rednaxela Posted October 2, 2021 Share Posted October 2, 2021 (edited) I've just finished installing a Turner ported cylinder head onto my 300Tdi. The original radiator was recored/refinned, and an Elring/composite HG was used, new head bolts, gasket sets, all from Turner eng. When filling the dry system with coolant, I started with all three caps/plugs removed (ie the expansion tank cap, the radiator nylon top plug and the thermostat housing nylon plug), firstly I filled up through the expansion tank until the coolant was just about at the top of the threads of the radiator, then I screwed up that radiator plug. Then I filled up through the thermostat housing until the coolant was consistently remaining halfway up the threads of where the plug screws into. I was patient when doing so. The expansion tank cap was still off at this stage of filling. On the first drive, to help the cooling system move about, I opted to run the heater at full blast/full temp/window demisters. There was consistent warm/hot air. I was quite certain I had no airlock issues. In the two outings/35 miles of vehicle use after doing this work, I noticed the water temp gauge seemed to get to half way a bit sooner than normal (normal before was a few miles). I put this down to the results of the work done helping the system work better, or something to do with the new head. (?) Then when I got home at the end of the second short journey, with engine still running but to stop to open a gate, I noticed steam coming from the engine bay and coolant spillage on the ground. The water temp needle remained in the middle; I didn't lose a great amount of coolant, so I think I may be lucky. The nylon plug on the radiator had blown apart, and the one on the thermostat housing looked a bit deformed, as if it was about to go the same way. When fitting these (original) plugs, I decided to finally use new o-rings from a Halfords set I had lying around. They seemed slightly on the big/thick side although could still fit into the recess - I wonder if tightening down the plugs to get the o-rings to seal weakened them? If the engine is revved, there's no bubbling/serious turbulence in the expansion tank, but I'll reluctantly add that when torquing up the head bolts... I first did them all to the 40nm in the correct sequence, then again I went over them to double check they were still all 40nm in the same correct sequence. Then I went through the first stage of 60 degrees, what I thought was in sequence. It was when doing the second sequence of 60 degree tightening, I noticed bolts 5 and 6 hadn't been touched since the second 40nm check. (I had marked them all with tip-ex) I presumed it was during the first 60deg sequence, the '6' of '60 degrees' being in my mind, obviously I went straight from bolt4 to bolt 7. Anyway I tightened bolt 5 120 deg and then bolt 6 120deg, then carried on as usual, ie, bolt 7 60deg. In also doing the further 20deg for the largest bolts, I felt that I would get away with this error. What are the thoughts? Thanks Edited October 2, 2021 by rednaxela Quote Link to comment Share on other sites More sharing options...
pete3000 Posted October 2, 2021 Share Posted October 2, 2021 I don't use the plastic ones any more, they are horrid things. I had to remove the remains when trying to remove one which had been bodged in by a previous owner of the engine. Get some Brass ones with the nut profile on the top. Quote Link to comment Share on other sites More sharing options...
rednaxela Posted October 2, 2021 Author Share Posted October 2, 2021 Yes, I have ordered two brass ones. Hoping the plastic/nylon plugs just gave up. Quote Link to comment Share on other sites More sharing options...
Eightpot Posted October 2, 2021 Share Posted October 2, 2021 If you change the HG then add water in the expansion tank you'll get an airlock as the thermostat is shut and you're just filling the rad. 1 Quote Link to comment Share on other sites More sharing options...
mmgemini Posted October 3, 2021 Share Posted October 3, 2021 Yes metal plugs are best. You will get them from any plumbers merchants. Now filling a 300Tdi. Remove both the thermostat plug and the radiator top plug Fill header tank to level Fill engine through thermostae housing until full, make sure air is purged by squeezing hoses. again fill at thermostat housing until radiator is full, again purging air from systen When coolant is full at thermostat housing and radiator, fit level plugs Check coolant level in header tank and fit cap Test drive NOTE although called the header tank. The header than is not the highest coolant level Neither is the 300Tdi fitted with a crossflow radiator Quote Link to comment Share on other sites More sharing options...
uninformed Posted October 3, 2021 Share Posted October 3, 2021 Turning the heater on does not change coolant flow. The coolant is ALWAYS flowing through the heater matrix (small radiator), all turning it on does is move a flap to change the air flow direction so the air passes over the heater matrix and into cab. The factory temperature gauge is terrible. It has a very broad range in the “normal” position and by the time it moves and you notice it, it’s too late. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted October 3, 2021 Share Posted October 3, 2021 2 hours ago, uninformed said: Turning the heater on does not change coolant flow. The coolant is ALWAYS flowing through the heater matrix (small radiator), all turning it on does is move a flap to change the air flow direction so the air passes over the heater matrix and into cab. The factory temperature gauge is terrible. It has a very broad range in the “normal” position and by the time it moves and you notice it, it’s too late. So true As for the temperature gauge, I fitted one from SPA very accurate Quote Link to comment Share on other sites More sharing options...
mmgemini Posted October 3, 2021 Share Posted October 3, 2021 You should also fit a coolant loss sensor Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 4, 2021 Share Posted October 4, 2021 I use one of these: https://www.ebay.co.uk/itm/SPILL-FREE-NO-SPILL-COOLING-SYSTEM-FILLING-FUNNEL-KIT-ACCESSORIES-/274717737596?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&customid=CjwKCAjwzOqKBhAWEiwArQGwaJtLxrNcgCZVlPC6iPgzd3WJ9O3SNopIrcuEfKxz7jM1TG4g9GHlBhoCKiYQAvD_BwE So simple. Brilliant Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 4, 2021 Share Posted October 4, 2021 The rad cap is a 1/2" BSP for reference, any pneumatic / hydraulic supplies will be able to sell you a blanking plug in a material of your choice for pennies. Quote Link to comment Share on other sites More sharing options...
Nonimouse Posted October 4, 2021 Share Posted October 4, 2021 1 hour ago, FridgeFreezer said: The rad cap is a 1/2" BSP for reference, any pneumatic / hydraulic supplies will be able to sell you a blanking plug in a material of your choice for pennies. Radiator blanking plaug - you could buy one with a bleed nipple Quote Link to comment Share on other sites More sharing options...
rednaxela Posted October 15, 2021 Author Share Posted October 15, 2021 Thanks guys. Well I got 2 plugs from ebay. They have the recess in them for the o ring also. Hoping the cooling system should be fine. I'm feeling pretty lucky I didn't end up overheating! Quote Link to comment Share on other sites More sharing options...
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