dave88sw Posted April 28, 2021 Share Posted April 28, 2021 Hi, I rebuilt the engine in my 110 last year, including a new elring head gasket and bolts. The head was skimmed and pressure tested by a good machine shop. I've done 5000 miles since, running well with good power. It has a boost pin and timing advance spacer fitted but the boost has not been turned up, it's done no towing, never been overheated, never lost a drop of water until last night. I was driving home, all running fine, not even up to temp yet when I noticed plumes of white smoke behind me. I pulled over immediately and it near immediately cut out. Opened the bonnet, it was spewing water out the header tank but it wasnt particularly hot water, thought I'd just see if it would fire up again but it wouldnt turn over. So. I took the glow plugs out, turned the engine, number 3 and 4 full of coolant. I then took the head off, block and head both look ok but I've dropped the head with the engineer again for a check. The gasket had blown between 3 and 4 into the triangular coolant passageway. I am absolutely confident it was fitted properly, I've done more 300 heads than I care to remember but ive never known one go after 5000 miles. Has anyone got any suggestions for things I should check? I really don't want to be doing it again. Thanks Dave Quote Link to comment Share on other sites More sharing options...
cackshifter Posted April 29, 2021 Share Posted April 29, 2021 That is truly annoying. Just wondering if there is a waterpump problem if the water coming out wasn't hot - or maybe a bolt for whatever reason wasn't clamping properly Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted April 29, 2021 Share Posted April 29, 2021 If the head gasket went between 3 and 4 into the coolant passage ways that would explain both your white smoke and water pouring out because not only would it be letting water into the pistons causing the white smoke but pressurising the coolant system causing your spewing of water that wasn't hot. As to why the gasket went in the first place the only reasons I can come up with so far are: Dodgy / damaged gasket Badly installed causing damage or the gasket to fail due to lack of clamping So can't really comment on those options but to me it sounds like your failure was the head gasket first for whatever reason and the other symptoms were caused by it. Unlike mine recently which was overheating but hasn't damaged the head gasket. Quote Link to comment Share on other sites More sharing options...
Tim2809 Posted April 29, 2021 Share Posted April 29, 2021 Was head and block checked for flatness when you changed it last Quote Link to comment Share on other sites More sharing options...
dave88sw Posted April 30, 2021 Author Share Posted April 30, 2021 Thanks for the replies, the water pump was new at the same time as the last head gasket, so it's only 5000 miles old. It's not shown any sign of overheating at all, the needle always sits in the middle, which is what makes the sudden failure of the gasket so surprising. I carefully checked the gasket before fitting and it was torqued down with a snap on digital torque wrench. The torque wrench also does the angle settings but i put a spot of paint on one of the points of the hex of the bolt and the head to check the accuracy too (each point on the bolt head should be 60 degrees apart). I checked the block with a straight edge and the head was skimmed prior to fitting so must have been flat. Is it likely to be anything to do with having the boost pin fitted? It's not particularly smokey, small amount of black smoke when accelerating up a hill but that's to be expected. I only fitted it because the car has a 1.2 transfer box and as such is a bit too high geared. I'm now thinking about removing the pin and trying to source a 1.4 transfer box. Thanks Dave Quote Link to comment Share on other sites More sharing options...
elbekko Posted April 30, 2021 Share Posted April 30, 2021 Was your heater working before the head gasket popped? Quote Link to comment Share on other sites More sharing options...
dave88sw Posted April 30, 2021 Author Share Posted April 30, 2021 Heater was working lovely, it was definitely circulating water, I'm confident it wasnt overheating but I do have concerns that perhaps the cylinder temp was too high with the boost pin fitted (I.e. cooling system coping but excess fuel causing high cylinder temp). As an aside, would the timing spacer ring be an issue if it was left in without the boost pin? Most people seem to suggest the 2 go together but i did find a post suggesting small gains with standard fuelling, theoretically lowering egt. Thanks Dave Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted April 30, 2021 Share Posted April 30, 2021 Have you got a picture of the head gasket failure? One of my (been through a couple of crankshafts a few years back) 300Tdis had the fueling wound up a lot and never had any issues with it. Given the coolant wasn't hot I'm struggling to see how the boost pins etc., caused any issues. Did you do the extra 20° required for the 10 main bolts? Having said all that the last four head gaskets I've done were just torqued up and then "judged" based off bolt angle rather than anything more precise and not had an issue with head gaskets. It's not what you wanted to hear but based off the information to hand I think it's probably just bad luck with the gasket, the 300s are pretty resiliant engines unless you've overheated them which it doesn't sound like you've done. Assuming everything is flat like you say then I can't think of another reason. After the crank issues (failed crank pulley) my 300Tdi's run for 2 years with a 1.2 transfer box and wound up fueling with no issues and a fair chunk of that has been towing heavy loads across the country. Quote Link to comment Share on other sites More sharing options...
Snagger Posted April 30, 2021 Share Posted April 30, 2021 I doubt it is anything to do with the pump mods. It’s almost certainly an issue with a bad skim, bad gasket or installation error. Did you use new head bolts? They can be used up to five times, as memory serves. Did you wick out the spilled oil and water from the head bolt holes in the block and tap the threads out? Anything in those holes or threads could cause a bolt to bottom out. Quote Link to comment Share on other sites More sharing options...
