Pagoda SL Group
W113 Pagoda SL Group => General Discussion => Topic started by: bsimaz on November 09, 2006, 07:51:30
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Well I'm finally enjoying car and I see a (hopefully not big) problem. I have alway had the traditional small puff of smoke when starting my car. After that nothing. While on the way to work this morning I'm about 10 miles into my 15 mile trip when I notice someone's car is blowing quite a bit of blue'ish/white smoke. As you might guess, that someone was me. :-( The first 2/3rds of my trip were fine and without incident. All of a sudden... Bam... smoke. I've searched the forums and found several things to check. There is no noticable differance in the car's running or handeling.
Where would be my most likely place to start my search. I waited until the car cooled a little and the oil looks good. As does the antifreeze.
Bill Simaz
'66 230sl
Back on the Road
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The first thing I would reccomend doing is to remove the spark plugs to see if there is oil or black soot on one more of the plugs.
Then look to see if that cylinder has a source (trans vacuum line, brake booster, etc) where oil or fluids could be entering the engine through the intake manifold. If not the sudden onset could also indicate that a valve guide has come loose from the cylinder head. The bronze valve guides are a press fit into the aluminum head and if they come loose will move up and down along with the valve, oil from the cam housing above will work its way around the outside of the guide into the intake or exaust port and make lost of smoke. The exaust guide will send the oil directly into the exaust and often will not show as much soot or oil on the spark plugs as it would if an intake guides were loose.
Al
113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket
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Bill,
I would also check the plastic valve stem seals on top of the valve guides. They are known to snap loose.
Per G. Birkeland
69 280 sl aut 834
Norway
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Hello Bill,
Do you have a little history on the engine. Possibly a tranmission modulator diaphram. Not that a big deal. Watch for problems at #6 spark plug and diminishing transmission fluid level to confirm this. Otherwise knirk or Al may have pegged it for you.
Joe Alexander
Blacklick, Ohio
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Thanks for all the advice. I did check some things before leaving for work and everything looked fine. I took it out during lunch and I saw no smoke while the engine was cold. Upon returning from lunch, there was the smoke again.
Leaving for home, again no smoke with a cold engine, and by the time I got home, viola, it was running like before. Not smoking at all.
Question: Could I have gotten something in the pistons that was burning up to cause the smoke? Once it burned off all was good.
OR
Is this a sign of something (bad) yet to come?
Anyway, the car is not smoking anymore and I'm glad (for the moment).
Bill Simaz
'66 230sl
Back on the Road
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Hi Bill
I had a similar situation a few years back, which turned out to be an exhaust valve guide, which initially came loose under hard acceleration. It subsequently slid back into place and was fine for a while ( I drove a lot easier after this) but eventually it came loose again and I knew it was time to get the head serviced. Joe A. helped talk me through this and his understanding was, as Al mentioned, that exhaust valve guide leaks don't end up in the cylinder and actually burn off the hot manifolds without entering the combustion chamber, so the plugs looked fine. Apparently because of the different expansion rates, the bronze guides can become loose with age and some folks have even resorted to having the guides knurled in an attempt to keep them in place. The new guides are slightly oversized and require machining to fit properly. The cost of the guides themselves was under $20 each, so I just replaced them all along with seals and haven't had any smoke since in over 20,000 miles. As Joe pointed out, if the problem was rings/pistons, the head would need to be done anyway and often the bottom end is fine, with the top end needing work 2 or 3 times before the bottom needs attention, so head work would not be wasted if you had to do a complete rebuild later.
I certainly have an embarrasing memory of the day I tried to blow past a little old lady and buried her in smoke so bad she had to pull over...a virtual fog machine on wheels :evil:
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quote:
Originally posted by Ricardo
Hi Bill
...and some folks have even resorted to having the guides knurled in an attempt to keep them in place......
Please don't try having a loose guide(s) knurled.
When the surface is knurled the grooves that are rolled onto the guide to enlarge it's outsied diamater will act as a pathway and oil will find its way into the ports. The plastic guide seals only protect between the valve and the guide, not between the guide and the cylinder head. After knurling, the guide may stay in palce, but oil can still make its way past.
There is a similar process called "peening" where an sharp punch is used to make hundreds of dimples onto the outside of the guide. This process also makes a tighter but porous fit between the guide and head.
These are usualy done as a "quick fix" without taking the cylinder head off, the results, at best, are temporary.
Al
113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket
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Brakes?
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto