Perkins 4.108 header tank reservoir

[BigAl.NZ]

Hi,

The coolant reservoir tank on our Perkins was empty, so we added some coolant so the reservoir was about 1/3 full and then went for a motor for a few hours.

When we got back the reservoir was empty and the coolant had gone through the overflow hose into the bilges. The reservoir now completely empty.

Anyone know why this might be happening? Temp's etc were fine at about 85 when engine running.

Cheers

AG

[Lepke]

If the overflow tank is completely empty (and the coolant in the bilge) you have a leak somewhere between the tank fitting and engine.
With proper plumbing and pressure cap the engine should expel coolant into the tank as it heats and draw coolant back as it cools. If the coolant hadn't ended up in the bilge then the engine would have drawn in all the coolant in the tank, indicating the engine was low on coolant.
The coolant tank overflow hose only passes coolant when completely full or possibly with a huge amount of air coming from the engine (as in blown head gasket).

[coopec43]

I have been told by the Perkins Agent in Western Australia that Perkins never marinised their 4-108 diesel engine but handed over bare engines to about six different jobbers who marinised them to their own design.

https://www.google.com.au/search?q=p...w=1078&bih=609

Yours looks different again so I'm wondering if there is a flaw in the design of yours?


Clive

[Uncle Bob]

Originally Posted by Lepke

If the overflow tank is completely empty (and the coolant in the bilge) you have a leak somewhere between the tank fitting and engine.
With proper plumbing and pressure cap the engine should expel coolant into the tank as it heats and draw coolant back as it cools. If the coolant hadn't ended up in the bilge then the engine would have drawn in all the coolant in the tank, indicating the engine was low on coolant.
The coolant tank overflow hose only passes coolant when completely full or possibly with a huge amount of air coming from the engine (as in blown head gasket).

I am inclined to agree, if the overflow is being emptied into the bilge via the overflow then I would suspect the head gasket.

[BigAl.NZ]

Hi Guys,

Thanks for the replies. She runs very smoothly and starts easily. I am told by people who have had blown head gaskets this would not be the case if she had one?

I was also a little quick perhaps to assume all the coolant is going out through the overflow pipe - truth be told thats what I assumed - it could be leaking from anywhere. Next time I go for a motor I will monitor it and report back.

[coopec43]

If that happened to my 4-108 set-up I think the first place I would look for a leak would be the gearbox heat-exchanger.


Clive

[WanderingStar39]

I had some coolant loss in my 4-107. I bought a test device that pressurizes the system with air. That proved a leak, close examination located a couple. One was a plug that needed tightening, another required some radiator sealer.

[Maka]

Id check the water pump.
On a car the water pump on the engine leaks onto the driveway where you can see it. On a boat it leaks into the bilge where you cant see it leaking.
This happened to me on my boat. Luckily the 3rd mechanic figured it out and fixed it ( new water pump on engine ) before it caused major overheating.

[B Tegge]

My 4-107 ran for 2 years with a blown head gasket. My eng exhaust exits the boat out of the side. The engine would not lose coolant as long as the exhaust was above the water. If you motor sailed long enough with exhaust submerged the back pressure would cause the coolant to blow out the overflow tank. Took a wile to figure this out .

[dneve]

I started losing coolant in my 4-108 but dont think I have a bad head gasket . My mechanic thinks there is a small crack in the exhaust manifold/heat exchanger which is allowing exhaust to enter the coolant thus forcing coolant out the overflow. I tried a radiator sealant called K & D (?) which stopped the leakage with no overheating problems caused by the the sealant.
It worked for me! Good luck!

[stnick]

I have a Perkins 4 108 in my Morgan 38 The engine heats up 165 if hotter the coolant goes into the overflow plastic tank . Nothing ever goes in the bilge.
Start that engine if you in a slip put her in gear take a strain. open up the engine room and just watch, clean engine diapers. If you have anti freeze you will see the leak soon as she get up to running temperature ! Good luck