F355GTS Posted April 17, 2005 Share Posted April 17, 2005 Sadly despite changing hte Head gasket the problem still continues, basically the Expansion tank overflows and there is air in the top of the radiator I've put a clear hose on the top vent (TB's to Expansion) From cold (thermostat closed) there is a small amount of air bubbles coming through the top vent hose, if I rev the engine to around 3k then a lot more air comes through, As soon as the thermostat opens loads of air comes through the top vent hose, if I rev the engine again to around 3k then it becomes mostly air rather than coolant Mark Edited by - F355GTS on 19 Apr 2005 13:25:39 Link to comment Share on other sites More sharing options...
Myles Posted April 17, 2005 Share Posted April 17, 2005 Oh bunnies. It's a sod isn't it - I pulled PSC apart/in-out of the car three times before we got it working - I know the feeling of putting in a load of time and money, crossing fingers, hoping-against-hope and then the despair when it still doesn't work. Ho-hum. Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Mick Day Posted April 17, 2005 Share Posted April 17, 2005 The expansion tank is too low in relation to the water in the head. You need to put a a self bleeding swirl pot/exp tank in the top rad hose. Link to comment Share on other sites More sharing options...
StewartG Posted April 17, 2005 Share Posted April 17, 2005 Did you look to see if the restrictor was fitted in the expansion tank hose? Link to comment Share on other sites More sharing options...
simonbell Posted April 17, 2005 Share Posted April 17, 2005 Mark Timbo and jj had a coolant problem on a VX car they worked on a couple of years ago. It kept spitting out the coolant.....turned out to be an issue with the hose configuration I think. I`ll direct them to your post.....maybe they can help. Simon Bell - Caterham 7 Duratec R I`ve seen the future.....and it`s powered by duratec Check out the website here Link to comment Share on other sites More sharing options...
Mr Locust Posted April 17, 2005 Share Posted April 17, 2005 Have you had the head pressure tested. Not sure if the XE is prone to casting porousity but it's always possible. Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
k.russell Posted April 17, 2005 Share Posted April 17, 2005 As StewartG says, there should be a small (about 8mm dia) aluminium restrictor in the TB to expans tank hose, it has a small (approx 1mm) hole in it , if you replaced the hose with clear were you aware that this resrictor was in the previous hose, I didnt have this in when I first built my car and had similar probs. kevin R J457 DNU black-ali HPC Link to comment Share on other sites More sharing options...
Bob Simon Posted April 17, 2005 Share Posted April 17, 2005 Mark, Have the entire system pressure tested. There's a tool that replaces your expansion tank cap that allows the system to be pumped up to see if it's holding pressure. System won't work right if it's not holding pressure. Kevin, Out of curiosity...I've never found a restrictor in my car. The nipple on the manifold is rather tiny though. Maybe 2-3mm or so. How big is the hole through this hose restrictor thingy? -Bob 94 HPC VX Link to comment Share on other sites More sharing options...
k.russell Posted April 17, 2005 Share Posted April 17, 2005 Bob, I have fitted this restrictor this morning so it is fresh in my mind, the hole is only about 1mm probably even less, you wouldnt know it was there unless you had fitted it yourself, it is about 8mm dia and 8mm long and is usually pushed in from the expansion tank end, if it is there you can feel the hose is solid in this area, I have moved the tank to the side to make room for my air filter canister and air box feed, as I have said i had problems when i first built my HPC back in 92, caterham sent me this restrictor, no probs since (fingers crossed), have just fitted direct to head TB's and the formost body has a casting which fits over the waterway as did the cat 45 manifold, this has an 8mm hose tail. kevin R J457 DNU black-ali HPC Link to comment Share on other sites More sharing options...
StewartG Posted April 17, 2005 Share Posted April 17, 2005 Just had a look at the plumbing on mine with no heater and carbs, it's fairly simple. Rad bottom hose goes to water pump. Two feeds are tee'd off from this. The front one goes to the bottom of the expansion tank. The rear one goes to the bigger outlet on the head. The small outlet on the head goes to the top of the expansion tank and has the restrictor in it. The thermostat outlet on the exhaust side of the head goes to the top of the rad. The restrictor is there to control the flow to the expansion tank without it when the engine is stopped coolant trapped in the very hot head boils and violently expands into the... err expansion tank. The restrictor in controlling coolant expansion also helps maintain coolant pressure which maintains a higher boiling point. Adding a restrictor should help the boiling over but lack of one may not be your problem. Are you sure you've no air in the system? Did you use the correct head gasket, did you fit it the right way up and tighten it OK? Did you fit the correct inlet manifold gasket? Do you have any leaks? I had a problem sealing the bottom rad hose until I discovered the jubilee clip must be at the top to align with the flat on the outlet. Hope this helps Link to comment Share on other sites More sharing options...
