Blue Smoke!

[d7ve_b 44 1 Cars]

Hi All,

 

As the title suggests my 205 GTI has developed a habit.

 

- When I start the car in the morning it turns over fine, starts first time and doesn't smoke at all.

- After about 5-10 minutes when the water temp has reached half way and the oil has just started to warm

the car still doesn't smoke (but I have been told that it does smell a bit)

- When I pull away from standing in traffic it puffs out some pale blue smoke.

- The smoke gets more apparent as the engine gets warmer.

- If the engine is warm and I rev it when standing it pumps out the pale blue stuff.

- The engine doesn't over heat but it does use oil, about half a litre in two-three weeks on current estimates. I've checked for leaks and there are some minor spots on my drive (about 5-6) but not enough for that to be the sole cause.

 

Its a standard 1991 1.9 with 108k on the clock and to my knowledge it has never been rebuilt or had any other works than standard servicing with OEM parts. The car pulls really well and goes like stink (pardon the pun) over 4k rpm.

 

The only problem I am aware of is that the SAD might be knackered or need cleaning as the idle sits at around 1400 rpm when warm, but from reading archived posts I don't think this would contribute greatly to the smoke issue.

 

I've read through the archives and they seem to point to either valve/stem seals, piston rings or problems with the breather pipes. Can anybody offer any advice? My drive to work consists of sitting in start/stop traffic and I think its starting to p**s people behind me off!

 

Many Thanks,

Dave.

[Veero 1]

It does sound like it might be valve stem seals.

 

Best way is to do a compression test (compression tester is only about £10-15). If the results for all 4 cylinders are nice and high and all within 10% of each other chancs are the rings are OK and this means it most probably is the valve stem seals. A largely different reading on one cylinder could be checked by putting a teaspoon of oil into that bore and retesting as the oil helps seal the ring and should bring the pressure up on a subsequent test.

 

Veero

[d7ve_b 44 1 Cars]

It does sound like it might be valve stem seals.

 

Best way is to do a compression test (compression tester is only about £10-15). If the results for all 4 cylinders are nice and high and all within 10% of each other chancs are the rings are OK and this means it most probably is the valve stem seals. A largely different reading on one cylinder could be checked by putting a teaspoon of oil into that bore and retesting as the oil helps seal the ring and should bring the pressure up on a subsequent test.

 

Veero

 

Thanks Veero, I'll try and get hold of a compression tester this weekend and give it a go. Is there a ball park figure of what compression is considered 'normal'? Also assuming it is the valve stem seals, how big a job is this?

 

Thanks,

Dave.

[lordvader 0]

I'm getting a comp test done this week (to hopefully rule out piston rings) too!

 

Good luck with yours!

Edited April 24, 2006 by lordvader

[Veero 1]

I'm not 100% sure on the exact reading TBH. I dont know what it should be but figures from other people's comp tests on here would suggest around 160-200 psi. So long as all cylinders are within 10% thats the main thing, unlikely for all sets of rings to die at the same time.

 

When I tested my 1.6 about 5 months ago all the cylinders were at about 180 psi.

 

Hope that helps

Veero

[d7ve_b 44 1 Cars]

I'm getting a comp test done this week (to hopefully rule out piston rings) too!

 

Good luck with yours!

 

Thanks mate, and good luck with yours. Let me know how you get on and i'll do the same!

 

Anyone else got experiences with valve seals and/or piston rings? (or just blue smoke in general )

 

Dave.

[hengti 2]

there's another thread on the go at the mo entitled 'smoking' (sorry - dunno how to link to other posts)

 

might be worth a look as there's an interesting comment about overfuelling thinning the oil

[d7ve_b 44 1 Cars]

there's another thread on the go at the mo entitled 'smoking' (sorry - dunno how to link to other posts)

 

might be worth a look as there's an interesting comment about overfuelling thinning the oil

 

Cheers mate, found the post.

 

Some of the symptoms seem slightly different but I might try removing and cleaning the breather pipes, sorting the SAD and then getting the fuelling checked before doing any other major works. I still have this gut feeling its something more serious though

[Simes 248 2 Cars]

Valve stem seals.

[Guest pugpowa]

could be valve stem seals,did yours require lead substitute stuff in it? although when one of mine had the stem seals gradually go,it would only smoke in the morning for about 5minutes,then it would stop, with just the odd puff of blue if you started it after a while, a temporary cure if you cant afford to have it done immediately is that 'stop smoke' stuff, worked in mine for about two weeks until i wrote it off! dunno how long it would have gone on for tho.was smoking bad for about 3weeks before i decided to do owt about it that was an 89f tho,with a 91 309gti engine fitted.was around about the same mileage too on the engine when it started.

[lordvader 0]

Thanks mate, and good luck with yours. Let me know how you get on and i'll do the same!

 

Anyone else got experiences with valve seals and/or piston rings? (or just blue smoke in general )

 

Dave.

 

Got the comp test done yesterday, first without oil in the cylinder, then again with (to make sure the piston rings weren't fuct).

 

I got between 160-170 psi on all cylinders, then it went up to about 200 psi with the oil. So it's not good, not great, and at lest the chances of the rings being gone have been reduced dramatically !

[GLPoomobile 958]

Ummm, I thought that an increase in compression WITH a teaspoon of oil in the cylinder indicates that the rings are gone as the oil helps to seal it.

 

But it's unlikely that the rings on all four pistons are fooked so I'm a bit confused about this.

[lordvader 0]

Ummm, I thought that an increase in compression WITH a teaspoon of oil in the cylinder indicates that the rings are gone as the oil helps to seal it.

 

But it's unlikely that the rings on all four pistons are fooked so I'm a bit confused about this.

 

Yes, but I was told that if the rings were gone, the comp would have gone up about 80psi, and I probably wouldn't have gotten 170-ish on the cylinders.

The bottom line is, there's still some life left in the engine

[ada205 2]

Ummm, I thought that an increase in compression WITH a teaspoon of oil in the cylinder indicates that the rings are gone as the oil helps to seal it.

 

But it's unlikely that the rings on all four pistons are fooked so I'm a bit confused about this.

Would have to agree with above I'm affraid. If rings were in good order, then oil would not be needed to help or improve seal. The usual rule of thumb is if smoking when hot, rings, and if from cold, stem seals.

 

The reason for the symptoms are, in the case of stem seals, the oil in the head leaks down past the knackered seals whilst the engine is not running, so when started, theres a nice puddle of oil in the bore or bores. This takes a while to burn off when the engines started, and obviously will be seen as smoke out the back, but clears eventually. In really bad cases though, smoking can be more long term.

 

In the case of knackered rings, it's simply a case of as the oil gets hotter, it becomes easier for the now thinner oil to find it's way between the rings and bores, hence more smoke the hotter the oil gets.

 

I've never had a Compression problem, though I've had two cars with stem seal problems, and both smoked badly from start up, with one clearing once warm, and the other smoking for much longer, though no where near as bad once warm. Both cars were completely cured when given new seals.

 

What ever u're problem is mate, hope it dont cost ya to much, cus it's stupidly expensive these days just running cars without having to pay to fix the baskets all the time. Good luck.