Volvo 131d Makes water

Johnnydeep

Cadet
Joined
Nov 8, 2004
Messages
13
I have a 1989 FWC 131d in a 2150 bayliner. when we first got the boat a couple of years ago it used water. Needles to say I eventually got to replace the head gasket! Since then it has leaked a bit of water out of the cap. as this year wore on the drip became a dribble became a stream and of course on this engine a stream from the heat exchanger cap runs right onto the distributer. I deduced that the heat exchanger core must be leaking and pulled everything down, pressure tested the core(insert) and found several pinholes that I solderd up, pressure tested it to about 35psi...no leaks . Back together and guess what...still makes water. Have had it apart several times since and I have learned a couple of things about its behaviour. 1) it will only make water at higher rpm and in the water. Will not do it in the driveway even at 5000 rpm. ( I am assuming the exhast backpressure is what is causing the Raw water to be forced into the cooling system) 2) if I troll all day I get very little water out of the cap(see #1) 3)The insert sits in the tank aganst a piece of rubber(chaffe protection) with a hole for the inlet and outlet tubes. The rubber looks as if the water is blowing past it and is bubbled back into the tank. I find it hard to beleive that this rubber is a seal and that the inlet and outlet seals would fail that way unless they were cracked( just thought of this!!)....i even rtv'd the crappola out of these... 4) I know beyond a doubt that it is raw waterpushing the coolant out...We are in the salt alot and I have salt in the motor....(BAD!!!)<br /> Now for th part that troubles me the most. I ran the boat last in lake washington about a month ago. Same problems, brought the boat back and parked it, went to mexico etc etc. (longest the boat has sat in 2 years)went out last night to dig back in and the heat exchanger tank was empty. Now I will assume that the core is still my problem and that the coolant just drained out the exhaust side(impeller would stop it on the other side right?)and onto the ground. After all I did find a dead rat next to the boat trailer a couple of weeks ago!! The only catch to that is that the coolant was right up to spec with the orange stuff and I did not run it long enough to dilute it down and when I drained the exhast manifold through the drain petcock I got clear stinky lake water...no trace of coolant.<br /><br />Couple of more things. The oil is fine, nice and clean and uses about a teaspoon between changes(fuel pump gasket weeps a bit), The only coolant in the bilge comes out the cap. We use the hell out of this thing, 300+ hours a year, and ther is no oil in the water!!!<br /><br />I hate to throw a new insert at it without ahving anybetter ideas ($300 to $560, have not been able to find a used one) <br /><br />Help...am I going in the right direction here :confused: <br />Sorry for the long post :rolleyes:
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: Volvo 131d Makes water

Hi johnnydepp, welcome to i-boats.<br /><br />Just a couple of observations, pin holes in the heatexchanger tubes are bad news - I'd be surprised if you could find and fix them all, also if the tubes are corroded then its a fair bet other parts are as well (raw pump housing etc). Did you pressure test the cap also? Is it a recovery system? Have you got the right cap?<br /><br />Aldo
 

Johnnydeep

Cadet
Joined
Nov 8, 2004
Messages
13
Re: Volvo 131d Makes water

Dunaruna<br /> No I have not checked the cap, and it is not a recovery system. Once it starts leaking it does not stop until I bring the rpms down. the water level in the tank stays pretty much even no matter how much water comes out of the cap. As far as the rest of the components, I have had no problems to this point and the only place I can think that the raw water and coolant "interface" is in the tank itself. I pressure tested the insert to 45 psi for about 30 min with no loss of pressure. I am wondering if heat is causing something to open up...<br />At this point I am trying to find a used core or I will get a new one after the christmas shopping is done.<br /> I hate being without the boat..even this time of year.....
 
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