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-   -   Clack-clack-clack noise? (http://forums.pelicanparts.com/porsche-911-technical-forum/771275-clack-clack-clack-noise.html)

nene 09-13-2013 08:03 AM

Clack-clack-clack noise?
 
Recently, I have noticed that when starting my 86 Carrera from a cold start, I hear a clacking noise (which sounds like the valves) on the drivers side of the valve covers area. It appears that once the OIL hits that area, the sounds goes away (yikes)!!:confused: Any suggestions gents?

Thanx,

T77911S 09-13-2013 08:09 AM

pull the valve cover and check it out. could also be a clogged hole in the spray bar

nene 09-13-2013 08:15 AM

Thanx, I will look into it once I dive in there to do the Valve Job!

Bob Kontak 09-13-2013 01:39 PM

Just talking here. Any change in oil viscosity from the heavier stuff the cars should use?

nene 09-13-2013 07:43 PM

Bob, I did recently did and oil change, but I don't think it's too thick.

Bob Kontak 09-14-2013 07:29 AM

New cars use pretty thin oil.

I don't know enough about oil to advise you. But if you did put oil in yourself and you don't know what the viscosity is, then you might want to replace it with the correct viscosity oil to be sure. That will cost you $75 or so with oil on sale as you probably know.

If you asked what you needed at the parts store and they told you, there is a very good chance it is fine.

Dodge Man 09-14-2013 08:38 AM

Valve Adjust?
 
Since you have to drain the oil to do a proper valve adjust/inspection, you may want to at least see if the rockers have small jiggle(proper crank position required) to see of any valves are too tight. This can be done while you are inspecting the oil sprayers. Do you have start-up smoke? Best of luck. :)

nene 09-14-2013 03:53 PM

Dodge, I do have some smoke on start up. Can loose or tight valves cause smoke (besides tired engine)?

Ronnie's.930 09-14-2013 04:17 PM

Horizontally opposed cylinder engines smoke at startup even when brand spankin' new (it's the nature of the design and has nothing to do with valve lash settings).

Hunt3R 09-14-2013 05:08 PM

Quote:

Originally Posted by nene (Post 7656579)
Dodge, I do have some smoke on start up. Can loose or tight valves cause smoke (besides tired engine)?

My 3.2 over time had started to blow out a white cloud of smoke on cold starts and for the first couple minutes driving off down the road I could see faint black smoke coming around the car as I would slow down to idle at a stoplight. Then I did a valve adjustment and now there's absolutely no smoke at all, none at all when starting up and none at all at idle when warming up. Changed the way my engine sounds now too.

So I'm gonna say yes. And make sure you're using a thick weight oil too like a 20w50. What oil did you put in?

hcoles 09-14-2013 05:24 PM

I have an 89. No smoke at startup or other times.
If the rockers, cam and valve stems are in reasonable shape and adjustment the sound at idle will be like a well oiled Singer sewing machine. Something like that, if you are hearing "clacking" you have some sort of issue. IMHO.

boyt911sc 09-14-2013 07:05 PM

No smoke at 146K miles.......
 
Quote:

Originally Posted by Ronnie's.930 (Post 7656608)
Horizontally opposed cylinder engines smoke at startup even when brand spankin' new (it's the nature of the design and has nothing to do with valve lash settings).

My '89 Carrera with 146K miles does not smoke during cold starts. But my other '78 SC does. And my son's '87 Carrera does not either too. So with my Subaru Impreza.

Tony

lonewolf 09-14-2013 07:22 PM

Quote:

Originally Posted by nene (Post 7655508)
Bob, I did recently did and oil change, but I don't think it's too thick.


Clacking on startup can also be from low oil.
If you did a change recently and before you go taking everything apart make sure you have the proper amount of oil in the engine.

Bob Kontak 09-14-2013 07:55 PM

Quote:

Originally Posted by Hunt3R (Post 7656651)
Then I did a valve adjustment and now there's absolutely no smoke at all, none at all when starting up and none at all at idle when warming up.

Let's think about this for a little second.

The valves move up and down all the time in the valve guides the height of the lobe on the ol' bump stick. That can be measured in fractions of an inch - I don't know, a quarter or three eighths?

You adjusted them this way or that a very few thousandths of an inch in the same direction the cam moves the valve.

I am not seeing any reason why a valve adjustment could cause an improvement in oil seepage through the valve guides.

I am thinking you are merely in the cosmic grace period before the next fog. (See Ronnie's post)

Also, from my experience, blowing smoke on start up is a hit or miss thing. I can go for weeks, even months, with no smoke then it fogs the neighborhood. Like, I should go to jail smoke. Maybe it has to do with where the engine stops?

Ronnie's.930 09-14-2013 08:29 PM

Bob, that is my experience with start-up smoke as well - no visible smoke for weeks, and out of no where, a juicy burst of it. I've experienced this with every opposed cylinder engine I've ever been around (including the Type IV in a 914 I drove for years, and the aircraft engines I've worked on). Of course, none of this with the glorious Opel lump! :D

nene 09-14-2013 08:36 PM

I don't know boys, back in the high school days (1986 or so) I bought my first Porsche (yes in high school) a 1975 911s with 86k miles on it and that thing never smoked and it even had a broken stud (which I thought was a leaking exhaust). Now this car that I have (picture) mainly pumps out smoke on start-up and generally smell the stench when coming to an intersection or stop!

