Souster Posted November 27, 2010 Share Posted November 27, 2010 Hello, I think my glow plugs are suspect on my 300tdi 90 120k on her. As it struggles to start in cold weather and takes a long time to fire after a long time cranking. Its a new started motor and battery which isnt related to the poor starting when cold. It doesnt burn any oil, and starts perfectly every time all day once its started and its the same when the weather is warmer, starts absolutly fine. So My question is, how do i go about pulling them out the engine and testing them? ive heard i need to apply 12v to them but at what point do i apply the +ve and -ve? Quote Link to comment Share on other sites More sharing options...
cackshifter Posted November 27, 2010 Share Posted November 27, 2010 You can test them with a multimeter between the terminal at the top and earth, before pulling them out. If you do take them out they can get very hot with 12v on. Disconnect the wires, and IIRC (please corrct someone if not) should each read about 1 ohm. If no multimeter, try disconnecting them and seeing if a (sidelight eg) bulb will light between the feed wire and the terminal at the top. That should at least indicate reasonable continuity. They are unlikely to have all failed, so maybe another possible cause is the oil in the engine is too thick or the battery is getting tired, as 300tdis don't nned much glowplug to start. Nigel Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 27, 2010 Share Posted November 27, 2010 A 300Tdi shouldn't need the glow plugs to start, it should do so happily without quite okay in this country. Have you checked the fuel injector leak-off pipes? Small pipes linking the injectors together and then back to the pump. They can either work loose on the banjo bolts, or the pipes perish, and air gets in and lets the fuel drain back to the tank. This means you have to crank it for a bit to get the fuel into the engine Quote Link to comment Share on other sites More sharing options...
tychoS Posted November 28, 2010 Share Posted November 28, 2010 You can test them with a multimeter between the terminal at the top and earth, before pulling them out. If you do take them out they can get very hot with 12v on. Disconnect the wires, and IIRC (please corrct someone if not) should each read about 1 ohm. If no multimeter, try disconnecting them and seeing if a (sidelight eg) bulb will light between the feed wire and the terminal at the top. That should at least indicate reasonable continuity. They are unlikely to have all failed, so maybe another possible cause is the oil in the engine is too thick or the battery is getting tired, as 300tdis don't nned much glowplug to start. Nigel Do a cackshifter tells you. The indicated resistance should indeed be approx 1 ohm when measured as he describe. My 2,5 TD had trouble starting recently. Turned out 2 of the 4 glowplugs were dead. With new ones fitted it starts perfectly even in tonights freezing weather. The failed glowplugs were only approx. 3 years old, and no they did not come in a blue box. Quote Link to comment Share on other sites More sharing options...
Souster Posted November 28, 2010 Author Share Posted November 28, 2010 Thanks for the reply guys. Did what cackshifter said and the glow plugs were barely showing on my multimeter allthough they were very slightly making the analogue multimeter needle hover, but i believe they should be kicking the needle right over nearest the 1 ohms.. I also tried them connecting directly to my battery, and they didnt even get warm not 1 of the 4. So they are almost deffinately my starting problem in the -10 celcius we had last night. Many thanks Guys, Appreciate it. Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted November 28, 2010 Share Posted November 28, 2010 I have found measuring the resistance in Ohms doesn't mean a thing. Use a battery and jump leads to power the plug - preferably held in a vice. Check that the tip glows red and not half way down the plug - this is why checking the resistance is only half the job - the plug must glow at the tip - that is the bit that is in the cylinder. And the OEM plugs are better than the carp stuff sold by Britpart etc. OK, they cost more but they work better and last longer. And I had a Britpart plug shear in the head so I now have only 3 out of 4 possible plugs to start with. Rather like the TD5 which has only 4 Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted November 28, 2010 Share Posted November 28, 2010 Absolutely agree about measuring resistance not being the best method of diagnosing the Heath of aglow plug. Much better to remove it can check it does indeed glow at the tip. Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted November 28, 2010 Share Posted November 28, 2010 I'll third the fact the multimeter testing means naff all on glow plugs. I tested all four on mine, noted down the readings, then removed them and tested them one by one in a vice with a battery. There was hardly any correlation between the meter readings and the actual test results. Further, Once one had failed the vice/battery test, I decided to replace all four anyway - it's only a matter of time before they're all likely to fail, if one's gone. Quote Link to comment Share on other sites More sharing options...
Yostumpy Posted November 28, 2010 Share Posted November 28, 2010 Holts 'EASY START' yes I know they're supposed to get addicted to it, but with the thick engine oil taking the whack out of the battery in -8 , you only used it when its needed. Quote Link to comment Share on other sites More sharing options...
Challo Posted November 28, 2010 Share Posted November 28, 2010 I too have a 300tdi and its always been fine starting until this last week, when temps have dropped. Cranked but not start this morning. Had to keep turning key til the heater plugs kicked in, switch off, then repeat for 10 mins then finally she started after flattening battery. Bought some more heater plugs today n will fit 'em tomorrow then let you know if this has cured cold starting problem. Hope it'll help. Quote Link to comment Share on other sites More sharing options...
