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Apr 17, 2017 10:45:45 GMT
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I rebuilt the engine in my cf and it has many small annoying leaks.
These engine are renowned for it but I'm going to do my best.
iron block, iron head. Ontop of the head is an alloy cam box, then rocker cover.
it leaks under the cam box so I need to take the cam belt off (cam timing is a nightmare on these). You cant get to the head bolts untill the cam box is off.
Now, its weeping water from the cylinder head. Head was blocked to check flatness when I had the valve seats done so I know its good. New head gasket was used, everything went back just fine.
I have a new gasket so I can replace if I want.
Problem is, once put back together you cant retorque the head without removing the cam box.
So, do I retorque the head and hope that cures the weep or put a new head gasket on? Its done about 1000 miles on the current gasket. I used no goop of any kind.
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rude
Part of things
Posts: 537
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Apr 17, 2017 11:03:31 GMT
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Did you retorque during the thousand miles? A thousand miles is a stretch before retorquing? I think you know where this is going to end up! Hope not though, I'd try retorquing now and getting everyone to cross their fingers.
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1986 Haunted BMW E24 635CSi
1999 Povo spec BMW E36 1.8i Touring Work Hack
2001 Petrol annihilating Discovery V8
2000 Jaguar S Type 3.0 V6 ~NEW~
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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head gasket adviceslater
@slater
Club Retro Rides Member 78
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Apr 17, 2017 11:56:40 GMT
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Where did you get the info about toruqing it up in the first place? Heads rarely actually need retorquing in my experience, it's more of a check. If you have followed the correct torque procedures in the first place I would say you need to look at the gasket. Must be somthing wrong for it to leak of its torqued correctly to start with.
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Apr 17, 2017 12:17:21 GMT
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Did you retorque during the thousand miles? A thousand miles is a stretch before retorquing? I think you know where this is going to end up! Hope not though, I'd try retorquing now and getting everyone to cross their fingers. No, you cant re torque without half dismantling the engine. In vauxhall world they sometimes use used gaskets to avoid this problem. Risky though. |
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Apr 17, 2017 12:19:51 GMT
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Where did you get the info about toruqing it up in the first place? Heads rarely actually need retorquing in my experience, it's more of a check. If you have followed the correct torque procedures in the first place I would say you need to look at the gasket. Must be somthing wrong for it to leak of its torqued correctly to start with. Torque specs from factory manual. You have the same thoughts as me, shouldnt need re torquing, especially as you need to take so much of the engine apart to get to the bolts. I was thinking if replacing gasket, I have one, but don't want to be in here again! Is there any goop I can use that isnt a bodge? Just something to make super sure? |
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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head gasket adviceslater
@slater
Club Retro Rides Member 78
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Apr 17, 2017 12:27:08 GMT
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I would say you need to look carefully at block and head surfaces for damage (corrosion?) near the waterways if it's leaking water. I'd have the head skimmed too for what it costs. Not so easy to do the block but a keen eye and a good clean up should show most faults. Iron blocks rarely warp.
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Apr 17, 2017 13:08:34 GMT
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Hi, Back in the day Viva HA engine head gaskets were specified to have Wellseal used on the head gasket. Not all motor factors stock it because it's horrible, messy, sticky stuff that seems to get everywhere so some people don't like using it, but is very effective. You can use over the whole head gasket surface or just round the water and oil gallery openings. It is available on Ebay because I've just looked.
Colin
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Apr 17, 2017 14:12:11 GMT
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Heads off. couple of pics. It was leaking from the water ways on the left of this pic. also looks like it was leaking compression out the side of cylinder 2 maybe? Also, a poc of the old gasket I fitted and the new one. New one is obviously black. Coated in something? Old one not coated? Old gasket hadnt stuck itself to head or block.    |
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Apr 17, 2017 14:59:21 GMT
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I'd be tempted to straight edge the head and block as best you can, if it looks all right, wet and dry with a long solid block to check for imperfections, then as we used to do on the Rolls and Bentleys, lay the head gasket on a piece of card and paint both sides of the gasket with wellseal and fit whilst wet. I worked on a fleet of CF' s in the '90's and know your pain. Good luck.
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Apr 17, 2017 15:21:19 GMT
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I have looked at head and block, both look great.
As I say, head was checked by the engine builders before I put it together and block surface was spot on.
Best straight things I have suggest this hasnt changed.
I need to get it back together ASAP, shouldnt have just took it apart really, so might have to give it the lightest coating of sealant and try again.
