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18th April 2009, 06:56 | #11 | |
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18th April 2009, 17:34 | #12 |
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This is an interesting thread, although old Kaiser seems to take umbrage at other peoples advice a bit toooo quickly. Clearly with liners like the K4 engine has, there is the possibility that the bottom ends of the liners can leak as well as the well known top end (aka HGF), they are only sealed with a small bead of Hylomar after all. I would think the sealant mentioned by Kaiser would be able to close off leakage at the bottom of the cylinder liners as these are only under the cooling jacket pressure not the combustion chamber. There used to be a product called Bars Leaks which was actually recommended by Jaguar
So lets see how Kaiser gets on. He seems to be a big softy for the Rovers despite his comments that I have read over the past few years on the 4 and 6 cylinder engines. I have to confess to having similar feelings of exasperation with MG Rover and their failure to deal with obvious faults promptly |
18th April 2009, 18:48 | #13 |
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You are entirely right, and this is exactly the leak I am talking about. This is a leak past the liner, in between the aluminium support, which extends up to say a third/half the length of the liner, and ends with a shoulder at 90 degrees, where the liners is pressed against, at 45%, sealed with hylomar.
With usage the liners tend to fret (move about very slightly) which helps breaking the seal, and lets tiny amounts of water through, between the aluminium and the liner. The tolerances are very close, so it will at first be minute amounts. If not arrested, the leak increases and the liner will become more loose, eventually start loosing the seal at the top as well, and then you have HGF. A loose liner, as described,will only result in water being forced past into the oil, thus moisture/mayo under the cap, and contamination of the oil. There will be no HGF, unless you allow the process to develop, where the liner will eventually start moving up and down, where it can even create a ridge in the cylinder head! Sodium silicate as used here has the consistency of water, it is a liquid under normal pressure and temperature, but it solidifies into a hard hard glassy substance at elevated temperatures. What happens is that water and silicate is finding its way into any leak past the cylinder liner. Here the water will pass into the oil, but because the silicate is entering a high temperature zone (just on the other side of the liner, you have the combustion taking place) it will solidify in the space it occupies, blocking further passage of water AND taking up the vacant space, thus stabilizing the liner! This last part is at least as important as the blocking of the water. It is a self healing process, and it is therefore, in my view, of tremendous benefit in this type of engine. If you have the stuff in the cooling system, it will actively seek out these tiny leaks before you even know they are there, and it will also stabilize the liners, crucially important in these engines. Now see what you made me do I will post some picture tomorrow, to see if I can make the situation a bit clearer for the non-technical members. In the meantime, as promised, I will keep you abreast with our car!. |
18th April 2009, 20:14 | #14 | |
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Good to know you have had success with the K-seal additive. The movement of the Cylinder Liners you refer to was sometimes a noted failure relating to the Freelander application of the 1.8 K Series engine. In this application the engine was subjected to more torsional stress than that found when used in the 75/ZT models. The Freelander engine sometimes infact cracked it's Cylinder Liners and this was traced to the movement of the Cylinder Head along with some movement within the Block itself. Following investigation and engineering work, the new Cylinder Head Gasket Kit KUA000080 was introduced, which included a new Oil Feed Ladder Rail design and also used with the previously introduced Steel Location Dowels for the Cylinder Head which replace the original plastic composite type. This new combination gives a more positive location for the Cylinder Head to the Cylinder Block, with the new Steel Dowels assisting in preventing sideways movement etc., of the Head. Engineers had suspected this movement was the possible if not the main cause in the majority of cases of cracked Cylinder Liners. The new Oil Feed Ladder Rail also contributes to the improved clamping arrangements of Cylinder Head to the Block and therefore used along with the new improved Head Gasket and shim, reduces the likelyhood of the Cylinder Head Gasket failing again, especially in a 75/ZT application. Subject of course to a good standard of workmanship and a sound no loss cooling system. Regards, Telfer. |
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19th April 2009, 11:14 | #15 |
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Hi All,
Kaiser asked for some evidence of problems with sealant additives for stopping coolant leaks. Here is some personal experience. In teh late 1980s I had a leak problem with my Vauxhall (aka Opel) Cavalier mk 1 (2000cc, cam in head, cast iron engine). It developed a leak in the radiator and, not wanting the hassle of removing the radiator, I added some 'RadWeld' (the best known product at the time) to the system. This did cure the leak but some time later the car started over heating. After some checks I removed the water pump and thermostat, both of which were partly clogged with hard depsits. After replacing these, the problem persisted. Eventually I removed the cylinder head to find such deposits in all the tight bends I could see in the coolant channels in the head. After hacking these out and relpacing the head it still over heated and I ended up scrapping the car. RadWeld says it consists of lots of short fibres that naturally accumulate near small leaks and seals them. They also seem to set hard with prolonged heat. This means that they will also collect in the tight waterways of the cyclinder head and block them. I was told subsequently that such problems with RadWeld and similar products were not unknown. Kaisers method of putting the sealant in for only a few days, or perhaps one long journey, may have prevented this, but it didn't mention this. Regards, Kearton |
19th April 2009, 16:22 | #16 |
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KV6 engine1.jpg
KV6 engine 2.jpg I have added these pictures from a KV6 engine, which has had an untimely death. There has been an obvious problem with the liners (and one problem clearly a leak past one liner in particular). This engine would for a long period have shown water loss (you can see the corrosion has been caused by prolonged exposure to water) Normally these sleeves should be sparkling clean if the water seal on the top works. When you open one of these engines, you just see pistons and water. The only seal is the top of the sleeve against the head, and at the shoulder of the sleeve as shown here, against the oil. |
19th April 2009, 18:55 | #17 | |
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19th April 2009, 20:04 | #18 |
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Two very, very, interesting pictures from Kaiser, proving something I had always thought must ocasionally happen, but never had confirmed, namely the liner seal failing where it fits into the block. As Kaiser says, the inside of the cylinder housing should be clean when dissembled and not corroded. Yet all the sealing provided is a bead of Hylomar, which is good stuff, but maybe not totally sufficient for an engine required to operate for 100,000 miles or more.
The Jaguar V12 engine is the same, and used the same stuff, Hylomar, to make the seal. There have been loads of open deck push-fit liner engines around over the years; did the RR Merlin aero-engine use the same design ? Another thought I had is that much emphasis is placed in the service instructions on not moving the crankshaft once the heads are off, as the liners can become disturbed, in fact one should bolt them down using a special tool. owever, if the factory processes are not foolproof, and sometimes through inattention, allow movement before the heads are clamped down, a timebomb fault can be created in the engine from new for the unlucky owner to find out about when it finally lets go. |
22nd April 2009, 09:16 | #19 |
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Well, I know you are sitting on tender hooks to see "will he, or won't he???""
OK, he will!! I am glad to announce, that the 1.8t has now run for almost a week, and not needed ONE drop of water. There is no doubt, had we left it, it would by now have had about half a liter added. So we can say with certainty, that the internal leak has been stopped! Time only will tell if it stays so. There has been no noticeable side effects. Temperature is fine and heater works fine, oil is clear, oil filler cap is dry. |
22nd April 2009, 19:38 | #20 |
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Congratulations, Kaiser ! A non-intrusive repair that has worked.
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