2001 golf 1.9 TDI Removing & Reffitting Turbo ALH

[wetcornflake]

Hi

My most recent problems with power loss, after diagnostic's points to Turbo problems.

I am now going to replace turbo unit. Not having a pit or ramp available. Has enyone ever carried out this type of repair or have <font color="blue"> </font> any information on removing turbo unit through the top of engine compartment, by removing manifolds Air inlets etc.

I was told by VW the recomended way is to remove drive shaft and pull out from underneath of vehicle whilst on ramp.

Any info would be appreciated

[Rustynuts]

Don't be too hasty. What's wrong with the turbo? If there wasn't a big bang and lots of metal on metal sounds, or oil pouring into the inlet manifold, I'd be a bit wary of replacing the whole turbo.

It's more likely that the engine is fine until you get n the go pedal a bit, then it loses power suddenly. Turning the engine off and restarting will cure the problem, is this correct?

[wetcornflake]

Hi

You are correct with your diagnosis

As I said in earlier posting I have changed MAF sensor and also checked the VNT actuating valve (On my model there is 2 identicle valves on the bulkhead VW part no's 1J0 906 627 one with white top controling VNT and one with black top controling EGR valve) I have swopped these over and tried engine and the problem is still the same. I have tried putting a mirror down back of engine and can see some movement on Turbo VNT mechasism when the engine is running at differing RPM. I did have it in a garage and they removed the Turbo and cleaned all the vanes and said it seemed OK. I am at a loss. The Diagnostic reported CHARGE PRESSURE CONTROL INTERMITTANT FAULT.

Question how does the ECU detect pressure faults in the charged pressure side of the turbo, there doesn't seem to be a sensor, and the MAF sensor works on the low or atmospheric pressure side of the turbo.

Answers Please

[Rustynuts]

How much movement is there on the VNT mechanism? There should be about 3/4 of an inch. If there's not this then the turbo isn't providing enough boost when you get on the go pedal, then the ECU sees a problem and "limp mode".

There may be a split in one of the turbo hoses and you could be losing boost this way. Check all hoses to make certain there's no holes or loose clamps etc.

Check all the vacuum hoses to the "N75" valve (which is the valve on the bulkhead), to the VNT actuator on the turbo, and from the .... Sorry, check all the vacuum hoses for leaks.

Turbo's generally either work or they don't. Yours is working on low boost but losing it on high so the problem is with the control system, not the turbo.

[wetcornflake]

You are correct there is about 3/4 inch of movement on the VNT actuator. I have checked all vac hoses for blockages/leaks all ok (must be ok VNT actuator is working)

as for charge pressure this model (ALH Engine 90 BHP) the turbo bolts direct to the inlet manifold and I can't hear or see any leaks.

I have spoken to the VAG agents several have told me that they have had this problem before and only turbo replacement has cured it. Although logicaly, as you say, I don't see how this can be.

Just an additional point this is my wifes car and has only done 21000 miles in 4 years. I only noticed the problem dropping it off for its MOT and I dont think she has ever gone fast enough to notice the problem. I wonder if something is carboned up.

[Rustynuts]

Could be the inlet manifold is blocked. Plugged up with soot and oil residue, and requires cleaning. This happens a lot if the car is chugged along and never gets a good blow out (Italian tune up, some people call it). Have a check at this first, but if it id blocked, don't even think about trying to clean any (ANY) muck out while the manifold is on the car. You don't want to make the engine try and eat that stuff.

[Rustynuts]

How does the car idle! Is the idle intermittently higher than usual?

Edit: and have the garage or you had it connected up to Vag Com to diagnose any fault codes?

[wetcornflake]

Hi the diagnostic was done by my local garage not VAG.Com

They contacted VW about fault codes etc. I sopke to local VW dealer £100-00 for diagnostic check.

Re manifold bunged up could be??

I have found a company that checks Turbo's and repairs them

my local garage is removing turbo on tuesday and I am Sending for Testing cost £20-00 including shipping both ways. I will have to pay for turbo removal and refitting at the garage but my options with VW are spend spend and it seems little knowledge.

I will get them to check inlet manifold when turbo is off.

I would have done this myself but VW tell me the Turbo has to go out of the bottom by removing a drive shaft. I have no pit or car lift, this is why I originally asked if anyone knows if can remove manifolds and there is enough room for you to pull turbo unit out between top of engine and bulkhead

[Rustynuts]

If removing the inlet manifold aswell, then IIRC the whole thing can be done from the top. No need to get underneath and roll about. Still need to know about the idle. Is it erratic and sometime higher than normal?

