Turbocharger Posted March 1, 2009 Share Posted March 1, 2009 Well, I've put around 100k miles on my 300Tdi over the last eight years or so and then strapped a VGT to it and found up to 2 bar boost at times. Not surprisingly, months later I found it was leaving a cloud of white/grey smoke if it was allowed to idle and then revved - such as at junctions. It's also been giving gradually worse mpg over the years. Big tyres + autobox + VGT + lead foot seems to give 18-20mpg around town which is expensive. I took the head off this evening and found the following. The block didn't drain fully so some water got into the bores, particularly #3 and #4. I soaked this up, turned the engine over a few times and then aggressively polished the bores with a light oil and a clean cloth - the water was in there for 5 mins or so. I have my own opinions which I'll reserve for now, I'd be interested to see what others think is going on. Sorry for the large photos, I need to show the detail: A number of small deformations on #1 piston crown: and water marks on the bore of #3 cylinder only. Quote Link to comment Share on other sites More sharing options...
ciderman Posted March 1, 2009 Share Posted March 1, 2009 no2 dosnt look too bad John ,You can still see the cross hatchings which is generaly a good sign . Just as well pull the sump off and pull the pistons out for a proper look . Quote Link to comment Share on other sites More sharing options...
Les Henson Posted March 1, 2009 Share Posted March 1, 2009 No1 piston looks ok apart from the pitting at around 2 o-clock. No3 bore is water stain, and the formation of the stain seems to indicate that droplets form while the engine is off, so perhaps reversed pressure as the engine cools down. There seems to be a fair few posts across the various websites about white smoke at idle/pulling away from lights. Have/will you have the head crack tested? Les. Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 1, 2009 Author Share Posted March 1, 2009 Yup, you've mirrored my thoughts. The bores look good, the diamond honing marks are still present even on the thrust side so oil changes at 7k miles have been doing their job. The pitting on the piston is restricted to the fuel spray star area so suggests the injector is hosing in that region - IIRC Tony Cordell melted a piston through the same fault further down the line? The water marks are more troubling to me - the gasket surfaces looked fine and there's nothing immediately visible on the head. I'll get some dye-pen and look for cracks. Does anyone have a Tdi piston loose and can measure the height difference between no 1 (top) and no 2 ring grooves for me please? I'd like to keep the pistons in mine if possible. Quote Link to comment Share on other sites More sharing options...
white90 Posted March 1, 2009 Share Posted March 1, 2009 Exactly what measurement do you want I have a piston as a paper weight Quote Link to comment Share on other sites More sharing options...
white90 Posted March 1, 2009 Share Posted March 1, 2009 here you are Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 2, 2009 Author Share Posted March 2, 2009 Umm - I want exactly the measurement in your second pic - thanks Tony Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 3, 2009 Author Share Posted March 3, 2009 Does anyone know where I can buy dye penetrant for crack-testing? I thought Screwfix would sell a kit but they don't and Google is unhelpful. Quote Link to comment Share on other sites More sharing options...
ciderman Posted March 3, 2009 Share Posted March 3, 2009 I am pretty sure I have seen it on the shelves of GR fastners in Avonmouth , Im in there tomorrow so I will enquire . Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 3, 2009 Author Share Posted March 3, 2009 Cheers Jase - can you give me a shout if they do pls? I'm in WSM tomorrow afternoon so I could dive into "that grotty backwater" on my way back... Quote Link to comment Share on other sites More sharing options...
bm52 Posted March 3, 2009 Share Posted March 3, 2009 google just gave me this....does it help? http://www.lawson-his.co.uk/scripts/produc...etrant%20System Quote Link to comment Share on other sites More sharing options...
steve_d Posted March 3, 2009 Share Posted March 3, 2009 Cromwells http://www.cromwell.co.uk/category_page/1110 Steve Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 3, 2009 Author Share Posted March 3, 2009 That's the badger, only (expensive and) I'd like to be able to go and buy it so I can use it this coming weekend... Quote Link to comment Share on other sites More sharing options...
gazelle Posted March 4, 2009 Share Posted March 4, 2009 You should be able to find dye penetrant kits in any welding consumable shop. Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 4, 2009 Author Share Posted March 4, 2009 Well, I didn't need the dye-pen. The head showed carbon on all the fire rings: and cleaned up well: Number 3 appears 'different' but not steam cleaned like you'd expect with a coolant issue. Anyway, I looked a little closer at #3: Two cracks, one from the heater plug hole and one between the injector hole and the inlet valve. #2 and #4 also show the heater plug crack: It looks like I need a new head, but that's not "economically attractive" at £300 - anyone got any bright ideas? Quote Link to comment Share on other sites More sharing options...
