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Golf MK4 Turbo cutting out

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Hi

I'm new to this forum and have a problem with my golf and wondered if anyone can help.

I have a MK4 Golf GT TDI and recently the turbo started cutting out on the motorway and doesn't start back up again unless i turn the engine off and back on again. I took it to my vw garage and they changed the air mass sensor but the problem is still there so they changed the boost sensor but still no luck. It only happens at motorway speeds, in the town it works perfectly.

If any of you have experienced anything like this could you let me know or if any of you have any sugestions it would be appreciated.

Cheers

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It sounds like your engine is going into limp mode.

I'd ask the dealer what the error code the VAG diagnostics was showing.

I've had similar on my S3 and it turned out to be a holed turbo hose. I'm not sure how relevant that is to a diesel though.

Welcome to Tyresmoke 169144-ok.gif

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Cheers

I'll ask them and I'll let you know how it gets on.

Thanks again

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Have you any ideas on what else can cause the car to go into limp mode?

Cheers

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The VNT mechanism may be stuck (carboned up) or not moving to its full extent. This is vacuum controlled (by the item below) and you may need to free it up by working it manually.

Another cause may be the N75 valve which controls the turbo VNT mechanism. It's an electrical solenoid operated valve which could be sticking.

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VW have changed the complete turbo and it seems to working now. Thanks a lot guys

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Was this done under warranty? If not, ask for the turbo they took off. I bet the VNT mechanism is stuck and with a pair of pliers, a bit of elbow grease and some wd40, you'll have a working spare!

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Yeah, thankfully it was done under warranty. Thanks for the help anyway.

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Hi

I am a new user to the forum

I have a simular problem with my 2001 golf 1.9 TDI

car has only done 21000 miles

I have a problem with power loss about 3200 rpm when pulling say up a incline, in lower gear when pulling less hard goes up to 4000 rpm before problem appears.

Once the problem has started (just feels like fuel starvation ) it carries on untill you switch of ignition switch on again and all is ok again untill you hit higher revs. I have had it in the shop, the turbo has been removed checked and cleaned, the valve on the air cleaner has been replaced, Also the valve on the rear engine bulkhead has been changed. (sorry not sure of tech names)

The shop tells me they have run a fault diagnostic and it reads ( CHARGE PRESSURE CONTROL INTERMITTANT FAULT )they have contacted VW main agent, they say fault nothing to do with fuel or turbo probs. confused.gif

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It could also be a vacuum leak in one of the hoses. The vacuum pump drives the turbo VNT mechanisn via the N75 valve. "Charge pressure control" fault code is generally the ECU asking the turbo for a certain amount of boost, and the turbo failing to provide this. Then the ecu sees a problem and cuts into "limp mode" until the ignition is turned off and back on. The problem generally is the VNT mechanism sticking, which can generally be freed up by hand. It should move about an inch.

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I had exactly same fault on 2001 GT tdi, especially when accelerating uphill, main dealer changed a relay initially, with no improvement. Then tried air flow meter, again with no difference. Warranty near to expiration,( two weeks ). Had car independently tested ( non VW )and diagnostic revealed faulty turbo.!! Turbo replaced under warranty ( just )and now running like new.

P.S Had same fault code as described. FIREdevil.gif

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again exactly the same fault on a gt tdi 2000. gleaned much from this forum (with thanks to wetcornflake and others) and removed and cleaned the inlet manifold and EGR valve. runs like a dream now. vw quoted £100 for diagnostics and i'm not even sure they would have found the problem. apparently you can stop this happening but obviously this would change your emissions...

http://tdiclub.com/TDIFAQ/TDiFAQ-7.html#j

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hi have a 2001 y plate bora tdi with power loss, had new air mass metre, turbo boost valve turbo valve, new hoses on turbo, and still loosing power every now and then, can anyone help as main dealer are just a waste of space, they seem to think it now needs a new wiring loom, i dont really see how this can make a difference. been told the vnt mechanism is sticking, can this be right? if so does anyone have any pics and what to do to sort it. cheers duncan

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I've got the same problem as Superd on a Y plate TDI Bora.

