4.6 Blue Smoke - sometimes????

Hi,

Well if this in the wrong place I am sorry......................

My 1997 P38 has decided to intermittently leg go of some blue smoke????

She has done 138k and has been on LPG ever since I bought her in 2005.

I have been checking the oil and coolant levels and have had to start topping up the oil once in while........

Today is the first time that I noticed in my mirror that she was 'Smokin', I stopped and reved her.........plumes of blue smoke!

She doesn't do it when she is cold or on short jouneys.........if pulling hard or holding in a low gear down a steep incline whe up to temp = Smoke

Oh........for some odd reason my temp guage stopped working years ago - don't think that is related.......BUT for the first time ever the Hot RED warning light came on............got her home OK

Any ideas? please 'Not sarki remarks' ---- She has been a great motor, one of the best around, done a lot of work to her to keep her good ---- I hope that this isn't the end of her.

Cheers guys.

Al.

blue smoke is burning oil so it could be worn rings - check compression ratio

POAH said:

blue smoke is burning oil so it could be worn rings - check compression ratio

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Cheers,

I have a mate who has one so will ask him to test them for me.....

Sounds like a big (Expensive ) job if it is rings........ might not be worth it????????

Put a thicker oil in it if the compression test shows ring wear and see how it goes.

But yeah it's going to be approaching a grand to do it properly...

your a bit stuck if bores are worn ,new top hat linered block or another engine

Mr Noisy said:

Put a thicker oil in it if the compression test shows ring wear and see how it goes.

But yeah it's going to be approaching a grand to do it properly...

Click to expand...

Cheers,

Just a though.........could putting 10/40 Magnatec Semi -Sinthethic oil in it be problematic?????

Technically no because your late model v8 is more than happy pumping that weight of oil, but try a 20w50 semi, that's the thickest you'll realistically source today.

If its still bad then it's definitely curtains

Internet forum rule 1: always suggest the worst / most expensive option first!

When you say 'plumes' of smoke how much are we talking? If the engine is just generally knackered as a result of wear I'd expect smoke when it was doing anything and just a little bit - not just a lot when it is very hot. Almost wonder if when you heated it up you've burnt through a flame ring on a head gasket into an oil way that opens up at temperature. Worn valves? How many miles has it done?

Not saying its not the rings but a few other things first to look at.

Is a compression test not the first course of action?

If it has great compression then at least it indicates it's not that worn...

No harm in doing a compression test but the fact that the blue smoke only comes out when it is hot does not suggest to me that it is generally knackered just through wear. Blue smoke caused by wear is generally a little bit all the time, perhaps getting a bit worse when it is hot.

If there are plumes of blue smoke it suggests a more direct injection of oil into the cylinders or a cylinder.

yeah but its still buring some oil which is coming from somewhere.

jonnyt said:

No harm in doing a compression test but the fact that the blue smoke only comes out when it is hot does not suggest to me that it is generally knackered just through wear. Blue smoke caused by wear is generally a little bit all the time, perhaps getting a bit worse when it is hot.

If there are plumes of blue smoke it suggests a more direct injection of oil into the cylinders or a cylinder.

Click to expand...

I agree with that - its just the search for that somewhere!!!

Do these motors have a crank case vent which could be faulty, Iv'e known these to cause problems on other vehicles.
I dont know the layout of a 4.6 ,its just a thought

One thing i do remember is when i almost fatally overheated my engine (forgot to turn fans on but only on tickover, it was just sat there and then boiled the expansion tank over) it was obviously very hot when i turned the fans back on and then after a few mins i drove off gingerly but it was a little bit knocky and also was blowing blue smoke.

i guessed it had expanded the bores a little or thinned the oil a lot...

any of that sound similar?

basically what im saying is that i have had instances of very hot running and it has smoked a little, has happened more than once probably but worst when i overheated it that time... (was about 18 months ago!)