Antifreeze smell in exhuast

[kraftada]

I have an 89 5.7 Mercruiser with full closed system. Started smelling antifreeze in the exhuast last fall. My local gm mechanic that I know firmly believes that I have head gasket or head cracked issues. Im wondering if there is any other suspects. I will do a leak down test on all 8 tommorow. Any input would be appreciated.

Thanks,
Adam

 

[arks]

Re: Antifreeze smell in exhuast

I had the same symptom 2 summers ago with a 5.7 Crusader.
If you're lucky, it could be a leak from an exhaust manifold or riser gasket.
Pull the spark plugs and analyze them.
In my case, we found 1 plug that indicated moisture. I pulled that head and discovered a hairline crack in the cylinder wall. Since the engine was 1984 vintage I bit the bullet and replaced it.
Good luck....

 

[Haut Medoc]

Re: Antifreeze smell in exhuast

It can also be the heat exchanger....
Pressure test it...
& the rest of the system...
Closed systems are much easier to test..
It should hold at least 16-20 psi all day long......

 

[Don S]

Re: Antifreeze smell in exhuast

I agree with arks on inspecting the spark plugs. If you find a clean one that looks brand new, it may be being steam cleaned due to a leaky head gasket on that cylinder.
A leaky riser/manifold gasket would happen after the cylinders and wouldn't show on a leakdown test either.
When doing a leakdown test, leave the cap of the heat exchanger and watch for bubbles. Bubbles are a bad thing.
If no bubbles during the leakdown test, drain the antifreeze and pressure check the system. If it leaks down, you can bet on a manifold/riser gasket failure or even a manifold failure.

 

[P 0 P E Y E]

Re: Antifreeze smell in exhuast

First off, Exhaust fumes can be harmful so be careful.

Are you having to add coolant?

are you having overheating issues?

Are you experiencing performance issues?

If you are not having any issues other than smelling antifreeze in the exhaust, you may want to enjoy the rest of the season or wait for it to fail.

Especially if the engine is that old.

 

[kraftada]

Re: Antifreeze smell in exhuast

Thanks all,
I will look at the plugs first. Ark, if I cant find anything impressive, might follow popeye's advice and runner. Worst case situtuation, we break down 5 mi out. Ill post a mail bouy watch on the wife and watch the sunset.

Thanks