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Funny blue smoke

Started by _Muzzy_ , Jul 29 2016 07:52 PM

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28 replies to this topic

#1 _Muzzy_

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Posted 29 July 2016 - 07:52 PM

Here's a funny one, when I park the car downhill, on start up it gives a puff of blue smoke,

so the background its new engine and head, done about 500km now. Start up on level or uphill not a problem, and to date no level change on dipstick that is noticeable

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#2 _imj411_

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Posted 29 July 2016 - 07:59 PM

How steep is the hill is it getting on the bottom of the bore? Cheers Aaron.

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#3 _Muzzy_

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Posted 29 July 2016 - 08:08 PM

How steep is the hill is it getting on the bottom of the bore? Cheers Aaron.

I live in Dubbo we don't really have hills LOL

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#4 TOERUNNER

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Posted 29 July 2016 - 08:20 PM

valve stem seals

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#5 S pack

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Posted 29 July 2016 - 08:34 PM

valve stem seals

+1

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#6 _Muzzy_

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Posted 29 July 2016 - 10:04 PM

Yes I would agree valve stem seal, even though they are new, then my question would be why down hill only, as mentioned it doesn't do it sitting on flat or pointing up hill , or idling at light or high speed back off, typical valve stem seals conditions

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#7 _LS1 Taxi_

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Posted 29 July 2016 - 10:15 PM

What sort of engine/carb/manifold?
Could blue smoke be black smoke?...fuel bowl overflowing into manifold due to angle? (Ie: float set too high)

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#8 Bigfella237

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Posted 29 July 2016 - 10:23 PM

How much blow-by does the engine have (being a new engine the rings may not have bedded in if you've been driving it like a "gran pa special")?

Is the PCV valve connected directly to the manifold? Are there any baffles inside the rocker cover?

Is it an auto? And if so, how old is the modulator? Is it changing gears as it should?

Does it have some super-duper high volume oil pump fitted? Are the drain-back holes from the rocker gear open or is oil pooling on top of the head when parked downhill?

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#9 LC-GTR-1969

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Posted 30 July 2016 - 07:35 AM

I had a mate who had an engine that only knocked when the radio was turned down (lol)...

Is it possible at all that you have only observed the condition when starting on a downhill? As in, perhaps it is happening at other times but haven't noticed? Just floating the possibility, not saying this is what is happening.

It certainly sounds like valve guides. I have seen them leak when new but on the motor the guides were 50/50 anyway

Edited by LC-GTR-1969, 30 July 2016 - 07:36 AM.

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#10 _Muzzy_

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Posted 30 July 2016 - 07:54 AM

Thanks for all the suggestions, I will look into it further, I'm thinking valves seals, I might have pinched one, when I built the head, I'm not overly concerned as it doesn't do it all the time, I havent treated it like a a grandpa special however haven't had it on a dyno as yet as I still need to knock some top end advance out of the weights it pinging from 3500 up

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#11 LC-GTR-1969

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Posted 30 July 2016 - 09:22 AM

I had a mate who had an engine that only knocked when the radio was turned down (lol)...

Is it possible at all that you have only observed the condition when starting on a downhill? As in, perhaps it is happening at other times but haven't noticed? Just floating the possibility, not saying this is what is happening.

It certainly sounds like valve ~~guides~~ seals. I have seen them leak when new but on the motor the guides were 50/50 anyway

I meant seals, just fyi

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#12 _Muzzy_

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Posted 08 August 2016 - 05:47 PM

So I'm going to change the valve stem seals, what is the best tool to use for the job, , part no and picture would great
Thanks
Heaps

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#13 _oldjohnno_

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Posted 08 August 2016 - 07:05 PM

The lever type ones are a pain because you need to use one hand to hold it down. The ones that look like a little puller leave both hands free but they get in the way. I like to use a short piece of flat (eg. 50x6) with one end forked to fit the retainer and a hole in the middle for the rocker stud/bolt. Tack a packing piece under the other end to rest on the rocker cover gasket ridge. With this you can pull the spring down with the rocker stud and have both hands free to fumble with the collets.

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#14 madtoranajzedded

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Posted 08 August 2016 - 07:16 PM

Pmed you johnno

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#15 EunUCh

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Posted 08 August 2016 - 07:57 PM

They used to look like the one in picture.

vsc.JPG 189.68K 3 downloads

Knock one up and improve the shitty angle just above the first turn with the slight curve where it sits on the retainer and you might

even need a modified spark spark plug that will take an air fitting to help keep the valve up a bit , lock the crank with something that will will prevent the engine from turning over while the piston is TDC .

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#16 _Muzzy_

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Posted 08 August 2016 - 08:33 PM

The lever type ones are a pain because you need to use one hand to hold it down. The ones that look like a little puller leave both hands free but they get in the way. I like to use a short piece of flat (eg. 50x6) with one end forked to fit the retainer and a hole in the middle for the rocker stud/bolt. Tack a packing piece under the other end to rest on the rocker cover gasket ridge. With this you can pull the spring down with the rocker stud and have both hands free to fumble with the collets.

Is something like your referring too

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#17 S pack

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Posted 08 August 2016 - 09:01 PM

They used to look like the one in picture.

vsc.JPG

Knock one up and improve the shitty angle just above the first turn with the slight curve where it sits on the retainer and you might

even need a modified spark spark plug that will take an air fitting to help keep the valve up a bit , lock the crank with something that will will prevent the engine from turning over while the piston is TDC .

No need to lock the crank with the piston at TDC the compressed air will hold the piston down at BDC and the valve up in the head.

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#18 _oldjohnno_

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Posted 08 August 2016 - 09:09 PM

Is something like your referring too

That's it exactly. You need both hands free to do the job comfortably, and good access too. Spend whatever time it takes to make a tool that works really well rather than getting frustrated by using some half-baked piece of junk that took 30 seconds to make (which is my usual method...)

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#19 Bigfella237

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Posted 08 August 2016 - 10:18 PM

No need to lock the crank with the piston at TDC the compressed air will hold the piston down at BDC and the valve up in the head.

Then if the air supply fails for any reason, the valve drops all the way into the cylinder and it's "off with their heads"!

I've always set each cylinder at TDC, that way you can even release the air and the valve won't drop more than half an inch or so. With a manual gearbox it's usually good enough just to leave it in gear with the handbrake on.

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#20 _LS1 Taxi_

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Posted 08 August 2016 - 11:17 PM

I always feed soft rope into the spark plug hole then wind the crank over until the piston reaches the top of the bore.
The rope holds the valves closed and is a stress free way to change them.

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#21 gtrboyy

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Posted 08 August 2016 - 11:32 PM

Have you tried Nulon Stop Leak?

Believe it or not tried it on engine with bad rear main leak seems to have improved somewhat,nothing to lose.

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#22 _Muzzy_

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Posted 09 August 2016 - 08:52 PM

Have you tried Nulon Stop Leak?

Believe it or not tried it on engine with bad rear main leak seems to have improved somewhat,nothing to lose.

I built the head about 500 k ago, I was talked into leaving the intake valve oil shields off, , so either that is my problem or I pinched an o ring when I built it, so either way it's my bad

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#23 TerrA LX

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Posted 10 August 2016 - 05:54 PM

Hmmm

Edited by TerrA LX, 10 August 2016 - 05:54 PM.

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#24 _oldjohnno_

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Posted 10 August 2016 - 09:14 PM

I think it's best to run the tin shields with the o-ring seals. Doesn't matter with wiper style seals or the old umbrellas but you really need to keep the oil off the stems with the factory style rubber rings.