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Author Pressure build up
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 11:36   View User's Profile U2U Member Reply With Quote

I've done some searching around about this, but basically i get a pressure build up inside my engine and when i remove either the dip stick or the oil cap i get a big rush of air as it releases. The air which comes out is a whitey smoke...and it is starting to show signs of turning creamy on the bottom of the oil cap and also on the end of the dipstick.

At start I ignored this, because i have my valves done not long ago due to a threaded tensioner bolt, therefore i put this done to a bit of water falling inside the block at this time which i thought would burn off with time. But this pressure build up is getting bigger now, and im starting to wonder if its just my headgasket? If i leave the dip stick out, it smokes from there like its a mini exhaust, as the smoke is the exact same colour, and if i use any throttle, its really smokey from the exhaust (white smoke indicating water?).

I thought it was just blow-by gasses causing this and a blocked crank case breather, but i've cleaned this out and now noticed the problem getting worse!

Any ideas? Cheers
Phillips_91
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Registered: 20th Jan 10
Location: Blackpool. Drives: Sapphire Black Mk4 Astra 1.8
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7th Mar 11 at 12:07   View User's Profile U2U Member Reply With Quote

i would be guessing but i would say headgasket
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 12:12   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Phillips_91
i would be guessing but i would say headgasket


Im guessing too, but i reckon i've got a small leak in my head gasket. I just want confirmation that this could cause this kind of pressure build up!
Gary
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Registered: 22nd Nov 06
Location: West Yorkshire
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7th Mar 11 at 12:54   View Garage View User's Profile U2U Member Reply With Quote

quote:
Originally posted by mar_cus
quote:
Originally posted by Phillips_91
i would be guessing but i would say headgasket


Im guessing too, but i reckon i've got a small leak in my head gasket. I just want confirmation that this could cause this kind of pressure build up!


yes
Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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7th Mar 11 at 13:05   View Garage View User's Profile U2U Member Reply With Quote

there shouldnt be any pressure under your rocker cover headgasket failiure or not, unless your breather is blocked
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 14:21   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Steve
there shouldnt be any pressure under your rocker cover headgasket failiure or not, unless your breather is blocked


What if the breather isn't blocked and the pressure in the bottom end is just using the breather to presurise under then rocker cover?
Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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7th Mar 11 at 14:28   View Garage View User's Profile U2U Member Reply With Quote

what you mean? the breather is just a vent to atmosphere pipe, well it usually goes back into the airbox or something.

unless im missing what you are saying

[Edited on 07-03-2011 by Steve]
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 14:42   View User's Profile U2U Member Reply With Quote

Right, well i thought my crank case breather was the the pipe that runs from the back of my block and connects to my rocker cover next to my coilpack etc.

Am i wrong?
AlexW
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Registered: 25th Oct 08
Location: Essex
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7th Mar 11 at 15:13   View User's Profile U2U Member Reply With Quote

If its more a build up in the bottom end, I'd say its prob piston rings.

Do a Dry AND Wet comp test.
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 15:27   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by AW06
If its more a build up in the bottom end, I'd say its prob piston rings.

Do a Dry AND Wet comp test.


its just had a full rebuild mate, brand new piston rings! They have covered about 5 miles tops!
Jenko_Sport
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Registered: 25th May 06
Location: Stoke-on-Trent
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7th Mar 11 at 15:27   View User's Profile U2U Member Reply With Quote

Blocked breather id say tbh.
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 15:35   View User's Profile U2U Member Reply With Quote

Whats the exact route of the breather then? It runs from the crank case to the rocker cover in the metal pipe. (its this pipe i know is NOT blocked) Then does it run from that little nossle on the rocker cover to the inlet? (because that bit i don't have connected!)
AlexW
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Registered: 25th Oct 08
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7th Mar 11 at 15:47   View User's Profile U2U Member Reply With Quote

Whoa hang on then, Its not even run in yet then, Get out and get ragging it.
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 15:50   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by AW06
Whoa hang on then, Its not even run in yet then, Get out and get ragging it.


Why would i have this sort of pressure though?
Cossie
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Registered: 17th May 02
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7th Mar 11 at 15:57   View User's Profile U2U Member Reply With Quote

with all that pressure y soon f**k an oil seal or sump gasket! you have oil breather blocked or a ring gone. get somone open up the oil tap will running and close it while your looking at the exhaust pipe to see if car is breathing to the exhaust !
Cossie
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Registered: 17th May 02
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7th Mar 11 at 15:58   View User's Profile U2U Member Reply With Quote

and forgot what the oil level more than max ?
mar_cus
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7th Mar 11 at 16:01   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Cossie
with all that pressure y soon f**k an oil seal or sump gasket! you have oil breather blocked or a ring gone. get somone open up the oil tap will running and close it while your looking at the exhaust pipe to see if car is breathing to the exhaust !


Mate it looks like you have got some useful information, but you've not really written it in the best of english! Don't suppose you could write it abit clearer?

"get somone open up the oil tap will running and close it while your looking at the exhaust pipe to see if car is breathing to the exhaust !"

