Thats better.
Many many thanks for your inputs. I'll stick my head under the bonnet and have a look at the suggested areas. It's one thing paying out for an expensive item, it's another to buy the wrong item!!!
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To the person who mentioned flushing oil,STP "engine-clean" works a lot better.
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I guess it's a bit late to add my bit - however: I had exactly these same symptoms on an Audi A4 with a similar TDI engine, and also thought it was the turbo. However the trouble suddenly cleared up and I suspect it was the cat in the exhaust causing a blockage and then probably breaking up. Since the problem hasn't, touch wood, reappeared in about 10 months I have left well alone - though the cat or something else on the exhaust has an annoying rattle and some time, I suppose, I will have to buy some new exhaust bits from German & Swedish...
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I reckon the EGR solenoid valve is sticking open at some point, causing the loss of power.
Seen it before on a SEAT Alhambra TDi
MAF Sensors give plenty of trouble (even on Saabs and Rover 75's!) so a clean may help. Constant motorway driving in spray conditions causes a film to build up on the hot wire of the sensor, giving bum readings.
It could also be a wastgate problem but I wouldn't jump in at the deep end and replace the 'snail' just yet.
It might be best to pay (!!) for a professional diagnosis - it could save you many £££'s
MG-Rover Questions? Click on www.mg-rover.org
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Hi guys, just got back from a week roving around, and towing a caravan! To aid further diagnosis (if you're stiil awake and willing!) I have narrowed the problem down further:
Using fifth gear up hill (towing remember) and running out of puff, change down into fourth i.e. higher revs and under load, the power drops off immediatley. I can restore the power by turning off the ignition and turning back on again. Found that it could be restored by turning off whilst still travelling and thus preserving momentum.
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I had a problem with loss of power on a TD once. The problem turned out to be a dodgy temperature sensor that was stuck on minus 1ºc and as a result there was an excessive supply of fuel to the engine resulting in flooding > loss of power.
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It could well be the good old MAF sensor......
MG-Rover Questions? Click on www.mg-rover.org
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Where/what is the Maf sensor?
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It's the Mass Air Flow sensor, usually situated between the air filter and the turbocharger air inlet. It has a wiring plug going to it.
These MAF's give quite a bit of trouble on both petrol and deisel engines from a variety of manufacturers
They seem to be sensitive from a build up of road dirt (!!) on the film - which can be washed away by pouring boiling water through the sensor and then rinsing with distilled water!
For some very comprehensive info on MAF Sensors (I know it's Toyota based..) try www.autoshop101.com/forms/h34.pdf
MG-Rover Questions? Click on www.mg-rover.org
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Isn't this engine drive by wire?
how about a dodgy throttle potentiometer?
This could give a fault code which resets after the switching off/on reboot.
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Ah ha. I have just spoken to a very nice man from the AA. He said that there is a lot of problems with the throttle switches. Apparently there are two. One allows the exhaust gas to be dumped when throttling back!
Got to be cheaper to change than the turbo!
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In my experience, take any diagnosis by the AA with a pinch of salt - not wanting to put them down - I've had many patrols pull cars into our workshop saying 'Oh it's a dead ECU mate' when in fact it is an ignition amplifier fault.
I'm not aware of throttle 'switches' on the Sharan, the same EMS is used on my A4 TDi and that just has a large throttle potentiometer (made by Mr Bosch) connected to the throttle pedal.
Any dealer should be able to interrogate the EDC system and see what is/is not happening and provide an accurate diagnosis.
I know we could with the MG-Rover/Bosch diagnostic tool we have :)
"One allows the exhaust gas to be dumped when throttling back!"
That statement rings true of my EGR valve theory, earlier!
MG-Rover Questions? Click on www.mg-rover.org
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Thanks Dr Dave. I'm reading the MAF download now.
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Any further ahead Graham?
MG-Rover Questions? Click on www.mg-rover.org
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I have an interest in this disscussion because my 95 Golf td turbo stopped working after the car stood idle for about 4 weeks but also just after an oil change, maybe both coincidence I dont know. The car still runs reasonably well but does not accelerate as well as it should. The turbo should come in at about 2200 rpm (who can tell me what makes that happen) and I recon you can hear it whin but there is no increase in power. From your discussion I wonder if its the waste gate stuck open. Does the turbo only start to spin as the engine speed builds up, hence the exhaust pressure increases.
Any comments would be appreciated,
cheers,
Ian.
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Sorry not to have replied earlier with the next thrilling episode but....
The local Skoda dealer claims to have an Octavia with a similar problem. They were going to replace a widget and see if it was cured. But the Octavia has never been back for the replacement. Since then "my" car was changed and now I use my wife's Sharan for regular long distance trips to work. The upshot of this is that the problem has dissapeared. It no longer gets lots of short around town trips, just 2hr plus motorway stuff. I wonder if there was something "clogged" and the Italian tune up has done it a lot of good. This last weekend we towed a caravan to the Lake District and back with no problems at all. In fact as far as I'm concerned it seems to be a perfect tow car.
Thanks for all your interest in the past.
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I had a similar problem with a TD of a differnet make. It always ran fine on a motorway but around town or on slower A and B roads, the revs and power would build up very slowly.
Basically there was a sensor reading that the outside temperature was always at -1ºc and as a result too much diesel was being supplied to the engine. Therefore when engine was not being revved very highly their was a much higher chance of being flooded. This might explain why your Italian tune-up cleared the problem but then it wouldn't cure it.
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air mass meter very common problem on vw/audi sdi and tdi engines
have seen loads replaced. but check the plastic dumpvalve for the turbo fitted in the intake trunking as these used to foul up and basically stop the engine making any boost.
