What's new
Porsche 911 UK Enthusiasts Online Community Discussion Forum GB

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Used Porsche and Prestige Cars For Sale | Harbour Cars

Intermittant tapping on idle

D

Drew1209

Spa-Francorchamps
Joined
31 Aug 2016
Messages
261
I went to view a 99 C2 over the weekend for a friend. The current owner has had the engine rebuilt due to a worn crank, anyway the works have been extensive going by the receipts and it's a well known specialist that have carried these works out.

The engine has done about 5k since the rebuild, car goes well but on idle there is a loud knocking/tapping sound, the noise comes and goes and it makes no odds whether the engine is hot or cold. Now the owner said that the car has done this from the rebuild and it actually states on the invoice that there is a tapping/knocking on idle and there is no concern over this ??

Surely something is a miss here, I have told my mate to steer clear but you would think a car with a rebuild done properly should be a safe buy.

Anyone any thoughts to what this might be
 
There was a write-up by Hartech somewhere on the forum where he talks at length about the random rattles and clanks that the engine makes.

do a search for his posts - its worth a read :thumb:
 
My car does this on idle, it actually sounds quite worrying, anyone that has heard mine has commented on it.

My engine has also been rebuilt and is not run in yet, I was told not to worry about the noise as it was nothing sinister.
 
Cheers Dermot, the sound is annoying but to be fair I was told there was nothing to worry about from the builder.

I would say you were dead on with the bank as well, sound is more prominent on the R/H/S.



I've already had a mate round that runs high powered Subaru's and he's told me in no uncertain terms it's piston slap as he's had this before with Imprezas, reckons I've wasted my money, Bearing in mind this guy is about as close to a mechanic as I am to being head hunted by NASA

I can imagine if someone came to view the car it would put them off
 
Halcyon I'll have a spy later tonight, thanks for the heads up.

Locosaki, That actually sounds a lot worse than the one we viewed, I agree if I heard that I'd be running for the hills, so this is potentially a tappet noise.

Can tappets be cleaned through with a flush, would that help matters even ??
 
Bear in mind it's a big and very complex engine with a lot of drive chains, so it'll likely always make the odd noise every now and again.

Mine makes a very light clatter for 30 seconds on a stone cold start, strangely that's worse since changing the oil to 10w50 NT+ and it's clear it's the hydraulic lifters filling back up again after an extended rest. Gentle revs to 1000-1100 or so for ten seconds gets the oil pressure right up and no doubt flushes any air out of the lifter galleries and quietens it down again, the engine never makes a knocking noise again during that run (even after a hot start).

What I have noticed is how much smoother and freeer revving it seems on the NT oil, it almost felt like I'd gained 10hp last time I drove the car, it really was that marked a change!

Car is a 72k early 3.4 C2.
 
Halycon - how do I fine this post of Hartech's, would be interesting to have saved

I've tried searching under 'engine noise' and Hartech and Baz but am struggling to find it.

Thanks
Steff
 
Here's one of Baz's recent posts about timing cam chain tensioners that may provide some info.

For more details search on Baz's past posts, mind you I'd allow a block of free time to do this as none of his replies are short! They are, however, some of the most knowledgable and informative posts on the forum so prepare to learn.

[/url]http://911uk.com/viewtopic.php?t=115643&start=40&sid=53425744d47f34ef47f2e1d89d9ef35c
 
As a rough guide, this may help?

If you are able....... Count the number of "taps" in a 10 second period. Times by 6 to give number of taps in a minute.

Check idle speed ie 720 rpm divide by 6 (no of cylinders) to give number of times a single piston reaches top dead centre in a minute.

If the numbers are V close then it's probably Piston related, if taps are half the engine speed number, then prob tappet related.....

Maybe!
 
Cool explanation to noises, never thought about that.....bang on. :thumb:
 
You must log in or register to reply here.

Similar threads

T
Confusing Oil Pressure Problem
2
Replies
18
Views
2K
bananaz
B
A
Engine running abnormally - air leak or air-oil separator?
Replies
3
Views
786
ap1818
A
S
For Sale Porsche 997.1 C4S Tip with FULL ENGINE REBUILD £24.000
Replies
9
Views
1K
Smiffy2303
S
M
P0011 recurring issue. Help!
Replies
2
Views
598
mi6_team
M
X
Looking at buying a 997.1 High Mileage advise for a newbie
Replies
5
Views
658
XMAN888
X
watchescarswinecigars
Portiacraft 997.1 Rebuild
2
Replies
24
Views
3K
911UK
911UK
Mark Vine
It's time for engine out and rebuild it.
2 3 4
Replies
46
Views
5K
Mark Vine
Mark Vine
Porsche Insurance

Latest posts

New Threads

Porsche Model Range

Porsche 911

Porsche 992: 2018- Porsche 992: 2018- Porsche 991: 2011-2019 Porsche 991: 2011-2019 Porsche 997: 2004-2012 Porsche 997: 2004-2012 Porsche 996: 1997-2005 Porsche 996: 1997-2005 Porsche 993: 1993-1998 Porsche 993: 1993-1998 Porsche 964: 1989-1993 Porsche 964: 1989-1993 Porsche Carrera 3.2: 1983-1989 Porsche Carrera 3.2: 1983-1989 Porsche Carrera SC: 1977-1983 Porsche Carrera SC: 1977-1983 Porsche 930 Turbo: 1975-1989 Porsche 930 Turbo: 1975-1989 Porsche Early 911: 1964-1977 Porsche Early 911: 1964-1977

Porsche Hypercars

Porsche 918 Spyder Porsche 918 Spyder Porsche Carrera GT Porsche Carrera GT Porsche GT1 Porsche GT1 Porsche 959 Porsche 959

Other Current Porsche Model

Porsche Taycan : (2019-0%) Porsche Taycan : (2019-0%) Porsche Macan : 2013- Porsche Macan : 2013- Porsche Panamera : 2009- Porsche Panamera : 2009- Porsche Cayman: 2005- Porsche Cayman: 2005- Porsche Cayenne: 2003- Porsche Cayenne: 2003- Porsche Boxster: 1997- Porsche Boxster: 1997-

Porsche Legacy Models

Porsche 928 Porsche 928 Porsche 968 Porsche 968 Porsche 944 Porsche 944 Porsche 924 Porsche 924 Porsche 914 Porsche 914 Porsche 912 Porsche 912 Porsche 904 Porsche 904 Porsche 550 Porsche 550 Porsche 356 Speedster Porsche 356 Speedster Porsche 356 Porsche 356

Forum statistics

Threads
124,563
Messages
1,441,543
Members
48,979
Latest member
Lb456

porsche insurance porsche parts porsche sales porsche car sales porsche for sale
porsche classic sales porsche tuning porsche sold porsche specialist porsche engine rebuilds porsche driver training porsche car sales porsche exhausts

Community platform by XenForo® © 2010-2024 XenForo Ltd. XenForo theme by xenfocus

www.911uk.com @Porsche911UK THE DEFINITIVE PORSCHE FORUM Copyright © 911UK 2002-2024 All rights reserved.

911uk.com is not associated and is wholly independent of Porsche Automobil Holdings SE, Dr. Ing.h.c.F.Porsche AG, Porsche Cars GB, its subsidiaries and offical Porsche centres. Any word, phrase or graphic that in any way resembles anything to do with the Porsche name or organisation are registered trademarks of Porsche Automobil Holdings SE and Dr. Ing.h.c.F. Porsche AG.

Back
Top