Volvo - water intake issues

[BIGMAX]

I have a 2000 Volvo 4.3 with SX drive and have been having an issue with the water intake into the cooling system. I recently added some fuel additive to the tank and connected the muffs in the driveway and fired her up only to notice that there was no water coming out of the exhaust area, as is normally the case. I have a sea water pump (on the front of the engine) and I decided to open the pump to check the impeller condition. Glad I did so as the impeller was in fairly bad shape. At least three of the vanes were torn off. I opened up the thermostat housing and could not find any of the impeller pieces there, but I went ahead and replaced the thermostat as well as the impeller. I reconnected the muffs only to notice that she still was not taking up water through the intakes. I removed the inlet hose from the pump and back flushed it and water came out the intake holes. I then placed muffs back on only to find that water barely came out of the inlet hose at the pump. I spoke to a local boat shop who suggested that I did not have enough pressure from my garden hose to allow water to travel up the inlet hose all the way to the impeller and that the impeller could not create enough suction to draw the water up as well. I have fairl good city water pressure. They suggested I put the boat in the water and run it under normall conditions, so I did this and I overheated within 5 min (I have never had any overheating issues before this). Does this seem like there could be a blockage somewhere between the intake on the drive and the pump? If there were a blockage past the pump, the pump should still draw up water?!? O' wise ones, please help this desperate chap find a solution to this problem. Thanks

 

[Don S]

Re: Volvo - water intake issues

Did you replace the oring on the pump housing? If that pump sucks air, it will not suck water from the drive.
Here is something that may help you understand how to troublshoot an overheat.
http://www.4shared.com/account/file/50572185/e88f1d89/Volvo_Penta_Overheat_Diagnosis.html

 

[BIGMAX]

Re: Volvo - water intake issues

Thanks so much for the link. I have just read it and will start this weekend on working through the parts of the diagnostics that I am capable of doing. I did not replace the O ring in the pump housing as the original looked to be in good shape.

 

[DeskJockey]

Re: Volvo - water intake issues

I am having the exact same problem. The troubleshooting guide was most helpful. Thanks Don! I modified it a bit by having a garden hose with muffs on the drive to move water to the seawater pump. Then i took a separate hose and connected it to the inlet hose going to the Tstat housing. I started the engine and it ran fine at idle for 4 or 5 minues. Temp read about 170 with a newly installed Tstat. Then I hooked the hoses back up as normal and started the boat back up with a hose on the muffs only. after 2 minutes, the temp started to creep up to nearly 200 maybe 210. So, it seems like there is a leak in the suction system to the drive. When on the muffs, i noticed a moderate drip coming off the bottom of the exhaust bellows on the upper drive housing. I think the raw water intake hose connects to the drive just above the bellows connection. Do you think that connection is leaking and dripping onto the bellows?

 

[mikeneal]

Re: Volvo - water intake issues

I recently had a slight over heat with my Volvo SX and the plastic fitting where the water tube exits the transom shield was cracked. When I pressurized the inlet system I had a leak out backside of transom shield and ran down on exhaust bellows.
When I went to local dealeer to buy it they had another one sitting on counter. I bet you a cold beer yours is cracked too. Good news the parts are cheap (like 20 bucks for fitting, nut and o-rings. )

I am having the exact same problem. The troubleshooting guide was most helpful. Thanks Don! I modified it a bit by having a garden hose with muffs on the drive to move water to the seawater pump. Then i took a separate hose and connected it to the inlet hose going to the Tstat housing. I started the engine and it ran fine at idle for 4 or 5 minues. Temp read about 170 with a newly installed Tstat. Then I hooked the hoses back up as normal and started the boat back up with a hose on the muffs only. after 2 minutes, the temp started to creep up to nearly 200 maybe 210. So, it seems like there is a leak in the suction system to the drive. When on the muffs, i noticed a moderate drip coming off the bottom of the exhaust bellows on the upper drive housing. I think the raw water intake hose connects to the drive just above the bellows connection. Do you think that connection is leaking and dripping onto the bellows?

 

[Moku'ula]

Re: Volvo - water intake issues

The vanes of your old impeller are probably somewhere in the system.

I thought I read that sometimes they go to the elbows of the risers?

I have a '99 4.3L VP with the SX drive - I poked and prodded the t-stat housing and basically pieced the shreaded impellar back together - there were a couple big chunks blocking the smaller openings - once most of the pieces were found, I installed the new t-stat and impeller with new orings and gasket (t-stat) and she's been cooling ever since.

I'd look for pieces again if Don's advice doesn't get it working...

Also - test the t-stat to see that it opens at 160...

Jef
Moku'ula
'99 Four Winns Horizon 180 4.3L VP SX

 

[DeskJockey]

Re: Volvo - water intake issues

Thanks for replies guys. I pressurized the system and noticed that there was a drip on the drive side of the intake hose at the fitting. It is the same fitting you described; just the other end... I'm not looking forward to getting to it...the drive manual looks pretty involved. Anyway, I re-primed the system and ran it at idle on the muffs. It ran around 175 to 180 (if the sensor is accurate). I put the drive in a rubbermaid container and ran it with the hose in the tub. It ran a little warmer, maybe around 190 at idle, but cooled down when I reved it up to 2000RPM. So, it looks like i'm ready for a water test. I'll let you know how it runs after that.

 

[cr2k]

Re: Volvo - water intake issues

POWER STEERING? Pull the water hose that goes to the heat exchanger. You said MOST of the pieces....NOT good enough, it is important you find ALL the pieces.

Other Volvo water issues...The seawater flows from the lower pick up to the engine through the outdrive and bushings. When these bushings get worn and sloppy you will suck air.

At this point you either disassemble the whole drive structure, or cut a hole in the bottom of the hull and put in a scupper and a seacock. (Way easier and cheaper>)