300tdi doughy when cold

Some people actually think that idling a diesel is better than stopping them and starting them again, particularly guys on big work sites who don't give a damn about their cars or the environment! Is there any substance to this or are they just destroying their engines?

There is one guy on one of my work sites who will leave his Hilux on all damn day, might only turn it off when he has lunch, and the thing barely gets out of second gear and is just sitting idling most of the time. I often get it and turn it off while he's off somewhere else. Jerk!

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Originally Posted by Tank

Good way to stuff your motor, letting it idle for so long will glaze the bores and contaminate the oil, get in it start it, all the dash lights out, drive off, Regards Frank.

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X2
John

ditto to frank and john.
Start it and drive it.
But, I had some probs about 18 months ago with mine, sluggish, sounded like it was running on 3 cylinders lumpy maybe even doughy, no power etc etc, coming back from brisbane one day, top speed all the way was 80kmph foot to the floor, does that class as doughy??
took it to the landy experts, Ricks at Nerang, they reckoned it could be the injectors,judging by the sound, (but couldn;t look at it as they were too busy) had to fill up before i got home, so put in some BP deisel at Chinderah , 10km down the road the bloody thing took off like a scalded cat, the rear end seemed to dig in and off it went got up to very fast before i realised it. I had been filling up at ye olde Caltex/Woolies in Lismore, So i changed all the filters, cleaned the water trap, Got another load of that fuel a few weeks later and yo wouldn;t read about it, it started doing the same again. Got fuel from another servo and its back to normal going really well( except for the water pump the other day) Have not been back there, No 1 son used to get fuel for his car at woolies, it woud run like a hairy goat, he now goes elsewhere and the car is going really well.
The moral of my short/long story is, don;t write off any engine probs until you have checked the quality of the fuel your using.


john

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Originally Posted by Young Angus

Some people actually think that idling a diesel is better than stopping them and starting them again, particularly guys on big work sites who don't give a damn about their cars or the environment! Is there any substance to this or are they just destroying their engines?

There is one guy on one of my work sites who will leave his Hilux on all damn day, might only turn it off when he has lunch, and the thing barely gets out of second gear and is just sitting idling most of the time. I often get it and turn it off while he's off somewhere else. Jerk!

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I am surprised his bores aren't glazed.

All engine manufacturers I am aware of recommend driving off slowly as soon as full oil pressure is reached, but driving gently until operating temp is reached.

Hot idling isn't as bad as cold idling for an engine, but it is still better to turn it off if you will be idling longer than about 30 seconds.

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Originally Posted by johncat07

most diesels if not all are doughy when cold. The 300 tdi is "doughier" than most for longer. I have noticed with my previous work truck nissan 4.2 and current model ford ranger are in operation temp zone quicker than my 300 tdi defender. One problem on mine i noticed is the clutch fan is always engaged. I could sit in the drive from 10mins and the temp needle only just moves. The 300 in my truck has only done 61k from new, the timing belt's never been done. The 4.2 patrol was real sluggish when cold, on colder than usual mornings i would give 3 or 4 shots on the plugs and start it... then go have breakfast. By the time i go to work she's warm and the heater has warmed the cab nicely.

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Originally Posted by Tank

Good way to stuff your motor, letting it idle for so long will glaze the bores and contaminate the oil, get in it start it, all the dash lights out, drive off, Regards Frank.

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LOL!

