hey guys.

quick question!
i have a 2000 TJ and her next service is going to be the big 200xxx:shock:
now my problem is in the last week or so if noticed on start up and after idling for awhile she blows abit of blue smoke an smells. this car has never chewed oil in its life and has no oil leaks anyware. now after only 7000kms the oil is black and has droped about 5ml on the dip stick. i've only ever used magnatech 10W40. the car is driven fairly hard and i havn't noticed any lack of power or compression. what could be the problem?

what sort of smell have you got? is it burnt oil/petrol or more of a weird pongy smell, because lately on my car i have this same issue, but the pongy smell only comes up with i push the car or full throttle it...and as you suggested when you drive the car hard...

yeah strong burnt smell like oil but as soon as i rev it or drive it you cant smell or see it?

In that case it must be oil, when oil is burned it makes blue smoke, one of your gaskets might be leaking, does the car misfire at all? if it is your rocker cover gaskets could be leaking into the sparks and the cylinder

It's possible that it could be valve stem seals.

Oh here we go again, must be a head gasket in everyone's opinion

It is actually the valve stem seals, on a third gen this is a lot more involved than a second gen

Now to move this thread to where it belongs

Black oil after 7000k's on an engine with that many k's? That doesn't sound normal TBH unless it gets driven very hard. Will the valve stem seals going hard cause the oil to lose its viscosity and go jet black in colour? Certainly give it a good oil change with a new filter. I am coming up to 7000k's since last oil change and it is still golden in colour with 130k on the odometer.

200,000??? shouldn't u be using somwthing a little thicker??? 20w50???
don't know could it be ure pcv valve???

Valve stem seals will be the problem. with the car at operating temp, let it idle for 5 mins then give the throttle a quick full throttle stab. The resulting blue smoke will be the oil that has dripped passed the valve stem seals into the combustion chamber burning off.
A thicker oil ie 20w-50 will help.

REgards

Epitrochoid

Black oil after 7000k's on an engine with that many k's?

As per the oil thread - black oil does not mean the oil is burnt.

Oils have detergents in them, these go black when you drive - this means they are doing what they are meant to (clean your engine).

If the oil is thick, smells burnt - then its a problem.

how much is a vrs set for the 6g74???

The S4 engines are a little harder to do stem seal in because of the recessed valves in the head

Best shot, if your oil is rubbish it could be breaking down, give it a change and put some Penrite HPR15 in it, see how that goes.

If that is not the cause, you will need to do the stem seals

On the 12v motors these can be done head on, on the S4 (24v) motors, you can do it this way but is damned painful and the valves are buggers to get to

thanks for the tip!
pulled up today after a long run and saw a small amount of smoke coming from the engine bay, turns out there's oil leaking around both headers were it bolts to the head. NOT HAPPY JAN!!!!!!!! i will try HPR15 at the next service in the mean time i will degrease and steam clean the engine bay at work to see if its leaking anyware else. might aswell get a VRS kit and do it properly! do header gaskets come with VRS kit? i cant remember?

thanks for the tip!
pulled up today after a long run and saw a small amount of smoke coming from the engine bay, turns out there's oil leaking around both headers were it bolts to the head. NOT HAPPY JAN!!!!!!!! i will try HPR15 at the next service in the mean time i will degrease and steam clean the engine bay at work to see if its leaking anyware else. might aswell get a VRS kit and do it properly! do header gaskets come with VRS kit? i cant remember?

Rocker cover gaskes are a very common thing, if it is looking like coming around the head gasket it is actually usually the cam seals leaking, the oil runs around and gives the look of a leaking gasket.

When you do the cover gaskets, make sure ALL breathers are very well cleaned out as well as the rear bank can get block and presurise thus blowing the oil out

thread digging I know, but hey, at least I did a search :P

Has anyone actually mentioned yet, how much it would cost to get the valve stem seals replaced? I may be needing one, as I have noticed that when standing at lights, and at first go, i have puffs of smoke coming out. (since the injector malfunction I had)

thread digging I know, but hey, at least I did a search :P

Has anyone actually mentioned yet, how much it would cost to get the valve stem seals replaced? I may be needing one, as I have noticed that when standing at lights, and at first go, i have puffs of smoke coming out. (since the injector malfunction I had)

This is a trick Graham showed me.

