www.iFourWinns.com

So here we are enjoying a beautiful day on the water, i glanced down and saw temp was reading 220+. No alarms,no engine in degraded mode, nothing that would indicate a problem. Brought her off plane and it went down to 160. Hmm maybe picked up some trash, pulled up drive all clean. As soon as i got back on plane temp shot right back up, off plane back to 160 and idles at 160.
So far i have changed impeller, T-stat, temp sensor, checked & flushed all hoses. Still same result.
Got out trusty temp gun (Lowes $20) when gauge says 220 gun gives me 150 when on t-stat housing and 134 on both risers. At idle 160 on gauge and 130 from t-stat housing and 124 on risers.

Any ideas?
Is the gauge bad? How do i test?
Water pickup/hose in drive? Since it only happens when on plane??

Thanks for all you help

Jeff


Its a 2000 VP 5.7L GSIPEFS with DP -SM drive.

_________________
JPEloian
2000 268 Vista

You need to check a few things. Go find the Volvo Penta Overheat Diagnosis PDF online. Maybe this link will work:
http://www.4shared.com/web/preview/pdf/IGmJGKyh

To confirm you gage works in the dash you need a secondary gauge to check. Go online and find one or go to any auto parts store. You also need to check to see if you are getting adequate flow of water from the raw water pump as well as water to each manifold. Both of these tests are in the pdf.

I'm going with a faulty VDO dash.

See
http://www.smwebhead.com/phpBB3/viewtopic.php?f=3&t=12745&hilit=gauges+replacement#p123384
http://www.smwebhead.com/phpBB3/viewtopic.php?f=6&t=12620
http://www.smwebhead.com/phpBB3/viewtopic.php?f=5&t=11733

Had this same problem on my 2000 Vista 268 after I had the Lower Unit Replaced; idle was fine and would overheat when under power. We hooked up a clear tube to the line going into the impeller housing and found that air was entering into the system when under power; cause was the rubber bushing between the upper and lower unit was not seated fully. That specific issue may not be your problem but an air leak into the system could cause this problem...

Good Luck!

_________________
2008 Vista 358 - 5.7 Inboard V-Drives
2004 Vista 288 - SOLD
2000 Vista 268 - SOLD

Thanks for the replies. Lots of things to look at.
I was speaking to a marine mechanic and he said that there is a small plastic fitting that connects between the drive and transom that cracks and sucks air. Its a $5 part but a PITA to change due to pulling the drive and disassemble the transom housing to change it all.

_________________
JPEloian
2000 268 Vista

Please, please do not let the marine mechanic talk you into what he described before you make double sure it isn't the gauge. I know there are a lot of reputable mechanics out there, but it seems lately most diagnose the most expensive fix first.

Get you an aux temp gauge at AutoZone for a few bucks, hook it up and take the boat out for a run with a buddy to eyeball the aux gauge and run the IR gun, while you eyeball the dash gauge.

_________________

1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X

_________________
Not Penny's Boat

1993 190 Horizon 5.0L EFI
http://www.smwebhead.com/phpBB3/viewtopic.php?f=3&t=11136
1977 14' CMF Skiff SOLD
2015 Emotion Stealth Angler 11

To see if your sucking any air use the clear hose method. Where the hose comes through and connects on the inside, just add a piece of clear hose and you will see if any air is leaking in

Just thought i would give an update.
I had the forklift operator simulate me getting on plane. Put boat in water and let it idle till it got to 160*, then i had him slowly lift the boat out till the upper end of the drive was out of the water(3/4 of drive still submerged), temp started to rise. had him slowly lower it and temp went down. Did same test again with reving to 3000 RPM and same results only quicker.

_________________
JPEloian
2000 268 Vista