That bit is just abit unclear! Do you mean to take the oil cap off whilst the engine is running, then close it to see if the engine is breathing to the exhaust? What changes would i see?
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 16:01   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Cossie
and forgot what the oil level more than max ?


And no, the oil level is about 75% mate, the water has dropped abit and so has the oil
DaveyLC
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Registered: 8th Oct 08
Location: Berkshire
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7th Mar 11 at 16:05   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Steve
what you mean? the breather is just a vent to atmosphere pipe, well it usually goes back into the airbox or something.

unless im missing what you are saying

[Edited on 07-03-2011 by Steve]


If the rings are shot the crank case will pressurise and so will the rocker cover area via the breather/pcv..
Steve
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Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
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7th Mar 11 at 16:08   View Garage View User's Profile U2U Member Reply With Quote

fair enough with mine, and my old 106 etc the breather vents externally so this wouldnt have been possible
Cossie
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Registered: 17th May 02
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7th Mar 11 at 16:09   View User's Profile U2U Member Reply With Quote

oh sorry just explain it to y again get the engine idle and get someone to open the oil filler tap and close it while your watchin the exhaust to see any white exhaust.
if the engine continues with all that pressure bleeding than vent the oil breather to atmosphere before y f** th oil seals
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 16:44   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by Cossie
oh sorry just explain it to y again get the engine idle and get someone to open the oil filler tap and close it while your watchin the exhaust to see any white exhaust.
if the engine continues with all that pressure bleeding than vent the oil breather to atmosphere before y f** th oil seals


Not 100% sure what your trying to say mate lol, the oil breather is to the atmosphere
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 16:45   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by DaveyLC
quote:
Originally posted by Steve
what you mean? the breather is just a vent to atmosphere pipe, well it usually goes back into the airbox or something.

unless im missing what you are saying

[Edited on 07-03-2011 by Steve]


If the rings are shot the crank case will pressurise and so will the rocker cover area via the breather/pcv..


I hope its not the rings the rings are brand new, so i really can't see them being that?! When i dropped them in, they didn't chip or anything
lee303
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Registered: 1st Jul 08
Location: under the nova usually
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7th Mar 11 at 16:53   View User's Profile U2U Member Reply With Quote

did you just replace the rings or did you have the bores honed? excess crankcase pressure can only come from the rings not sealing properly, seems odd though even new rings shoudltn see that much excess pressure while running in, hence why i ask what else you did
if you did hone the bores, you need to get the rings to bed, best method is not actually to pussy around with it as many people will tell you , what you need to do is 10 or 15 runs in second or third gear, from as low an rpm as the engine will allow, to about 3/4 of the rev range if the engine, at full throttle, then snap the throttle shut and let the engine coast all the way down to the start rpm again
there is some science behind this process as what this does is get the cylinder pressures up when you accelerate, which forces the rings into the cylinder bores so they will bed in, and when you snap the throttle shut you form a vacuum in the top of the cylinder which draws oil up the bores cooling them and preventing glazing
ideally this should be done with running in ol or some mineral oil, definitely not synthetic as this will protect the bores too well and the rings simply will not bed in properly, change the shit oil out after the 15 runs to some 10-40 semi and drive it fairly normally up to around 3/4 of the revs and throttle for 500 miles, swap the oil and filter and you’re done
hope this helps

[Edited on 07-03-2011 by lee303]
mar_cus
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Registered: 29th Apr 09
Location: Congleton, Cheshire
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7th Mar 11 at 16:57   View User's Profile U2U Member Reply With Quote

quote:
Originally posted by lee303
did you just replace the rings or did you have the bores honed? excess crankcase pressure can only come from the rings not sealing properly, seems odd though even new rings shoudltn see that much excess pressure while running in, hence why i ask what else you did
if you did hone the bores, you need to get the rings to bed, best method is not actually to pussy around with it as many people will tell you , what you need to do is 10 or 15 runs in second or third gear, from as low an rpm as the engine will allow, to about 3/4 of the rev range if the engine, at full throttle, then snap the throttle shut and let the engine coast all the way down to the start rpm again
there is some science behind this process as what this does is get the cylinder pressures up when you accelerate, which forces the rings into the cylinder bores so they will bed in, and when you snap the throttle shut you form a vacuum in the top of the cylinder which draws oil up the bores cooling them and preventing glazing
ideally this should be done with running in ol or some mineral oil, definitely not synthetic as this will protect the bores too well and the rings simply will not bed in properly, change the shit oil out after the 15 runs to some 10-40 semi and drive it fairly normally up to around 3/4 of the revs and throttle for 500 miles, swap the oil and filter and you’re done
hope this helps

[Edited on 07-03-2011 by lee303]


Thats really helpful mate cheers, i'll give this a go, i did hone the cylinders and replace the rings for your information, but really thought there shouldnt be enough pressure to give sort of the equivalent of a blow off valve sound from a turbo when i pull the dip stick out, and also the same if i remove the oil cap instead.

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