Ralphead 0 Posted January 28, 2012 I changed my rad a few weeks back due to a leak. Before this my oil occasionally got up to 108 but mostly sat between 96 and 102. Since putting the second hand rad in it's regularly up around 112 to 116 while cruising steadily. I had a good look at the rad before fitting it and all seems ok, not blocked or too heavy. My only thought is that I used the fan switch that came with the rad. I know the fan does come on now and again. But I've managed to mislay my old switch, doh! The thing is the water temp is still around 90 when fully warm, just as it was before so I'm a bit lost. Even so, just to rule it out.. Does anyone know the temperature(s) that the switch works at so I can test it please? Quote Share this post Link to post Share on other sites
dannyboy 0 Posted January 28, 2012 thats quite hot for a KR engine,especially this time of year. A rad may look fine on the outside but the inside tubes could be full of hard water deposits or covered in oil reducing its heat exchanging ability. the fan switch only turns on the fan,nothing else.if your cruising on the motorway the temps should drop as the fan isnt used unless its red hot outside,so it does sound very much like your rad has seen alot better days.Either that or you have a vapour lock in the rad,in that case try bleed the rad through the top rad hose. Quote Share this post Link to post Share on other sites
Ralphead 0 Posted January 28, 2012 Yeah I'll try that, thanks. Quote Share this post Link to post Share on other sites
Ralphead 0 Posted February 3, 2012 (edited) Well my plastic outlet pipe on the head split the other night along with the top hose. So I replaced them and flushed the system out well, filled and bled it. I'm still running hot according to the oil temp. I don't think the sensors lying, readings are consistent. I cleaned the rad for good measure but it didn't really need it. We have soft water here and rarely get build up in systems that are looked after. I filled it and flushed it through while it was out and I'm happy that it's not blocked at all. Can anyone tell me about this oil-water heat exchanger and any common problems with it please? It would seem the next suspect to me as the water temperature is not getting above the low 90's Edited February 3, 2012 by Ralphead Quote Share this post Link to post Share on other sites
seanl82 23 Posted February 3, 2012 Water temps shouldnt get above the low 90's though. Rad fan will kick in before it reaches above that, so unless your engine temps are uber high, the fan should be sufficient to cool the water in conjunction with weather at the moment! Quote Share this post Link to post Share on other sites
Ralphead 0 Posted February 3, 2012 But the water temperatures are ok, it's the hot oil which is the issue. Quote Share this post Link to post Share on other sites
joby 0 Posted February 3, 2012 But the water temperatures are ok, it's the hot oil which is the issue. I have the same issues with mine! Changed the heat exchanger and oil temp still reads high Quote Share this post Link to post Share on other sites
Ralphead 0 Posted February 3, 2012 I'm confused because the oil's only got really hot after changing the rad and yet the water temperatures are still the same as before.. Quote Share this post Link to post Share on other sites
Rustynuts 0 Posted February 4, 2012 I think it is possibly a wiring or sensor issue, I had an exaggerated problem with my g60 whereby it would read 150 deg c, then when I turned the manual fan switch off it would drop down to just over 100. So best bet is get some new sensors, ie oil temp sender and fan switch. Quote Share this post Link to post Share on other sites
joby 0 Posted February 4, 2012 I think it is possibly a wiring or sensor issue, I had an exaggerated problem with my g60 whereby it would read 150 deg c, then when I turned the manual fan switch off it would drop down to just over 100. So best bet is get some new sensors, ie oil temp sender and fan switch. i think your right rusty. my rad seems clear so dont think its that and the oil cooler is fairly new and the rad fan comes on at the right temp so hopefully its the temp sender Quote Share this post Link to post Share on other sites