Bob Kontak 09-14-2013 08:39 PM

Quote:

Originally Posted by Ronnie's.930 (Post 7656848)
Of course, none of this with the glorious Opel lump! :D

LOL - For those that never owned an Opel GT like Ronnie and me......... If you have to ask you wouldn't understand. http://forums.pelicanparts.com/suppo...leys/freak.gif

nene 09-14-2013 08:47 PM

Quote:

Originally Posted by nene (Post 7656856)
I don't know boys, back in the high school days (1986 or so) I bought my first Porsche (yes in high school) a 1975 911s with 86k miles on it and that thing never smoked and it even had a broken stud (which I thought was a leaking exhaust). Now this car that I have (picture) mainly pumps out smoke on start-up and generally smell the stench when coming to an intersection or stop!

http://forums.pelicanparts.com/uploa...1379220427.jpg

lonewolf 09-14-2013 09:55 PM

smoke on startup can also be caused by slow closing /sticky the odd time injector or another fuel source.
The tiny bit of fuel washes the cylinder and hence the smoke on startup.
That's why it only happens every now and then .

also if say you started the car but only let run a few secs to maybe check something and then it was off for couple days . it could smoke on startup for a few secs.

As an old pro engine builder told me many years ago ,if it doesn't happen all the time .dont worry about it.

Ronnie's.930 09-14-2013 10:18 PM

Quote:

Originally Posted by lonewolf (Post 7656894)
smoke on startup can also be caused by slow closing /sticky the odd time injector or another fuel source.
The tiny bit of fuel washes the cylinder and hence the smoke on startup.
That's why it only happens every now and then .

Sorry, but this is not at all accurate. It takes far more than a "tiny" amount of fuel to result in cylinder washing (more like a grossly rich running condition, or a water/methanol injection system that is not working properly) and if oil was washed from the cylinder(s) when the engine was not running, then there would be no oil there to burn when the engine is started, and therefor, no startup smoke. The reason that the startup smoke is intermittent is that, due to the cylinder layout, "sometimes" oil, enough to result in visible smoke, travels past the rings, and into the combustion chamber, when the engine is not running.

Hunt3R 09-15-2013 04:06 AM

Quote:

Originally Posted by Bob Kontak (Post 7656824)
I am thinking you are merely in the cosmic grace period before the next fog. (See Ronnie's post)

Also, from my experience, blowing smoke on start up is a hit or miss thing. I can go for weeks, even months, with no smoke then it fogs the neighborhood. Like, I should go to jail smoke. Maybe it has to do with where the engine stops?

Well it's been 2.5 months since I did the valve adj and since then I have never had any smoke at all, not even a single wisp, none, and I don't have a cat conv either. Before I was puffing out a big cloud of white smoke at say maybe 90% of cold starts. I didn't expect the valve adj to change that, but at this point my money says it did.

Ronnie's.930 09-15-2013 08:10 AM

^^^ I'm curious as to what your oil level was when you had lots of smoke at startup compared to what the oil level has been at the last 2.5 months.

What you have observed is incredibly strange since valve lash has absolutely nothing do no with oil getting into the combustion chamber.

Hunt3R 09-15-2013 10:21 AM

Quote:

Originally Posted by Ronnie's.930 (Post 7657251)
^^^ I'm curious as to what your oil level was when you had lots of smoke at startup compared to what the oil level has been at the last 2.5 months.

What you have observed is incredibly strange since valve lash has absolutely nothing do no with oil getting into the combustion chamber.

I've never overfilled. I maintain the oil level towards the lower mark, let it run below it, refill and record how much it takes in my maintenance log.

When I first purchased the car 15 months ago it never had any smoke coming out of the pipes. It was overdue for a valve adjustment time-wise but not been driven hardly at all for the previous decade, however I drove 4k in the first year including a 2k mile trip shortly after buying it. Slowly it started to develop the smoke on cold starts and kept getting progressively worse, including an overly rich smell from the exhaust, hence the light black smoke for the first couple minutes while warming up too. It seemed as though I could never lean it out enough before, but immediately after doing the valve adj the rich smell was gone along with all of the smoke.

Each of my valves were slightly too tight, only 2 were too loose, but all were out of spec. I didn't expect the valve adjustment to have such positive effects on the startup smoke and the A/F ratio but this is what I'm seeing, and hearing too b/c now it has a much more recognizable air-cooled engine sound.

ant7 09-15-2013 12:10 PM

hi All,
I mainly find with my 3.2 that if i wait until the oil tank level rises to its maximum before shutting the engine off, the next time i start it [within a few days] the car seldom smokes on start up, of course' if you let the car sit for a couple of weeks or more, the oil from the tank will slowly seep back down into the crankcase, and will eventually creep past the rings and into the cylinders, where on start up it will get burnt off...
As others have said, depending on where the engine has stopped can have a more or less affect too on the amount of smoke produced...
Anthony...

Hunt3R 10-15-2013 06:06 PM

Quote:

Originally Posted by Hunt3R (Post 7657011)
Well it's been 2.5 months since I did the valve adj and since then I have never had any smoke at all, not even a single wisp, none, and I don't have a cat conv either.

Went to Germany for Oktoberfest so my car sat in my garage for nearly 3 weeks and on the first start a small puff of white smoke came out and was gone in a couple seconds. First time I've seen any smoke at all though since the valve adjustment.


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