Valve stem seals... Arrrrhh!!

FFS... After doing the compulsory search, and reading through a few threads, I think my valve stem seals are shot!

After being ran, and engines warm, bit of blue smoke at idle :-(

Only got a BPU 9 days ago, one thread said going decat basically kills old seals... Nice one! Sick, as, a, chip!

going decat will show the weakness in old seals on the Turbos, not the VSS.

Old rock hard seals are the cause of the smoke if its valve stem seals, my car was de

catted for years before the vs seals went so don't see a link there

VS seals failing usually only smoke on start up for a few seconds as the oil thats leaked into

the cylinder is burnt off, mine were totally shot when we changed them and it didn't smoke

on tickover

Mines had an amount of blue smoke on startup for years now, its not the end of the world mate, plenty of time to get them done, im sure its about a thousand quid to get done though

Old rock hard seals are the cause of the smoke if its valve stem seals, my car was de

catted for years before the vs seals went so don't see a link there

It's just what I'd read, and no one said he was wrong, me however... No idea.

A few said valve stem seal, some turbo seal. But it's only on idle after warming up. No blue after boosting.

Does it smoke from stone cold ?

Does it smoke from stone cold ?

Nope. Just turned it over then. (A random massive wasp got blown out the exhaust tho haha)

Smoke on first starting suggests valve stem seals. Smoke whilst parking or in a queue after running suggests turbo seals. Increased turbo loading after BPU suggests turbo seals. It's 2:1 on turbo seals, but either way it's not a cheap fix.

Nope. Just turned it over then. (A random massive wasp got blown out the exhaust tho haha)

Then i doubt very much it's valve stem seals

Dammit!

Smoke on first starting suggests valve stem seals. Smoke whilst parking or in a queue after running suggests turbo seals. Increased turbo loading after BPU suggests turbo seals. It's 2:1 on turbo seals, but either way it's not a cheap fix.

Then i doubt very much it's valve stem seals

Balls, and balls!

Costly, YES...

Risky to continue driving?

Balls, and balls!

 

Costly, YES...

 

Risky to continue driving?

If you stop driving when you first spot the smoke (or soon thereafter) then it's probably turbo rebuild time. If you wait until the seals blow it's odds-on replacement turbo(s).

Can get a new set of turbos for 200ish so it's not the end of the world.

Look here:

http://www.mkivsupra.net/vbb/showthread.php?49859-How-To-Valve-Stem-Seal-Replacement

Turbo oil seals are certainly indicated by smoke on hot idle. Risky to continue driving? No, if you don't mind smoke coming out of your exhaust. But its not going to get any better.

So, after a 5 mile drive on a low boost setting (stock ish) and on an A road flooring it, park up, no blue smoke...

Now I'm guessing it's certainly turbo seals, and they don't like the new 120 kpa boost. Hmmm.

Were you running stock boost settings before you went BPU? If so my guess is the extra boost pressure has caused the turbo seals to show their weaknesses. If it's turbo seals it will probably have blue/black smoke on boost, and shortly after boosting. A bit of black smoke is to be expected though, but there shouldn't be much.

If there is a bit of a delay between coming off boost and the smoke appearing it could still be vss as oil can get pulled through on vacuum, but afaik that isn't too common, watching for smoke on startup is a more reliable indicator.

Worth doing compression and leak down tests as that will confirm if the problem is in the engine or the turbos.

Yeh, the exhaust, and engine were 100% stock until the BPU.

Talk about gutted!

Things like this put me of going BPU

I thought blue smoke = VVS and white smoke = turbo seals?

I have the blue (darker) smoke on start up and sometimes when pulling away after running at a constant speed. From reading the forum I though it was the VVS but this thread has just confused what I've read previously. I've spoken with SRD about repairing the issue and I don't consider the cost to be expensive and I'm not on an unlimited budget!

Generally dark smoke = oil and white smoke = water

Were you running stock boost settings before you went BPU? If so my guess is the extra boost pressure has caused the turbo seals to show their weaknesses. If it's turbo seals it will probably have blue/black smoke on boost, and shortly after boosting. A bit of black smoke is to be expected though, but there shouldn't be much.

 

If there is a bit of a delay between coming off boost and the smoke appearing it could still be vss as oil can get pulled through on vacuum, but afaik that isn't too common, watching for smoke on startup is a more reliable indicator.

 

Worth doing compression and leak down tests as that will confirm if the problem is in the engine or the turbos.

Compression and leak down tests wont show vss problems or turbo problems, they only show if there is

a problem with the rings in the cylinder bore or if either inlet or exhaust valves aren't sealing properly.

I thought blue smoke = VVS and white smoke = turbo seals?

 

I have the blue (darker) smoke on start up and sometimes when pulling away after running at a constant speed. From reading the forum I though it was the VVS but this thread has just confused what I've read previously. I've spoken with SRD about repairing the issue and I don't consider the cost to be expensive and I'm not on an unlimited budget!

If its VSS then its not too bad, depending on what method you use. But Im telling you from experience that smoke on hot idle is turbo oil seals. If someone follows you you many well also get some on the over run.

Compression and leak down tests wont show vss problems or turbo problems, they only show if there is

a problem with the rings in the cylinder bore or if either inlet or exhaust valves aren't sealing properly.

Sorry, didn't explain myself very well! I meant if the OP did a compression and leak down test it would help identify where the problem is. I.E; if the results of the comp test came back fine then it's it's a good chance the problem is turbos. If one or more cylinders were low though it could be rings, and if a few drops of oil didn't help numbers go up it could suggest vss. That last part is a little flawed now you mention it though as even if it is vss, if the valves seal properly you wouldn't know!

Obviously there are other indicators to consider along the way too, conditions under which smoke is produced being the most reliable

There's some misinformation in this thread...

Blue smoke is oil smoke. White smoke is burning anti freeze or brake fluid. Unless it's steam, which dissipates much more quickly than smoke particles, and will condense immediately on anything cold held near the exhaust.

If the thing started smoking straight after removing the cats it's extremely indicative of tired turbos. The cats present some back pressure to the exhaust ports and the turbos. Back pressure helps to keep oil within the cassettes of the turbos. They shouldn't need this back pressure, but when the turbos are elderly they may show their age by smoking when the back pressure is removed. If re-fitting the cats stops the smoke it's almost certain you need new turbos. If you don't mind a bit of exhaust smoke, and some extra oil usage, it may happily run like that for thousands more miles. this is not to say renewing the valve stem oil seals is not a good idea, on a 20 odd year old car it's almost certain valve stem seals are hard and partially ineffective, but so too are probably the valve guides themselves.