Tapping noise

[Cooks]

2003 2.7 has a tapping noise up to 2000rpm then dissapears. No noises at higher rpm when driving even under higher -6000 rpm , but can hear it when pulling away away. 

Car is due an oil change getting done this weekend. Only done 700 mile since the last change. Was sat since end of 2017 until motd recently not had it long .

Any ideas? Scared myself reading about stuff online ?. 

Thanks 

[edc]

If it's just happened after a long period of rest then it's probably a sticky lifter. Just drive it and the noise should quieten down and go away. 

[grantcos]

Does it do it when it's cold? Or only when it's hot? 

Has it sat for a long period? 

 

[Cooks]

Sorry for late reply. Changed oil and filter. Used 5w 40 oil.

car makes this ticking / grumbling noise when you blip the throttle up to just under than 2000 rpm. Does it both hot and cold. Does not get any louder or quieter depending on engine temp. Above 2000rpm you cannot hear it. Can hear it more when driving on roads with walls either side. The sound seems to bounce.

i think it may be an exhaust leak. Had a good look around and cannot seem to see a thing. The manifolds look very corroded but gaskets seem ok. Car has had a replacement back box and on closer inspection seems to be hard white paste on the clamps that join the clamp to the back box. 

Any ideas on how to find a exhaust leak? 

[Jaykay495]

Hi Cooks,

Do you have an independant Porsche specialist nearby? I ask because they know the cars well, and should be able to diagnose the issue quickly.

if not, and you think it may be exhaust, i’m sure quik fit would look at it and give you their opinion.

If they think its not exhaust-related, then deffo go to a specialist.

good luck, hopefully it is a small leak and cheaply fixed ?

[the baron]

I think as above posted, take it to an indie and get them to listen to it or even a friendly machanic at an OPC might Ben prepared to give it a listen for free.

[Cooks]

I wouldn't say there was a specialist  close but there is a decent indie down the road. 

Another thing to say.  Once warm it is quite quiet. It's only really noticeable  when you accellerate up to 2000rpm when driving or in neutral rev to 2000rpm the goes. If you were to cruise with the revs a 3000rpm no noise other than exhaust note. Noticeable more when pulling away and going up a hill in a 30mph zone (more acellerator applied to get it up the hill) due to low speed and reduced wind/ road noise. Crusing at 30mph at around 2000rpm on the flat with cruise control on. There is no noise. 

[Nobbie]

Does sound like an exhaust leak to me, especially as it's worse going uphill where the engine is under load. Can you get the car up on ramps or axle stands? If so, let it idle and attach a fluffy feather to the end of a stick and probe around all the joints in the exhaust. Any leak should be fairly obvious. Maybe get someone to rev the car a little if you'r unsure about a leak.

[Cooks]

5 hours ago, Nobbie said:

Does sound like an exhaust leak to me, especially as it's worse going uphill where the engine is under load. Can you get the car up on ramps or axle stands? If so, let it idle and attach a fluffy feather to the end of a stick and probe around all the joints in the exhaust. Any leak should be fairly obvious. Maybe get someone to rev the car a little if you'r unsure about a leak.

Yeah I had it on stands last night and got some one to rev. I used a piece of paper to check for leak. Good idea with the feather though! Will try that when I get a chance. 

I suspect someone has used exhaust paste to seal the clamps up, but doesn't sound like it's coming from there.  But it sounds loudest under the mainfold on the right had side. Tempted to try to snip the bolts up but they are rotten and worried they will round off or snap! 

[Lonewolfgjp]

+1 on the exhaust leak, I had several on my 986.

 I had a ticking/tapping noise and I drove me mad, I was convinced it was a sticking lifter or something worse but it turned out the Porsche shop exhaust gaskets were leaking.

When you replace your rear exhaust gaskets get oem and some decent stainless nuts and bolts.

You will find the car with respond and sound better with regular use but my money is on the exhaust leak, so annoying but nothing to be worried about ?

[Cooks]

Thanks for the input!! Will take a look this weekend. I don't think it's a leak from the gasket between the manifolds and the cat. They good good. 

Lone wolf - not at home to view the car this week. When you you say dear echaust gaskets. Do you mean the cat to manifold or are there more between backbox and cat as I could only see clamps? 

Cooks 

 

[Bike Loon]

Sticking lifter has the same symptoms though so still could be that. Had it on my first 987 and could only hear it on tickover and low revs.

[Cooks]

@Lonewolfgjp - were your bolts that joined the cats to the mainofold totally rotten. How did you get them out? 

I hope it is not a sticking lifter! Thanks for the input so far. 

Need to take a look this weekend. Do you recon the clamps on the pipe from the cat to back box could cause a leak? 

[Nobbie]

24 minutes ago, Cooks said:

@Lonewolfgjp - were your bolts that joined the cats to the mainofold totally rotten. How did you get them out? 

I hope it is not a sticking lifter! Thanks for the input so far. 

Need to take a look this weekend. Do you recon the clamps on the pipe from the cat to back box could cause a leak? 

My exhaust clamps were shot and that just makes the exhaust sound louder as it is effectively a bypass. It was only when I replaced these that the ticking from the leaking manifold gasket became apparent. If you reckon the manifold/cat joints are good, maybe the leak is on the exhaust manifold/head.

[Cooks]

Finally had some time to have a look tonight. I thought it may be a loose plug after looking on line. Only had abit of time so checked the right ride plugs ( noise sounds like it's from the right) they were not up to 30nm but it was maybe a quarter turn. Nothing major. Definitely not slack my hand. Noise still there. Positive , coil packs look fine with no cracks. Had a good look around the right ride manifold and joints to cat when wheel was off. Used a feather. Couldn't see anything obvious. My not so steady hands made it hard! 

This is the noise - 

Any thoughts ? 

Also a faint high pitch whine has appeared just before idle  suspect it's the belt ? 

Going to check the left tomorrow. 

[Cooks]

Forgot to add there is no noise at idle only when you blip the throttle.

@Nobbie any ideas? I have the Porsche paranoia ?

[Cooks]

Update - found a leak on the right side exhaust. Feather blowing about under ideal. Bolt where the leak is it so corroded got no head on it! 

Suspect this may be of. Also got the panel cabin off too loook at belt. Belt looks spot on but gonna take it off tomorrow to make sure it isn't a pulley or water pump. 

Oh and replaced rear brake pads! 

[Nobbie]

Whereabouts on the exhaust is the leak? Is it on the triangular flange between the exhaust manifold and the cat or one of the later joints?

[Cooks]

6 hours ago, Nobbie said:

Whereabouts on the exhaust is the leak? Is it on the triangular flange between the exhaust manifold and the cat or one of the later joints?

Mainfold to head. The bolts are rotten. I'll upload a video of the feather trick may help others in future. No leaks that I can see from the mainfold to cat joint. 

I don't know if I dare tackle the mainfold. It is rotten!! No heads on the bolts?!  It's funny once I found it with the feather I noticed the joint was very slightly wet just after start up. Guess it's condensation. See photo below.

Have you tackled it? 

[Nobbie]

No, I've not done that, only replaced one of the bolts on the flange and have left the rest until autumn. I'll tackle most stuff, but that is one job where I'd take it to an exhaust specialist who is experienced in removing rotted studs. Equipment and experience makes a huge difference. Better than getting stuck halfway through the job with the manifold off and having to get it trailered to a garage.