View Full Version : Exhaust Leak????

05-07-2012, 02:32 PM
Actually it is a water leak:

1987 Prostar Looks like it is leaking on the passenger side exhaust. A pretty good stream of water seems to track along the top the the exhaust on the floor and then as it gets closer to the engine it drops before the exhaust turns upward towards the engine.

Where do I start??

05-07-2012, 02:59 PM
Pull up the floor panel, verify what is leaking, replace that. Likely the exhaust hose.

05-07-2012, 04:35 PM
you can buy new silencers for around $250 for both sides - fiberglass gets weak over time - if you need to replace one, go ahead and do both - skidim.com has them. worse part is having to take out the gas tank - about a 3 hour repair for both - not hard though

05-08-2012, 06:03 PM
Great stuff thanks

05-08-2012, 07:32 PM
Make sure all your clamps are tight first - had this issue before. Like said above, pull up the floor and see exactly where it's coming from. The thru-hull fittings may be leaking.

05-08-2012, 08:04 PM

07-05-2012, 01:22 PM
??? -Fiberglass does gets weak over time - I have an 85 SS...I want to silence my boat, but I am afraid that the same straight fiberglass exhaust will not be much better than what I have. Any suggestions?

07-05-2012, 01:27 PM
Just fixed this problem on the silent master mufflers in the 96. Bought a F-G repair kit from NAPA and went at it yesterday. Let it cure all day in the 100+ heat and tested it last night. No more leaks! Of course, after fixing the side that was leaking bad, I noticed a very small leak in the other muffler. Going to fix that one tonight.

07-05-2012, 02:18 PM
i had a few pin hole leaks in my silencers as well..15 bucks worth of epoxy and some fiberglass mat and no more leaks. I would not replace a silencer if its a minor leak. mine was leaking where the retaining straps screw in..the silencer over the years rub against the screw creating a leak..not a big deal to patch up and go.

07-05-2012, 06:30 PM
Could be a bad flange:


07-05-2012, 08:17 PM
I had 2 large cracks on the back side of both silent masters. Napa and got 2 fiberglass repair kits, $18 each. I did both the back and front along the seams so I would not have to do it again. No more leak and did not cost a lot. I do recommend letting the 3 inch tube heat up in the sun as they are not as stiff when removing or installing.

07-07-2012, 11:18 AM
Had the same thing happen to me. Someone must have jumped of dock into boat and floor gave just enough for a screw to puncture a tiny hole in fiberglass exhaust. Didn't find out until it was almost to late due to bilge taking care of the water. Had to patch fiberglass