JJC Posted February 25, 2011 Report Share Posted February 25, 2011 On reassembly my engine leaked water. It leaked before starting, shows up when pressurising the cooling system. Seems to be water travelling around the head gasket, appears through stud holes, rocker oil feed, and weeps from the back corner of the head to the outside. All in all a bit disastrous. Work on the head and block done by reputable engineering firm, new liners etc. Head passes pressure test. Anyone experienced this before?of course it might be some dumb mistake I've made but I can't think what. Quote Link to post Share on other sites
Richard71 Posted February 25, 2011 Report Share Posted February 25, 2011 I'm not familiar with the 4cyl engine. Could it be possible the head gasket has been fitted upside-down? Richard. Quote Link to post Share on other sites
TomMull Posted February 25, 2011 Report Share Posted February 25, 2011 (edited) On reassembly my engine leaked water. It leaked before starting, shows up when pressurising the cooling system. Seems to be water travelling around the head gasket, appears through stud holes, rocker oil feed, and weeps from the back corner of the head to the outside. All in all a bit disastrous. Work on the head and block done by reputable engineering firm, new liners etc. Head passes pressure test. Anyone experienced this before?of course it might be some dumb mistake I've made but I can't think what. Sorry about that, certainly not the outcome you wanted. My guess is that it should be apparent when you remove the head, a misaligned or broken head gasket or very low liner heights. We assume the machinist checked for a warped or cracked head. Most block cracks leak into the sump not at the head. Tom Edited February 25, 2011 by TomMull Quote Link to post Share on other sites
MadMarx Posted February 25, 2011 Report Share Posted February 25, 2011 The block likes to crack at the stud next to the head oil feed. The block is thin there and if the head studs were screwed in too tight then it cracks the block. Water is entering to the tappet area or to the oil feed and depending how the head gasket was installed even to the outside is possible. Hope that is not the case at yours = not reparable. If you are lucky then only something went wrong with installing the head gasket. Which gasket do you use? Cheers Chris Quote Link to post Share on other sites
Badfrog Posted February 25, 2011 Report Share Posted February 25, 2011 Hi, Sorry about that. I would check a bad or poorly installed head gasket first, then studs then block crack. Good luck, Badfrog (bin there) Quote Link to post Share on other sites
JJC Posted February 25, 2011 Author Report Share Posted February 25, 2011 You know the brilliant thing, sorry two things, about this forum, are the speed of replies and the sympathy! No, the gasket is the right way up but it doesn't look quite as podgy a gasket as I would expect. It is a Moss part in Payen type packaging but who knows where it's made. Just looking at it, to my very non engineering eye, I can't see how it seals round the water ways but then if that was the problem everyone (with these recent gaskets)would have the same difficulty wouldn't they? Anyone know how thick an uncompressed gasket should be (not round the liners obviously). If the head had a crack round the rocker oil feed would it pass the pressure test? Prize for coming up with the solution, especially if it doesn't cost too much, is a pint at CLM in 2012 (assuming I'm still drawing my pension then).JJC Quote Link to post Share on other sites
Alec Pringle Posted February 25, 2011 Report Share Posted February 25, 2011 Hi JJC, and yet more sympathies . . . . ! Apologies in advance if I'm teaching you to suck eggs . . . . Apart from the ideas already put forward, two more for consideration - both situations which I've encountered previously, albeit not on TR engines. First, torqueing up the head studs/bolts in the wrong order, distorting the head seating - even worse with an alloy rather than an iron head. Second, using an inaccurate torque wrench - if the head is meant to be torqued down to 60lbs for example, then 50lbs is unlikely to suffice. Afterthought, did you use any type of sealant on the gasket ? Cheers, Alec Quote Link to post Share on other sites
JJC Posted February 25, 2011 Author Report Share Posted February 25, 2011 Alec - better and better, help from the great and good! I follow the workshop manual order for tightening nuts very carefully, even turning the book round so it matches the way I'm standing, like some people do with maps. Funny thing about torque wrenches. In the TR6 my wheel nut wrench is a Draper torque wrench. because one of my expert friends took it off to calibrate it and declared it incapable of calibration, so it's now just a long handled gash wrench. Then, friends being what they are, he long term (as in see my will) loaned me a calibrated Snap On version. So, ignorant being though I am I reckon the head was put on correctly. However, the first time I put the head back on there was some debris that caught in the gasket. I thought that was the cause of all my woes. No such luck, new gasket, careful reassembly, still leaks. That pint is still on offer. Might be several just for the sympathy. JJC Quote Link to post Share on other sites