[wetcornflake]

No Idle is perfect

the engine runs great till you hit 2800 rpm on an incline then immediatly goes into limp mode. ignition off ignition on system resets and all is ok untill you hit 2800 rpm again.

My wife never even noticed the problem.

I am still trying to get my head round how the ECU works, I understand readings sent to the ECU have to conform to preset map but as I said earlier do you know how it detects boost pressure problems, there is no pressure detector on the boost side of the turbo. the only way I can figure is that back pressure created by the turbo is detected by the MAF

I read on an earlier string that if you unplug MAF it goes into default and does not go into limp mode. I have tried this unplugging the MAF and the engine runs realy rough and sluggish and cant get over about 3000 rpm but does not seem go into limp mode.

[Rustynuts]

Boy, what an oversight. The MAP (manifold absolute pressure) sensor is located just after the intercooler, down by the drivers side front headlight. Not sure how to get to it, you might need to take the bumper off to get at it, but this measures how much boost the turbo is making. Try checking this.

Regarding my question about the idle, you might want to check this:

Fuel cut-off valve O-ring unseated - especially if the idle speed is intermittently higher than normal. With the engine cover removed, the fuel cut-off valve is located on top of the injection pump just above where the four steel lines go into the end, and has a single wire going to it. Remove this valve (disconnect the wire first!) and make sure the black O-ring is all the way against the body of the valve, then re-assemble.

[wetcornflake]

Hi thanks for the quick reply

I have just been playing round in my head and thought if turbo is ok as you think the only other thing that could cause limp mode would be too much exhaust gas getting into inlet manifold.

On my golf the EGR valve is fixed on top of the inlet manifold just behind the engine stop ventury valve, I have just removed the vacuam pipe and blocked it off tempereraly

taken for a test drive and engine is reving to full rpm without going into limp mode.

I suppose the emissions will be out but engine reving is fine

I dont realy know what I have achieved apart from isolating the problem. Will have to think about it and check valve tomorrow. I swapped the two vac control valves over last week and nothing was any different, so if the control valve is ok, I suppose it must be EGR diaphram.

Ive looked down the front behind the h/lamp for switch, but its just a plastic pipe (no intercooler) to feed the inlet manifold

[Mollox]

Just picked up this thread and really suspect you have a hose issue. I had a holed hose (return hose from the main turbo pipe - its the big metal one on the S3) and I had similar symptoms. Because of the pressure leak, the car was reading boost incorrectly. It was determining that actual boost was far higher than requested and so the car was overboosting. As a precaution it went into limp mode whenever the engine was under load. Again, switching on and off would reset the code and the car would run fine until I summoned up big boost.

I still have £70's worth of perfectly good MAP sensor here as I changed it thinking it MUST have been the problem.

Try and get along to a meet and get someone to datalog with VAG-COM: you want to be looking at the graph of requested vs-actual boost. A consistent gulf between the two is indicative of what i suspect.

Have you had a good luck under the engine cover? Oil spray should lead you to the hole if there was one.

As an aside, disconnecting the MAF only causes it to run the default default static table and not dynamic real readings. Its fine for diagnostic purposes but won't prevent the car from going into limp mode.

I'm not entirely convinced by the quality of diagnosis you've received and would probably recommend going to one of the tuning specialists as they tend to have more experience of turbo-related faults.

Incidentally, my car ran like a DOG while I had the holed hose. It took me a while to get to the bottom of it and it was horrible. I can remember struggling to hit 80 on the motorway....A 10 minute fix and £80's worth of hose later and its run faultlessly like a beast ever since. At the time I was terrified that the damage was very serious as it drove that badly

Let us know how you get on - I'd be very surprised if you had an expired turbo at 21,000 miles. As has been said they're normally either fine or fecked and if its fecked its likely it blew up and caused knock-on damage in the head. Doesn't sound like you have this or that your wife works the turbo hard enough to blow. Not on a standard car with 21,000 miles. Turbo replacement is very costly, make sure you've looked into everything else first

[bbbbb]

Hi I've got a 2001 pd 130 tdi passat (60k miles) and it sounds as though it has the same problem. I'm going to take a look at it on Thursday. I've replaced fuel and air filters which seemed to make a difference for a day so my view is that it may well not be the turbo.

