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Author Topic: Help my car is smoking.  (Read 4929 times)
René Holm
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Posts: 47


« on: March 17, 2019, 09:01:20 pm »

Hello.
I have a problem with the engine in my murena 2,2.
When I accelerate, there comes blue smoke out of the exhaust, I thought it was the valve stem seal, because the sparkplug at cylinder number 4 was wet, contrary to the 3 others that were dry.
So I changed both seals at cylinder number 4.

But the car still smokes, and the sparkplugs is still wet. 
There is fine compression at all 4 cylinders.

Are there some people who have an idea of what the problem may be?
 
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1983 Matra murena 2,2
Colin
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« Reply #1 on: March 18, 2019, 09:07:21 pm »

That sounds like a carburation problem, Valve stem oil could be the culprit,  but they normally cause smoke on the over-run, not under load, you would also see a huge increase in oil consumption.
I think I would take the carburettor to bits and check it's not something blocked up in there...
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roy4matra
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« Reply #2 on: March 19, 2019, 01:58:18 am »

Hello.
I have a problem with the engine in my murena 2,2.
When I accelerate, there comes blue smoke out of the exhaust, I thought it was the valve stem seal, because the sparkplug at cylinder number 4 was wet, contrary to the 3 others that were dry.
So I changed both seals at cylinder number 4.

But the car still smokes, and the sparkplugs is still wet. 
There is fine compression at all 4 cylinders.

Are there some people who have an idea of what the problem may be?
 

First René, can I check we are talking about the correct cylinder.  You say No.4 has the wet spark plug.  You understand that this is the cylinder next to the timing chain?  Unlike just about everyone else Simca/Talbot number their cylinders 'backwards' so No. 1 is next to the flywheel and therefore No.4 is at the timing case end.  Is the engine perfectly standard with the Solex 34CICF down-draught carb. and original PCV system?  The PCV is the pressurised crankcase ventilation system and has a green oil separator with hose connections to the cam cover, the top air intake elbow and a small connection to the inlet manifold below the carburettor.  Have you checked if the connection to the manifold is clear, and you can feel a suction there when idling if you remove the hose?

If the plug is wet, does it feel oily, or does it smell of petrol?  Does it misfire?  If that one plug was getting very oily it should misfire and produce less power than the others, making the engine a little rough.  You say you have good compression on all cylinders.  Can you give us the figures please.  Has the engine been rebuilt at any time?

If there is some oil still in the exhaust silencer from a previous leak, it may take a while to burn it all away, so it might be smoking even though the fault is now cured.

Also please do one other test for me and report.  When the engine is hot and idling, if you remove the oil filler cap, do you get any crank case fumes, or smoke venting out from the cover?

When I know all the answers to these things I may be able to tell what is happening.

Roy
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René Holm
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Posts: 47


« Reply #3 on: March 24, 2019, 12:10:03 am »

Hi Roy.
Now I have tried a couple of things.

The engine is standard with Solex 34CICF down-draught carb, but with another airfilter.
Like you said, it´s cylinder number 1, the plug is feeling very oily. Yesterday I bought new plugs, but it didn’t help much. It was the same result. As you can se at the Picture.

I have an idea, that i can be the pistolrings.
 
I have checked the connection to the manifold, and it´s feel a suction there when I remove the hose?
I can´t remember the value for the compression, and I do not know if the engine has been rebuild. When I remove the oil filler cap, black smoke comes up and I can feel pressure.

René
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1983 Matra murena 2,2
René Holm
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Posts: 47


« Reply #4 on: March 24, 2019, 12:14:54 am »

And i have alredy changed the gasket on both valves, on cylinder 1.
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1983 Matra murena 2,2
Jon Weywadt
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« Reply #5 on: March 25, 2019, 01:12:05 pm »

Hi René.
Please reduce the size of your photo. We have to scroll sideways a lot to read the post. Grin
Regards. Jon
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roy4matra
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« Reply #6 on: March 25, 2019, 10:30:16 pm »

Hi Roy.
Now I have tried a couple of things.

The engine is standard with Solex 34CICF down-draught carb, but with another airfilter.
Like you said, it´s cylinder number 1, the plug is feeling very oily. Yesterday I bought new plugs, but it didn’t help much. It was the same result. As you can se at the Picture.

I have an idea, that i can be the pistolrings.
 
I have checked the connection to the manifold, and it´s feel a suction there when I remove the hose?
I can´t remember the value for the compression, and I do not know if the engine has been rebuild. When I remove the oil filler cap, black smoke comes up and I can feel pressure.

René


Your picture (which I have reduced in my post) has two plugs but you don't say what these are.  Is the clean one on the left from another cylinder and the one on the right from number 1 cylinder?  Or is this an old plug (on the right) which has done some mileage on the road?  How much mileage?  Was the new plug on the left fitted in the same Number 1 cylinder and for how long?  Did you do any road mileage on the new plug?

The ceramic insulator on the new plug is very white and clean (except for the small black mark near the tip which I suspect is just oil on it from getting it out where it has touched the threads or side, as you can see by the threads that the entry is very oily)  If the cylinder was getting a lot of oil in it, the ceramic insulator should be coated in oil and be black all over.  Even if the cylinder was not getting much oil in it, the ceramic insulator should NOT be that clean and white - today with the low-leaded fuel all plugs get black but it should be dry not wet.

Your last statement that you are getting black smoke and pressure from the cam cover when you remove the oil filler cap tells you, you have something badly wrong!  There should be a vacuum in the crankcase not pressure, as I said when explaining the PCV system, and there definitely should be no smoke!

You are going to have to strip the engine to find out exactly what is wrong.

Roy
« Last Edit: March 25, 2019, 10:36:06 pm by roy4matra » Logged

René Holm
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Posts: 47


« Reply #7 on: March 26, 2019, 07:43:52 pm »

The right plug is from number 1 cylinder, the left one is from cylinder number 2, the two other plugs is look like the plug from number 2. I have drived car for 45 minutes and around 25 kilometers. So I also think, that something is badly wrong  Embarrassed
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1983 Matra murena 2,2
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