JJC Posted February 25, 2011 Author Report Share Posted February 25, 2011 PS Sorry - no, I didn't use any sealant. I never have. A smear of oil but that's it. Some people say you start the motor because there's some sort of varnish on modern gaskets. My leak would have needed more than a whole tin of varnish to stop it! Quote Link to post Share on other sites
pfenlon Posted February 25, 2011 Report Share Posted February 25, 2011 I dont know the answer either, but can certainly know the misery involved, years ago I didnt know you had to put wellseal around the fig of 8 gasgets ( cost a crank regrind). what about perosity, can an iron block like this suffer some form of weeping, I would put well seal around the next gasket for certain and if it does again fail, when you take off the head it may indicate where the problem area is situated. I know its not what you want to hear. Quote Link to post Share on other sites
Alec Pringle Posted February 25, 2011 Report Share Posted February 25, 2011 Hi JJC, sorry to disillusion you, but neither great nor good . . . . just another amateur bodger ! If it's leaking that much, a lack of Wellseal probably isn't the cause. Liner height might be a possibility - but it does sound more like either the block or head face is out of true, or that there is a crack. Pulling the head yet again is probably the only way to find out, unfortunately. A problem with the figures of 8 wouldn't, I think, explain water pissing everywhere from the head gasket ! I'd be amazed if the head gasket was at fault, but anything is possible, and if all else fails I probably have at least one Stanpart or old pukka Payen head gasket spare . . . . and I too would recommend Wellseal. Cheers, Alec Quote Link to post Share on other sites
Rob Salisbury Posted February 25, 2011 Report Share Posted February 25, 2011 Hi JJC, the torque value for 4 pot iron heads is 100 to 105 ftlbs, and it take quite a lot of pulling, unless you're a Charles Atlas type!!..... I've had head studs that have visibly stretched in the past. Hope this helps. Cheers Rob. PS........ dry and clean both head and block faces, fit the gasket with no sealant, torque up, then run the engine for just a few minutes without any water in the head so that it gets really hot and allows the varnish on the head gasket to do the final sealing, let the engine cool right down before completly filling the cooling system. PPS.......... you can't do this with an aluminum head,....... well you can, but it will be shaped like a banana afterwards!!!. Quote Link to post Share on other sites
Ade-TR4 Posted February 26, 2011 Report Share Posted February 26, 2011 Hi Have you used a new set of piston/ liners? I had a set where one of the liners was on the p1ss: The measurement from the seating face to the top was off, so the liner wouldn't seat vertically. It was also about 15 thou too tall in the block! Glad I measured them all - swapped for a new set, which were all within a couple of thou. These were then surface ground/ table top ground (VERY handy when there's an engineering shop in the family...!) to obtaine a consistent deck height. I used sealant also (aerosol verion which gave a very even coating) on a Stanpart copper head gasket (TR Bitz seem to have a huge stock of them). That was 3 years ago and so far, so good (Original problem was a corroded Fo8 gasket leaking coolant into the sump). I would say, like the rest, that if it's not an assembly problem (liner heights, gasket seal, correct torques, bit of debris etc, then it's a crack). Hope it turns out to be a simple fix! Cheers Adey Quote Link to post Share on other sites
RogerH Posted February 26, 2011 Report Share Posted February 26, 2011 Hi JJC, Simple things first - The head gaskets (HG) are made in their thousands and nobody has reported this big failure so the HG can be eliminated. Is it the right way round!! this shouldn't produce a leak - it will bugger up the cooling though. Sealant on the HG. Many HG's are fitted without sealant and don't Leak. Liner sitting 'low' - this may cause a failure of the FO8 gasket but not the HG. However this could allow water into the cyclinder. Liner sitting too high - this could definately cause a probem as it would not allow the head to sit down fully/evenly You mention debris on the HG. There is not a washer etc on a stud between head and block A crack in the head would cause problems but necessarily as in your case - this is an odd one. Roger Quote Link to post Share on other sites
