Hello

When I start my car and give it a little rev I get white smoke coming out the exhaust. Someone told me its my valve guides or stem seals.

Any ideas?

http://wiki.answers.com/Q/What_can_cause_white_smoke_from_the_exhaust :)

Answer 2

If the exhaust billows white smoke for a few seconds when first starting the engine after it has been sitting for a while, such as overnight, and then runs normally, it could mean that the rubber valve stem seals have perished - especially if the vehicle is a few years old and has done over 60/70,000 miles.
Another clue is: does the exhaust smoke smell like fresh, rather than burnt oil.

What do you mean smell like fresh?

Now we are using Wiki as our mechanic lol

The best way to tell is idle the car for a while with a hot engine and give it a good rev, smoke that clears is stem seals, smoke that continues for the time you are reving is rings.

Get the stem seals done and you are 99% good to go as it is rare for a Magna to blow, crack or wear rings under 350k's (unless it has been cooked)

What do you mean smell like fresh?
Fresh oil.

Burnt oil normally comes out as Blue smoke.
White smoke is normally just condensation or the cars running excessively lean, usually the former. :D

White smoke is burning water/coolant. At best, your head gaskets needs replacing, at worst, you've got a cracked block or head. Burning oil produces a blue smoke (which I had in my old KS after it has been off for a while or idling at the lights). You can check the colour of the engine oil and see if it has been contaminated with coolants. I'll have a murky colour.

White smoke is burning water/coolant. At best, your head gaskets needs replacing, at worst, you've got a cracked block or head. Burning oil produces a blue smoke (which I had in my old KS after it has been off for a while or idling at the lights). You can check the colour of the engine oil and see if it has been contaminated with coolants. I'll have a murky colour.

It's not that, its only we he starts it. not during normal driving.

white smoke can also be a symptom of coolant making its way into the cylinders. I have never heard of a failure on the 6G72/6G74 making this happen. It might be possible if the water jacket around the cylinder was seaping through a broken head gasket

I love how after a brief description of "some white smoke" he all of a sudden has a cracked head or block, hell, lets tell the guy that the car is about to turn into a hydrogen bomb and blow up a small country!!!!!!!

What many perceive as white smoke is often the blue smoke we have all come used to seeing. Many cars will not have that much distinction between white or blue due to the high combustion temps of modern cars coupled with the more accurate mixture and cat as well.

There is a huge difference between smoke and steam. Smoke will linger if there is no breeze, steam will dissipate quickly.

OP, have you been using any water at all? Is you rad level consistent or does it drop? In more extreme cases, you MAY and only may have water in oil or oil in the coolant, if this was the case I am sure you would have stated same. Do you have overheating issues, again I am sure if you did you would have stated that you have these issues?

white smoke can also be a symptom of coolant making its way into the cylinders. I have never heard of a failure on the 6G72/6G74 making this happen. It might be possible if the water jacket around the cylinder was seaping through a broken head gasket

You would have to do something very bad to blow a head gasket in a 6g72/4 imo, they are made of metal.

It's not that, its only we he starts it. not during normal driving.
During normal operations, the pressures in the cylinder keeps the water away much like how it prevents oil from entering. Thus water/oil only enters when the engine is off or idling.

If this guy had a cracked head, blown gasket (given that these have graphite/metal gaskets and when they go, they really go) he would have more symptoms than a little smoke or steam on start up

You would have to do something very bad to blow a head gasket in a 6g72/4 imo, they are made of metal.

hence why i said I have never personally heard of it. The last head i pulled off a 6G72 had only that gasket-in-a-tube stuff. Probably why it died lol

I love how after a brief description of "some white smoke" he all of a sudden has a cracked head or block, hell, lets tell the guy that the car is about to turn into a hydrogen bomb and blow up a small country!!!!!!!

What many perceive as white smoke is often the blue smoke we have all come used to seeing. Many cars will not have that much distinction between white or blue due to the high combustion temps of modern cars coupled with the more accurate mixture and cat as well.

There is a huge difference between smoke and steam. Smoke will linger if there is no breeze, steam will dissipate quickly.

OP, have you been using any water at all? Is you rad level consistent or does it drop? In more extreme cases, you MAY and only may have water in oil or oil in the coolant, if this was the case I am sure you would have stated same. Do you have overheating issues, again I am sure if you did you would have stated that you have these issues?

