What am I looking at??
06-04-2001, 01:24 PM
#1
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Thread Starter
What am I looking at??
Hi All,
Some of you may recall I have been restoring an 85 930. I have removed the motor, cleaned it and disassembled everything down to the block (except the heat exchangers).
Here is my question... Once I had the intake removed I looked into the intake onto the valve. The back of all of my intake valves have a considerable amount of carbon deposits...
Is this normal?? Could this be the cause of the oil in my intake and smoking on start??
I have never looked into a 911/930 motor...
Any help or advise is appreciated...
BTW) the motor has 72k on it...
-LeoD
Some of you may recall I have been restoring an 85 930. I have removed the motor, cleaned it and disassembled everything down to the block (except the heat exchangers).
Here is my question... Once I had the intake removed I looked into the intake onto the valve. The back of all of my intake valves have a considerable amount of carbon deposits...
Is this normal?? Could this be the cause of the oil in my intake and smoking on start??
I have never looked into a 911/930 motor...
Any help or advise is appreciated...
BTW) the motor has 72k on it...
-LeoD
06-04-2001, 02:42 PM
#3
RL Technical Advisor
Hi Leo:
Without seeing this for myself its somewhat difficult to say but I would tell you that its mostly normal.
The effects of burning unleaded gasoline containing MTBE is what causes that fluffy carbon buildup and associated running problems. This also causes carbon buildup in the injector tips that affects the atomization of fuel.
Using Techron or LubroMoly Jectron and Ventil Sauber will go a long way toward removing these deposits and prevent more buildups.
In the case of a 930, you might also be seeing the results of some oil getting by the turbocharger seals or valve guides so a final determination should be done by an experienced individual. If you have a digital camera and can send me some good pics, I would be happy to help evaluate what you are seeing.
Smoking on startup can be caused by too much oil in the system, worn intake guides and seals, leaky turbocharger seals, and even broken rings. I would need to know more about your engine and whether its original or not before I could offer an informed opinion.
Normally speaking, a 72K 930 engine is truly ready to be freshened up. We find that valve guides, valve stems and guide seals are worn and many times rings are broken from detonation.
Hope this helps,
--
Steve Weiner
Rennsport Systems
Without seeing this for myself its somewhat difficult to say but I would tell you that its mostly normal.
The effects of burning unleaded gasoline containing MTBE is what causes that fluffy carbon buildup and associated running problems. This also causes carbon buildup in the injector tips that affects the atomization of fuel.
Using Techron or LubroMoly Jectron and Ventil Sauber will go a long way toward removing these deposits and prevent more buildups.
In the case of a 930, you might also be seeing the results of some oil getting by the turbocharger seals or valve guides so a final determination should be done by an experienced individual. If you have a digital camera and can send me some good pics, I would be happy to help evaluate what you are seeing.
Smoking on startup can be caused by too much oil in the system, worn intake guides and seals, leaky turbocharger seals, and even broken rings. I would need to know more about your engine and whether its original or not before I could offer an informed opinion.
Normally speaking, a 72K 930 engine is truly ready to be freshened up. We find that valve guides, valve stems and guide seals are worn and many times rings are broken from detonation.
Hope this helps,
--
Steve Weiner
Rennsport Systems