johnbyron Posted March 22, 2014 Report Share Posted March 22, 2014 Well a week or two ago I put up an add in the wanted section for a diesel lupo or arosa... to cut a long story short I ended up traveling to london for a bronze 1.4 tdi with 106k miles on the clock... I topped her up with £20 when I picked it up then did quite a few miles round london area before coming back up to scunthorpe that night and I was astonished by the fact I managed to get 250 odd miles from the £20 :-o, im really chuffed with the car itself for the price I paid and its only a work car but I now have the dub bug and I now want to modify it haha so ill make a project thread a some point in the future. Now there is one problem... the cooling system keeps becoming pressurised and the pipe from the stat to the rad is always stone cold so I read up on here and saw rich said somthing about the stat housing and the stat so I bough the housing from tps and the stat from eurocarparts and specifically asked for the volkswagen one and not the volvo one after receiving a volvo one first time round.I fitted the stat and housing today and the old housing had a lug/stick missing from the inside and I noticed the original stat was the same design as the volvo one!Still I went ahead and fitted the volkswagen one and unfortunately after bleeding a few times and taking her for a spin a few time its still got the same problem so to rule out the stat tomorrow I will be completely removing it....Any suggestions as to what else this problem could be??Baring in mind theres no mayo on the cap, the coolant wasnt contaminated and there has been no loss of water other than bits thats shot out when iv been a bit fast releasing the pressure. Quote Link to comment Share on other sites More sharing options...
pkrboo Posted March 22, 2014 Report Share Posted March 22, 2014 Sounds like it could be air in the system to me. Is there a bleed screw? Not sure what the procedure for bleeding is Quote Link to comment Share on other sites More sharing options...
johnbyron Posted March 22, 2014 Author Report Share Posted March 22, 2014 Iv tried all sorts in terms of bleeding it and iv ran it without the cap on the tank... no bubles or anything,all the pipes feel full :-/ Quote Link to comment Share on other sites More sharing options...
pkrboo Posted March 22, 2014 Report Share Posted March 22, 2014 Stat in the right way round? Quote Link to comment Share on other sites More sharing options...
johnbyron Posted March 22, 2014 Author Report Share Posted March 22, 2014 Definitely! I could only put it in one way Quote Link to comment Share on other sites More sharing options...
pkrboo Posted March 22, 2014 Report Share Posted March 22, 2014 What does the temp gauge get to? Quote Link to comment Share on other sites More sharing options...
Dblock Posted March 23, 2014 Report Share Posted March 23, 2014 Sounds like it could be air in the system to me. Is there a bleed screw? Not sure what the procedure for bleeding isTdi is self bleeding. Scrap the thermostat. Get a GENUINE one with GENUINE housing. Will fix your problems I promise. Although your housing is from TPS so should be legit. Rinse the rad and block out make sure there is no gunk like radwell or that rubbish in there and refill with g12+ g12++. Let me know how you get on. Quote Link to comment Share on other sites More sharing options...
johnbyron Posted March 23, 2014 Author Report Share Posted March 23, 2014 Thanks for the advice people, today I removed the stat and took it for a couple of runs , takes forever to get to temperature and didnt hold its heat very well when the heaters were on but after it had bled all the pipes were the same temperature (only 70°c) so it looks like I got the wrong thermostat. There was pressure in the tank the first time I took it out but the second time I took it out there was very little pressure there. Quote Link to comment Share on other sites More sharing options...
pkrboo Posted March 23, 2014 Report Share Posted March 23, 2014 (edited) Yep Without a stat it will take forever to get warm. I would go to tps and get a genuine thermostat and go from there Edited March 23, 2014 by pkrboo Quote Link to comment Share on other sites More sharing options...
johnbyron Posted March 28, 2014 Author Report Share Posted March 28, 2014 Hmmm ive fitted a genuine thermostat from TPS and my water gets up to around 85-90°c and my heaters keep blowing warm but I noticed that the thermostat isnt fully open until 87°C so the bottom pipe is still fairly cool compared to the rest apart from when you go on a long motorway run! The temp doesnt go above 90 though so it won't be sticking. Plus I still have pressure in my coolant tank! Beginning to think its my head gasket but there are no other signs of the gasket blowing what so ever, I think ill just run it and if it gets any worse ill rip the head off and skim it and fit a new gasket.One thing I did notice was there is a solid mass in one of the return pipes from the head, is this normal? I checked it but cant see what it is but I can blow through both ends of the pipe. Quote Link to comment Share on other sites More sharing options...
jon_273 Posted March 28, 2014 Report Share Posted March 28, 2014 It's sounds like it's working fine now, why do you suspect the head gasket? Quote Link to comment Share on other sites More sharing options...
pkrboo Posted March 28, 2014 Report Share Posted March 28, 2014 90 is the correct temp. Quote Link to comment Share on other sites More sharing options...
