Severe vibration under acceleration

Broken_VW

Hi All,

My 2007 VW is undriveable and I hope somebody here can offer some advice.

I have a 2007 golf with the 1.9 BXE diesel engine.

Recently it has started vibrating severely under acceleration, between 1500 to 2500 rpm. Above 2500 rpm there is no vibration. It happens in all gears but most noticeable in 3rd, 4th and 5th. When it vibrates there will be a cloud of black smoke. When it doesn't vibrate there is no black smoke. There is also a hesitancy when it is vibrating and a slight ticking from the engine.

The vibration is so severe the gearbox mount broke a couple of weeks ago. I gave the car to a mechanic, he fixed the mount and cleaned the EGR valve. He said it just needed to be driven hard, but still the vibration persists. Sometimes when the engine is cold the car will vibrate so badly when accelerating that it will go into limp mode and not rev above 2000 rpm. I have to stop the engine and restart it.

Strangely, with the car parked the engine will rev up with no vibration whatsoever. It only seems to happen under load. The problem is permanent at this stage but I have found that if i take it above 4000 rpm when accelerating in 2nd gear the engine will behave itself for the remainder of the journey or until I stop in traffic.

I have changed the fuel filter, taken out the injectors and fitted new o-rings and cleaned the EGR valve with no resolution. My mechanic still thinks it is EGR related. There are no warning lights showing and no fault codes. I am pretty certain it is engine and not driveline.

I need some advice on where else to look.

Broken_VW

I forgot to mention the injector wiring loom was also changed by my mechanic with a known good one. Also I have Dipetaine and diesel fuel system cleaner in the tank.

I don't know what else to do.

heroics

DMF maybe?

Broken_VW

I thought it might be the dmf when it first started happening but it doesn't have the normal dmf symptoms. The gearbox, drives and dmf all seem fine. Feels more like a misfire or knocking but no warning lights or fault codes.

Broken_VW

I've tried to book the car into the main VW dealers but at this time of year the mechanics are on holidays so there is a 2 week waiting list.

Cerebrum

Have ye had the injectors themselves tested?
Would really expect there to be a code stored on VCDS if it enters limp mode.

What county are you based in?

CJhaughey

Is it knocking? That model engine is known to have problems with the big ends, resulting in some cases with a con rod trying to escape through the crank case.

nd

Does it sound like this?

It's not that engine but that was big end bearings.

Broken_VW

I have had the injectors out and cleaned and changed the o-rings. On 2 of the injectors the o-rings at the nozzle were frayed. I was hopeful changing the o-rings would solve the problem, but no effect at all. I haven't had the injectors tested. I can't do without the car at the moment but I have a couple of weeks leave coming shortly I'll send them off for reconditioning if the problem isn't fixed by then. A friend has a VCDS reader, it could communicate fine with the ecu, it could read live sensor data etc, but there were no fault codes.

When I said it was knocking it didn't sound like a mechanical knocking of 2 metal parts. It sounded more like pre-ignition. That made me suspect a leaking injector but I have very limited knowledge of these things. I watched the video and no it doesn't sound like that. It strictly only vibrates/knocks,smokes when I press the accelerator. When I hold the accelerator constant on the flat it is fine. It is only when i depress the pedal further or come to a hill in cruise control that it vibrates/knocks,smokes. And only when driving. And only between 1500 rpm and 2500 rpm.

When I described the problem to the main vw dealer his first thought was fuel issue and suggested changing the fuel filter. The old filter was black with contamination.

As I said previously I can clear the problem by redlining it in 2nd gear. It will be fine then for the remainder of the motorway journey but when I have to stop in traffic it returns.
It seems something is sticking. It is noticeably harder on diesel too.

I'm leaning towards injectors at the moment but it is an expensive and time consuming 'Hail Mary' shot. The intake and egr were surprisingly unclogged. When I had the egr out I pushed in the valve all the way by hand and and then held a finger on the vacuum nipple. When I released the valve, with my finger still on the vacuum nipple, it partially closed, not the whole way. Does this mean the egr has failed?

martyc5674

I think it's your EGR, can you blank it even temporarily to prove the point?... it should close all the way.
Marty.

Broken_VW

I mean the egr valve opens and closes freely. If I force it open all the way and then block the vacuum nipple with my thumb and then release the valve it closes maybe 3/4 of the way. Should it be able to hold the vacuum against the spring? I know it is not a great test but just an observation. There is an egr cooler as well. I don't know how it works or if it could be causing this vibration.

Would injector issues cause black smoke or blue smoke? The smoke coming from the car is black. Could the turbo be causing this?

martyc5674

Cooler is just that..water circuit around the egr it won't be that unless its leaking inwards!(not impossible)
So it is closing all the way?
Pop off that vac pipe and see how it behaves

Broken_VW

Thanks for the suggestion, Marty. I will try on the commute home.

