Puzzling coolant leak - Universal

[gabosifat]

Hi All,

I'm hoping someone will have a solution for me. I have a Universal M35A 30hp 4 cylinder on my E35/3. I have an annoying coolant leak which I can't find. I've removed the heat exchanger, cleaned it, put new gaskets on it - no leak there. I've checked all hose clamps on the fresh water side. I've felt all the hoses for possible leaks in their walls. I can't see or feel any coolant on the sides of the engine block anywhere. Last weekend we motored for about 4 hours and today when I went down to the boat there was about 10 - 15 ml of coolant under the engine (on the starboard side of the centre line). The underside of the oil pan is clean & dry. When I first changed the coolant last year, I drained it from a drain plug on the starboard side of the engine block so I thought it might be comming from there but it's dry & I've tightened it up just for good measure. It got me to thinking - maybe there is a frost plug somewhere on the engine block?

Anyone have any suggestions?

Much appreciated.
Steve Gabbott
E35/3 "Silent Dancer"
Vancouver

 

[Sean Engle]

Have you been looking at the block and all the connections when the engine is running at speed?

//sse

 

[gabosifat]

Hi Sean,

Thanks, yes I've looked at it when idling but not while running at cruise RPMs. I'll give it a try. By the way - do you have a boat right now? The picures of O Barquinho looked very nice - I'm just trying to get mine all sorted out - lots of projects but they're always enjoyable.

Steve

 

[Sean Engle]

Leak-ola

Hi -

No, I had to sell O Barquinho in September 2003 to a nice German physicist who took her on a trip up to AK. She's up at Pt. Roberts now - down the dock from Azgard (another E35-3) that we knew from some time ago...

On the leak - I think if I suspected a leak at the block - I would try and clean it as best I could - so you have zero residue on the block - then take the wife and some take out dinner out for a cruise for a couple of hours.

Take a roll of white paper towels and a good set of muffs for your ears...let her run the boat while you go below and go over every square inch of the engine with the towels (just be extremely careful around the belts -wear a tee shirt - and shut down the engine when you do the front). This is one of the things I did that pointed me away from a leak on the outside and towards my rotted out exchanger...

When you do the cleaning prior to the cruise, make sure you clean the pan out below so it's spotless. Also make sure you get one of those flexible mirrors (cheap - like $5) so you can look behind and beneath. You basically need a known state to work from. Hopefully you'll find the leak...if you're sure it's not the exchanger or other obvious source (hoses, clamps, waterheater, etc) then you have to start looking inside the engine...

We're going to see you guys in Sidney - right??

//sse

 

[gabosifat]

Unfortunately not, we have a trip planned to the West Coast of Vancouver Island this summer & I just can't swing any more time away from work. Would love to be there as there are so many things I'd like to check out.

Best regards,
Steve

 

[Sean Engle]

Unfortunately not, we have a trip planned to the West Coast of Vancouver Island this summer & I just can't swing any more time away from work. Would love to be there as there are so many things I'd like to check out.

That's too bad - but there's always next year! Good luck in the leak - please do let us know what you find out - I would be interested to hear...

//sse

 

[hodo]

Steve, I had a coolant leak that I finally chased down to the drain cock on the starboard side of the block. It looked ok, but the vibrations of the engine running, caused it to drip. Replaced it and ended the problem. You might try and pressure check the system with an automotive type cooling system pump. Find out what your cooling system is rated at . Probably around 9 psi. Also check the cap with the same tester. You can do the tests with the engine off, and cold if you want. Cheers, Harold S/V Mischief Maker

 

[Sean Engle]

...the vibrations of the engine running, caused it to drip. Replaced it and ended the problem. You might try and pressure check the system with an automotive type cooling system pump. Find out what your cooling system is rated at . Probably around 9 psi. Also check the cap with the same tester. You can do the tests with the engine off, and cold if you want...

Yeah - that sounds pretty good. You said about 10-15ml of fluid was found - right? Either way - hot or cold - pressure up and check them...I'll bet you'll find your leak...

//sse

 

[NGB]

I had a puzzling leak following the removal, cleaning, and installation of the heat exchanger on my Universal engine. I could not figure out the problem, because it would be low on coolant sometimes and not others. I finally figured out that it was the coolant hose attached to the heat exchanger. The mystery was that it did not leak when it was under pressure, i.e., when the engine was running but did leak when it was not under pressure, i.e., immediately after I shut down the engine. I readjusted the hose and clamp and all is well.