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The turbo spins up as there is sufficient pressure from the exhaust to drive it.
If you can hear it spin, could be wastegate, more likely to be a lose hose, or leaking intercooler (if it has one). Check all of the air hoses, and you may find it's leaking somewhere.
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I have an Escort TD whose turbo would whistle away quite happily after 2.2k revs but without the expected increase in power. With the use of this site I eventually tracked it down to what Ford part suplliers call "Turbo boost pipe". This goes from the fuel pump to the turbo unit (near air intake bit). This pipe is metal for the majority of its journey but there are two 90 degree bends in its route which are achieved with rubber pipes. (WHICH TO ME SEEMS DESIGNED SPECIFICALLY TO FAIL!!!) So carefull inspection with a torch showed up a crack right on the bend. Another tell tail sign is an oilly spray on the radiator/fan that seems to come from the pipe. To confirm this I wrapped the pipe up tightly with insulation tape and tried it out. BAMM! The car went like a rocket (well for a deisel and i had been putting up with this problem for 8 months). This only lasted a couple of days before it started unraveling. So I would advise to look for every pipe leaving the fuel pump and follow it as far as you can looking carefully for cracks.
P.S. the pipe costs £6 from ford part suppliers but you have to purchase the whole pipe kit not just the rubber parts that go. And to get on your nerves even more this rubber pipe is different diamiters at each end, one is spring clipped the other is crimped just to make sure you take it to the garage!!!!
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I just bought a passat 1.9 td, more practical than my old merc coupe I thought, yet everytime I get into it something else seems to fail. Terrible probs with loss of power, now I reckon it could be a combo of a collapsed exhaust and a dodgy vacuum valve. My cam belt skipped 4 teeth which was interesting and I wonder if my sluggish?suffocated turbo was to blame. Luckily it only skipped on the injector pump so not fatal. The turbo stifle problem seems to get worse when I've been driving for a while, but not necessarily in connection with engine temp. Any ideas? Ps. does anyone know the whereabouts of the chump who designed the electric window motors? I'd like to chat with him!
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thanks spencer like you have been driving for months with no power all the mechanics said it was the fuel pump needed overhauled your post about that pipe saved me a fortune on repair bills i changed the pipe as it had a tiny spit and the car runs like new again my car is a mondeo td 1.8
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graham/dave
I have exactly the same problem - sharan 1.9tdi, now 103,000 miles but been doing this since around 30k. VW diagnostics tried, nothing showing. Turbo goes off (about once every 3/4 months, but sometimes twice in a few days) resets straight away when engine restarted. I have noticed in several incidents that coming off the power and going back on in a hurry seems to be the trigger, it rarely happens with a contant throttle. No VW dealer has ever been able to get to the bottom of it.
Don't mind paying for a diagnosis but who/where (telford area)
Other problem is you can't prove it's fixed, as it's so intermittent.
Dave can you explain what an EGR solenoid is, thanks
John
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Hi everybody, just reading all your comments about sticky Turbos & I must say i find they rather amusing, been there, seen it before and solved the problem by just flushing out the oil system... the problem found was just carbon deposits on the phosfor-bronze bearings...
I strongly suggest to see to it as it is potentially dangerous, not to the engine but to yourself and passengers in the vehicule when the turbo becomes "unstuck" you get a rather vivid and undesired acceleration similar to a cossie beeing suddenly thrashed..
Best Regards & all the best
Tristan
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Are you aware VW/Audi had a MAJOR problem with catalysts from 1995-1999? The stailess steel plates inside wee badly welded, come adrift and block the exhaust outflow.
My A4 TDI sysmptons were an exhaust rattle at idle. Cat replaced FOC under Audi warranty although 4 years old:-)
I suggest that such a strange intermittent fault MAY be due to that. Ask your garage to check if cat has been replaced if it falls under the age as described. If not, they should replace it: manufacturing fault and well known to Audi garages.
madf
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John,
"Dave can you explain what an EGR solenoid is, thanks"
I hope that Dave does not take offence at me putting my limited knowledge forward but, the EGR solenoid is the device (electrical or vacuum) which allows some of the exhaust gases, at low throttle openings, to be re-circulated through the induction manifold, hence Exhaust Gas Recirculation valve/solenoid. The theory (although I have my doubts about the practice) is that it helps to keep the emissions figure within prescribed limits. From my experience, it seems that a lot of owners blank this off to avoid the inevitable build up of gunge in the inlet manifold.
What I should like to know, if someone would be so kind, is an explanation of the operation of the Wastgate on a turbo. I am new to Turbo's (MY Ford E93A certainly did not have one) and a concise run down on it's operation would, I am sure, help a lot of us.
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How does a turbo work?
www.howstuffworks.com/turbo.htm
Answers to most things there! Bookmark the site. Great
madf
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Many thanks MADF. The site is excellent and, as advised, it is bookmarked for future study.
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Exactly the same problem on my Audi A2 1.4TDi.
Only 10 months old and 8500 miles, this weekend, accereating \'briskly\' through the gears away from a roundabout, hit around 4000 rpm in 3rd and had a sudden loss of power. Managed to maintain close to 70mph on the level but soon dropped to 40 on an incline. Stopping the engine and re-starting cured the problem but it recurred many times that day.
The EGR valve is mounted close to the passenger bulkhead on the A2 and ours has been getting very noisy over the last few weeks - sounds like a cow mooing every time the throttle is depressed!!!
Hoping the loss of power and bovine sounds are related because the mooing sound is a known fault on the A2 and I\'m hoping to get it fixed under warranty.
tikki
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