Eightpot Posted April 30, 2021 Share Posted April 30, 2021 Yeah all other things being good I'd go with oil or water left in the bottom of a bolt hole - I always go round a couple of times with an airline to blast it all out. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted April 30, 2021 Share Posted April 30, 2021 TBH it might have just been a weak gasket. 300tdi seem to need a periodic gasket change, they don't seem to last indefinitely, so there is probably no margin for anything not being absolutely bob-on. There is no doubt the boost pin would increase cylinder pressures (otherwise what is its point), but plenty of folk seem to run them without issue. I'd just check the flatness again and if Ok stick a new gasket in. Quote Link to comment Share on other sites More sharing options...
nickwilliams Posted May 1, 2021 Share Posted May 1, 2021 Watching this with interest since I have almost exactly the same issue, albeit that the leak in mine is pressurising the coolant system and the engine still runs fine. What did you do about checking and selecting the right thickness gasket after you had the head skimmed? Quote Link to comment Share on other sites More sharing options...
nickwilliams Posted May 1, 2021 Share Posted May 1, 2021 And after a few hours work today, I think we have found the culprit, between No. 4 cylinder and the water gallery between pots 3 & 4: Quote Link to comment Share on other sites More sharing options...
simonpelly Posted May 1, 2021 Share Posted May 1, 2021 9 hours ago, nickwilliams said: Watching this with interest since I have almost exactly the same issue, albeit that the leak in mine is pressurising the coolant system and the engine still runs fine. What did you do about checking and selecting the right thickness gasket after you had the head skimmed? My understanding is that the gasket thickness does not need to be changed if only the head is skimmed - only needs to be changed if the block is skimmed. Quote Link to comment Share on other sites More sharing options...
simonpelly Posted May 1, 2021 Share Posted May 1, 2021 44 minutes ago, nickwilliams said: And after a few hours work today, I think we have found the culprit, between No. 4 cylinder and the water gallery between pots 3 & 4: Worth taking the effort to find out. Watching this thread with interest as about to fit a new gasket. Simon... Quote Link to comment Share on other sites More sharing options...
Ed Poore Posted May 1, 2021 Share Posted May 1, 2021 Just now, simonpelly said: Watching this thread with interest as about to fit a new gasket. What for a how to - just done one last night... Quote Link to comment Share on other sites More sharing options...
western Posted May 1, 2021 Share Posted May 1, 2021 20 minutes ago, simonpelly said: My understanding is that the gasket thickness does not need to be changed if only the head is skimmed - only needs to be changed if the block is skimmed. Correct head gasket thickness is relevant to the highest piston protrusion. Tdi head gasket sizes. Quote Link to comment Share on other sites More sharing options...
Eightpot Posted May 1, 2021 Share Posted May 1, 2021 3 hours ago, nickwilliams said: And after a few hours work today, I think we have found the culprit, between No. 4 cylinder and the water gallery between pots 3 & 4: Looks like the gasket was clamped down ok, might just be an errant bit of carbon or crud dropped when fitting the head, or a bad gasket? Quote Link to comment Share on other sites More sharing options...
Tim2809 Posted May 1, 2021 Share Posted May 1, 2021 I would be checking the block is flat in that area. Quote Link to comment Share on other sites More sharing options...
nickwilliams Posted May 2, 2021 Share Posted May 2, 2021 12 hours ago, western said: Correct head gasket thickness is relevant to the highest piston protrusion. Tdi head gasket sizes. The 300TDi overhaul manual actually says "If, however, cylinder head, pistons or crankshaft have been replaced, it will be necessary to check piston stand proud in order to determine the correct thickness of gasket." but thinking about it, there is no reason why the stand proud figures would change if only the head is replaced. The book also says that heads should not be skimmed so I guess it's a case of 'guidance for the wise, obedience of fools'. Quote Link to comment Share on other sites More sharing options...
nickwilliams Posted May 2, 2021 Share Posted May 2, 2021 9 hours ago, Tim2809 said: I would be checking the block is flat in that area. Indeed. That will be this afternoon's project. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 2, 2021 Share Posted May 2, 2021 52 minutes ago, nickwilliams said: there is no reason why the stand proud figures would change if only the head is replaced. Correct, however unless you have full knowledge of the engine, and that it hasn't had the bottom end rebuilt, it is possible that the piston height has changed from factory. Quote Link to comment Share on other sites More sharing options...
Popular Post dave88sw Posted May 2, 2021 Author Popular Post Share Posted May 2, 2021 Well, i got my head back from the engineers, they gave it a very light skim apparently. Checked the block, absolutely nothing wrong there and all the bolt holes were clean. Nevertheless, i thoroughly flushed out the holes, wound an old bolt in to each one in turn to measure the depth and all are the same, no tight spots on the threads etc. I'll try and add some pics of the gasket soon, but not only had it burnt through from no 3 and 4 into the triangular coolant passage, no 1 had also burned through the fire ring but hadnt yet burned through to coolant/oil passageways. So, the original gasket (that only lasted 5000 miles) was ordered online, it came in an elring branded package and i had no reason to think there was anything wrong with it. However, the new one came from a local spares place that i absolutely trust, it too was in an elring branded package but there are a number of differences between the 2. Mostly in the markings on the gasket, there is a small impression of the elring logo on both, but on the new gasket, the logo is bigger, also, the "top" marking is much bigger on the new gasket. It's difficult to say because its been almost a year since i fitted the last one but i think the coating on the new gasket is "stickier" too. Anyway, it's now back together again and running well, i borrowed a snap on digital torque wrench (that also does angles) to put the head on. It's nice to use because it beeps when you reach the required angle but also tells you what torque was required to achieve that angle, which is nice because it gives you a good idea if any of them have bottomed out or are tight in the threads. I'm happy to say, they were all very similar. Time will tell if it lasts this time. Thanks Dave 6 Quote Link to comment Share on other sites More sharing options...
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