Coolant smell in exhaust on start

F

Finnerty

Petty Officer 3rd Class
Joined
Sep 20, 2010
Messages
75
I've been loosing coolant every time out, about 200 ml or so, with no sign of leaks on the engine. I noticed a smell of coolant on start up for a few seconds and some white smoke. No sign of milky oil on the dipstick.
I removed the distributor and see coolant on top of the block near the closest lifter rod and some milky oil as well.
I'm wondering if the leak could be from the intake manifold such that most of the leak gets passed out via the exhaust and only a bit makes it into the block area where I see it. In other words it's probably not a head gasket failure?
On the vacuum gauge at idle it ticks between 11.5 and 12", not a big amount (would expect more if it was a head gasket?).
As far as running it shuts down suddenly under load, restarts after an hour or so.
Next step will be to remove the intake manifold.
Am I missing anything? I'm aware that the sudden shut down under load may not be directly related to the coolant leak.
I've had that problem for longer than the coolant leak, ruled out a fuel issue, removed the distributor to try a points distributor rather than the Electronic Ignition.
Any help would be appreciated.
Thanks
 
alldodge

alldodge

Moderator
Staff member
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Mar 8, 2009
Messages
42,555
I'm thinking there are several issues going on. Weak vacuum (18 to 21 in hg), coolant leak under intake and shut down under load.

Suggest pressure testing the coolant system
Do a compression and leak down test

After those test then we would have a better idea of what to remove and check
 
H

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Finnerty said:
I've been loosing coolant every time out, about 200 ml or so, with no sign of leaks on the engine. I noticed a smell of coolant on start up for a few seconds and some white smoke.
Click to expand...

I would vote for a leaking riser gasket that is leaking into the exhaust in small enough amounts to lose coolant in more than a few hours of running. But it's hard to say not knowing if this is a Mercruiser 470 or a VW diesel......
 
F

Finnerty

Petty Officer 3rd Class
Joined
Sep 20, 2010
Messages
75
So, an update on on my coolant loss, 200 ml per outing, smell coolant in exhaust on start-up, see coolant in lifter valley through distributor hole near cylinder #8 on my 1977 Mercruiser MIE 330 s/n 5551947
I drained off an oil sample and let it settle, finding coolant in the oil.
I removed the intake manifold and found the gasket around the coolant port next to the #8 intake was deformed and looked like it has been leaking coolant into the lifter area and into the air intake for #8 as well.
I'll replace the intake manifold gasket and see if that's the problem.
 
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