Broken_VW

So, I took off the vacuum pipe and plugged it. The engine stumbled a bit when starting and it felt a bit more lively on the drive home but the vibration remains the same. I don't know what this result means. Is the egr stuck closed? Or it's not the egr at all?

martyc5674

Stuck closed would be a fine thing... it could still be the egr if it's not closing fully, it's sounding less likely to be the case though.
Ideally you'd need to leak test it or blank it to rule it out.
Have you unplugged the MAF yet to see if that helps?(couldn't see it contributing to the vibration your having but it's an easy try)
Marty.

Broken_VW

I have disconnected the egr valve and unplugged the maf sensor tonight and it has been very difficult to test because the vibration has become very intermittent when previously it was permanent. Now, I did get a fill of diesel this evening after work and I am putting it down to that. The last tank of diesel had both dipetaine and redex cleaner in it whereas this tank has no additives. Obviously the additives didn't cause the vibration but the car is now running on straight diesel and the problem has all but gone. As I said the problem is so intermittent it is hard to draw conclusions but I will know better tomorrow after my commute to work.

JohnBoy26

Worn camshaft lobes maybe? Another common enough problem on those engines.

Broken_VW

I've read about the camshaft issue on these but the vibration came on all of a sudden rather than a sudden deterioration.

Disappointed after my drive to work. Problem still persists. Disconnected egr last night, made no difference. Unplugged the maf, no difference.

It's probably the injectors, I'll send them off for reconditioning when I get a few days leave from work. In the meantime I'll let the remainder of the cleaner run it's course.

JohnBoy26

Broken_VW wrote: »

I've read about the camshaft issue on these but the vibration came on all of a sudden rather than a sudden deterioration.

Disappointed after my drive to work. Problem still persists. Disconnected egr last night, made no difference. Unplugged the maf, no difference.

It's probably the injectors, I'll send them off for reconditioning when I get a few days leave from work. In the meantime I'll let the remainder of the cleaner run it's course.

You should get someone to inspect the camshaft and replace the bottom end bearings just to be on the safe side anyway.

Broken_VW

I previously ruled out the driveline as being the source of the vibration. This was because the engine was performing so badly i.e. hesitant, black smoke, harder on diesel etc. My mechanic also thought it was firing on 3 cylinders.

I have studied the vibration further and noted a couple of things. The frequency of vibration is related to road speed. The amplitude is related to load i.e. gear, incline, accelerator position. If I jump from 2nd gear to 5th the frequency remains the same but amplitude increases greatly. Same if I am driving on the flat and then encounter an incline. Same If I hold the accelerator steady and then depress further.

I'm guessing the engine difficulties are caused by the knock sensor.

The clutch feels good and there are no mechanical noises. I've read the inner cv joint is a possibility. It is not behaving like a failed dmf. Any suggestions on other possibilities?

Broken_VW

No improvement in vibration.

I took the valve cover off today and the camshaft has 2 obvious flat spots on one of the lobes. Intake I think. Could this be responsible?

Broken_VW

Picture attached

PukkaStukka

Broken_VW wrote: »

Hi All,

My 2007 VW is undriveable and I hope somebody here can offer some advice.

I have a 2007 golf with the 1.9 BXE diesel engine.

Recently it has started vibrating severely under acceleration, between 1500 to 2500 rpm. Above 2500 rpm there is no vibration. It happens in all gears but most noticeable in 3rd, 4th and 5th. When it vibrates there will be a cloud of black smoke. When it doesn't vibrate there is no black smoke. There is also a hesitancy when it is vibrating and a slight ticking from the engine.

The vibration is so severe the gearbox mount broke a couple of weeks ago. I gave the car to a mechanic, he fixed the mount and cleaned the EGR valve. He said it just needed to be driven hard, but still the vibration persists. Sometimes when the engine is cold the car will vibrate so badly when accelerating that it will go into limp mode and not rev above 2000 rpm. I have to stop the engine and restart it.

Strangely, with the car parked the engine will rev up with no vibration whatsoever. It only seems to happen under load. The problem is permanent at this stage but I have found that if i take it above 4000 rpm when accelerating in 2nd gear the engine will behave itself for the remainder of the journey or until I stop in traffic.

I have changed the fuel filter, taken out the injectors and fitted new o-rings and cleaned the EGR valve with no resolution. My mechanic still thinks it is EGR related. There are no warning lights showing and no fault codes. I am pretty certain it is engine and not driveline.

I need some advice on where else to look.

If the car is going into limp mode then there has to be fault codes there. What tool was the car scanned with?

I had vibration like this in a car once and the cause was a broken inner CV joint. It wasn't the engine at all.

brian7cwl

Hi did you ever find what the problem was ?

I had a similar incident in my YW on the motorway but the tyre had torn.