establish and I have no documentary evidence of it. What should I look for?

I would say the noise is much less noisy than a chain over a dustbin lid! Could be more like a teaspoon stirring a mug of tea. Its one of those noises that you notice because it wan't there before, but might not be noticeable otherwise to anyone not an experienced Porsche mechanic.

The other point is that the noise seems to disappear once the engine is warm.

 

[AirCooledExcellence]

Hi Sib,

Look at the cam covers each side of your engine. If the tensioners have been upgraded you should see some extra plumbing going into the covers, like this:

But I think if you had a failed one you'd get more noise than a teaspoon in a mug of tea!

See if you can hear where the noise is coming from, pehaps use a long screwdriver to touch on various parts of the engine case whilst holding the other end to your ear. BE CAREFUL OF THE FAN & FAN BELT THOUGH []

Good luck & keep us posted!

Cheers,

Tim.

 

[bones]

When did you last have the valves adjusted , it's hard to tell without hearing it but they are noisier cold than hot.

 

[sib8292]

Tim thanks for your clear photo; which as I suspected confirms that mine has not had the upgrade, so thats a job to be done.

Bones thanks for that thought and the answer is that having left servicing in the hands of the independent that I have used for the last 10 years I haven't a clue when the valves were adjusted.

Well the car is due for its annual service/MOT soon; much to my sorrow the independent has retired and sold his premises for re development. So since I live about 3 miles from Paragon looks like they are going to get some business.

I did try the screwdriver stehorscope trick. Didn't help.

The noise sounds as if its coming from the blower fan blades; I wondered at first if the the blades were fouling on the housing but they aren't. However is there a bearing in that area which could be worn?

Regards

SIB

 

[ClubSport 911]

Tim - what a fantastically clean engine ! where on earth did you get it from ? Rebuilt ? By whom ? Nice looking and a credit to you

STEVE

 

[Melv]

Er, fan just clipping the housing????

Melv

 

[AirCooledExcellence]

ORIGINAL: ClubSport 911

Tim - what a fantastically clean engine ! where on earth did you get it from ? Rebuilt ? By whom ? Nice looking and a credit to you

STEVE

Ha Ha Steve!!!

If only it was my engine!!, I grabbed that photo from the pelican parts site!

SIB, I guess you'll have to get it booked in and have a specialist look at it. I would also get the tensioners upgraded at the same time!

Cheers,

Tim.

 

[ClubSport 911]

Ooeer... trusting chappie me, will think again before heaping praise on fellow member ! [][]

 

[Martin Perry]

Could be more like a teaspoon stirring a mug of tea.

Could you let me know if you get to the bottom of this? I have what I think is just the same noise on my car (82 Targa). I've been trying to think of an accurate description for some weeks so as to be able to ask for advice, but you've got it spot on!

Thanks

Martin

 

[sib8292]

Martin, I will; it has just been suggested to me by a work colleague (with a 400bhp Carrera turbo) that the tension of the blower fan drive belt may need checking. Its adjusted by shims as you may know. I might get time over the weekend to look at this.

Have just been quoted labour of £600 to fit hydraulic tensioners. Any views about that? Sounds like an engine out job then. I am going to save up first!

 

[AirCooledExcellence]

Hi again Sib!

£600 just for labour sounds expensive! It's not an engine out job, in Wayne Dempsey's 101 projects book it is classed as a 3 (out of 5) spanner job which should take around 5 hours.

I would phone around if I were you!

Good luck & keep us updated.

Cheers,

Tim.

 

[Guest]

Could it be the bearings in the alternator?
Any history on the alternator?[8|]
You could drop the fan belt when the mtr is cold and start the mtr, if the sound has gone:-> there's your answer. Won't hurt the mtr if only for a few minutes.
Check it out.[]
Peter

 

[bones]

Checking the fan pulley tension takes 5 seconds. Simply press the belt in a horizontal direction mid way between the two pulleys, you should be able to depress it by about halft othree quarters of an inch before it becomes too hard to press further.