Puff of blue smoke

[Audax]

Sounds to me as though it's the turbo on the way out. Blue smoke on startup, sometimes lots of it and at other times not present are classic symptoms for turbo replacement.

[Steve440]

Thanks

I had better start saving up then

That is the last thing I need at the moment.

Lets hope it hangs on for a few more weeks.

Steve

[Audax]

Oh, you should be OK for some time, mine was doing this for nearly 3 months until I got around to replacing the turbo. Just be warned that if it does let go big time with clouds of smoke then get the engine off as quickly as possible, if not you'll need a new engine too. 

[Norfolk Jim]

Apart from whistle I had no notice of impending doom for turbo on my 9-5 aero but it was a spectacular display of smoke when it went but no noise!

Second hand turbo (courtesy of Neil of Stevenage) and large puff of smoke on start up with replacment fitted which obviously cleared exhaust etc out and had absolutely nothing since. Not the tinniest hint of smoke at start up whether hot or cold - sorry Neil if you still get it.

Try Saabtech - when I spoke with them Jen (I think that's her name) had a couple on the shelf TD04's and she said she very rarely was asked for one so cheap?

[Neil of Stevenage]

Not the tinniest hint of smoke at start up whether hot or cold - sorry Neil if you still get it.

Still there 

[Audax]

Apart from whistle I had no notice of impending doom for turbo on my 9-5 aero but it was a spectacular display of smoke when it went but no noise!

That does seem to be a more common failure on the Aero, they just let go violently without warning. Saying that, if they start smoking then they *tend* to get worse over several months and that's a reasonably common way for the GT1752 turbos to fail.

[Norfolk Jim]

Steve

The total cost of sorting mine with good secondhand turbo was about £450. A lot cheaper than main dealer who wanted £1200 + VAT!!!!!!

Got gasket set from Abbotts, oil return pipe (a must) from Saabtech and turbo from Neil. Then it was just oil and filter and labour. Took my chap (at £35 per hour) just under 2 hours with no problems.

When old turbo off (which rattled like a can with stones in it) it was examined and found a small nick in one of the vanes that had obviously made it out of balance. It had lasted from October to March like that and then just felt it had had enough so pop!

Call Jen and see if she has one. I'm pretty sure she was looking at around £250 and they have been fully checked by them who are good (sure Neil will vouch for them as well)

[TomPaine]

Call Jen and see if she has one. I'm pretty sure she was looking at around £250 and they have been fully checked by them who are good (sure Neil will vouch for them as well)

I can vouch for them as well if that helps. I do a 150-mile round trip to have my car serviced by Saabtech.

[Neil of Stevenage]

Slow down everybody!  It has not been proved that it is the turbo, and I, and others, can attest to the fact that a puff of blue smoke at start up, (in my case clouds of smoke), does not necessarily mean the turbo is shot.
Unfortunately, other than a major stripdown, there is no way, in my case, to diagnose it further.  Topping up the oil is a lot cheaper!!

[ScarbSaab]

Exactly, Neil. My 1998 SE still blows smoke sometimes on startup and has done for most of the 9 years I've owned it, despite sump drops, pipe changes and even the new turbos and an engine rebuild. Recently I discovered that it is most common when it is topped up to MAX - and I have always tried to keep my cars topped up! It has a leak so it goes down anyway, but I've found that by only topping it up to halfway on the dipstick it rarely smokes. If it's at MIN it never seems to smoke, but as the most regular user never opens the bonnet (or the petrol cap!) I'm nervous of keeping it that low.

[Norfolk Jim]

Oops - not suggesting do it but just to check if she has one so possible worst scenario could be budgeted for.

I agree look at all aspects first.

We see clouds of smoke outside ours daily as my youngster starts his old pug 106. We know that is valve stem seals but it still trundles along and we just top up with oil as needed. At least its a known problem with that! Just choking us but still went through MOT!

[Steve440]

I pulled my sump off yesterday as it has never been done ( had the pieces of metal blocking the 2 holes still in) and gave it a clean out. I am glad I did it but in truth there was only a couple of bits of stuff and it only took 15 mins to clean up.

While I was under there I pulled  the other pipe off the Turbo. Completely dry and no play in the shaft.

So if its dry in the air pipe where is the puff of smoke coming from?

For all those that have never pulled a sump on a 9-5 allow about 3 hours and invest in a 1/4 drive socket set.

Steve

[Neil of Stevenage]

So if its dry in the air pipe where is the puff of smoke coming from?

I wish I knew! It is definitely not oil on the pistons as the "puff" does not appear instantly - it takes about 5 secs.

I'm convinced it is "sticky rings".

[Audax]

I had to replace the GT1752 on my 9-5 recently due to smoke on startup. When the turbo was removed there was no oil on the inlet and very minimal play on the shaft. The theory is that what happened was that after the sump drop (which wasn't bad as there was no sludge in there but the strainer was partially blocked by carbon) the increased oil pressure to the turbo caused oil to leak past the seals into the exhaust side. Anyhow, now the turbo has been replaced the blue smoke on start-up has totally gone.

[Neil of Stevenage]

The theory is that what happened was that after the sump drop (which wasn't bad as there was no sludge in there but the strainer was partially blocked by carbon) the increased oil pressure to the turbo caused oil to leak past the seals into the exhaust side. Anyhow, now the turbo has been replaced the blue smoke on start-up has totally gone.

If the strainer was partially blocked how would that increase the oil pressure to the turbo?