Problem manisfest itself as loss of power, turbo not smooth, turbo not switching in and seems ok when you switch the ignition off and on. I'm also getting smoke under load on occasions.

At the moment my suspects are (in priority) n75, the air mass sensor and tubes and pipes loose. I'll let you know if i get it solved.

[wetcornflake]

Hi

Ive solved my problem

It initially started when the the car kept going into limp mode about 3000 rpm

After gleening much info from the forums

I have discovered the problem the inlet manifold is absolutly clogged with gunge, which I cant believe is possible (the car has had oil and filter changed every year after only doing about 4-5000 miles)21000 miles total.

The car has been operating with the EGR valve sticking slightly open, and once 3000 rpm has been reached, this has caused the exhaust back pressure to boost the inlet pressure, subsequently causing high boost pressure in the inlet. This in turn causes boost pressure to be exceeded, and the engine switches into limp mode.

RECTIFICATION

I first pulled the vac pipe from the EGR valve and stuck a screwdriver in the hose to prevent vac loss. Tried the car it runs perfectly right up to red rpm, removed screwdriver from hose and replaced, then unplugged vac valve so EGR wont work. All still OK. I now intend to remove inlet manifold at a later date and clean out as much muck as possible.

After reading the american forums I understand this problem is acute on all VW 1999-2001 90bhp tdi's but was not as bad on 2001 onwards, but still presents problems.

Also advice from forums is, after cleaning out inlet muck (apparently sometimes you have to have manifold bead blasted)

Leave EGR valve disconected engine runs much cleaner and gives you extra 5 miles per gallon. Although wont do much for emmisions.

I have spoke to VW about this problem, They no nothing about it.

[Mollox]

I am genuinely pleased that you didn't replace a turbo!

[Rustynuts]

Intake plugging is more prevailant in the States due to poor quality, high sulphur diesel and also a more aggressive EGR to cope with their emmissions regulations. Disconnecting the EGR is one way of stopping the inlet plugging, but a far more fun way is to drive the crap out of the car every now and again.

Take great care when cleaning the inlet, as when you take it off, you could end up with stuff in the inlet valves and then into the engine. It's not unknown for the engine to sieze when this happens!

A good overnight soak in kerosene (heating oil) or parafin will remove most of the stuff and the rest should come out with a pressure washer. Bead blasting will damage the gasket sealing faces and cause turbo leaks, They look very nice when done, but not recommended.

BTW, How much would a new turbo have set you back?

[v6dunc]

hello same poo different day .... just wondered if turbo swap solves prob could it be actuator overboosting causing fault and subsequent limp mode ps get a decent make of car ha ha

[wetcornflake]

Hi

Local VW quote £80-00 + Vat for diagnostic

Then £1200-00 Turbo & fitting ??

would they have noticed the manifold

I THINK NOT

I did contact www.speedways.co.uk who supply and repair turbo's

they quoted me £20-00 for pick up and return postage and would bench test turbo. No fault No Charge. There stock turb's are half the price of VW, They also recondition or carry out repairs to your turbo, All work guaranteed.

Spoke to guy very helpfull.

[richardhughes]

[ QUOTE ]

I first pulled the vac pipe from the EGR valve and stuck a screwdriver in the hose to prevent vac loss. Tried the car it runs perfectly right up to red rpm, removed screwdriver from hose and replaced, then unplugged vac valve so EGR wont work.

[/ QUOTE ]

Sorry to dredge up an old post but I've had all the same problems as described in this post with my A3 1.9 tdi 110 engine code ALH. At the moment i have plugged the vac hose with a bolt and I can now get to the redline without going into limp mode at 3100 rpm. Can anyone now tell me how the above poster then plugged the vac valve back in but then unplugged the vac valve so the EGR wouldn't work.

Thanks

Richard

[dadidog]

i had the same problem. audi a4 tdi going into limp mode at certain rpm. i found that i had a leaking hose that went from the intercooler to the inlet manifold. i changed the hose and it worked fine after that. total cost was £1 from local scrap yard or you could buy a new one from audi/vw dealers

[benjie]

This EGR gunk issue is becoming more common here in the uk as the engines get older and have done more and more miles. Personally, I've cleaned mine twice on my remapped TDI 90 (AGR) 170k miles. Both times they weren't that bad, but a mate's 110TDI (AHF?) was awful. The PD's seem to have this problem too as I have cleaned a 115PD one too.