Hercu Posted March 18, 2016 Share Posted March 18, 2016 Hi all Thank you for allowing me on this very informative forum. I know there is a lot of threads on 300 TDi's overheating and a lot of good advice given. But after following all the advice, recoring radiator, replacing water pumps, fan and even fitting another recon head and still blow head gasgets...ouch !!! This is my fourth head gasget in 3 years (2nd this year) (2 notch gasget) and every time skimmed and pressure tested (new head bolts) New expansion tank and hoses. New thermostat working and fitted correctly. I have installed the VTDi turbo and boost up to 1.2 bar, EGT monitor (Madman) never exceeds 720 deg. (With the VTDi turbo can drive 120 km/h in 5th gear normal up and down hill roads.) I do not abuse the truck on off road tracks but use as a holiday and weekend vehicle. Came back from Inhambane Mozambique and blown gasget at Xai-Xai. It has 320 000 km on the clock Things not done on cooling system...Not blocked radiator bypass. Not removed Aircon Radiator in front of radiator.. Any advice will be appreciated...I Love my Disco... Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted March 20, 2016 Share Posted March 20, 2016 what symptoms have you got, have any pictures of the failed head gasket? i take it head dowels are present and block isnt warped? Quote Link to comment Share on other sites More sharing options...
Boydie Posted March 21, 2016 Share Posted March 21, 2016 From my limited experience very few 300Tdi's have pistons that require a 2 hole gasket, the majority require a 3 hole. Have you measured the rise of ALL four pistons to ascertain the required gasket thickness ? This would be your first check, if your pistons are rising over .006 above the block and you have a two hole gasket this would be a prime reason for blown head gaskets, in any case its always wiser to go thicker than thinner to prevent the piston from coming into contact with the head and valves. Secondly there is a "Evolution" head available with larger water journals, I'd go for one of those if you can afford it, especially if your current head is warped. Lastly there are three triangular water jacket ports in the block between 1-2; 2-3 and 3-4. These do nothing as there is no matching port in the head, consequently small air bubbles collect in these dead ends and cause corrosion that weakens the seal between the piston/bore and the seal of the gasket, When I re-built my engine I had them welded up. Lastly NO NOT use a steel multi-plate gasket, these will only seal on a perfectly smooth block and head, the slightest amount of corrosion will cause them to fail. Quote Link to comment Share on other sites More sharing options...
Hercu Posted March 21, 2016 Author Share Posted March 21, 2016 Landy Novice....Thanks for reply I will take some pics today No 1 mistake there is only 1 dowel present but the block isn't warped. Boydie....You have answered a lot of my questions. I understand the 1, 2 and 3 hole better now and agree 100% The three triangular water ports caused serious pitting of the head and definitely 1 of the reasons. The current head is warped and I am considering a new head (If Budget allows) The "evolution" head ? is that the so called 2.8 head ?...I can not find a lot of info on this. (Especially in my 3 world) Thanks for warning against steel/copper gasket I was already quoting one of these. Did you close the ports on the block ?....Interesting....! Is there no channels in the head to open the ports on the head and might get more cooling in the head !!!!! Can the 1.2 bar boost contribute to head gasket failure ???? Once again Thank you for very usable information.... Let us see if I can be 5th time lucky ! Quote Link to comment Share on other sites More sharing options...
Hercu Posted March 21, 2016 Author Share Posted March 21, 2016 OK...armed with my pics and will try to upload.. I have found the head to be seriously warped seriously taking the gap on the straight edge steel ruler. The pitting from the unused water ports is serious and do not know if there is anything else that can be done except stitching... Quote Link to comment Share on other sites More sharing options...
Disco RonL Posted March 21, 2016 Share Posted March 21, 2016 you will need the 3hole gasket for sure. also 2 dowels I assume you follow up the sequence for mounting the head bold precisely? be sure the small water hose that runs from thermostat housing to the 3 way plastic thingy and from that to the expansion tank is not blocked, if so, the air can't escape from thermostat housing and thermostat will get stuck resulting in overheating. been there done that. and 1.2 turbo pressure is a bid on the limit, would do 1.1. Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted March 21, 2016 Share Posted March 21, 2016 admittedly mines a 200 and run 1.2/1.3bar real boost for 6+mnths and fine so far. i would probably put money on it that the missing dowel would be the cause of the head gasket failures as with out them head will 'float' about. i would use a composite gasket rather than mls and deffo 3 hole use. personally i would worry about the warped head, its very minor. ive used sealant on headgassket on a very warped block (4d56) with composite HG with success. Quote Link to comment Share on other sites More sharing options...
