PDA

View Full Version : A little smoke on first acceleration in the mornings...



repenttokyo
04-11-2008, 02:16 AM
I second the valve guides being the problem.

525iZA
04-11-2008, 04:39 AM
Yes, my 525i doesn't smoke at all when he's started up in the morning, but when you first accelerate some smoke can be seen. (I.e. just turned into the street from driveway).

This clears up nearly instantly though.

Is this cause for concern?

Dave M
04-11-2008, 05:21 AM
Yes, my 525i doesn't smoke at all when he's started up in the morning, but when you first accelerate some smoke can be seen. (I.e. just turned into the street from driveway).

This clears up nearly instantly though.

Is this cause for concern?


MMmmmm, perhaps.......

But seriously, you could be burning off oil from a leaky valve guide/seal (or two). Might be a good excuse to do a compression and/or leak down test.

Any other symptoms?? Missing oil/coolant?? Hesitation?? Blue smoke?? Have you smelled the stuff (in case its fuel)??

Dave

Morgenster
04-11-2008, 05:33 AM
Yes, my 525i doesn't smoke at all when he's started up in the morning, but when you first accelerate some smoke can be seen. (I.e. just turned into the street from driveway).

This clears up nearly instantly though.

Is this cause for concern?

If white smoke upon driving away it could just be condesnation in the tailpipe evaporating. This can take a while before it disappears on wet days.

525iZA
04-11-2008, 06:57 AM
MMmmmm, perhaps.......

But seriously, you could be burning off oil from a leaky valve guide/seal (or two). Might be a good excuse to do a compression and/or leak down test.

Any other symptoms?? Missing oil/coolant?? Hesitation?? Blue smoke?? Have you smelled the stuff (in case its fuel)??

Dave

Would the burning off oil thing be bad?

I'm still monitoring the coolant. Not sure if the car's loosing some. No hesitation, no blue smoke at any other stage apart from acceleration after start up in the morning. After other start ups it's fine. Full bore acceleration also no smoke.

What happens when missing coolant causes smoke??

whiskychaser
04-11-2008, 02:55 PM
Would the burning off oil thing be bad?

I'm still monitoring the coolant. Not sure if the car's loosing some. No hesitation, no blue smoke at any other stage apart from acceleration after start up in the morning. After other start ups it's fine. Full bore acceleration also no smoke.

What happens when missing coolant causes smoke??
Burning a bit of oil on start up isnt good but its not terminal either. It just means something is worn and letting too much oil into the cylinders. Normally this is valve guides/valve guide seals or the piston rings/bores are worn. Coolant loss + white smoke can = head gasket gone. Compression/leakdown tests will help you confirm if its the pistons/rings or the valves are leaking. It wont identify worn valve guides but will eliminate the other causes

e34.535i.sport
04-11-2008, 05:17 PM
If white smoke upon driving away it could just be condesnation in the tailpipe evaporating. This can take a while before it disappears on wet days.

+1 I get this on cold mornings, not too worried about it now as it doesn't use any fluids, so its all good. Wouldn't white smoke be coolant not oil?

525iZA
04-12-2008, 03:35 AM
Burning a bit of oil on start up isnt good but its not terminal either. It just means something is worn and letting too much oil into the cylinders. Normally this is valve guides/valve guide seals or the piston rings/bores are worn. Coolant loss + white smoke can = head gasket gone. Compression/leakdown tests will help you confirm if its the pistons/rings or the valves are leaking. It wont identify worn valve guides but will eliminate the other causes

What other symptoms would blown head gasket have?

whiskychaser
04-12-2008, 05:39 AM
What other symptoms would blown head gasket have?
Classic symptoms are water in oil or vice versa. Symptoms:
Temp needle goes into red whenever you run the engine
Creamy deposits under the valve cover or in the sump (take off the oil filler cap and dip the oil to see though the latter isnt foolproof)
Loss of coolant-a lot. It either goes out of the exhaust as steam or into the lubrication system as steam-hence the creamy stuff.
Coolant has a strange smell or is black-garages use a sniffer to check if there is too much exhaust gas in it and therefore gasket gone etc

Dave M
04-12-2008, 06:29 AM
Would the burning off oil thing be bad?

I'm still monitoring the coolant. Not sure if the car's loosing some. No hesitation, no blue smoke at any other stage apart from acceleration after start up in the morning. After other start ups it's fine. Full bore acceleration also no smoke.

