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Smoke from breather and dipstick LM 318

S

stuski

New member
I have smoke coming from breathers and dipstick tube.It happens as soon as engine is started. pushing a little water from cap. No evidence of water in oil. Everything I have read indicates blow by from rings. Did compression check last night numbers seemed ok even on high side. Dry test slightly warm.135 to 165 psi although I forgot to open throttle. Not sure if that would change anything. Valve job done 5 years ago but engine was not used much.
Could I have good compression with ring damage and blow by? Not smoking from exhaust. I suppose it is time for a leak down test. Motor seemed to start to ping at high rpm. I guess from all of the exhaust back into the carb. Did not see the smoke until back at the dock. Would not reach 3000 rpm
port side 3500. Runs about 10 - 15 degrees hotter than port engine also.

Thanks for any advice, Stu
 
I don't believe it has them just tubes to the spark arrestor. I believe I have excessive blow by. Port motor set up the same and has no issues. I thought I would find low compression but readings were high 135- 165 psi. I think I may have a couple of issues slight head gasket leak as well as blow by. Don't see evidence of water in the oil or vice versa yet.

Stu
 
Initial condensation burn off from breather, is this a fresh start of the season? I doubt you have any issues with compression readings like that.
 
Is the PCV circuit hooked up? If not, that ill happen (and the bearings will be harmed by acidy sludge build up).

Jeff
 
I believe compression gauge is accurate. Did another test last night.

Dry Wet

2 148 155
4 150 165
6 152 170
8 160 176
1 140 151
3 150 160
5 150 165
7 150 162
Ran motor after to 160 degrees and smoke from breathers and dipstick right away. Some smoke from exhaust also. Now I do see some condensation in odd side breather tube along with milky oil residue. Can smoke enter the crankcase any other way than bad rings? Perhaps valve job from a while back was too much compression for the old rings and I have a head gasket leak also? Noticed bubbles in coolant at expansion tank. Not sure if I should waste time and money replacing head gasket if rings are gone. Thinking may have to get new long blocks installed.

Stu
 
I don't think it is all steam, the smoke appears as soon as I start the engine. I believe the steam comes into play when the temp gets up.

Stu
 
A marine engine MUST have a functioning PVC system or it will produce sludge (and the problem you're seeing).

Jeff
 
Thanks Jeff, I will try and post some picks of how it is set up. I have seen the diagram in the engine manual that looks to show a connection at the base of the carb. Intake through 1 valve cover down through crankcase, up and out through other valve cover to base of carb? I have 1409 Edelbrocks. The spark arrestor has two places to hook the breather tubes from valve covers. I presume this connection provides some draw from the intake of air at carb.
Both motors have been set up this way for years. Only having problem with port side.

Thanks for input, Stu
 
Worn valve guides and or stem seals, especially if they are letting excess engine oil into the combustion chamber. Crankcase pressure prolly not excessive. You can run it like this for as long as you can stand it. At some point you'll want to do the heads.
 
stuski said:
I believe compression gauge is accurate. Did another test last night.

Dry Wet

2 148 155
4 150 165
6 152 170
8 160 176
1 140 151
3 150 160
5 150 165
7 150 162
Ran motor after to 160 degrees and smoke from breathers and dipstick right away. Some smoke from exhaust also. Now I do see some condensation in odd side breather tube along with milky oil residue. Can smoke enter the crankcase any other way than bad rings? Perhaps valve job from a while back was too much compression for the old rings and I have a head gasket leak also? Noticed bubbles in coolant at expansion tank. Not sure if I should waste time and money replacing head gasket if rings are gone. Thinking may have to get new long blocks installed.

Stu
Click to expand...

With that compression I would think the compression rings are acceptable.

How are the plugs looking after running to temp? Your trying to isolate the oil burning cylinder.

A leak test at TDC and BDC should reveal the leakage into the crankcase I would think.

Do you have twist style breathers or plug in? Here is a breather pack for twist on PCV that may help ......................

http://www.ebay.com/itm/Mopar-Perfo...Parts_Accessories&hash=item2327a7f616&vxp=mtr


You may be able to find them in push on also.
 
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