Seriously mate, just trying to help. I have a fair bit of knowledge on the Family 1/2 GM engines and simply going on past knowledge and experience. There is a fair bit of difference visually between water vapour and burning oil smoke. The smell alone is enough to tell. The OP lives in WA i presume, which has been getting some mega hot weather. Its unlikely to just be condensation collecting in the exhaust if its really noticable out the back. Compression test should be done IMO

I love how after a brief description of "some white smoke" he all of a sudden has a cracked head or block, hell, lets tell the guy that the car is about to turn into a hydrogen bomb and blow up a small country!!!!!!!

What many perceive as white smoke is often the blue smoke we have all come used to seeing. Many cars will not have that much distinction between white or blue due to the high combustion temps of modern cars coupled with the more accurate mixture and cat as well.

There is a huge difference between smoke and steam. Smoke will linger if there is no breeze, steam will dissipate quickly.

OP, have you been using any water at all? Is you rad level consistent or does it drop? In more extreme cases, you MAY and only may have water in oil or oil in the coolant, if this was the case I am sure you would have stated same. Do you have overheating issues, again I am sure if you did you would have stated that you have these issues?


No water has been used. Coolant only. No oil in the coolent. has been tested(needs a flush though) no over heating issues. only happens when engine has been in idle over a minute and i rev it. it goes out then disappears. any prices on the seals?

Not flaming but forget compression tests and the like, if you are really in doubt try a monoxide test but you state you get this after idle which again ties back to stem seals

When I say water, I really mean coolant or cooling fluids, is it using any, ie do you have to top up the radiator at any time

Stem seals or condensation from the exhaust. This is a funny thread some of the causes here are amazing lol...:nuts:

Regards

No water has been used. Coolant only. No oil in the coolent. has been tested(needs a flush though) no over heating issues. only happens when engine has been in idle over a minute and i rev it. it goes out then disappears. any prices on the seals?

Did you ever resolve this. My tj is doin the same thing. If im idling for ages then take off heaps of smoke comes out exhaust.

You sure its not just steam? Condensating in your exhaust system and just cooking the water out of it in the mornings.... you see it all the time in WA.

Nah fairly sure its not steam. It lingers around and steam usually goes away quickly doesnt it? Its not only in the mornings but its also not like constant smoke pouring out of the exhaust, only when I idle for a bit then take off.

but then this smoke clears up once you have driven for a bit?

Did you ever resolve this. My tj is doin the same thing. If im idling for ages then take off heaps of smoke comes out exhaust.

It's your valve stem seals on the exhaust side. The oil gets sucked straight into the exhaust. Mine did the same and went away completely after doing them. Have seen it on older pajeros as well.

It's your valve stem seals on the exhaust side. The oil gets sucked straight into the exhaust. Mine did the same and went away completely after doing them. Have seen it on older pajeros as well.

Same with my TM Magna many years ago. Had to get the exhaust valve stem seals replaced twice, once at around 50,000k and again at around 120,000k.

KJ.

Yeah valve seals seems to be the problem. Took it to a guy whos worked on quite a lot of magnas and he said the same as you guys. Only problem is that its gonna set me back around 500 which sucks

Yeah valve seals seems to be the problem. Took it to a guy whos worked on quite a lot of magnas and he said the same as you guys. Only problem is that its gonna set me back around 500 which sucks

Just wondering, any AMC members in Sydney area able to suggest a mechanic or have the tools and skills to help me out with changing my Valve Seals, my local mechanic quoted me $1k for parts and labour, I somehow think that's a little steep. I've read somewhere that if I do it without removing the Head, I will need a special tool? Has anyone in Sydney done it before?

Cheers

have fun with your rock hard gaskets if you decide to DIY it

Just wondering, any AMC members in Sydney area able to suggest a mechanic or have the tools and skills to help me out with changing my Valve Seals, my local mechanic quoted me $1k for parts and labour, I somehow think that's a little steep. I've read somewhere that if I do it without removing the Head, I will need a special tool? Has anyone in Sydney done it before?

