Mark Adams Posted May 16, 2011 Share Posted May 16, 2011 Hi, I have recently removed the head on my 300Tdi Discovery due to the header tank pressurising. I had the head skimmed and pressure tested and have now replaced the head with a new 3 hole gasket (The same as the one that was removed), new bolts and new gasket kit (manifold etc). I have tried starting it for the first time and it makes a strange noise on turning over and does not start, on each rev it tries to start but instantly cuts out. If anyone want to hear what it sounds like I can e-mail them a sound file as this web site does not allow me to attach it. Mark. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted May 16, 2011 Share Posted May 16, 2011 Put a video on Youtube and link to that? From what you say maybe the timing but post up and we'll have a listen Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted May 16, 2011 Author Share Posted May 16, 2011 The timing should not have changed as the timing belt is not touched to remove and refit the head. Do you mean the valve clearances? Mark. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted May 16, 2011 Share Posted May 16, 2011 No I meant the timing - the only thing that I can think of offhand that sounds a bit like what you describe is if the timing belt is broken on a Tdi it turns over in an odd 'hunting' way that sort of sounds like it is trying to start and then failing. I know you don't touch the timing to take the head off but coincidental failures do happen. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted May 17, 2011 Author Share Posted May 17, 2011 The cam shaft is definatly turning as I have removed the rocker cover a couple of times and the rockers have moved position. The Cam belt was only changed about 5000 miles ago so I am fairly confident about its reliability. Mark Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted May 17, 2011 Share Posted May 17, 2011 After skimming the head did you check the valve 'stand down' as I think it is called. That is the distance from the head surface to the valves. Often after skimming this distance is reduced so that the valves will hit the pistons when the engine turns over. The distance is corrected by recutting the valve seats. It is also possible after skimming that the glow plugs protrude further and hit the centre of the pistons. I think the head has to come off again to check these things. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted May 17, 2011 Author Share Posted May 17, 2011 I did mention the problem about pistons hitting valves to the engineering company that resurfaced the head as I wanted to know if I needed to get a different gasket. They told me that it was non-sense and I should always use the same thickness gasket. Anyway the problem is now solves and the car starts, the problem turned out to be the clearances on the rockers, despite being reassembled in the same place they were completly out of adjustment. The car starts fine, I have noticed a hissing noise coming from the engine now so I will need to investigate that next (the problems continue). The pressurising of the header tank has also stopped, so that problem is solved. Mark. Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted May 17, 2011 Share Posted May 17, 2011 The valve clearences need adjusting because with the head skimmed the rocker shaft is now closer to the camshaft. The clearnece needs adjusting by about twice the amount you had skimmed off. Valve head stand down is in the LR manual, whilst you can often do a skim without it being a problem it shouldn't be ignored. You can check the valve hitting the piston by slipping an old feeler gauge in the rocker, if you can get the feeler in then the valve isn't jammed against the head. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted May 18, 2011 Author Share Posted May 18, 2011 Range Rover Blues, Thank you for explaining that I had not considered that but it is obvious if you think about it. Mark. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 5, 2011 Author Share Posted June 5, 2011 Well just when I was happy that all was well, it all went very horribly wrong. I used the car for a while and all seemed well, I did some motorway driving and town driving and everything seemed fine. I then decided to let a friend use the car for a day to move some pigs as his 4x4 was off the road. I asked him to take it easy but unfortunatly I received a call later in the day saying the car had overheaded and the RAC are towing it back. It seems worse this time as the car does not even start, I have just removed the head (Again) and found cylinders 2,3 and 4 are full of water. I am unfortunatly sure that it is not just the gasket this time but I am not sure if it is the head or the block that is damaged (or maybe both). Any way or checking which has fried? Mark. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 5, 2011 Share Posted June 5, 2011 If you don't drain the cooling system first, then cylinders full of water is the norm. Although 300TDi engines are well-known for head cracks, I wouldn't expect to find a cylinder full of water - let alone 3 of them. They told me that it was non-sense I wouldn't touch that garage with a barge pole to be honest. Running in an engine after a head build is really just a precautionary measure, and failing to do so will not necessarily cause problems if you don't do it. Because of the reputation of this engine - I suggest you get it crack tested again, and the head checked for flatness (not necessarily skimmed again). I wouldn't be at all surprised that it's still ok, which points then at the repair procedure. Les. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 5, 2011 Author Share Posted June 5, 2011 Les, Thank you for the reply, I do understand what you are saying about getting the head tested again but I am reluctant to spend about £60 for the testing and then having to buy another head anyway. The engineering works charges £60 for testing and £39 for skimming/flatness testing. Is there any other way of doing any basic testing? Mark. