Porsche Enthusiasts Club Forum

Hi everyone,

In the quest to find the source of my engine rattle I decided to remove the balance shaft belt. I noticed I couldn't turn the bottom balance shaft by hand. I'm guessing this isn't good, so does anyone know what could be causing this? the top one turns relatively easily.

BTW, went for a test drive and the car feels alot quicker, I can see why people take them off. Although more vibration, oddly through the pedals. Also, this isn't the cause of my rattle, so I'm still hunting for that.

the rattle wouldnt be little ends or anything? best way to find a rattle is by way of a long thin screw driver or object, use it as a stethoscope put it to different parts of the engine while its running and put your ear to it. you can pretty much find a direct noise this way or source of direction anyway.

is the oil pressure good?

how much more vibes without the belt?
will it not shake the engine mounts to bits

As we said the other week the race motors run without balance shafts & the belt A. to save weight, B. to save power & C & most importantly if the balance belt comes off then it invariably takes the cam belt with it & bang.

The rattle isn't alternator pulley or similar? The other is belt slap on the cover.

Hi,

Thanks for those replies. The oil pressure I believe is good although the sender is a bit tempermental. I'll give the screwdriver trick a go, I'm pretty sure the noise is coming from the top end.
Running without the balance belt isn't to bad, although I have recently changed the mounts. At the moment I'm not going to put it back because of the bottom balance shaft won't turn by hand and this obviously puts a strain on everything else. Does anyone know how to free the balance shaft up?

You might be lucky and there's a bit of gunge in the bearing, a good clean might do it. Unfortunately I think it's more likely to be the bearings are knackered and will need to be replaced. While it's out, best to check the shaft isn't damaged too.

Thanks Dave, I've had a look in the manual about taking the balance shaft out, not the easiest job in the world is it? especially the lower one. I put a spanner on it and it at least it turns albeit stiffly. So I'm going to put some engine flush in and change the oil and see if that helps. My lucks got to change sooner or later!

Hi Andy,

Just finished a big h/gskt/front end job, i would only strip it out to investigate the balancer shaft issue... if you have a few days off work and a full wkshop,,,your right the lower one is a pita to work on (have you got access to a lift).

The balancer shaft housing :- see

http://www.arnnworx.com/front_seals.htm

hope this helps

cheers

Thanks Derrick, pictures speak a thousand words, I'm just waiting for an oil filter to turn up then I'll put the balance belt back on, then try the engine flush. I'm now of the opinion that the engine rattle is more serious. So, I'm probably looking at some sort of re-build in the near future so the balance shaft can be sorted then, if the engine flush doesn't work.

i dont think you will be alone on the rebuild side, i will have to do sarah's sometime soon it drinks oil on decel so i'm assuming the VSOS are gone snf possible ring wear but i'll do a compression test on that to check compressions first.

Hi all,
Well, the saying is, if I didn't have any bad luck I wouldn't have any luck at all.
On the plus side at least I know whats causing the engine rattle, Unfortunately, after seeing Andy at SussexPerformanceCentre, He diagnosed (within seconds on hearing it) big ends gone. c£1500 to fix.
So the question is do I throw it off a cliff or set fire to it?
Obviously I'm not going throw £1500 at it. So do I have a stab at doing it myself or should I take a punt at one of the engines on ebay?

see what price i can get mains and big ends for mate. i bet its nowhere near that price

i need the engine code or registration number for the price on mains and big end shells, if its the same code as sarahs i can go off that, but if porsche are like mitsubishi the mains/big ends are colour coded.

It'll be the engine number you'll need. EBS are cheaper in the US for these sort of bits, but I'd give EMC in Brum a ring as they rebuild dozens a year if not hundreds they may have an engine for less money, not a 5 minute job to swap though.

Thanks colt, the engine number is 41G02417.
I've decided to have a go at doing it myself as I haven't got much to lose. Its just a question of timing, I've still got half a tank of fuel so whan thats gone I'll take it off the road and start work.
I've never taken an engine apart before so its going to be a pretty steep learning curve. So expect lots of stupid questions. I'll start with this one- Do you have to take the head off to change the main and big end bearings?