fbpx

 

On my 618 today I got 750F on the one cylinder and 130F on the other one, All these on the runup.
I went back to the hangar and switched the sensors, I did another runup This time the same thing happen but in reverse, I think that issue can be solved with 2 new sending units.
But I also notice oil spiting out of the 2 ends of the elbow connector that connects the mafler to the manifold, I notice this as well on the 1st runup but the amount of oil spited out from the 2 ends had been doubled on the 2nd runup,
I also my full throtle only give me 3400RPM whch is about 1/2 of what it supposed to be.
Is there a posibility for one of the cylinders not to run?
I suspect that The RPM issue can be a PROP pitch issue as it is a new prop, Although a got me 6800 rpm on my static test but before I start with the prop I want to fix the manifold issue first.
Any assistance advise or idea wil be apreciated, I did attach a picturer showing the elbow connector and the oil on the mafler.
Rgards
Yanis
EGLEAK1.jpg (You do not have access to download this file.)
  • Re: EXHAUST MANIFOLD ISSUE

    by » 9 years ago


    Looks like you may have a bad joint there...take it apart and see if the is somthink spoiling the seal,

    Not sure about the RPM issue...did you get 6800 with that prop on during your static check at the pitch it is now.

    Nick.

    Thank you said by: yanis karvas

  • Re: EXHAUST MANIFOLD ISSUE

    by » 9 years ago


    Hi Nic,
    Thank you for your input, The more I think about it the more releaf I get of not having a major issue,
    Yes I do suspect both ends of the elbow not to seal properly, and the mild oil spiting to be normal,
    I will figure a way to redo both connection parts with something better, replace the senting units of both sensors, IF the temperature readings are proper on both I will close that issue and concetrate on the RPM, starting with another static run,
    Yes the previous static run was on the same pitch seting.
    Thank you Nic, and regards to all.
    Yanis

  • Re: EXHAUST MANIFOLD ISSUE

    by » 9 years ago


    Hi Yanis...not saying the spitting is normal just that it shouln't leak past the joint....maybe somthing like a carbon build up or even a crack if the joint has not been kept free to move,

    Does the engine sound like its only making 3400 RPM.

    Nick.

  • Re: EXHAUST MANIFOLD ISSUE

    by » 9 years ago


    Yanis,

    I would pull the plugs and see if they are oily black in one cylinder. I don't think prop pitch would account for a sudden drop of 50% of RPMs. If you changed the wires on the sensors but not the sensor location, that would change the readout on your instruments but would not necessarily mean the sensor is bad. It does prove that the instrument is working. If you now switch the sensors themselves but leave the same wiring on the same sensors, if the sensor is bad, the gauge readings will stay the same. If the sensors are good, the hot one will read cold and the cold one will read hot. Sudden drop of RPM and unburned oil in the exhaust sounds like one cylinder not firing.

    Bill.

  • Re: EXHAUST MANIFOLD ISSUE

    by » 9 years ago


    Hi Nick,
    I though it of as, if inside the connections of the elbow are any seals that been cracked due to vibration then the spiting of whatever unburned substance are in tansition in my case black oil it could be expected, The question is, is it normal for oil to be present? more likely I was expecting more noice from the cracked joint than the oily staf,
    I am taking into the consideration Bill's suspecion that 1 of the cylinder may not be running, I don't know, I did clean up the sending probes on both sensors today, i started it up the engine and I notice another wird thing the instrument on the bad suspected sensor was reading 0 it's should have been some heat there as i had it run for almost a minute, I also did pull 4 plugs out as Bill sugested, they was normal not build up or overburn, I did clean them up before re instaling them, and now I got a very low reading on one of the cylinter CHT, I will go back tomorrw and see if that will hapen again and if the low reding cylinder is the one that has 0 reading on the EGT.
    I apreciate your input.
    Reagards
    Yanis

You do not have permissions to reply to this topic.