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Apr 18, 2017 15:07:15 GMT
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that does not look like its sealed well at all with all that rusty stain mark on the gasket, on these engines the head bolts almost bottom out so before you fit the head make sure the head bolts screw all the way down and measure the gap between the top of the block and the shoulder under the bolt head and compare that to the thickness of the head, its not uncommon to take a bit off the ends of the bolts once the heads been skimmed and the block decked to stop the bolt bottoming out, I always use blue Hylomar in aerosol form on both sides of the gasket with a new gasket or a nearly new used gasket
Also there are some rubbish head gaskets about so try and get a good brand, use the hylomar and make sure the head bolt threads are clean and dry, don't oil them or they can hydraulic lock
these can be great engines if you know how to put them together but unfortunately there are a lot of badly built examples out there
Don't forget the seal for the main oil feed up to the cam housing or the next thing will be an oil leak running down the block!
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Apr 18, 2017 17:16:33 GMT
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that does not look like its sealed well at all with all that rusty stain mark on the gasket, on these engines the head bolts almost bottom out so before you fit the head make sure the head bolts screw all the way down and measure the gap between the top of the block and the shoulder under the bolt head and compare that to the thickness of the head, its not uncommon to take a bit off the ends of the bolts once the heads been skimmed and the block decked to stop the bolt bottoming out, I always use blue Hylomar in aerosol form on both sides of the gasket with a new gasket or a nearly new used gasket Also there are some rubbish head gaskets about so try and get a good brand, use the hylomar and make sure the head bolt threads are clean and dry, don't oil them or they can hydraulic lock these can be great engines if you know how to put them together but unfortunately there are a lot of badly built examples out there Don't forget the seal for the main oil feed up to the cam housing or the next thing will be an oil leak running down the block! Bit late, its back together. I think it was just a rubbish gasket. I cleaned the surfaces, cleaned the bolt threads and put it back together dry (with a new o ring). I decided not to use any compound. I didnt check the bolt lengths but this is the original block, original head, original bolts and the head wasnt skimmed. It didnt need it. So, hopefully it will be ok. Its out of test so I need to get it back together ASAP. Should have checked mot date before I took it apart! If it leaks, ill just do it again. The first gasket just seemed like plain metal on the surface. It may have had a thin layer of stuff once, but its an NOS gasket and I think it was a bit naff. New gasket looked better and has that black sealing surface. |
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Apr 18, 2017 17:40:07 GMT
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I haven't used sealant on my head gasket, and while the engine has the odd weep (and a massive one from the rear main as I haven't had chance to swap it for the new-style seal) the head gasket and cam carrier have been fine. And yet I know others have talked about using Wellseal on it.
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Apr 18, 2017 17:49:39 GMT
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I haven't used sealant on my head gasket, and while the engine has the odd weep (and a massive one from the rear main as I haven't had chance to swap it for the new-style seal) the head gasket and cam carrier have been fine. And yet I know others have talked about using Wellseal on it. Where does yours weep? As long as the headgasket seals I'm reasonably confident this will be quite dry. All the leaks I had were down to damaged gaskets (cam box gasket had got torn around a bolt when fitted, no wonder it was pouring oil over the plugs and manifold!). they are renowned for leaking arent they! I was loosing maybe 250ml of oil and water every 300 miles. That was enough for me to take it apart again. |
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Apr 18, 2017 18:35:27 GMT
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New one looks like a Payen one with a heat activated coating. Some say to do the first start of the engine without coolant, run for a couple of minutes to melt the coating then switch off and allow to cool for 15 - 20 mins before slowly adding coolant.
I know it's a lot of work but probably worth doing the re-torque quite soon after - maybe after 4 or 5 heat cycles and then again after a 1000 miles. Beats doing the whole job again.....
Nick
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1967 Triumph Vitesse convertible (old friend)
1996 Audi A6 2.5 TDI Avant (still durability testing)
1972 GT6 Mk3 (Restored after loong rest & getting the hang of being a car again)
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Apr 18, 2017 18:41:29 GMT
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New one looks like a Payen one with a heat activated coating. Some say to do the first start of the engine without coolant, run for a couple of minutes to melt the coating then switch off and allow to cool for 15 - 20 mins before slowly adding coolant. I know it's a lot of work but probably worth doing the re-torque quite soon after - maybe after 4 or 5 heat cycles and then again after a 1000 miles. Beats doing the whole job again..... Nick It is payen. Previous one was supposed to be too. Thing is these nos gasket sets are always messed with. This second set had the better head gasket, it also has a better looking rocker cover gasket. Unfortunately alot of rhe smalls were missing and one of the inlet gaskets was a (badly) home made one! Luckily I had another real one as the first set came with 3! NOS gasket sets, always a gamble  I will try the running dry thing. It doubt it will get retorqued though, retorquing is 3/4 of the whole headgasket job! |
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Last Edit: Apr 18, 2017 18:43:18 GMT by VW
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Apr 18, 2017 18:47:26 GMT
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A bit late now it's all together but just in case you ever need to attack it again.