JJC Posted February 26, 2011 Author Report Share Posted February 26, 2011 Well, yes, I had the same sort of feeling about the gasket, can't be at fault as hundreds must have been replaced in the last couple of years. But! Have you heard about the cylinder block drain taps? That's another story. Unlikely to be the gasket, measured the liners and they are a fraction shy of the manual tolerance but shouldn't be a water leak problem. No debris now, certainly no washers. Looking more and more like a cracked block. If cracked would it show up on the block face? Just remembered, I did put the head back with no gasket, pinched it down, and checked round with a feeler guage. The corner by the heater supply (back, driver side) was 1 thou down on the others. Would the gasket take this up? Or is this a serious case of straw clutching and do I really need to see if John Sykes has got a second hand block? Quote Link to post Share on other sites
RogerH Posted February 26, 2011 Report Share Posted February 26, 2011 Hi JJC, on my block I noticed a slight weep when first installing the head after rebuild at the rear lefthand corner. As per MadMax's comment there was a small crack from the stud/oil way/water jacket (can't remember precisely). In my naivety I put some silicone sealant around the area and stuck the head back on - all sorted. Now, when I remove the head, you can see where the sealant has gone into the crack. I think I stil put a dob of sealant there whenever the head comes off. The point is it shouldn't be terminal unless you're really unlucky. I thnk your head needs removing again. Keep us updated on progress Roger Quote Link to post Share on other sites
Guest ntc Posted February 26, 2011 Report Share Posted February 26, 2011 (edited) I was told after replacing fo8 or liners always keep the old gasket and fit dry, fit the head and torque up,remove light smear both sides of the new gasket with blue hoylamar not where the liners are, job done,worked for me Edited February 26, 2011 by ntc Quote Link to post Share on other sites
JJC Posted March 13, 2011 Author Report Share Posted March 13, 2011 Just to keep you up to date......the engineering firm came round to look at the problem. In short they can't really see what's wrong. So the plan is to try again with a new gasket and using Wellseal this time. The head isn't cracked and there's no sign of cracks in the block, also no leaks with no pressure, so bit of a mystery. Could be some blunder on my part. Anyway, the new gasket supplied by the engineering firm has the same blue striped packaging as the Moss version but this one has Payen labels on it! It will take me some time to do the reassembly as I'm not going to attempt it without expert supervision. JJC Quote Link to post Share on other sites
Guest ntc Posted March 13, 2011 Report Share Posted March 13, 2011 Just to keep you up to date......the engineering firm came round to look at the problem. In short they can't really see what's wrong. So the plan is to try again with a new gasket and using Wellseal this time. The head isn't cracked and there's no sign of cracks in the block, also no leaks with no pressure, so bit of a mystery. Could be some blunder on my part. Anyway, the new gasket supplied by the engineering firm has the same blue striped packaging as the Moss version but this one has Payen labels on it! It will take me some time to do the reassembly as I'm not going to attempt it without expert supervision. JJC Just a thought you did get the head studs in the correct order? Quote Link to post Share on other sites
88V8 Posted March 13, 2011 Report Share Posted March 13, 2011 Many years ago I had a car, not a TR, which persistently blew its gasket. Eventually I discovered that some DPO must have overtorqued the studs, and several of them had lifted slightly where they threaded into the block, so the head was sitting on the raised bits of block and not clamping properly. Only apparent with the studs out. Would only need one. Just a thought. Ivor Quote Link to post Share on other sites
vivdownunder Posted March 13, 2011 Report Share Posted March 13, 2011 Before the head goes back on, check the block and head surfaces for any sign of warping. Use a straight edge and feeler gauge. Check each liner on four sides for uniform .003 to .005 proud of the block. (a liner obviously doesn't have sides, but you know what I mean). You say the liners might be a fraction low - they really need to be min .003 proud for good sealing, but Wellseal should help. Don't re-use head stud nuts unless they're the ARP high tensile ones. (the threads degrade). Don't use any oil on the head stud threads - they should be tensioned down dry. Good luck this time. Viv. Quote Link to post Share on other sites
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