The fault code is P1557 - Charge pressure control : positive deviation.

So far I have checked all vacuum hoses and have checked the actuator rod which seems to go in and out easy enough. Any other ideas that may help ...?

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Hi

I have just overcome the same problem UK model 1.9 TDI

Mine was reading a VAG fault code 17964 which translated means low boost pressure is being read by the engine control unit and as a safety measure puts the car into limp mode, this usually happens about 2600 rpm when engine is pulling under load.

the problem of low boost pressure can be caused by :=

Boost pressure control valve located on the bulkhead behind the engine. (there are two simular valves with vac pipes going to them, it is the one nearest the passenger side and has a white top) A vacume pipe goes from the top of this valve to the VNT operating mechanism on the turbo.

If you can get someone to press the accelerator while you watch the lever on the turbo, if it moves when revs are altered it usually means the valve is OK.

The turbo's are usually OK if you can see movement on the VNT (veriable nozzle turbo)Lever as I said, But if the car has been driven slowly in the past they can clog up the vains and stick open or shut, by looking down the back of engine at turbo lever you should be able to see if working OK. If the turbo is sticking try to free with some light oil or WD40. Or if it does need repair Try www.turborepairs.com they run a 3-4 day pick up repair and return service a 1/4 the price of VW.

The next thing is to check for leaks on the pipe from the turbo to the inlet manifold where it joins the EGR valve.

If this seems ok try pulling off the vacuam pipe on the EGR valve and block up the rubber pipe with a screwdriver while you try car. the car should run fine like this but nox emmisions would be high. (I have been told if you run perminantly like this you get extra 5 mpg and engine runs cleaner but you would have to refit for MOT emissions test)

The next thing to check is the MAP sensor (Manifold absolute Pressure sensor) This is located on the drivers side of the engine, If you find the washer bottle and remove, you will be able to see on the top of the intercooler, a flat black switch with a plug going to it, it is held in place with 2 philips screws. this is the pressure sensor that relays boost pressure to the ECU. there is no real way of checking this without doing a diagnostic, but sometimes when removed you can see a crack accross the diaphram which means its bust, then you would just replace it.

Unfortunatly VW have got you by the B???? without the Vag-Com diagnostic tools you cant check everything out.

In lay-mans terms the computer or ECU constantly checks the sensors around the engine Rpm, Pressure, fuel, heat, Air flow, and if they do not read within the pre defined Verables preset within the ECU it puts the car into safe Limp Mode to avoide engine damage.

Hope this will help.

By the way my problem was the MAP sensor on top of the intercooler new one was £72.00 + VAT from VW, but had to have a diagnostic done to find problem. When I spoke to my VW garage they said they had never ever had to replace a MAP sensor before.

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Thanks to RUSTYNUTS and WETCORNFLAKE for posting their advice on the web. Sorted my TDi problem out. Same symptoms as above, runs perfectly well for a ages, then goes into limp mode, which resets with the key. Had fault code reading done which mentioned the pressure difference. Turned out to be a sticking actuator arm on the VNT unit. Bit of a pig to get to, but sorted in about an hour with half a can of WD40 and a sore thumb !!

If its as common a problem as it appears to be, how come VW haven't done anything about it ? - imagine going for an overtake, getting alongside the 42 tonner, and then the car goes into limp mode !!!

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Hi, I have Similar flat spot at 3200 all the time. No falut codes reported and I have access to the VAG COM software. MAF checked and within tolerance.

Will check the things suggested in this thread and will keep you posted.

Cheers guys.

Holmesy

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N75 valve again, but at 4000rpm your engines running out of power anyway, change gear!!

