SPendrey Posted January 11, 2016 Share Posted January 11, 2016 Hello, I'm changing the head gasket on my 300Tdi because it is/was blowing out the back of cyl. #4. After cursing a few times trying to undo everything, I found a bunch of hard crusty stuff in the cylinder. Should I just scrape it out and carry on with the H/G replacement? Thanks, Scott Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 11, 2016 Author Share Posted January 11, 2016 Really? 'Carp'? :-( Quote Link to comment Share on other sites More sharing options...
ejparrott Posted January 11, 2016 Share Posted January 11, 2016 That's a big build up, what have you been running it on?! Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 11, 2016 Author Share Posted January 11, 2016 I've had it just over a year, and have always used normal diesel. Perhaps the previous owner used something else? The other cylinders were nice and clean! Quote Link to comment Share on other sites More sharing options...
Les Henson Posted January 11, 2016 Share Posted January 11, 2016 A blowing cylinder will get a build up of carbon as the burn is weak. The orange and black flaky bits are bits of the old gasket. Otherwise it looks like normal gunk and mess to me Les. Quote Link to comment Share on other sites More sharing options...
GW8IZR Posted January 11, 2016 Share Posted January 11, 2016 It looks like most I see as well, when you say 'scrape' remember that means scrape not gouge great lumps out of it ;-) I always end up blowing debris / spilt oil and coolant out of the head bolt threads with an airline as well. Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 11, 2016 Author Share Posted January 11, 2016 It looks like most I see as well, when you say 'scrape' remember that means scrape not gouge great lumps out of it ;-) I always end up blowing debris / spilt oil and coolant out of the head bolt threads with an airline as well. Yep, makes sense. There must be little bits of rubbish that fall in to the bolt holes. Will remember to do that before putting it all back together again. Ta. Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 12, 2016 Share Posted January 12, 2016 The cam followers could do with a flush of clean oil once you finish scraping (carefully) the carbon from around the tops of the bores. You could use decoking fuel additive neat to dissolve the deposits and wipe them clean (let it soak in for a couple of minutes), and I'd recommend doing that on the head and injectors. Quote Link to comment Share on other sites More sharing options...
integerspin Posted January 13, 2016 Share Posted January 13, 2016 Really? 'Carp'? :-( is it common? Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 13, 2016 Author Share Posted January 13, 2016 One more question... been hunting for a definitive answer on which way the sealing washers on the injectors go. Many sources online imply the ridge is upwards (towards the injector), but a few claim downwards. What is the opinion here? A or B?? 1 Quote Link to comment Share on other sites More sharing options...
ejparrott Posted January 13, 2016 Share Posted January 13, 2016 A Quote Link to comment Share on other sites More sharing options...
Boydie Posted January 13, 2016 Share Posted January 13, 2016 If it were my engine, (and I'm totally anally retentive and fastidious) and, if on removing the head I found that two or more of the cylinders were that badly coked I would drop the sump, remove the big ends and push the pistons out and fit new rings and give the bores a very light hone, but thats just me. EJ is right (of course) it's "A" but I don't think it really matters too much so long as they are new gaskets. While the injectors are out get them ultrasonically cleaned. By the way. what caused you to need to replace the head gasket in the first place? Quote Link to comment Share on other sites More sharing options...
reb78 Posted January 13, 2016 Share Posted January 13, 2016 A Not questioning your answer Ed, but whats the reason and why does it matter? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted January 13, 2016 Share Posted January 13, 2016 "I'm changing the head gasket on my 300Tdi because it is/was blowing out the back of cyl. #4" :) Les Quote Link to comment Share on other sites More sharing options...
ejparrott Posted January 13, 2016 Share Posted January 13, 2016 Not questioning your answer Ed, but whats the reason and why does it matter? On A, the raised ridge is formed into a seal against the injector as it's tightened. On B the raised lip gets forced into the hole and distorts, potentially not forming an actual seal Or at least that's what I was taught Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 13, 2016 Author Share Posted January 13, 2016 All back together, and seems to be working, but made some odd sounds at first. However, after a moment of "what the hell is that?" I soon realised it was leaking water from the thermostat main hose onto the aux belt tensioner and making an odd chirp! One issue I have is that I managed to strip the thread out of one of the inlet manifold bolt holes :-( Ordered some 8mm helicoils, tap & drill to fix that, but of course it would have been much easier to do it with the head out! Oh well. Quote Link to comment Share on other sites More sharing options...
Boydie Posted January 14, 2016 Share Posted January 14, 2016 Thanks for that EJ, that makes sense, I was told as per A but never knew why and on some things Land Rover, you don't ask, you just do . 1 Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted January 14, 2016 Share Posted January 14, 2016 I've always done A.. Stops the ridge being driven into the soft aluminium. Quote Link to comment Share on other sites More sharing options...
SPendrey Posted January 19, 2016 Author Share Posted January 19, 2016 Helicoils arrived, will sort that later, although it seems OK with only three bolts on the manifold?! Anyway, I noticed a warning on the box. It says "Always think safety before using this product". When i stripped the thread, I thought "boll*cks!", I'll have to go back and think "safety" now or they might not work. On another note, I think the old radiator had seen better days. I'm sure there are supposed to be fins on those bars? Lucky I'd saved my old one from the broken Disco. Quote Link to comment Share on other sites More sharing options...
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