st1g Posted November 30, 2012 Share Posted November 30, 2012 i was asked today which way the coolant flowed through the radiator ? i said it went in the top warm/hot and out the bottom cool/cold , but then a discussion took place on this with 3 people saying it went in the bottom and out the top because the water pump pushed it that way and only 1 person agreeing with me ? so now im a tad confused which isn't hard to do on a Friday lol . Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 30, 2012 Share Posted November 30, 2012 In the top (hot). Out the bottom (cold). Quote Link to comment Share on other sites More sharing options...
steve200TDi Posted November 30, 2012 Share Posted November 30, 2012 You are right! It does go in at the top and out at the bottom as hot air rises so the coolant at the bottom will be colder for the coolant pump to circulate around the engine. It's just more efficient that draeing coolant in from the top as it will be that much hotter! That's also why you have a short hose (on a TDi) going from the thermostate house to the top of the radiator. Steve Quote Link to comment Share on other sites More sharing options...
st1g Posted November 30, 2012 Author Share Posted November 30, 2012 thank you . i can now enjoy my beer Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 2, 2012 Share Posted December 2, 2012 In general - yes. In some cases - no. LS engines are reverse-flow. Pass the anorak Quote Link to comment Share on other sites More sharing options...
mmgemini Posted December 2, 2012 Share Posted December 2, 2012 Or in the case of a 300Tdi where both hoses go into the same tank ???? Which is top and which is bottom ? Quote Link to comment Share on other sites More sharing options...
simonb Posted December 2, 2012 Share Posted December 2, 2012 300Tdi in at top, cooling tubes are horizontal so flows right to left when facing engine, header tank on pipe side has a baffle half way down, so it only flows R-L in top half off tubes, then through oil cooler in other header tank and back L-R in lower section. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted December 2, 2012 Share Posted December 2, 2012 300Tdi in at top, cooling tubes are horizontal so flows right to left when facing engine, header tank on pipe side has a baffle half way down, so it only flows R-L in top half off tubes, then through oil cooler in other header tank and back L-R in lower section. As you say it's a crossflow rad. So it all depends which way the rad is turned. LOL Only an African rad should have the baffle. Not all UK rads were fitted with it. Also it's a heat exchanger. The oil heats the water LOL Quote Link to comment Share on other sites More sharing options...
zim Posted December 2, 2012 Share Posted December 2, 2012 Surely if it was suction from the top, in the event of your water level being a little low your pump wouldn't get suction ? Quote Link to comment Share on other sites More sharing options...
western Posted December 2, 2012 Share Posted December 2, 2012 Tdi pulls coolant from the bottom hose, hot goes in the top connectoin. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted December 3, 2012 Share Posted December 3, 2012 Tdi pulls coolant from the bottom hose, hot goes in the top connectoin. Is that the connection on the bottom or top of a 300Tdi ? Which is the top and which is the bottom on a crossflow radiator ??? Or are you talking physical top and not radiator top. The tanks although on the side or still top and bottom tank. Quote Link to comment Share on other sites More sharing options...
simonb Posted December 3, 2012 Share Posted December 3, 2012 On 300Tdi, when facing the engine, the pipe on right, at the physical top of rad is hot water in, pipe below is cold water out. On a cross flow rad, like any rad, bottom of rad is nearest the floor, and top of rad is nearest the bonnet.... Quote Link to comment Share on other sites More sharing options...
western Posted December 3, 2012 Share Posted December 3, 2012 Is that the connection on the bottom or top of a 300Tdi ? Which is the top and which is the bottom on a crossflow radiator ??? Or are you talking physical top and not radiator top. The tanks although on the side or still top and bottom tank. top = uppermost nearest bonnet, physical & rad top = same thing. Quote Link to comment Share on other sites More sharing options...
JST Posted December 3, 2012 Share Posted December 3, 2012 In some cases - no. LS engines are reverse-flow. same as the RRV supercharged...... Quote Link to comment Share on other sites More sharing options...
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