fluid leaking from exhaust manifold gasket m40 1.6 engine

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arrisbmw
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Post Fri Dec 21, 2018 8:54 am

Hi , has anyone any idea what could be wrong. when i first start up the car fluid appears from the no 1 pot ,exhaust manifold gasket where is contacts the cylinder head. only drops it appears water like colourless , as the engine warms up the fluid evaporates. if i blip the throttle the engine dies.
car runs fine once it is warm. after a few minutes.
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arrisbmw
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Post Fri Dec 21, 2018 3:20 pm

follow on , checked a couple thing today. car is using no oil or coolant. there is no water in oil or vice er versa. starts well, runs well when warm.
its doing 7 miles per ltr which is about right for a m40 i understand.

thanks and happy xmas to all petrol heads
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Brianmoooore
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Post Fri Dec 21, 2018 11:56 pm

You have an exhaust manifold gasket leak. Burning hydrocarbon fuel produces large quantities of water in the form of steam, which will condense on the cold metal of the engine parts immediately after start up.
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arrisbmw
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Post Wed Jan 02, 2019 5:21 pm

thanks very much for the reply. sounds like i need to fit a new exhaust manifold gasket. its a very slight leak , do you think that would cause the engine to die when i blip the throttle on a cold engine. thanks in advance .
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Brianmoooore
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Post Wed Jan 02, 2019 6:54 pm

A significant exhaust manifold leak can cause problems on a car with a lambda sensor, but I can't see a small leak like yours affecting anything, even in the unlikely event that you actually have a lambda sensor fitted.
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arrisbmw
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Post Wed Jan 02, 2019 7:31 pm

Brianmoooore wrote:
Wed Jan 02, 2019 6:54 pm
A significant exhaust manifold leak can cause problems on a car with a lambda sensor, but I can't see a small leak like yours affecting anything, even in the unlikely event that you actually have a lambda sensor fitted.
thanks again, i have no lambda sensor on mine. So its back to the drawing board for the " issue i mentioned earlier " just wondered if the mixture on idle was wrong, rich or lean either way , do you think that would cause the engine to die when i blip the gas when cold.
i,ve try alot of things to cure it, and don,t know if its linked to the fact that the icv does not work right on start up
revs up to approx 1300 then drops to 600 -700 quickly.
If I let the car idle for 2 / 3 mins in park then its o.k to drive.

thanks again for your time. much appriciated.
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Brianmoooore
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Post Wed Jan 02, 2019 9:32 pm

Lean idle mixture makes the engine hesitate or die when the throttle is snapped open. The mixture is designed to be about as lean as it can be at idle, and if it is weaker than it should be, the extra air admitted leans it out that little bit extra, and it fails to ignite.
The problem can be aggravated if the TPS is incorrectly set, and doesn't switch between the idle map and 'run' map before the throttle is opened too much.
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arrisbmw
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Post Wed Jan 02, 2019 11:29 pm

Brianmoooore wrote:
Wed Jan 02, 2019 9:32 pm
Lean idle mixture makes the engine hesitate or die when the throttle is snapped open. The mixture is designed to be about as lean as it can be at idle, and if it is weaker than it should be, the extra air admitted leans it out that little bit extra, and it fails to ignite.
The problem can be aggravated if the TPS is incorrectly set, and doesn't switch between the idle map and 'run' map before the throttle is opened too much.
that could well be my problem then . ( is it clockwise or anti clockwise to turn the mixture screw in the a.f.m to richen the idle mixture )
I have turned it in the pass and nothing seems to change . but I suppose i really need a gas analyzer to set it correctly.
I believe my TPS is adjusted correctly as you can hear the switch click when you open the throttle slightly ( engine not running ) and i,ve check it with a multi meter via instructions on wiki . and it shows continuity when it should. ( it was not like that when i first bought the car someone had whacked the throttle stop screw up to increase the idle .) and the tps was telling the ecu it was in the run mode.

thanks again for your advice . interesting