Cheers

A cheap fix is to use silicone RTV sealant (blue sensor safe Loctite or Permatex) to block the gaps between the collets. Most oil gets down the valve stem and valve guide via the space between the ends of the collets. If you block those gaps the oil consumption and smoking will mostly go away. You will need to remove the cam covers and rocker gear. Then degrease the valve caps/collets so the RTV will stick. Use an old tooth brush dipped in unleaded, then wipe dry. Just poke a small amount of RTV down the gaps with a small screwdriver, thin wire, or straightened paper clip.

Years ago many engines used an "o" ring in the bottom of the valve cap to do the same thing. Then high tech stem seals came along.

In race engines you don't want extra friction from stem seals and you don't want the valve stem weakened by an extra groove for an "O" ring so some tuners went to using the "splash hats" like you find on the old 6 cyl Holdens and American V8s. That helped oil consumption but didn't get oil flowing over the valve springs to cool them. Blocking the collet gaps with silicone RTV helps both ways.

Cheers,
Alan

As usual, more great info. Thanks Alan!!!

Sorry Alan, I have to totally disagree with you here 100%

By the time you go to all the hassle of removing the oil etc from the tops of the valves and collets and then get the RTV to actually stick for more than 2 minutes why not just do the stem seals?

In a race engine that will be pulled down on a regular basis this is a fine way and most use the "O" ring but in a street car that will see many miles this is simply not a fix

You also need to understand again that the 6G engine, like many more modern engines have a lot more oil up top than the old overhead valve engines such as those rubbish holden engines and the awsome ford engines (lol) due to this again the RTV will not work and if it does for a short time you will find it does not work very well.

Another issue is when all this RTV starts coming off as it certainly will, where does it go, into your sump ready to block up your oil pick up.

Also, the amount of oil being splashed around the top end of a 6G motor, most of the oil will go through the spring onto the stem anyway given that the exhaust valves are often sitting in oil as well

Most of the cause is actually the inlet valves, on de accel and at idle the amout of vac is quite large and thus more oil gets sucked through that does not really burn all that well.

If you want a proper fix, you need to repair the problem and not try and mask or cover it with a bit or RTV

Good points Mal but the RTV does work and it does stick. When it is squeezed between the collet gaps I defy anyone to get it out without a lot of picking and poking. I have done it on the inlets of all my road engines for probably 20 years including my Magna when I had the heads reworked recently.

Apart from reducing carbon on the back of the inlet valves for good flow modern engines give the valve springs a pretty hard time and the extra oil flow helps the springs live. Just as a side point the Ralliart Magna and 380 springs must get it pretty hard. Graham pointed out to me how hot the inlet springs had been getting in the 380 engine he bought. They were quite dark but the ex springs looked new by comparison. Probably the extra lift on the inlets was working the springs harder.

True replacing the seals is the proper way to fix but the $$$$ are hard to justify unless you intend to hang onto the car for a long time. To pull the cam covers and clean up the inlets and squeeze in RTV is a handyman job that many guys that can handle a spark plug change can do. Changing valve stem seals takes a lot of patience and nimble fingers when done with the heads in place. Even with the heads off the Magna heads aren't easy to do stem seals.

I'm not advocating pumping in a load of RTV. Its only a tiny gap that needs filling on each inlet valve. So less than a match head of RTV is more than enough to fill each gap.

Cheers,
Alan

Alan I'm going to have to disagree with you too.

why would someone go to the trouble of removing the rocker gear to do a botchy job when the can do stem seals properly and have it last for alot longer? the 'special tool' s the overhead valve spring compressor for those who are asking and from memory it is possible to do them without removing the rocker gear.

Alan, dont give shoddy info to people. if you do something dodgey on your car, thats fine, but for the love of god dont share bad info to others with less knowledge who may try what youve done with catastrophic results. be responsible.

-Ian

Thanks for all your replies, the quote from mechanic came back as $1k to do stem seals and seal behind fly wheel, I'll sit on that for a bit, I think I'll change cars instead of paying that much, for me it's only the early stages, no smoke if I'm on a flat road, but it does smoke on an incline in idle. Thanks for all your input.
Jack

mate... i don't think you have much to worry about, i have a 2000 TJ sports got an exhaust on it, in the morning when i start it up mine blows some white smoke, i believe it just some condensation as the engine is stone old. So when the warmer exhaust gases exits the pipe or before it exits it mixes with the cooler air and forms white condensation (condensed water vapor), so i wouldn't worry to much mine does the same. it blows it until the engine begins the warm up.

This thread is 8 months old mate...!