Challo Posted November 29, 2010 Share Posted November 29, 2010 Fitted new heater plugs this morning and she fired up straightaway. That was one of the few jobs that has gone to plan. Only another 1279 jobs left to do... Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted November 29, 2010 Share Posted November 29, 2010 That's good news - hopefully will cure mine of its ills too. My set of NGK's are on route ! Quote Link to comment Share on other sites More sharing options...
Souster Posted November 29, 2010 Author Share Posted November 29, 2010 Just a bit of an update. Fitted four new glow plugs today, and the landy is starting as good as when its warm. Just been out to test her and its 5 below 0 with a cold engine...Its fantastic. Thanks for all your help again folks, really pleased now Quote Link to comment Share on other sites More sharing options...
RaDi90Hybrid Posted November 30, 2010 Share Posted November 30, 2010 As a matter of interest::- Don't know about the Defender but on my 300TDi Disco the glow light goes off after about 6 Seconds although there is still power getting to the plugs for about 12, don't understand the logic of this but I'm sure Landrover had their reason for it! I too have a 300tdi and its always been fine starting until this last week, when temps have dropped. Cranked but not start this morning. Had to keep turning key til the heater plugs kicked in, switch off, then repeat for 10 mins then finally she started after flattening battery. Bought some more heater plugs today n will fit 'em tomorrow then let you know if this has cured cold starting problem. Hope it'll help. Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted November 30, 2010 Share Posted November 30, 2010 As a matter of interest::- Don't know about the Defender but on my 300TDi Disco the glow light goes off after about 6 Seconds although there is still power getting to the plugs for about 12, don't understand the logic of this but I'm sure Landrover had their reason for it! It can be referred to a 'post start heating' by the glow plug manufacturers, or at least those that supply control units. The aim is to assist complete combustion of the fuel while the combustion chamber is still 'cold', and is a significant aid to stopping the puff of exhaust smoke that a lot of older diesels make immediately after starting. 'Everybody' does post start heating nowadays. It's part of diesels becoming acceptable for run of the mill saloon cars, not just 'trucks'. HTH Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 30, 2010 Share Posted November 30, 2010 Oh, so I don't have to hold the glow plugs until I hear the relay click? I thought the relay was faulty or something as my light goes out well before the relay finishes too. I guess the time for the light to go out is Land Rover's determined length of time that is enough to aid starting then? Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted November 30, 2010 Share Posted November 30, 2010 Are you taking the Michael? Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 30, 2010 Share Posted November 30, 2010 No...how do you mean? Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted November 30, 2010 Share Posted November 30, 2010 You have over 2,300 posts, my impression is that many of them display a technical awareness, which not all posters show, even on a forum that is biassed towards technical interests, and you drive a diesel. I'd have expected you to know about post start heating, even if not under that phrase. I'm sure 'glow plugs remain powered after the light has gone out' has been mentioned many times before, and that you would have picked up that knowledge. That's why I asked the question. Oh, re "length of time that is enough to aid starting then?". Post start heating is to aid cold running, not starting. The time duration is probably arbitrary, set by the designers. Cheers. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 30, 2010 Share Posted November 30, 2010 I am flattered that you think my posts show a technical awareness, but I am by no means what I would call experienced in technical matters, I've only been around Land Rovers for two and a bit years! I wasn't aware of post start heating and believed my relay to be faulty or incorrectly installed, however I'm sure if I had looked it up then it would have come up and I would have learned the truth. I was merely asking the question on the end of this thread as I happened to see it mentioned. Thanks for clearing it up though, will probably give me a couple of days over the rest of my (or the car's) life with those extra few seconds each time I start it from cold! Quote Link to comment Share on other sites More sharing options...
Yostumpy Posted November 30, 2010 Share Posted November 30, 2010 I have never heard of ' post start heating' either, but then there IS a lot I 've never heard of. I can see the point tho. and often wondered, but never thought why, the light goes off, then 8 secs later there is a click. Live and learn, I've always waited till the click, by then I suppose its gone cold by then. Quote Link to comment Share on other sites More sharing options...
Yostumpy Posted December 3, 2010 Share Posted December 3, 2010 So, just to check this, I've put new ones in, and thought I'd check the old ones, so out with the jump leads, on to battery, earth lead clamped around the body, whilst I hold the earth clamp, then pos lead clipped on to the end nut, should it glow in this situtation, coz none of them even got warm! or am I doing it wrong!? i mean 4 out of 4 duff! Quote Link to comment Share on other sites More sharing options...
jbs Posted December 3, 2010 Share Posted December 3, 2010 Yes-what you typed is right!-does the engine now start much better than before? Quote Link to comment Share on other sites More sharing options...
Yostumpy Posted December 3, 2010 Share Posted December 3, 2010 wont know till tomorrow, as I had to run around a bit this morning, so the engine was warm (nice) when I did it, I layed the sockets on the rubber sound mat on the engine and they were nice and warm to use in no time. So they were ALL duff then, no wonder it wanted easy start again! Will let you know. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted December 3, 2010 Share Posted December 3, 2010 So the saga of my poor starting 300 tdi continues. Fitted all new Ngk glow plug - they were all duff. Got multimeter out to check they were working result 0 v. Poo!! The dash glow plug light work and there is a relay click. But clearly all is not well. Glow plugs definitely all wired correctly . Is there only the one starter relay far right had relay in cabin disrupt or is there another on thebulkhead?? Quote Link to comment Share on other sites More sharing options...
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