Troubleshooting M20 rough running

[Son of Marty]

If your plugs are that black I'd think you could have fouled your o2 sensor and the car is in limp home mode (full rich) but IMHO theirs no reason to go on until you solve your water problems.

[jimk]

Rev it and hold it there to clear things out.  Just gunning it and letting it idle won't dry it.

[jimk]

50 minutes ago, TurkisM2002 said:

It certainly looks white to me. I had to top off the coolant since it was pretty low.

That doesn't mean much at this point, it hasn't run enough to get all the air out.

[jimk]

1 hour ago, flagoworld said:

Hold a piece of white paper over the exhaust for a minute and then post a pic of it and describe it as best you can.

The exhaust is so loaded with water from all the cold starts, a paper test won't tell much at this time.

[TurkisM2002]

1 hour ago, jimk said:

Rev it and hold it there to clear things out.  Just gunning it and letting it idle won't dry it.

 

How long should I hold it open?  I held it steady for a good 15 seconds (not in the video), which seemed like an eternity. Oh the HOA is going to love this. Maybe I'll do it after dark....

 

After taking this last video, I tapped the gas pedal and the car just died which is a first, but it was a cold start. 

 

I did perform another vac test and I did find a very small leak with the ICV valve that I fixed .No change of course. 

 

Another thing I noticed is that I have a significant oil leak coming out of the back of the oil pan.   It's not a weep it's a stream. JHC. 

 

 

 

 

 

[TurkisM2002]

1 hour ago, ray_ said:

Was that a cold start? Put the inductive timing light on each wire....

 

 

Yes it was...  I'll try that again. I had spark on each cylinder before I swapped the plugs. 

[TurkisM2002]

1 hour ago, ray_ said:

Oh yikes.  

 

Try the Bar's Leaks or pull the motor.... I mean the head...

 

I read that post about the Bar's leaks ... seems almost like a religious debate putting that stuff in the motor  Question - if I do put it in, is it possible to get that gunk out if I replaced the head gasket anyway? 

 

 

[TurkisM2002]

 

 

[Son of Marty]

Are you seeing coolant mixed with the oil in the crankcase or just some white sludge under the valve cover?

[TurkisM2002]

5 minutes ago, Son of Marty said:

Are you seeing coolant mixed with the oil in the crankcase or just some white sludge under the valve cover?

 

So right now I only have distilled water in the engine - since really at this point I was mocking up the cooling system and didn't want to waste coolant until I knew everything was tight.  However, I didn't drain the block, so there is I'm sure some old coolant in there.  I noticed the milky oil in the compression test hose when I did a wet compression test in one of the cylinders. 

 

The oil leak I have coming out the back of the oil pan looks like clean oil. No milk. 

 

[Son of Marty]

OK, thats just another sign of a wet engine IMHO your not going to get it dry until you can drive it, warming it up in the driveway is not going to get it done completely.

[ray_]

2 hours ago, TurkisM2002 said:

 

 

Yes it was...  I'll try that again. I had spark on each cylinder before I swapped the plugs. 

I'd assume a cold start on fresh plugs, with cold start parameters, isn't likely to foul plugs immediately. 

 

You might, if feeling industrious, test the coolant for exhaust gases.

 

Where did you see coolant in the oil? If condensation under the valve cover, don't worry yet. If on the dipstick, worry more ?

 

I think the head will need to come off.....

 

Edit: I see some responses above wrt my thoughts...

Edited May 26, 2020 by ray_

[TurkisM2002]

So this rough idle when cold could it be attributable to the cold start running rich or possibly leaking head gasket?  I have spark and I have fuel for each cylinder. 

[ray_]

If we assume the cold start circuit is properly functioning I am more inclined to think you'd have a smooth(er) idle when cold.

 

Assuming the motor behaves similarly when cold or warm, I think the head may need to come off.

 

Free advice for you -- worth every penny!

 

[TurkisM2002]

3 hours ago, ray_ said:

If we assume the cold start circuit is properly functioning I am more inclined to think you'd have a smooth(er) idle when cold.

 

Assuming the motor behaves similarly when cold or warm, I think the head may need to come off.

 

Free advice for you -- worth every penny!

 

 

 

Just remembered I had to cap the evap purge valve port since I didn't have the rest of the system and was told this was OK to do, however the connector is hanging loose.  It's not shorted or anything.