western Posted March 4, 2009 Share Posted March 4, 2009 cracks there are common, provided the water jacket isn't leaking in the cylinders/piston crown combustion chambers, can't see a problem. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted March 4, 2009 Share Posted March 4, 2009 John, Realistically you have three options in order of increasing cost and (probably) decreasing risk: Live with what you have Chance a secondhand head Splurge on a new one but you have probably worked that out already yourself!! Quote Link to comment Share on other sites More sharing options...
white90 Posted March 4, 2009 Share Posted March 4, 2009 few on ebay from brand new to recon to take a chance starting around £100 I'd go for the brand new one at £275 Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted March 4, 2009 Share Posted March 4, 2009 Give it a blast with the mig, get an angle grinder on it to make it flat and splonk it back on. What can possibly go wrong? Quote Link to comment Share on other sites More sharing options...
Mark Posted March 4, 2009 Share Posted March 4, 2009 I would be inclined to have your current one pressure tested to see if the cracks that you have identified make any difference to the operation of the head. I would be more concerned about the carbon trace between no2 and the water way. It looks like the fire ring has not held up but the next seal has not been breeched. Mark Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 4, 2009 Author Share Posted March 4, 2009 Yes, I'd noticed the leaking on #2 as well. Presumably that would be fixed with a new gasket though. My current thoughts are: £100 second-hand head could be worse than the one I've got - why was it taken off and reconned/skimmed/cleaned? They generally claim to be 'pressure tested' but where's the comeback if it turns out to be duff? £275 'new' head on Ebay is £20 less than a head from Turners (and £5 less than a Paddock head), which would come with a guarantee. My head might not be a problem, but I'd have to test it to know The cost of testing would eat into the ££ for a new head, which would probably turn out to be necessary anyway. From the bore marks, water has been getting into #3 from somewhere - if it's not the head then it's via the head gasket, and that looks strong on #3 Using the engine as its own test bench, it looks like there's a crack to the water jacket somewhere in the head thus I probably need a new head I'd rather give my ££ to Turner than Paddock but I don't see that I'd get £20 more value (and I'll be passing Paddock in couple of weeks, so I'd save the postage). Some forumeers have had 'performance' heads before and been underwhelmed so I don't think I'll go that route. Is there anyone I've not considered? Quote Link to comment Share on other sites More sharing options...
MECCANO Posted March 5, 2009 Share Posted March 5, 2009 [*]£100 second-hand head could be worse than the one I've got - why was it taken off and reconned/skimmed/cleaned? They generally claim to be 'pressure tested' but where's the comeback if it turns out to be duff? I made that mistake... Its not until you get it home and attack it with some degreaser you really start to realise you screwed up Anyway heres my 200tdi head with similar cracks. Although it was running fine before i removed the head. Quote Link to comment Share on other sites More sharing options...
honitonhobbit Posted March 5, 2009 Share Posted March 5, 2009 Jon 300tdi head in garage if you want it - yours as and when. Can get it to Brizzel on Sunday if required Quote Link to comment Share on other sites More sharing options...
Gremlin Posted March 5, 2009 Share Posted March 5, 2009 cracks there are common, provided the water jacket isn't leaking in the cylinders/piston crown combustion chambers, can't see a problem. X2 Skim it and pop it back on. G Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 5, 2009 Author Share Posted March 5, 2009 I "borrowed" some dye-pen and found that the cracks I could see with my eyes are still there when tested... The consensus is that I need a new head (... on the engine, that is). I'll pressurise the water jacket to see if there's any bubbles but, to be honest, the water stains in #3 bore are enough to tell me that water's been getting in somewhere. The good news is, piston #1 shows some distress marks where the fuel injector has been hosing, but no cracks so that will run again: Where's best to get a new head from? My options look like being: ACR: £410 + VAT Turner: £295 + VAT (or £410 with valves etc) Foundry 4x4: £276 incl VAT (via Ebay) Craddock: £250 + VAT Paddocks: £245 + VAT A "performance" Turner head at £495+VAT is way out of my league. Any other peddlers of quality merchandise that I've forgotten? Dave - I've PM'd you. Quote Link to comment Share on other sites More sharing options...
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