where in my post did i say i idle the engine? The patrol has a hand throttle which i set. the defender i warm up by moving up the revs on say 900 then 1100, 1200 and so on. incrementing as the engine will allow. and thats on only if we get a cold snap. Maybe i should of wrote a novel and not a paragraph. There's more fiction than fact on this thread. Glazing of bores happens when the engine is run for prolonged periods under no load, though it's more likely during the run in period or when the engine's cold. Automotive engine are less likely to get glazed bore because of variable rpms, more likely in the main marine engines charging batterys, because their cold from the start and water to water cooled so there colder for longer. If you use a large tractor for light work it will soon start blowing blue smoke/oil past the rings. the remedy is hook up a big plough and go at it for a good few hours. Large diesels of tractors and bulldozers or large site machinery require starting and running until all cylinders are firing right, then oil pressure observed and running the throttle up to 1/3 to 1/2 governed speed for a period of 5 mins before commencing work. Oil pressure is higher when oil is cold,the viscosity is greater. relying on a oil light is just bogus it's just a pressure switch that can be inaccurate. oil pressure gauge or nothing. and even they can give bad readings if old. many a engine has smashed it's self to bits because of the " i had oil pressure before is stated work, but cluck cluck an the rod went thru the side of the block". lights on drive off. LOL. I guess the manufacturers just wants you to wear your engine out quicker. Just a quick side story stihl recommends running 50:1 ratio in the 2 stroke gear. ( a chainsaw in this instance) A logger who runs all the chainsaw courses for councils says run 25:1. Why? because running 50:1 the motor wears out quicker so you buy a new saw. I don't know how many people put the saw in the shed and pull it out 6-12 months down the track and it's locked up. To repair the saw cost more than buying a new one.

Hi All

My 300 TDi goes better when it warms up!! :D:D, If I suspect the thermostat is crook, I simply replace it instead of guessing.

It never ceases to amaze me to find the thermostat missing in a worn motor, to throw the thermostat is the result of a perpetual misguided myth by morons.

Cheers Arthur

So literally it is a good idea when starting a cold 300Tdi to just start it, wait for the lights to go out (no time at all) and just drive off slowly and gently until you reach full operating temp? I usually let it warm up maybe for 30 seconds to a minute if I'm sitting in the driveway and until now I thought I was doing a good thing...am I wrong?

Also when you say "drive gently" until operating temp is reached I live close to a freeway so I'm on the freeway doing 100km/h while the operating temp of the engine is probably still quite cold. Granted it doesn't stay cold for long but is this generally okay so long as I don't floor it hard to get up to 100km/h?

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Originally Posted by Young Angus

So literally it is a good idea when starting a cold 300Tdi to just start it, wait for the lights to go out (no time at all) and just drive off slowly and gently until you reach full operating temp? I usually let it warm up maybe for 30 seconds to a minute if I'm sitting in the driveway and until now I thought I was doing a good thing...am I wrong?

Also when you say "drive gently" until operating temp is reached I live close to a freeway so I'm on the freeway doing 100km/h while the operating temp of the engine is probably still quite cold. Granted it doesn't stay cold for long but is this generally okay so long as I don't floor it hard to get up to 100km/h?

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It reportedly does take 30-60s for full oil pressure/flow in the upper engine galleries. So waiting 30-60s for warmup is no problem - especially if you will be straight onto the freeway. Drive gently just means dont accelerate hard until up to temp.

Well, I now have a question related to this!

After fitting a new head and new timing gear to my 300Tdi - and correcting the cam timing (which was previously one tooth out). The engine runs MUCH better.

It also starts straight away - whether you glow or not.

HOWEVER!

It blows clouds of white smoke after starting (previously if you glowed 3-4 times before starting it would blow no smoke).

It will not rev properly until you have driven it 100-300m. After that it runs fine and blows no smoke at all.

It is not as bad when the weather is warmer, but the problem is still there.

Possible culprits I can think of are:
Injectors
Glow plugs (unlikely?)
IP
Leaking valve stem seal(s) on the new head? (very unlikely as the smoke seems white...?)

Re-check the timing. I had a defender that was gutless when cold and blew a lot of white smoke, mainly when first started and when engine was coming down from high idle, ie coasting. I did the timing belt and found the engine to be retarded quite a bit. White smoke is unburnt fuel, as long as it's not steam. I have since, whilst tinkering, advanced a 300 tdi too much and found it did the same, went like stink when it was warm but couldn't handle the advance when it was cold. I am not 100% but im pretty sure that these engines have an automatic advance on cold start up. Ie the engine advances itself slightly until warm. If your timing is set up to be advanced, the autoadvance can move it to far forward, making it smoke.
So anyway, that's where i'd start, check the timing.....