| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 2319.1 | Worn valves | LARVAE::TILLING_S | | Mon Oct 03 1994 16:09 | 5 |
| Try the valve guide oil seals/ worn valve guides.
Simon.
|
| 2319.2 | | FORTY2::HOWELL | Just get to the point... | Mon Oct 03 1994 16:18 | 2 |
| Does it do it when you start the car up, particularly after its been
standing for a while? If so, this reflects .-1 even more.
|
| 2319.3 | could be guides, could be rings | GRANPA::BBELL | | Mon Oct 03 1994 17:09 | 20 |
| During engine braking, when any particular cylinder is in its intake
stroke, the intake valve is open and the piston is going down drawing
the combustible fuel/air mixture into the combustion chamber. But if
your foot is off the accelerator pedal, the carburetor valve is closed
so a very strong vacuum is created within the cylinder. This vacuum is
what creates the engine braking. It also tries to equalize the large
difference in pressure by any other means possible. If the gap between
the valve stems and valve guides is great enough, or if the piston
rings are worn, broken or not seated properly, this vacuum can draw oil
into the combustion chamber. In the case of rings and valve guides,
motor oil is present in its normal role of lubricating the moving
parts.
While not as important as it used to be in older engines, this is one
important reason to follow the break-in or wear-in procedures for a new
engine; that is, to wear in the rings and guides properly to provide
the proper mating surfaces which will seal out the motor oil.
grins,
bob
|
| 2319.4 | Not after left standing | NETRIX::"@BSO" | | Mon Oct 03 1994 17:23 | 13 |
| Re .2
No, I've never seen this after it's been left standing, only when running downhill.
Thanks for the responses.
If it is worn Piston rings or valve guides, is this life-threatening? It runs fine
currently but it's going for service tomorrow, and I wonder whether I should mention it?
I imagine fixing it could be expensive.
- Andy
[Posted by WWW Notes gateway]
|
| 2319.5 | | FORTY2::HOWELL | Just get to the point... | Mon Oct 03 1994 17:41 | 17 |
| When my piston rings went, more smoke came out of the engine breathers
than the exhaust. When I was coasting no smoke was visable out of the
engine breathers, and a VERY little could be seen out of the exhaust.
Vice versa applies, under throttle the exhaust smoke went away but
there was a MAJOR amount of smoke pouring out of every engine
breather!!
Seeing as you don't find any effect after standstill, presuming it's
something serious and bearing in mind I'm an evil pessimistic little
blighter, I'd say your piston rings are shot. But then I would. I've
had it happen to me :-)
Dan
P.S. Yes it is expensive. I needed a new engine. Ouch. It depends on
your engine, of course. Tipo blocks might be linered, etc...
|
| 2319.6 | Inlet guide? | BLKPUD::ROWEM | Frank Gamballi's Trousers! | Mon Oct 03 1994 18:14 | 6 |
| I'll have 2:1 on a worn inlet valve guide, exhaust guide would smoke
after being stood? rings would blow oil vapour out of the breather.
Matt.
ps. I was wrong on the rumbly Nova, maybe I'll be lucky on this.....
|
| 2319.7 | | WELSWS::HILLN | It's OK, it'll be dark by nightfall | Tue Oct 04 1994 09:48 | 21 |
| First disconnect the pipe that should run from the engine to the air
inlet, which stops the oil mist venting directly to atmospheer.
Then do one of these downhill runs and whilst its still smoking, stop
the car and open the bonnet.
If the smoke is all coming from the exhaust pipe then it's the valve
guides.
If it's all coming from the engine breather then it's the rings.
If it's coming from both then it's rings and guides.
Then reconnect the breather.
If it's rings then it's a costly bottom half engine.
If it's guides then it's a slightly less costly top end.
If it's both then it's a complete recon engine, which is cheaper than a
strip down and rebuild of the pistons and valves.
|