Dblock Posted March 28, 2014 Report Share Posted March 28, 2014 +1 my car gas a grill block and I have to be hammering it for it to get above 90c on the scangauge. Quote Link to comment Share on other sites More sharing options...
johnbyron Posted March 28, 2014 Author Report Share Posted March 28, 2014 Ah right I wasnt sure if it was supposed to sit a bit cooler than that, never had a diesel before lolWell I suspect the headgasket simply because there is pressure in the header tank :-/ more than iv seen in my 206 and my old corsa but then again its not a ridiculous amount of pressure, just enough to squirt a bit of coolant out when you open the cap but only when its warm/hot Quote Link to comment Share on other sites More sharing options...
pkrboo Posted March 28, 2014 Report Share Posted March 28, 2014 Don't open the cap when it is hot then!! Quote Link to comment Share on other sites More sharing options...
Dblock Posted March 29, 2014 Report Share Posted March 29, 2014 Don't open the cap when it is hot then!!Plus one I wouldn't do that on the rad or the tank. Quote Link to comment Share on other sites More sharing options...
johnbyron Posted March 29, 2014 Author Report Share Posted March 29, 2014 Im pretty sure its not supposed to have enough pressure to squirt coolant out the tank when warm though?? I thought theyre suposed to run at atmospheric pressure?? Even when its been ran up hot then you let it cool right down, after 5 hours its still got pressure there when you release the cap. Quote Link to comment Share on other sites More sharing options...
jon_273 Posted March 29, 2014 Report Share Posted March 29, 2014 It's perfectly normal and just how they are. As said, don't open the cap when it's warm! Quote Link to comment Share on other sites More sharing options...
Kes Posted April 1, 2014 Report Share Posted April 1, 2014 Coolant needs pressure to raise the boiling temperature. Perfectly normal. Quote Link to comment Share on other sites More sharing options...
johnbyron Posted April 2, 2014 Author Report Share Posted April 2, 2014 Ah okay I didnt realise they where like that, so should there still be pressure when its cold?? What if this pressure keeps rising over a period of time without being released? Wouldnt it blow a hose or a gasket??I could understand if the pressure was there due to the rise in temperature of the coolant because it expands but surely the pressure would drop once the water cools?? Quote Link to comment Share on other sites More sharing options...
Kes Posted April 2, 2014 Report Share Posted April 2, 2014 Yes it should drop when the car is cold? Is there a vent tube blocked possibly? Quote Link to comment Share on other sites More sharing options...
johnbyron Posted April 3, 2014 Author Report Share Posted April 3, 2014 Im not entirely sure if there is or not?? I did notice a solid mass in a return line from the head to the header tank but when I took the pipe off I can blow through both ends.... Quote Link to comment Share on other sites More sharing options...
jon_273 Posted April 3, 2014 Report Share Posted April 3, 2014 Ah okay I didnt realise they where like that, so should there still be pressure when its cold?? What if this pressure keeps rising over a period of time without being released? Wouldnt it blow a hose or a gasket??I could understand if the pressure was there due to the rise in temperature of the coolant because it expands but surely the pressure would drop once the water cools??The coolant reservoir cap has some kind of pressure relief vent in it I believe.There always seems to be some residual pressure if the car has been driven that day, even after letting it cool, but as soon as you undo the cap the pressure should dissipate. You should hear this briefly as you unscrew the cap. Quote Link to comment Share on other sites More sharing options...
johnbyron Posted April 4, 2014 Author Report Share Posted April 4, 2014 I see what your saying jon but this is enough pressure to spray coolant out the overflow/relief hole unless caution is taken and the pressure is released very very slowly.Maybe the pressure relief valve in my cap is faulty, suppose its worth a shot before I rip the head off.Even with pressure in the system the temp still sits nicely around 87°c which is when the thermostat opens. Quote Link to comment Share on other sites More sharing options...
pkrboo Posted April 4, 2014 Report Share Posted April 4, 2014 might be worth changing the coolant resevoir cap then Quote Link to comment Share on other sites More sharing options...
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