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 5, 2011 Share Posted June 5, 2011 In my experience, a cracked 300TDi head doesn't fill any cylinder. Although the crack in theory will leak both ways - compression to cooling system, and (theoretically) - the other way This doesn't usually happen. engine stops, so no suction to pull the water into one or more cylinder. With the head off - lay the edge of a steel ruler across the head diagonally, along the head, and across it (as many angles as you can think of). Shine a light from behind the ruler, so that a gap is more easily seen. If the head is warped, then you should get it crack tested yet again. Ok if you can do the work yourself, as you can do the gasket yourself and see how it goes. Les. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 6, 2011 Author Share Posted June 6, 2011 Hi Les, If you do not think that a cracked head would normally cause water to enter the cylinders, then do you have any idea what would normally cause this? I think I am going to check the head as you mention and then refit it with a new gasket to see what happens. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 6, 2011 Share Posted June 6, 2011 If the cooling system isn't drained prior to undoing the head bolts, then water will enter some or all of the cylinders. In my experience, cracked 300TDi heads don't dump water into a cylinder - the crack is usually unseen, but within one of the valve ports. If it is a crack that has let water into the cylinders, then it would be a huge crack and easily visible. Also - if the head was cracked initially, and it wasn't spotted, then there would be no delay at all in the symptoms of it - replacing the head gasket the first time wouldn't have temporarily cured it) Les. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted June 6, 2011 Share Posted June 6, 2011 Even if it is, you usually get some water in the cylinders. If it's enough to fill the cylinders, it would have hydraulic'ed the engine. I've seen cylinders that look "washed" where there has been some water getting in but not a lot. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 6, 2011 Author Share Posted June 6, 2011 I was told that the car was running until the driver noticed the temp gauge off the scale and then pulled over. I did the quick check with the ruler and noticed that the middle of the head had a slight gap against the ruler, the rest of the head looked ok, it has obviously warped slightly. Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted June 9, 2011 Share Posted June 9, 2011 It sounds as if they didn't torque the head properly. The 300Tdi head is quite a performance to torque, you need a torque wrench, an angle gauge and an IQ greater than a mouse. Also, preferably a manual of some type - even the Haynes will do for the torque settings. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 16, 2011 Author Share Posted June 16, 2011 Hi Jim, I fitted the head myself and yes the bolts were torqued correctly, I first torqued them and then did the two stages using an angle gauge and then a final stage on the largest bolts also using the angle gauge. I used the RAVE manual as a reference. Something else has caused the overheating and not a problem with the head bolts (not sure what as yet), I will investigate that when the car is up and running again. Mark. It sounds as if they didn't torque the head properly. The 300Tdi head is quite a performance to torque, you need a torque wrench, an angle gauge and an IQ greater than a mouse. Also, preferably a manual of some type - even the Haynes will do for the torque settings. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 20, 2011 Author Share Posted June 20, 2011 I decided that I would obtain another cylinder head as I do not trust the one I had so I ordered a second hand head and had it skimmed and tested just got it back so I decided to check the Valve head stand down (as adviced last time). The thicker feeler gauge I can get in all the valves is .6mm some will take slighly thicker but most are just .6 Does anyone know what it should be? Is this something the engineering works should check when they skim the head? Mark. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 20, 2011 Share Posted June 20, 2011 0.05 - 0.06 = 1 notch 0.61 - 0.70 = 2 notch 0.71 - 0.80 = 3 notch 0.81 - 0.90 = 0 notch Les. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 20, 2011 Author Share Posted June 20, 2011 Les, I am not sure what you are referring to, are you talking about the thickness of the head gaskets? I was not aware that the valve stand down was effected by the head gasket? I thought it was the gap between the flat of the head and the top of the valve. Mark. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 20, 2011 Share Posted June 20, 2011 Sorry Mark - the figures I posted are for piston protrusion (which determines which thickness head gasket you should use). Valve stand down should be (and if necessary - adjusted to be within) - Inlet - 0.81 - 1.09mm Exhaust - 0.86 - 1.14mm Les. Quote Link to comment Share on other sites More sharing options...
Mark Adams Posted June 20, 2011 Author Share Posted June 20, 2011 So .60 is not enough then, you say they need adjusting, how can they be adjusted? Thank you Mark. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 20, 2011 Share Posted June 20, 2011 You re-seat the valves with carborundum grinding paste. It generally comes in 2-grades (coarse and fine). The difference between what you have and the minimum isn't that much to be honest, so shouldn't take much work. http://www.halfords....tegoryId_165469 Les Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.