If you can limit how much oil goes onto the valve stem then there is less oil able to get past the stem seals. Most oil gets onto the stem through the gaps between the collets. Fill those gaps with silicone RTV, Permatex blue/Loctite blue, and the oil from the rockers then goes onto the valve spring retainer and flows over the spring rather than down the valve stem. Actually Graham started doing this on race engines to cool the springs, then found it cut oil consumption in endurance engines too.

The silicone RTV won't just stick to an oily surface so you will have to carefully degrease between the collets, retainers and valve stem with petrol on a toothbrush, then metho on a toothbrush. Give it time to dry or use compressed air then squeeze and poke silicone into the gaps. Give it a few hours to dry before starting the engine.

To get access you need to remove the rockers so you have to be careful to clip the hyd lifters in place and plug the oil drain holes in the heads so that if a lifter slips that it doesn't fall through into the sump. You can easily make clips out of bent pieces of steel packing straps.

Cheers,
Alan

This is a trick Graham showed me.

If you can limit how much oil goes onto the valve stem then there is less oil able to get past the stem seals. Most oil gets onto the stem through the gaps between the collets. Fill those gaps with silicone RTV, Permatex blue/Loctite blue, and the oil from the rockers then goes onto the valve spring retainer and flows over the spring rather than down the valve stem. Actually Graham started doing this on race engines to cool the springs, then found it cut oil consumption in endurance engines too.

The silicone RTV won't just stick to an oily surface so you will have to carefully degrease between the collets, retainers and valve stem with petrol on a toothbrush, then metho on a toothbrush. Give it time to dry or use compressed air then squeeze and poke silicone into the gaps. Give it a few hours to dry before starting the engine.

To get access you need to remove the rockers so you have to be careful to clip the hyd lifters in place and plug the oil drain holes in the heads so that if a lifter slips that it doesn't fall through into the sump. You can easily make clips out of bent pieces of steel packing straps.

Cheers,
Alan

If you go this far, shouldnt you just change the seals?

If you go this far, shouldnt you just change the seals?

Well it depends. You can plug the collet gaps in about a third the time, you don't need special tools, and the car may be getting close to its use by date anyway.

Getting 24 valve springs off with the heads in place isn't easy, its slow and fiddly. There is a big risk of dropping collets into the engine too and some aren't very careful removing the old seals either so the valve stems can end up with scars that start new oil leaks.

Then on big mileage engines it may not just be the seals but valve guide wear causing some of the smoke, so replacing the seals doesn't fix the smoking.

Cheers,
Alan

Don't know whether it will do anything in your case, but Nulon Engine Stop Leak can help where blue smoke is involved. Use it after your oil change and it can be left in there till the following one. It takes a few hundred km's to work. Don't use any of the stop smokes put out from various companies, they're just oil thickeners. ESL os a seal rejuvinator...
http://www.nulon.com.au/products/Engine_Stop_Leak/

I have heard of many cars and even a lawn mower (not a full bottle in a lawn mower of coure :)) that have benefited from using this product. Its benefits will depend on how the seals actually are, but even if it doesn't help with the valve stem seals it may help with other seals around the engine! - can't hurt.

Well it depends. You can plug the collet gaps in about a third the time, you don't need special tools, and the car may be getting close to its use by date anyway.

Getting 24 valve springs off with the heads in place isn't easy, its slow and fiddly. There is a big risk of dropping collets into the engine too and some aren't very careful removing the old seals either so the valve stems can end up with scars that start new oil leaks.

Then on big mileage engines it may not just be the seals but valve guide wear causing some of the smoke, so replacing the seals doesn't fix the smoking.

Cheers,
Alan
Brilliant idea , doing the stems is a royal pita.