What happens when missing coolant causes smoke??

If you're confident its blue smoke, then its oil. As it doesn't occur to any significant degree outside of a cold morning start/acceleration, Ii wouldn't lose too much sleep over it. However, this would definitly peak my interest and result in the compression and or leak down test i mentioned. This will:

1) Identify the problem cylinder(s)
2) Help determine whether its upper end (valve) or lower end (piston ring) related

Best of luck,

Dave

BMWDriver
04-12-2008, 10:22 AM
I didn't go through the whole thread, but have you synthetic oil in there ? Ever since I switched back to the synth, the clickings I*had on the first few turns of the engine have gone. Also, I had a bit of blue smoke going out of my exhaust at one point, but after a while, I realised I put in a bit too much oil in the engine. No problems since.

525iZA
04-12-2008, 03:36 PM
Classic symptoms are water in oil or vice versa. Symptoms:
Temp needle goes into red whenever you run the engine
Creamy deposits under the valve cover or in the sump (take off the oil filler cap and dip the oil to see though the latter isnt foolproof)
Loss of coolant-a lot. It either goes out of the exhaust as steam or into the lubrication system as steam-hence the creamy stuff.
Coolant has a strange smell or is black-garages use a sniffer to check if there is too much exhaust gas in it and therefore gasket gone etc

Phew! I think we can safely rule out the gasket.

Checked for creamy deposits. Oil looks brand new through oil filler hole.

I think I might be losing a bit of coolant but very little. Topped up coolant around 400km of town driving ago and it's maybe about 2cm under the "full" mark. How does this coolant bleeder valve thingy work?

When you turn the key and start the car, no smoke at all. Reverse out of driveway no smoke. Accelerating down the street, one small puff of smoke. Not sure about the colour though. But that's it.

Oh and I get some tappet noise for about 2 to 5 seconds after startup on cold mornings. I know the car must have hydraulic valve lifters and it just takes a second or two for the oil to reach them. Should I be worried about this?

whiskychaser
04-12-2008, 05:11 PM
Phew! I think we can safely rule out the gasket.

Checked for creamy deposits. Oil looks brand new through oil filler hole.

I think I might be losing a bit of coolant but very little. Topped up coolant around 400km of town driving ago and it's maybe about 2cm under the "full" mark. How does this coolant bleeder valve thingy work?

When you turn the key and start the car, no smoke at all. Reverse out of driveway no smoke. Accelerating down the street, one small puff of smoke. Not sure about the colour though. But that's it.

Oh and I get some tappet noise for about 2 to 5 seconds after startup on cold mornings. I know the car must have hydraulic valve lifters and it just takes a second or two for the oil to reach them. Should I be worried about this?
I dont think your head gasket is gone. Seems like you have a minor leak somewhere: a drip from a hose, the rad, the pump or even the heater matrix. The bleeder is next to the filler cap. But you dont need to touch it unless your system has been emptied or got very low. Viz colour-get somebody to follow you and ask them what colour it is. Lifter noise for a second or two is normal. Being paranoid doesnt mean they are not out to get you:D

Ross
04-12-2008, 06:38 PM
An easy test for worn valve guides on a manual trans car is to let off the throttle from higher revs on the highway(3k or so)and allow the car to coast down awhile with the throttle closed. When you reopen the throttle look for smoke out of the tailpipe. The coasting down from high speed creates a high vacuum condition that will pull oil past worn guides, reapplying the throttle then burns off the accumulation.
Oil smoke on hard acceleration is usually rings. Smoke after coasting and at start up indicates valve guides.

Dave M
04-12-2008, 07:12 PM
An easy test for worn valve guides on a manual trans car is to let off the throttle from higher revs on the highway(3k or so)and allow the car to coast down awhile with the throttle closed. When you reopen the throttle look for smoke out of the tailpipe. The coasting down from high speed creates a high vacuum condition that will pull oil past worn guides, reapplying the throttle then burns off the accumulation.
Oil smoke on hard acceleration is usually rings. Smoke after coasting and at start up indicates valve guides.

Just to make it clear for the original poster, this will also cause oil to breach worn rings. Prior to the rebuild, I had a single cylinder that did this on cue, almost every time I coasted in gear down a hill longer than 1 km.

Dave