Hercu Posted March 22, 2016 Author Share Posted March 22, 2016 you will need the 3hole gasket for sure. also 2 dowels I assume you follow up the sequence for mounting the head bold precisely? be sure the small water hose that runs from thermostat housing to the 3 way plastic thingy and from that to the expansion tank is not blocked, if so, the air can't escape from thermostat housing and thermostat will get stuck resulting in overheating. been there done that. and 1.2 turbo pressure is a bid on the limit, would do 1.1. Disco....Thank you....Yes.. definitely needs the dowels... Yes the torque sequence was strictly followed .. although I did not do a re-Torque on 2000 km ??? Bought new expansion tank and installed copper three way splitter because the plastic one broke on me the first time the gasket blown...New cooling system pipes installed January I also thought to bring it down to 1.0 or max 1.1. Quote Link to comment Share on other sites More sharing options...
Hercu Posted March 22, 2016 Author Share Posted March 22, 2016 admittedly mines a 200 and run 1.2/1.3bar real boost for 6+mnths and fine so far. i would probably put money on it that the missing dowel would be the cause of the head gasket failures as with out them head will 'float' about. i would use a composite gasket rather than mls and deffo 3 hole use. personally i would worry about the warped head, its very minor. ive used sealant on headgassket on a very warped block (4d56) with composite HG with success. Landy-N....Thank you for advice..I believe the missing dowel played a huge part in my misery... I want to believe the boost is not the cause although lots of friends (Maybe bit jealous) states that a 300 TDi can do max 0.8 boost without damaging something... It ran for over a year and 48 000 km on 1.2 boost and then I had a radiator hose rubbed threw by the alternator pulley and my problems started.... Thinking of it...that is the first time and I needed to change the head because the injector was seized and could not be removed...That is were my Dowels has gone..!!!! Quote Link to comment Share on other sites More sharing options...
honitonhobbit Posted March 22, 2016 Share Posted March 22, 2016 Can you get the head skimmed true? If not use the old method of a sheet of glass and grinding paste Quote Link to comment Share on other sites More sharing options...
Disco RonL Posted March 25, 2016 Share Posted March 25, 2016 Yes the torque sequence was strictly followed .. although I did not do a re-Torque on 2000 km ??? I have never read anything about re-Torque the head bolds, If that's needed I will have to do that also shortly, but I can't inmaging that that is needed. Can Anyone confirm on this??? Quote Link to comment Share on other sites More sharing options...
BogMonster Posted March 26, 2016 Share Posted March 26, 2016 Don't think so. I seem to recall that the final torque on a Tdi head is angle tightening anyway, so how do you re-torque an angle tightened bolt? Quote Link to comment Share on other sites More sharing options...
Boydie Posted March 27, 2016 Share Posted March 27, 2016 Okay, Newbie, read the thread on this site I wrote regarding cylinder head gaskets. There are 4 available, they are as follows:- 1 hole. ERR5261; 1.3mm thick. This gasket is for piston protrusion 0.50 mm - 0.60 mm 2 hole. ERR5262; 1.4mm thick. :: :: :: :: 0.61 mm - 0.70 mm 3 hole. ERR5263; 1.5mm thick. :: :: :: :: 0.71 mm - 0.80 mm (this is the most common 300Tdi cylinder head gasket) 0 hole. ERR7154; 1.6mm thick. :: :: :: :: if over 0.81 mm Okay, if your cylinder head has been skimmed in excess of 0.50 mm toss it away, the valves can strike the pistons with cataclysmic results. To measure the piston rise, the best way is with a dial gauge and magnetic base. Set the base midway between two piston, zero it on the block face and then turning the engine over slowly measure the piston rise above the block, Do this for all four pistons, they can vary. If you dont have a dial gauge, clean the crowns of the pistons, turn the engine over and with a 150 mm steel rule held flat on each piston using feeler gauges measure the rise ( the distance from the underside of the ruler to the block face) The pitting on you block needs to be rectified. clean out the pitting with neutralized acid - obtain a small bottle, about 250 ml and use a small nylon brush to apply it to the pitted surface, (natural hair will disintegrate very quickly). Wash the acid away after the pitting is clean with clean water and dry thoroughly - make sure that NO acid/water gets into any of the the bores "plug" them up tightly with oily rags. Next, once all the pitting has been cleaned using normal ladies nail varnish fill in the pitting, this will take several coats, allow each to dry before applying the next coat. With a NEW FLAT wet stone, lap the varnish flat, you can use the course side first and then finish with the fine, again ensure that no grit gets into the bores. It you existing head can be machined then do so and carry out this same procedure to fill in any pitting, DO NOT use acid, just a stainless steel wire brush and fill in the pitting prior to having the head machined. If you ever have reason to have the engine block out of the car have a good TIG welder fill in the three triangular water holes in the block and than have it skimmed by say 0.001 mm to give you a flat surface (I did this on my block). Just why LR left these open is beyond my understanding ! Your boost pressure is way too high, drop it down and fit the second dowel pin to prevent the gasket from floating. Use a composite gasket, I can all but guarantee yours will be a three hole and use NEW head bolts, you WILL need a good torque wrench and well as a dial torque gauge as the final torque is by angles to stretch the head bolts. Quote Link to comment Share on other sites More sharing options...