CHARGE PRESSURE CONTROL INTERMITTANT FAULT = knackered N75 (normally)

lol

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hi im also new to this, i have 2001 golf mk4 gt tdi, with 65,0000 miles, it cuts out at about 3-4000 revs, not good on m/way, only works if i stop engine and restart again. so what do you think? do you recommend i change the turbo, only i have no warrenty, think its going to be expensive for a new one! thanks

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Sitting next to a guy at the dealer and his MKIV GT TDi was in with similer problem - he told me their standard answer was to replace the air mass meter..........£115

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Hi

I am new to this forum and there seems to be a similar problem with my MK4 Golf 1.8 Turbo. I have had the car remapped by Jabba Motorsports just before Christmas and everything was running perfect unitl recently.

When I hit the gas hard on 1st gear its fine, 2nd gear is sort of fine but 3rd, 4th and 5th is terrible. The car seems to be jerking when the revs reach just over 3000 rpm after the third gear. I thought it might be the Dump valve causing the problem but even with the d/v blocked off the problem is there, however when im gentle on the throttle or when the engine is cold, the car goes very smooth and does not jerk. The problem is only there when I hit the gas hard.

I have no mechanical knowledge and no idea as to what the problem could be. Please help me if any one has had the same experience in the past

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Can anyone offer me any advice on looking after the turbocharger (I am new to this forum - a quick google search on failed turbos led me here).

My problem is much the same as others on this forum in that my 2000 Golf GT TDi PD goes into limp mode at about 2000 revs when pulling (ie uphill). In my case however I have had a new turbo fitted only 18 months ago (about 16k miles). Would the various components which have been suggested by people on this site as likely causes for the turbo failure (VNT mech, N75 valve, EGR valve or MAP sensor) be replaced as part of the new turbo unit? I had the turbo replaced under warranty but now my warranty has expired!

I would expect the turbo to last considerably longer but if any of these additional components have failed and are not replaced with a new turbo then I suspect it is likely to be one of these. Given the relatively low mileage since replacement however, is it likely that any of these components were on their way out at that time?

I have been told by many people that you should always let your car tick over for a while after each journey to allow the turbo to "spin down" and allow the oil to cool the turbo. Is this true or complete rubbish?

Any help would be greatly appreciated.

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Hi Non of the items mentioned would be replaced.

As far as I am aware the MAF sensor in the air cleaner if not working does not cause car to go into limp mode. so that rules that out. To check the n75 valve (On the bulkhead at the back of the engine compartment are two valves both look alike with lots of pipes going to them. If you look down the back of the engine you will see the turbo, if you feel the bottom of turbo there is a vacuam pipe coming up to one of the valves on the bulkhead. first pull off the pipe and suck with your mouth you should feel or see some movement on the turbo linkage to the VNT actuator on the turbo unit. If you feel or see movement the VNT turbo is usually OK.

Next EGR valve remove engine cover on the left side of the manifold is a round vac unit, again with vac pipe going from the other valve on the bulkhead next to the n75 to it, pull off pipe, you have disconected the EGR valve (car will run ok without) and block vac pipe with a screwdriver or a bolt or something just so you dont lose vacume try a test drive. If this does no cure it the other thing is the MAP sensor remove the windscreen washer bottle ( located on the ofside front) bit fiddly but will come out, below you will see the intercooler with a black sensor mounted on top with a plug going into it, remove the 2 star screws and chech the sensor, these are difficult to check and not always showing an obvious problem. usual visual prob is cracking on the inner face if its cracked youve found it, but it could be a electrical switch malfunction wich will not be visable.

If these dont help you will have to have a VW diagnostic done. I live near Bradford and had one done recently at Dixons VW £65-00 + VAT Please dont go to a none VW diagnostic centre you will probably be throwing your money away. A VW diagnostic is only as good as the guy using it make sure he is fully trained lots of cowboys about.

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I am a vw tech (4 years)

This sounds like the a common problem on ajm anu arl asz atd auy axr engines

It Is caused by the turbo over boosting and cutting out,not to blow the engine. It is caused by the waste gate not opening.

To cure the fault 'sorry but' New Turbo.

The reason why the the dealership did not find this out is because it is to much of a piss on the test

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