2nd time I write this!! there must be some sort of time out feature. This time I will highlight and copy the message b4 I press "post this message".
OK so breifly, when compared to my first version :o)
2.0 16V Omega
what function does the engine coolant serve to the throttle housing, I find it hard to believe it could output any noticable heat to the housing, hence to the temperature of the air coming into the engine, given that it only briefly mates with the throttle housing.
what is the engine coolant pipes function where they join a vacuum pipe (from the rocker cover) where the pipe joins to the throttle housing just below the throttle valve.
why is there two pipes from the rocker cover to the throttle housing, the larger one joins the air intake duct, the smaller one vacuum quality joins below the throttle valve. What do these two pipes do? why does the engine function when these pipes are blocked up.
I also discovered that later Omegas have an oil separator on the top of the cranckcase breather hose, which can be easily fitted to older engines which don't have it, it helps to stop the breather pipes from blocking up. GM partnumber 9 193 502
Wouldn't it be nice if GM were to have a website where you could enter the GM part number and you could get a price & description of the part aswell as those exploded assembly drawings which you see at the dealers it would save a lot of phone calls or visits to the dealers.
Kev
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The pipework you ask about is all part of the engine breathing system.The large diameter pipe from the valve cover to the inlet trunking vents any blow-by fumes to the inlet side of the engine.The smaller diameter pipe is a vacuum pipe designed to maintain a slight depression in the crankcase at low engine speeds and to divert any blow-by fumes away from the throttle plate and idle valve where they could cause an irregular idle.Because of the small diameter of the vacuum bleed it is necessary to prevent it sludging up,so it is heated by means of the coolant pipes which are connected to it.The coolant pipes also prevent the breather system freezing up from any water vapour drawn from the crankcase.Unfortunately this system does not entirely prevent blockages occurring and because of the way it is designed it is about an hour's work to clean it out.So it simply gets ignored at routine services,and the engine starts to stall occasionally or idles badly.I'm sure you'll get more on this.
David Davies (Tune-Up Raglan)
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Well it makes a little more sense now, thanks, I can see that the coolant hoses going to the vacuum pipe, help to keep the oil sludge in a liquid form.
btw in the process of renewing that vacuum pipe, which was 100% full throughout its full length of clogged up dirt, I decided that the metal pipe through the throttle housing must also be blocked, I unblocked it using a drill bit. But the hole did not appear to go all the way through to the inside of the housing. I removed the throttle valve assembly and drilled from the inside, again unable to pass the bit all the way through. I cleaned out the old vacuum pipe and reconnected a cut portion of it. I filled a syringe with white spirit and injected it into the pipe, at first nothing came through , then a little and eventually it flooded through. I can now be sure that the hole is clear.
It is weird though that it has been designed so that the hole can not be cleaned easily, because, it is not in a straight line.
But what about the coolant hoses which mates with the throttle housing? what is the function of that part. Again thinking about it it is near another vacuum pipe which joins at the rear so I guess it is to try to help keep that from becoming blocked.
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2nd time I write this!! there must be some sort of time out feature.
Kev, for future reference should it happen again www.honestjohn.co.uk/forum/post/index.htm?f=3&t=78...5
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