Hercu Posted March 28, 2016 Author Share Posted March 28, 2016 Boydie...Thank you once again for excellent Information and usable tips...! I have brushed the pitting well and got the tip from a very good old timer to use women's nail polish and filled...Came out very nice... Got the second dowel and a no hole gasket...Pistons protruding 0.80 and 1 (No 3 at 0.83) Old timer recommended no hole gasket ... Got new bolts and had engineering remove 2 mm ....(prevent from bottoming) Got tip to put high heat silicone in triangles which I did ???? (Grasping straw) Torque 40 Nm and then 60 + 60 and 12 X 140 bolts another 20 deg. And yes...You cant re-torque on degrees...Once torqued it is done !! Reset valves on the rule of 9 and started yesterday, very smooth run... Bleeded the water and made sure there is no air pockets... Today will take it on a few up and down hills ....... The story I have heard is that the block is suitable for petrol with just another head where this ports is open in the head ????? Yes... The boost is not good for this engine and I will bring it down to Max 0.9. Would rather move the android diaframe slightly...? Boydie...Yes I have decided to save up a little bit more and get myself a new sub and head and then close those three holes.... I might be able to Import @ US 1800...! Quote Link to comment Share on other sites More sharing options...
Boydie Posted March 29, 2016 Share Posted March 29, 2016 I would have preferred that you used 18 off 1.5 mm stainless steel 314 grade flat washers on the head bolts rather than reducing the length of thread, other than that you seem to have done everything right. Good traveling :-) Quote Link to comment Share on other sites More sharing options...
Hercu Posted March 29, 2016 Author Share Posted March 29, 2016 Report....Boydie...Never thought to use washers and would surely have been a better solution ! The Disco did well and temp stayed constant with the heat gauge on quarter and EGT never rising above 700 on normal slight up and down hill drive. Have a 2.7 km uphill done on 120 km in 5th gear and about 500 m from top got EGT alarm on 720 Bit sluggish on the pull away because I have redused the Diesel a quarter of a turn and redused the boost to 0.9 Bar There is no Black smoke and might lower the star screw in the android 2 to 4 turns. Let us hope for the best and again thank you for your valuable Input. Quote Link to comment Share on other sites More sharing options...
Hercu Posted April 13, 2016 Author Share Posted April 13, 2016 OK....The disco has done 1000 km after head gasket replacement but not without some incidents..... After the initial 50 km test drive up and down hill I was very pleased and decided to go on a weekend trip 2 weeks ago: Within the first 30 km the heat gauge rises into the red and I was loosing coolant through the expansion tank's cap.... Phoned and got towed back home and decided it is time for a new engine in this Disco... But first I will drive this one till a connecting rod or something jumps through the bonnet !!!!!!! . Was not happy with the viscous fan and drilled it solid.....Put the garden hose into the expansion tank, opened the water and started the disco... removed the return hose at the housing and let it run on 1000 RPM for 2 hours whilst enjoying some cold drinks and watching the Rugby game... Closed every thing up and leveled the coolant and took the Disco for the drive of it's life 1st gear 4500 RPM 2nd 4000 3rd 4000 4th 4000 5th 3700 @ 160 km/h Geared back from 5th to third...Burned it on EGT 800 deg on a uphill for 50 seconds... Boost 1.2 I was really trying to burn this engine...and ???? the heat gauge rises to normal and there it sits Last weekend tried again and had a cool run on a round trip of 800 Km.. The engine ran cool and I could even feel inside the cabin there is no excessive heat... So not yet time for a new engine ....? Quote Link to comment Share on other sites More sharing options...
hangover Posted May 1, 2016 Share Posted May 1, 2016 So a dead viscous unit and possibly a bad air lock as well . Quote Link to comment Share on other sites More sharing options...
JB750 Posted May 3, 2016 Share Posted May 3, 2016 I spent many a long day/night trying to get to the bottom of my Disco 1 overheating issue, and after various components, head skims, gaskets etc. I found a pinhole in the core plug at the back of the block (the one buried by the bulkhead! > ) I whipped the engine out - over a whole day! - and replaced all the core plugs for the hell of it, I figured if one was going then the rest would probably be not far behind. That was around 1600 miles ago, and 'touch wood' she's been solid as a rock temperature-wise since. Hope that is of some help Quote Link to comment Share on other sites More sharing options...
cackshifter Posted May 4, 2016 Share Posted May 4, 2016 Thanks for posting how it turned out. That has to be a priority to check with overheating. How did you spot it, was the a stain? Quote Link to comment Share on other sites More sharing options...
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