Raw water strainer...

[DoctorJD]

I've been on a Summer-long mission to get the temp. stabilized on my 91' Conbrio. Thus far, I've got it stabilized at 176-180 (closed coolant system engine) but I'm still thinking that's a tad high. I tightened all of my hose clamps this weekend and found a couple that were a little loose. That helped immensely. I want to check to see if I have any blockages but I don't see a strainer anywhere. When the intake line comes in through the hull, it goes directly into a black 8"-10" cylintrical (sp?) housing that has hoses that divert water to the transmission cooler.

The reason I'm thinking I might have a blockage is that it tends to run about 5-8 deg. hotter when idling. As soon as you bring it up to speed, it drops back into the 178 range. Again, this is a "salt water" setup and has a captive coolant system that runs antifreeze, so the raw water simply comes in, goes through the trans cooler, through the pump, into the heat exchanger and out the manifolds.

If I've picked up trash, where should I look? Is there a strainer on the housing that I mentioned earlier? The one that sends water to the transmission cooler.
Thanks!

[87SunSportMikeyD]

Unless yours is different it should have some kind of strainer before the pump. I won't comment further since I don't know how your salt water cooling system works firsthand.
It can become clogged with weeds pretty easily.

Do you have any kind of impellor on a pump that might need to be replaced. Maybe you don't have the same use for the raw water pump - is there a pump for the antifreeze cooling system? Good luck!

[DoctorJD]

Thanks MikeyD!
Actually, I replaced the raw water impeller at the beginning of the season, so I think its okay. Let me clarify something: The item I was referring to as the "housing that diverts water to the transmission oil cooler", is the transmissioin oil cooler (newbie, sorry). Got to poking around in the PCM351 manual and this is something that I need to check out since it hasn't been cleaned since I bought the boat last Fall. Based on other things in the boat, I doubt very seriously that the previous owner ever ever looked at it.
JD

[Salty87]

yes, there's a 'screen' in the transmission cooler. if you disconnect the intake hose, you can clean it. it's not an effective screen though. you might want to add a sea strainer...

http://skidim.com/images/she18005.jpg

[csuggs]

The trans cooler is nothing more than a single-pass heat exchanger like you find in many industrial applications. I would be surprised to see a screen in one unless someone added it - but maybe there was an option . . .

The heat exchanger can be a place for build-up of river "sludge" and can cause a restriction of your water flow. You can clean it out by removing the inlet and outlet hoses, then carefully running a wire through the tubes, being careful not to punture one. If you install a strainer, put it between the water inlet at the hull and the inlet to the heat exchanger (or trans cooler). I think some boats have a strainer and many don't, so don't be surprised if you don't see one. I would talk to Vince at skidim.com to make sure you get a strainer rated for whatever flow your engine needs. I'm considering putting one on my boat.

[DoctorJD]

Nope, no strainer before the trans. cooler/heat exchanger. Looks like I need to invest in one, skidim.com here I come...yet again.

Thanks guys!

[saltare inverts]

I found a indentical screen filter housing at Tractor Supply Company. It is identical to the one on Skidim. It is black but every other aspect is same. Even company that makes it. It is all SS and plastic. It cost less than just the replacement screen cap from Skidim. 19.99. 39.99 at Skidim. I love skidim but much cheaper and no shipping cost on top of that.

[FoiltechLaunch21V]

I'll be hitting Tractor Supply in the morning. Thanks

[DoctorJD]

I found a indentical screen filter housing at Tractor Supply Company. It is identical to the one on Skidim. It is black but every other aspect is same. Even company that makes it. It is all SS and plastic. It cost less than just the replacement screen cap from Skidim. 19.99. 39.99 at Skidim. I love skidim but much cheaper and no shipping cost on top of that.
Wow, thanks! There's a Tractor Supply about 15 miles up the road from here.

[csuggs]

Good call Saltare! I'll be checking that one out myself. Thanks!!

[bryan632]

My rig has a strainer on it and it still runs a bit hotter at idle. I wouldn't worry about a few degrees. a lot of i/o's get way hotter than a few degrees when idled too long. you're just not sucking the amount of water through. I'd still get a strainer to prevent future problems but I wouldn't worry about the temp way too much.

[DKJBama92Mariah]

Engine temps that rise at idle and come down when underway often indicates a failed or failing raw water impeller.

I installed a strainer last year and it has not caught a single thing as of yet. Kinda feels almost like a waste of money.

The transmission cooler can be blocked by a single leaf. Pull the top water hose and look down in there to make for sure it's clear.

[saltare inverts]

I was on vacation several years back with my 1983 ski naughty. The lake was way high had all kinds of crap floating. Every boat in our crew(5 boats) got clogged pickups and ran hot. Had tro be cleaned out several times and three never clould get clean. My strainer caught all debris and never broke down. I had to tow all five boughts. I will never go without one. When I bought my supra it was one of first items I bought.