isbjorn Posted October 20, 2011 Share Posted October 20, 2011 (edited) Hi. A quick question. Ive just installed a renovated head on my td5 due to overheating, and are having troubles with massive diesel exhaust smoke, low power, difficult start and a loud thumbing noise when idling up. We run a diagnostic and got these max values; Cylinder roughness no.1 +25 no.2 +2 no.3 -10 no.4 -15 no.5 -5 I know these are showing how much the ecu need to compensate/tune the injectors to level them. But would these numbers be possible due to a bent con rod, or maybe a crack between the cylinders. The early td5s seams to be prone to cracking. Everything else in the computer seamed quite correct, and the injectors are in the right positions. We have also set the chain timing with the original lr looking pins and everything looks fine, and it rotates fine manually. I forgot to mention one more strange thing, that the air flow reads 0 all the time. Maybe not that important, but any how. Edited October 20, 2011 by isbjorn Quote Link to comment Share on other sites More sharing options...
BogMonster Posted October 22, 2011 Share Posted October 22, 2011 Those figures are pretty high and certainly consistent with an engine that's running like a bag of bolts! If the airflow is zero then the AFM is buggered. However that in itself should not cause rough running. Unplug it and the ECU will use a default value; if that doesn't improve anything then there is another problem (which I think will be the case). Td5s will run quite happily without an AFM just that they run slightly better with it. Were the injector plungers etc up properly when they were refitted? There is a process to do it, and if you didn't have the workshop manual (or prior experience) you will have got it wrong as it is far from obvious. How overheated was it? You may be in for some sad news on the rest of the engine. If you can find a compression tester, do a compression test on cylinders 1-4 and post up the readings. You can't do no. 5 as there is no glow plug in that cylinder but comparing the values for 1-4 will give you a good idea if there is a mechanical/compression issue. There isn't a published value for Td5 compression but it should be 20+ bar per cylinder (usually around 25-30 on a good Td5 engine I think, you get more than the published compression ratio on any engine which I have always assumed due to the compressive heating effect in a diesel). If the compressions are less than 20 bar, or wildly different, then it's probably a scrapyard job. I know a few people who have tried rebuilding cooked Td5s and the majority are never the same again so in that situation I'd cut my losses and find a decent second hand engine. I guess the other possibility is, depending on how hot it got, the injectors might be damaged. Your description of the way it runs sounds a bit like injectors that are spitting great gobs of fuel into the cylinders rather than atomizing properly, which means the nozzles are knackered, which could happen with overheating. So you may just need a new set of injectors but there is no way of testing them without seriously specialist kit. If the compressions are OK I'd try and borrow another set of injectors from somewhere, and you'll need access to a computer to do the injector grades in the ECU. I don't look in the Defender forum a lot so if you need any more info post on here and PM me to let me know something needs a reply Quote Link to comment Share on other sites More sharing options...
chrisbowler Posted October 23, 2011 Share Posted October 23, 2011 Disconnect the injector wiring on injector no 1, blow out with an airline and run engine checking readings. If no 1 continues with high reading, change copper washer on cylinder 1 injector.No 1 is your problem - the others are OK and the -15 is just compensation for the +25 ChrisBowler Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 18, 2011 Author Share Posted November 18, 2011 Ok. Here is a reminder of all that we have done so far. Water temp meter drop to 0 stopped, fixed broken return hose intercoler filled her up with water drove 5 min normal temp, filled upp with more water+glykol drove 10 min to hiway when entering hiway the engine started hammering that follow rev. Not very mutch smoke and the engine/water/oil seamed fine. Called a guy with a trailer and sent it to workshop. removed head. professionally skimmed and renovated head. Skimmed valves and replaced all sealings and so forth. replaced head gasket (3 holes) and dowels. Replaced lower crankshaft bearings. nr 1 was badly worn and not very streight in the edges. The piston and vents looked good, no direct burn, and the cylinder edges was smoth. Looked almost new. The pistons had no free movement/glitch up or down. Just a tad sideways. The rotation of the engine manually is smooth and nice. It does hower build up quite a bit of compression when rotating so it is a bit heavy. remounted everything. set the timming correctly and started the car. Now we have cleaned and replaced the injector loom just in case. The pressure test showed 18kg on cyl 1 and ruffly 30-35 on the other 4. All the injectors are in the right place. Since the head is newly renovated it should not be any leaks upwards, but you never know. My mechanic want to take of the head again and check the piston bolt (gudgeon pin) and the piston rings. Status now: A bit of smoke, not to bad but the way it should look if one of the injectors dont work. A hammering noise that follow ref. So more rev = louder banging. When its at ide you cant here it at all. But speeding up is really painful. The things i think it might be causing noise 1. Worn upper small connect rod bearing 2. The bad compression and failure to ignite causes the hammering. 3. worn gudgeon pin 4. Electrical error with injector nr1, but that should not make the pressure in the cylinder drop. 5. The head gasket is blown again, but we cant find any evidence like air coming out, water going in or anything usual. 6. The mechanic who renovated the top made something wrong when installing the cyl1 vents and the air leaks out that way. What are your guys opinion? IS there any test to be done before removing the head again? many thanks for all help... Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 18, 2011 Author Share Posted November 18, 2011 Here is a pic of the lower connecting rod bearings. They did not sit correctly, they had slided 90 degree so the halves was not on top, but sideways. Don't know if that means anything... Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 18, 2011 Share Posted November 18, 2011 I can't see properly in the picture but they look like they welded to the crankshaft and released again, hence them being rotated. What state was the crankshaft surface? Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 18, 2011 Author Share Posted November 18, 2011 To me it looked quite smooth and nice. But I could only see the lower part. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 18, 2011 Share Posted November 18, 2011 Lower part could describe any part of the surface depending on the position the crankshaft was in...... Anyhow that bearing looks very unhealthy to me and I would have been inclined to check the crankshaft surface carefully or it may happen again quickly. I'm not saying it is the cause of your problems, but it could be the cause of the noise if it has eaten that bearing again...... Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 18, 2011 Author Share Posted November 18, 2011 good point. Still don't explain the loos in pressure. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 18, 2011 Share Posted November 18, 2011 good point. Still don't explain the loos in pressure. If that bearing has been eaten enough to bang then it might also explain the loss of pressure as the 'play' will mean the piston isn't being pushed up so far..... Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 19, 2011 Author Share Posted November 19, 2011 Ah. perfect.. thanks. Then we have to remove the head again.... better to do stuff well form the beginning. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted November 19, 2011 Share Posted November 19, 2011 What they said ^^ That set of bearings is kaput - overheated or oil starvation (or maybe both). As Mr Rabbit said, it looks like it has momentarily welded to the crank. The crank and the inside of the No. 1 conrod is therefore probably not the right size/shape ... low compression would happen for the reasons stated above, ie the piston isn't going up as far as it should, and a heavy metallic knocking is classic big end noise. You may be lucky but I suspect you'll need a new crankshaft at which point if it was mine, on a Td5 that has been overheated I'd consign it to a skip and ordered a replacement engine from a breakers as I've had a bit of experience of spending lots of money on an overheated Td5 and still ending up with a very expensive doorstop.... and then buying another engine anyway. You may be lucky and get it rebuilt but once a Td5 has been too hot it's never right IMHO. You'd need to identify why the new No.1 big end bearing failed again to have any confidence in rebuilding it again and I just wouldn't do it because I've seen it go expensively wrong more than once and wished I had cut my losses at the beginning. Fortunately it wasn't my vehicle or engine it was a company one, but it still hurt Quote Link to comment Share on other sites More sharing options...
RustyNissanPrairie Posted November 19, 2011 Share Posted November 19, 2011 check the piston heights at TDC with the head off using a DTI , i'd be incline to be having a look at the crank bearing surfaces closely again and checking new shells with some plastigauge; http://www.plastigauge.co.uk/ Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 21, 2011 Author Share Posted November 21, 2011 Ok. We have decid to replace it. It seams like it has (as written above) been welded to the crank and its just a bad idea to repair it.. Thanks for all the tips. You have helped me a lot and im looking forward to getting her running again, Nothing is more sad then a LR standing still. Quote Link to comment Share on other sites More sharing options...
Maverik Posted November 21, 2011 Share Posted November 21, 2011 Interesting, I'm just working with a V16 high speed marine diesel and something quite similar happend to it, one set of crank bearings shells rotated and blocked off one of the oil galleries causing oil starvation and the engine to seize up, rather messy, but I've got a hell of an engine to play with now - mind it is sat in a million bits in the workshop. Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 29, 2011 Author Share Posted November 29, 2011 How do I know what td5 engines I can install in my 99 without needing to swap ECU? I have some memory of it changing in 03? Quote Link to comment Share on other sites More sharing options...
isbjorn Posted November 30, 2011 Author Share Posted November 30, 2011 Ok. Did my homework. Ive got a 10p. Can I just plug in a 15p or do I have to fiddle with the ECU to make it work? Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 30, 2011 Share Posted November 30, 2011 Just get the ECU and looms etc. that come with the 15p engine and then problem solved surely? Quote Link to comment Share on other sites More sharing options...
isbjorn Posted January 1, 2012 Author Share Posted January 1, 2012 Ive now got a 10p from a crashed disco (same year) and mounted in the defender with my old ecu. Trouble is cylinder 4-5 refuse to ignite, but the engine rotates fine and starts ok. Is there anything special/strange I should think about considering it being a disco td5? Nothing I should know but don't? Anyhow, so far we tried new injector, new loom but no luck, but the fight continues. Quote Link to comment Share on other sites More sharing options...
landy andy. Posted January 1, 2012 Share Posted January 1, 2012 Are you using injectors that are matched to the ecu? Andy Quote Link to comment Share on other sites More sharing options...
isbjorn Posted January 2, 2012 Author Share Posted January 2, 2012 Should be. I thought the ecu could run all 3 types of injectors, but i guess im wrong. How do you figure out wich types are compatible with the ecu? And 2 injectors are aparantly working... Quote Link to comment Share on other sites More sharing options...
landy andy. Posted January 2, 2012 Share Posted January 2, 2012 I thought that the injectors had to be matched/programmed to the ecu. Andy Quote Link to comment Share on other sites More sharing options...
isbjorn Posted January 3, 2012 Author Share Posted January 3, 2012 They do, otherwise it won't know in which order they are. But the injectors are the same type as my old ones. Quote Link to comment Share on other sites More sharing options...
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