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TR2/3/3A Smoke coming out of crankcase vent?

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Snowkilts

Jedi Hopeful
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Hi folks,
I have recently noticed an increase in the :smile:normal:smile: smoke and burning smell under the hood. I used to think it was just oil or grease on the exhaust, but I looked around today and it's actually coming out of the crankcase vent near the fuel pump. It's pretty dramatic on a cold startup although it drops off a lot as the engine warms up. Any ideas what could be causing this?

Some other possibly relevant info. I have had crusty deposits which I assume to be burnt oil building up on the the #3 spark plug pretty consistently for many years. Other plugs are clean. Compression is good across all cylinders. No noticeable smoke from the tailpipe.

I've been hearing a gradually louder ticking sound from the motor. I haven't adjusted the valves in a while so I thought it might be that but now I'm wondering. It sounds a lot like my '65 Mustang used to with it's cracked exhaust manifold. I shot short a video of the engine running: https://photos.app.goo.gl/MUV2IdRXvgMtV38C3

Thanks!
 
A little smoke from an old engine breather would not be unusual but the emphasis would be on little. If it's excessive, my first guess would be a head gasket or other combustion leak but that's a sheer guess and there are several things you could do before you pull the head. Check for smoke and blow by at the oil filler cap too. Then I'd check change the oil. While at it I'd send off a sample for analysis to see if there are contamination or other issues. I've used the company with very good results: https://www.blackstone-labs.com/free-test-kits.php
You might also check the coolant for oil or even get a compression leak tester. (you can get a tester for less than you'd pay a shop to do it). Then I'd drive it for an hour or two and check again for smoke. If you are very lucky it might go away.
Then I'd address the noise and fouling plug which may or may not be related. Does the noise go away if you pull the wire off #3 or another cylinder? Is it quieter when hot? Does it change under load? Does the fouling improve with a new plug?
I don't want to be too much of an alarmist but it looks like you might be looking at a rebuild in the future. Of curse, it may also run decently for quite a while before that.

Tom
 
Your compression is bypassing the rings pressuring crankcase. This symptom is commonly know as blow by. If you don't have a compression gauge take a latex glove, place it over the oil fill opening held tight with rubber bands. Crank engine, give it some throttle to see if glove blows up like a balloon, if it does them you have blow by, maybe time for a engine overhaul?
 
Compression was good when I checked it about 4 months ago (150, 150, 140, 140), but I should probably check it again. This does seem to have gotten worse since then.
 
Does the 'smoke' increase or decrease when the engine is fully warmed up ?
 
Just checked compression again. It's now 135, 145, 125, 155. Looks like I found my project for this winter.
 
BlueMax said:
...take a latex glove, place it over the oil fill opening held tight with rubber bands. Crank engine, give it some throttle to see if glove blows up like a balloon...
Click to expand...

You might have to block the road draft tube to get a meaningful result.

Same test can be done with a 'product' from your local pharmacy. Results are similar but possibly more amusing.

Similar technique can also be used over a radiator neck to test for combustion leaks into the cooling system.
 
Snowkilts said:
Just checked compression again. It's now 135, 145, 125, 155. Looks like I found my project for this winter.
Click to expand...
I wouldn't be planning a teardown based solely on those numbers, but since the lowest cylinder is the one fouling the plug, the evidence does seem to be mounting.
One thing you could to is run it with the plug wire off number 3 and see ff the smoke goes away. Not conclusive of course, but another bit of evidence.
Add that to the fact that the smoke goes away when warm might point to a combustion leak (head gasket) at #3. I'd pull the head first since the engine seems to have no other issues.
Tom
 
Well I also have the ubiquitous rear main oil leak. Maybe I'm just looking for an excuse to do the motor. :smile: I'm also a little concerned that #1 and #3 seemed to have dropped in just a few months after being stable for many years. I don't put a lot of miles on it but i did loan it to a friend in August and he drove it 500 miles or so. Wondering if something's starting to break down.
 
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That's certainly a lot but I've had engines with similar blow but they showed other issues, incrased oil consumption, lower oil pressure, exhaust smoke etc. The only thing I can say with confidence is that a tear down and rebuild will probably cure the blow by. The part that is somewhat odd is that you have good oil pressure and compression and no other complaints other that the rear seal leak, which may be a good enough reason for tear down in itself.
The only easy fixable problem I can think of would be contaminated oil, which is why I suggested analysis or at least a change earlier. Otherwise, I think you are in for it.
Tom
 
Geo Hahn said:
Same test can be done with a 'product' from your local pharmacy. Results are similar but possibly more amusing.
Click to expand...

