big loss in power engine heaps louder d4oauto

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rondoppla

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hey guys,

08 thai diesel d40 auto - 108000 ks. ive only owned it for 4000 of those k's.

A few weeks back i started noticing the engine becoming louder and a lack of power through to rear wheels. like, the revs behave as normal but engine/drive line seems strained or not engaged properly.

so i did this service. engine oil, oil filter, fuel filter, air filter, trans oil and trans filter.

all individually and over the course of a week. now as soon as i changed the air filter, the car behaved like brand new one. loud noise went away, more power (it seemed) than ever and i thought prob solved. that lasted about 20 k/s.

the exact same thing happened with the auto service. behaved perfectly for a day and the next morning - shit house again.

ive scince taken it to 2 mechanics. the auto specialist drove it with me next to him and told me its operating great and whats wrong with me?!

the next mechanic plugged it into a fault reader. no faults came up he said.
he found the air sensor to be filthy with oil from turbo, - cleaned it up, took it for a spin and told me he had fixed it $120 later. when i picked it up and drove it home there was no improvment. im assuming these blokes just dont have a decent comparison of how one should run.

please help. im lost and am trying to avoid the dealer if possible for fear of them telling me nothing is wrong and costing me $180 for a diagnosis.
 

big zetor

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Your dealer could give you hint's as to what the problem is, 180 bucks could be a lot less than what the other dohpy c#nt's charge in the long run. see what they can find eg if they say it's a fuel rail or pump then it could possibly be a fuel rail pressure sensor which can be bought seperate or maybe it has an aftermarket fuel filter wich dont seal properly, anything like that i guess.
 

Old.Tony

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I'd be wary of taking it to the dealer just yet. They follow a recipe, which often works, but sometimes costs more than it should because they have to follow the steps in their diagnosis - and they generally won't stray, more often than not because the person doing the diagnosis is relying on the procedures to tell them what to do - without them they're lost!

So back to your problem - I'm wondering if there's an exhaust issue. The EGR tube has cracked for a few people, and worse for them it cracked near the exhaust manifold (behind the alternator on the left hand side of the engine). Check the pipe and make sure you can't see any black powdery emission from anywhere around it. If you do, just block the bugger off on BOTH ENDS. Watch the EGR cooler at the front - just join the two ends together.

You may also have deteriorating vacuum hoses, which connect from a vacuum pump on the right hand side of the motor across to the turbocharger on the left hand side. This small hose connects to the actuator on the top, and if there's a leak, the actuator won't be moved exactly as commanded, your turbo won't provide boost as intended and performance will dramatically suffer. Check them: if any feel loose, the inner part of the hose has hardened and will allow the vacuum to be lost. Just replace the whole lot.
 

rondoppla

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cheers for replies,

i replaced fuel filter with an aftermarket one but i fail to see any difference what so ever between new and old. diaphram pump on top is solid after 2 pumps, so i think there is no air leak issue. i have blanked off EGR on inlet manifold side, no indication of leak or crack near exhaust. vacuum hoses seem fine. i mean the thing is in top nick. the old bloke i bought it off near shed a tear.

old tony, i read a thread relating to suction control valve and you had recommended unscrewing the cap and the guy had sort of simmilar symptoms. thought id try loosening the fuel cap right off, and i think its done the trick! is there any kind of valve or breather in the cap ( which might be damaged as i had to pry it off while locked once (didnt have the key) is it possible its the cap? or does the release of pressure only indicate the SCV?
 

shaunus88

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The fuel cap fix is only temporary mate. Go take the Nav to a place that really knows Diesel motors and they can either A) Service the SCV for you (just over $200 and an hour or so of time) or B) Replace it. It really is a small fix.

My Nav ran louder, slower and hesitated on take off and through gear changes (auto). Got it fixed and instantly it felt like a new car again! Don't hold off a month like I did.
 

Old.Tony

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The SCV is not a difficult thing to manage. Unplug it, clean it, plug it back in - it should be good to go.

The fuel cap is just treating part of the symptoms and wasn't a cure, in fact for Mark the problem came back at a later stage.
 

rondoppla

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so ive pulled it out. when you say clean it up do you just mean the contact tabs? im not seeing anything else to clean up.
 

maria

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That is what was happening to my Nissan d40 we took it to the dealer and they said nothing wrong with it Now it has snapped the timing chain and we r up for big bucks to change the motor my suggestion is go to the dealer ASAP I wouldn't want what happen to us to happen to you as well
 

rondoppla

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thanks mate, the engine is now running quieter and smoother. would you recommend putting the ecu into learning mode after something like this?
 

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