Porsche Enthusiasts Club Forum

It is currently Thu Jul 10, 2025 8:58 pm
Classic Line Insurance


All times are UTC




Post new topic Reply to topic  [ 6 posts ] 
Author Message
 Post subject: I've just started smoking .....
PostPosted: Mon Mar 21, 2016 8:06 pm 
Offline
User avatar

Joined: Sat Jan 25, 2014 7:22 pm
Posts: 548
Location: Wimborne
TIPEC membership: 7458
:shock:

Yes, smoking. I first noticed it today when I started the car as a persistent grey/blueish plume for the first few seconds of running from cold. Then came the dual carriageway test by spanking it up to 4th then changing down quickish to third on a closed throttle and there it was, the dreaded blue haze... And not in a good two-stroke way.

So, the big question...

Engine out, or engine in?

If I'm going to do it, I may as well do the job properly, so I'm considering replacing the valve stem seals as a matter of course, and maybe the lifters too. If the head's coming off then I'll re-grind the valve seats just as a spring clean ...

Now, with the head off, can I change the rings with the engine still in the car? Obviously the sump will have to come off to get to the crank, but can that be done with the cross member still in place? I may as well do the big-ends too ...

Whaddya think??

_________________
'89 944 S2 Cabriolet
Aprilia "Falcuono" road weapon, KTM LC4 400E Desert Special for desert adventures, an RD350LC nostalgia generator and an RG500 mortgage extender.


Top
 Profile  
Reply with quote  
 Post subject: Re: I've just started smoking .....
PostPosted: Mon Mar 21, 2016 8:32 pm 
Offline
User avatar

Joined: Sat Aug 01, 2015 10:48 am
Posts: 251
TIPEC membership: 0
my first question would be what mileage has the car done? these engines are pretty strong with little to fear in the way of bore wear, unless you've removed the balance shaft belt that is...my guess would be worn valve stem seals and possibly guides but probably best to do a leak down test and compression test to see what's going on. Personally I wouldn't try changing rings (if actually needed) with the engine in the car, yes it can and indeed has been done, but it's not the best way for these things, far better to take the engine out and rebuild in a clean environment. If tests show that the engine does need work other than just the head then expect a rather costly affair, it's not worth cutting corners here, replace anything that shows wear. I'm not familiar with 16v so best talk to someone who's done this on the same engine, I've rebuilt an 8V and it wasn't cheap although to be fair I did go a bit OTT...:)

good luck

Pete

_________________
86 951 heavily modified...400+bhp


Top
 Profile  
Reply with quote  
 Post subject: Re: I've just started smoking .....
PostPosted: Mon Mar 21, 2016 9:56 pm 
Offline
User avatar

Joined: Sat Jan 25, 2014 7:22 pm
Posts: 548
Location: Wimborne
TIPEC membership: 7458
My mileage is around 150k, but I don't baby the thing...

_________________
'89 944 S2 Cabriolet
Aprilia "Falcuono" road weapon, KTM LC4 400E Desert Special for desert adventures, an RD350LC nostalgia generator and an RG500 mortgage extender.


Top
 Profile  
Reply with quote  
 Post subject: Re: I've just started smoking .....
PostPosted: Mon Mar 21, 2016 10:23 pm 
Offline
User avatar

Joined: Sat Aug 01, 2015 10:48 am
Posts: 251
TIPEC membership: 0
Greggers wrote:
My mileage is around 150k, but I don't baby the thing...



haha...who does?? 150k isn't too high as long as it's had regular oil changes and the pressure is good...I would expect the issue to be just with the head but as I say you need to test it first. These engines need good oil and it needs to be pretty fresh...long periods on old oil will cause wear, more so on the Turbo's than N/A though....

_________________
86 951 heavily modified...400+bhp


Top
 Profile  
Reply with quote  
 Post subject: Re: I've just started smoking .....
PostPosted: Tue Mar 22, 2016 6:45 pm 
Offline

Joined: Thu Aug 20, 2009 11:58 pm
Posts: 1296
Location: Warwickshire
I would check the breather system as well. Blocked breather hoses can also cause smoking.

_________________
The member otherwise known as Chas

Ex Owner of a 1989 944 S2 and a 1991 944 Turbo (Ex Andrew Sweetenaham (ProMax) car)

Now Porkerless! Now with a 2003 BMW M3 and 1991 Mercedes W124 250D


Top
 Profile  
Reply with quote  
 Post subject: Re: I've just started smoking .....
PostPosted: Tue Mar 22, 2016 7:06 pm 
Offline
User avatar

Joined: Sat Jan 25, 2014 7:22 pm
Posts: 548
Location: Wimborne
TIPEC membership: 7458
Ahhh ... that might explain the slight stumble in the idle that morning...

I'll have to have a look..

G

_________________
'89 944 S2 Cabriolet
Aprilia "Falcuono" road weapon, KTM LC4 400E Desert Special for desert adventures, an RD350LC nostalgia generator and an RG500 mortgage extender.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 13 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group