Smoke from exhaust - with video

[Graham]

I've noticed quite a bit of smoke coming from my exhaust.

Here is a video I've taken at about 1,600rpm: https://photos.app.goo.gl/m51VyKX9BXeN4jJT9

In the video, the engine is running at 180 degrees

Engin is under load (in drive) tied up at the dock

Oil pressure is 135

Outside temp is 22 C / 71 F

I did a compression test: 110/110/115/115 psi (cold)

Thanks in advance for any advice!

[ndutton]

Looks like steam to me, dissipates quickly. RWC or FWC? Atmospheric humidity level at the time of the video?

[Graham]

Looks like steam to me, dissipates quickly. RWC or FWC? Atmospheric humidity level at the time of the video?

Thanks Neil,

Humidity around 47%

RWC in Lake Ontario

[ndutton]

180° seems high for a RWC engine. Do you have a thermostat? Bypass valve (assumes late model cooling system)? Just to be on the safe side I'd do a cooling system pressure test and an oil change. Check the color of the old oil for signs of water incursion.

[Graham]

180° seems high for a RWC engine. Do you have a thermostat? Bypass valve (assumes late model cooling system)? Just to be on the safe side I'd do a cooling system pressure test and an oil change. Check the color of the old oil for signs of water incursion.

I do have a thermostat with a MM bypass installed and fully open. Yes, it is a late model cooling system.

I did an oil change 10 days back. I can pull some out tomorrow and have a quick look at it.

The engine does seem to be running hotter than normal. Water is about 22 C / 72 F.

I'll have to read up on how to do a cooling system pressure test

[ndutton]

Try closing the bypass valve, 50% to start and watch the temp (hopefully) go down. What thermostat do you have, original Holley 3 spring, the substitute for the Holley with spacer when it was discontinued or a new one from MMI?

[Graham]

Try closing the bypass valve, 50% to start and watch the temp (hopefully) go down. What thermostat do you have, original Holley 3 spring, the substitute for the Holley with spacer when it was discontinued or a new one from MMI?

Will do on the bypass front.

I have the replacement upgrade thermostat kit ( with spacer) from MMI. Replaced spring 2017.

[ndutton]

If it's this one, I learned the condition of the port in the center of the underside of the thermostat housing is critical to the proper function of the thermostat. You might want to take a good look at it.

Here is a post that discusses it in detail. Check out the temperature tables at the bottom.

http://www.moyermarineforum.com/forums/showpost.php?p=111781&postcount=6

edit:

I have the replacement upgrade thermostat kit ( with spacer) from MMI.

In that case, let's see what closing the bypass valve does.

[Graham]

Thanks Neil - I'll close the bypass 50% and see how we make out.

I'll report back after I get to the boat tomorrow.

Thanks!!

[ndutton]

Stay tuned. Others may have different ideas.

[Graham]

I'll also do an acid flush tomorrow

[ndutton]

I'll also do an acid flush tomorrow

I was thinking that may have merit. The thermostat is removed and the bypass closed for the acid flush.

[Graham]

Reading up on how to do a cooling system pressure test. Any idea what the barb fittings sie would be from this pic?

https://photos.app.goo.gl/FF32Ag3jVaNqM7DT8

[ndutton]

Any idea what the barb fittings size would be from this pic?

Has to fit your cooling system hoses because that's where they attach. Mine are 5/8" throughout but there is no guaranty yours are the same.

[JOHN COOKSON]

I've noticed quite a bit of smoke coming from my exhaust.
Here is a video I've taken at about 1,600rpm: https://photos.app.goo.gl/m51VyKX9BXeN4jJT9
In the video, the engine is running at 180 degrees
Engin is under load (in drive) tied up at the dock
Oil pressure is 135
Outside temp is 22 C / 71 F
Thanks in advance for any advice!

OP of 135 sounds about double to me. Not sure of the significance, if any.
Graham: What oil and what viscosity are you using?

ex TRUE GRIT