Yes they do leak - but usually from cam cover and rear main seal, not the head. Always use a good quality gasket (Payen are excellent if you can find them). If it's a composite gasket (black or multi-coloured) then it should go on dry with no sealant, but the plain pressed metal type will usually need a sealant like Wellseal. I've found the composite type are more forgiving. I've never re-torqued a head on these - that's usually only needed on iron/alloy mix because they expand at different rates.
For the cam carrier a light coat of wellseal works well, but make sure the surface is spotless.
Make sure the cam cover hasn't been distorted by over-tightening the bolts (flatten it out with a small hammer if necessary). Coat the cork gasket with red hermetite (or semi-hardening rtv sealant) and place it into position inside the cam cover then use loads of clothes pegs or bulldog clips to hold it in place (the more the better). Leave it overnight and it should be stuck in place. Put another bead of sealant on the gasket before fitting and it should be nice and oil tight - you won't get it off again without destroying the gasket though!
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Apr 18, 2017 18:52:34 GMT
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To give you an idea, retorque means...
Air filter off, Drop coolant, rad out, rad shround out, aux belt of, fan off, crank pulley off, front cover off, cam belt off, rocker cover off, cam box off.
After that when you put it back together, to set belt you have to line up pulleys, belt on, semi tension, cover on, pulley on, rotate engine, pulley off, cover off, set tension. Cover back, pulley back, then refit cooling system.
This is why no one does it and no manuals mention it.
Your only manifolds off and head bolts out away from doing the whole gasket!
This is why people reuse gaskets with sealant on these.
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Apr 18, 2017 18:56:23 GMT
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A bit late now it's all together but just in case you ever need to attack it again. Yes they do leak - but usually from cam cover and rear main seal, not the head. Always use a good quality gasket (Payen are excellent if you can find them). If it's a composite gasket (black or multi-coloured) then it should go on dry with no sealant, but the plain pressed metal type will usually need a sealant like Wellseal. I've found the composite type are more forgiving. I've never re-torqued a head on these - that's usually only needed on iron/alloy mix because they expand at different rates. For the cam carrier a light coat of wellseal works well, but make sure the surface is spotless. Make sure the cam cover hasn't been distorted by over-tightening the bolts (flatten it out with a small hammer if necessary). Coat the cork gasket with red hermetite (or semi-hardening rtv sealant) and place it into position inside the cam cover then use loads of clothes pegs or bulldog clips to hold it in place (the more the better). Leave it overnight and it should be stuck in place. Put another bead of sealant on the gasket before fitting and it should be nice and oil tight - you won't get it off again without destroying the gasket though! I think thats what happened, the first gasket was ment to have sealant. It had obviously been swapped over for the one that should have been in the kit! I'm sure new one will be fine. Cam box gasket got a smear of sealant. The cover didnt leak! The old gasket was almost plain cork. The new one is far more rubberised. I plan on sealing it to the cover but not the cam box. If it leaks ill clean it ip and seal it to the cam box too. |
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ChasR
RR Helper
motivation
Posts: 10,195
Club RR Member Number: 170
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head gasket adviceChasR
@chasr
Club Retro Rides Member 170
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Apr 18, 2017 23:05:56 GMT
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Where did you get the info about toruqing it up in the first place? Heads rarely actually need retorquing in my experience, it's more of a check. If you have followed the correct torque procedures in the first place I would say you need to look at the gasket. Must be somthing wrong for it to leak of its torqued correctly to start with. Depends on the gasket IME. On Stags and Dolomites almost all of the HGs require retorquing bar the now extinct Payen gaskets. But yes, on modern stuff the half decent gaskets seem to be fine ; I didn't need to retorque the gasket on my RST but it did have a very specific procedure for torquing it. It was a case of Stage 1, leave for 15 mins, Stage 2, leave for 15 mins and so on. |
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