F355GTS Posted April 17, 2005 Author Share Posted April 17, 2005 Mick Can it be too low? it's a std Caterham fitment and worked fine with the previous engine and I beleive countless other VX cars Stewart/ Kevin No restrictor but my plumbings different to yours I think, only one take off on bottom hose which goes to bottom of expansion tank and then the vent hose from TB's to top of expansion tank Simon Thanks Bob Thanks for the info Mark Link to comment Share on other sites More sharing options...
Nick Woods Posted April 17, 2005 Share Posted April 17, 2005 Hi Mark I'm no expert in this whatsoever, but I remember seeing a thread over on the (whisper) Westfield BBS about this. Apparently the heads can go porous after a few years but it may be possible to re-sleeve the waterway and fix the problem. There is a thread here which includes a link to a Word document about the problem Good luck Nick Red and Black 1.6K supersport visit Carrotland.co.uk Link to comment Share on other sites More sharing options...
EFA Posted April 17, 2005 Share Posted April 17, 2005 Mark, "only one take off on bottom hose which goes to bottom of expansion tank and then the vent hose from TB's to top of expansion tank" Same as my car - no probs. Do the pressure test....... Link to comment Share on other sites More sharing options...
Bob Simon Posted April 17, 2005 Share Posted April 17, 2005 Kevin, you wouldnt know it was there unless you had fitted it yourself, it is about 8mm dia and 8mm long and is usually pushed in from the expansion tank end Egads! I just replaced my hose with some nice bling-bling stainless braided whatnot. So far no problems, But I'm definitly looking at the old hose when I get back to the garage. Thanks, -Bob 94 HPC VX Link to comment Share on other sites More sharing options...
StewartG Posted April 17, 2005 Share Posted April 17, 2005 The second take off from the bottom hose allows coolant to ciculate through the engine and head before the thermostat opens and allows it through the radiator. You might ask where the coolant goes without this pipe returning it to the inlet of the pump? Perhaps it gets forced into the expansion tank from the other head outlet and then back to the pump inlet from the bottom of the expansion tank . Link to comment Share on other sites More sharing options...
Mark Durrant Posted April 17, 2005 Share Posted April 17, 2005 Bad luck Mark ☹️hope you get it sorted soon Mark D Su77on Se7ens Link to comment Share on other sites More sharing options...
F355GTS Posted April 17, 2005 Author Share Posted April 17, 2005 Stewart, that's right it circulates through the expansion hoses until the thermostat opens Mark Link to comment Share on other sites More sharing options...
Bob Simon Posted April 17, 2005 Share Posted April 17, 2005 Stewart, Seems to me that you'd have to run a restrictor washer instead of a thermostat without a pump bypass. If there is no circulation under the stat to heat the wax button, wouldn't the engine boil and blow the cap before the stat had a chance to open? I've seen a similar issue in a ponton Mercedes 220S. -Bob 94 HPC VX Link to comment Share on other sites More sharing options...
Joachim Westermann Posted April 18, 2005 Share Posted April 18, 2005 I can not read and translate everything in that threads, maybe thta wahat I write somebody write before. A German customer which have nearly the same problem has his car in our workshop told me about this thread. We lift the car in the front to the highest car jack position and bleed the air out of the system. Then we change the filler cap of the expansion bottle. That was the causal problem. Maybe it help you. Regards Joachim mog-racing.com Link to comment Share on other sites More sharing options...
gmdh555 Posted April 18, 2005 Share Posted April 18, 2005 Probably only slightly relevant, but I had a thermostat put in my VX 8v at Christmas and subsequently had constant problems during warming up, with excessive pressure leading to coolant blowing out of the cap. Eventually a hose split under the pressure. On replacing the hose I realised my system wasn't laid out to the standard design. I replaced a couple of hoses to correct the layout, and everything now works correctly - there is virtually no pressure/temp buildup prior to the stat opening. The problem was in the twin feeds on the inlet side of the stat housing - I don't have a heater and these were simply connected by a U-pipe, instead of going to the submarine pipe and expansion bottle as intended. Gareth Yellow and black 1.8 VX, pics here Link to comment Share on other sites More sharing options...
Marius Posted April 18, 2005 Share Posted April 18, 2005 Give Nick Dinsmore a call, he supplied me with one of the self-bleeding tanks. This is one of the best parts I fitted for the last 5 years. No more air in the system (this occured also only at high revs on track with my car) and filling the coolingsystem now only takes 5 minutes: fill up the system, put the cap on, start the engine, let it warm up (thermostat opens) once, check coolant level, add a bit if needed, et voila, ready. No more radiator bleeding etc. I went mad during the last years with the bloody air in the system. Link to comment Share on other sites More sharing options...
F355GTS Posted April 19, 2005 Author Share Posted April 19, 2005 Thanks for all the contributions, can somebody tell me where I might get a pressure test done? Mark Link to comment Share on other sites More sharing options...
normalbloke.29 Posted April 19, 2005 Share Posted April 19, 2005 Not sure if it is any help, but i have a cooling system pressure tester if you're really pushed. Link to comment Share on other sites More sharing options...
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