Almost put a mouthful of coffee on my keyboard this morning.
 
Snowkilts said:
I don't have a good feel for how much blowby should be happening normally, so I tried to make a short video to give a qualitative idea of how much air is coming out of my engine. Is this a lot?

https://photos.app.goo.gl/HxR9WuUfaGXDdOCx2
Click to expand...

That paper is too big, as it will also catch the cooling fan airflow too. If you have an electric fan that is not on in that video...then you have way too much blowby. I bet you could hold a ping-pong ball suspended!

For a better understanding of the TR3 crankcase venting...

If you study the oil filler cap/vent, you will notice that the vent is on the front, bottom of the cap. This is so it will catch the airflow from the cooling fan, which in turn will provide a slight higher pressure to force fresh air into the valve cover. That is why the cap also has a filter. The draft tube is then angled in a way so as to draw a vacuum at the end of the tube, from the air flowing while the car is in motion. There is no filter on the draft tube, since it is only an exit. That's it. Very simple and very fool proof.

1) I would check the end of your draft tube for a dirt dobber nest or other blockage. Or...the tube may be missing altogether.

2) If the draft tube is plugged, combined with the slight positive pressure formed by the small hole int he filler cap...then you will blow oil out of every seal on the engine.

3) Blowby gas is normally blue or whitesh in color...not normally clear like in your video.

If the crankcase ventilation system is unblocked and still blowing that badly...then you have bad rings and need a rebuild.
 
What I can see of the car, it looks nice. Is that original paint? Sounds like you have had the car for some time and plan on keeping it, so yes a new engine would be nice.

I have somewhat - fixed motors in the past by just putting rings on and leaving the crank in and using the same rod bearing by pulling the head and oil pan. You can get that done inexpensively if you want to go that route. they even show in the manual you can rotate the sleeves. I say that because sometimes these cars do not get driven that much and if you do a whole rebuild with clutch, radiator, valve job, ect ect the apron comes off and sometimes never gets back on.

Anyways I would say the rings are tired and maybe the valves also and perhaps number 3 oil ring is toast.

One thing I thought I heard was a deeper loader knock other than the lifters, and if that is the case you would need to do a quality rebuild.
steve
 
Snowkilts said:
I don't have a good feel for how much blowby should be happening normally, so I tried to make a short video to give a qualitative idea of how much air is coming out of my engine. Is this a lot?

https://photos.app.goo.gl/HxR9WuUfaGXDdOCx2
Click to expand...
I tried to add something to the data by checking my own engine but this may not be useful as the condition of my motor is pretty much unknown. It does run fine and has done so for two seasons now.
When cold there is a noticeable pulse at idle that I can feel with my hand about a foot above the oil filler. It is reduced to almost nothing by revving the engine to 2000. It is also reduced considerably even at idle (I'd say by more than half) when warm.
For what it's worth,
Tom
 
Hi Folks, thanks for all the responses. I wanted to address some of the points that were brought up.

Here is another video of my highly precise "paper towel over the vent" method of measuring blowby.

https://photos.app.goo.gl/P4U3L8xBzOGAROLj2

I don't remember if the fan was running (electric fan) in the earlier video so I just did another one with the fan definitely not running. This is all from the oil fill opening.

Steve: probably not original paint. A 40/40 paint job at best, but it still attracts attention. :smile: The apron has been off twice (once for radiator and once for steering) and always managed to get it back on.

John: The draft tube is definitely not blocked. As I mentioned earlier in the thread, there is smoke coming out of it. I would subjectively say less air coming out of the bottom of the engine than the top, but smoke coming out the bottom, no visible smoke on top. My crankcase vent cover has holes all around the bottom of it, perhaps not correct?

Edit: my vent cap looks the same as the one being sold on Moss.
 
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You would think the oil would smell and the bottom of the car would have a lot of oil if the blow by was too bad. I did not hear that lower thud I heard the first time. What do you mean by holes in the breather? There is that 1 inch oil in the bottom that should be enough. I have heard stories about how the engineers needed to rework the breather by lengthening it and changing shape to get the draft correct, but that should not be applicable here. Plus I would think there would be oil coming out the top also. There is a big difference between idle vacuum and higher RPM vacuum also, so does the air stop blowing when you raise the throttle? Anyways at the least I would say rebuild your rocker shaft and put some rings in it.
steve
 
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