G60 running real rough

[welshside 10]

I recently had the pleasure of the crank pulley bolt snapping when driving which ruined the pulley key and slot in crank.

An engineer friend came around and put two 3mm dowels through the pulley into the crank for me which sorted that problem out fairly quickly.

 

Another friend (who's into his old golfs) came to help me with the timing, and check the compression to try rule out any bent valves.

We got readings of about 150psi in each cylinder, and engine seemed to turn over fine with a breaker bar on the pulley bolt.

 

I was hoping that had fixed the problem, but no. It's running rough from cold which doesnt clear up when the car has warmed up, it's missfiring and has a real rough idle, sounding like a tractor.

 

We have checked and reset the timing a few times to make sure it's correct (bts out, rev to 2500)

 

At idle revs stays at about 900rpm, needle doesnt bounce and boost gauge reads 13HG at idle, dont think theres a vac leak, sprayed carb cleaner and no change in engine note.

 

It's a new vac hose to ecu and it's 1m long, carbon canister has been removed and hose ends blocked.

 

The fuel filter is new

 

The ISV vibrates slightly when the ignition is on, but I can feel a click every few seconds, is that normal?

I gave it a good clean with carb cleaner a few months back.

 

The spark plugs from cylinder 1 and 2 are black, 3 and 4 brown

 

It hessitates to accelerate at lower revs but seems to pull after about 3000rpm but has a definite missfire

 

When cold, removing the blue temp sensor causes the revs to drop to 600, if you remove it when its warm there is no noticeable difference in revs. The BTS is only a few months old.

 

If you press the WOT switch it seems to make the idle a bit smoother and revs increase a bit

 

Can anyone try help me get to the bottom of what is causing the bad running. I have done a lot of forum searching and not found a good answer yet, most of the posts seem to have the problem occur when the engine was up to temp, mine is happening as soon as it's started.

 

Are there any tests I can do, unplugging things or with a multimeter to try figure out whats gone bad.

 

Sorry for the information overload but I just wanted to cover everything I have done so far.

[16VG60 1]

If I were you I would firstly want to check more thoroughly the possibility of valve damage, and whilst I am sure your friend has made every effort to pin the crank correctly, are you sure the timing is now correct? You have pretty much answered your own question. The engine was running fine before the bolt broke, and now it is not. What has changed? Check the valve integrity, and cam / crank / dizzy timing alignment. A number of features of the engine now suggest disorder in these areas.

 

 

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[steveo29 0]

you can unplug the o2 sensor while running to see if that cures anything

 

multimeter the blue sensor and compare the readings to the manual , if it was a ebay one maybe consider a genuine vw one

[welshside 10]

To thoroughly check the valves I would have to take the head off which is a last resort.

 

I think the pinned pulley should be all lined up to the crank because there was enough of the key left to know the position it was sitting in.

 

I'm pretty sure the timing is correct, we found cylinder 1 tdc, lined up the 2 dots on the cam pulley between the tab on the rocker cover but had to mark the flywheel in the centre with white out because there were no markings there. The timing gun was set to 6 degrees using the white out mark to set timing.

 

The distributor rotor didn't line up with the notch on the body but I have read that as long as it's pointing at the cylinder 1 terminal on cap it's ok.

 

I have tried it with the O2 sensor unplugged and it made no difference.

The blue temp sensor isn't a genuine vw part, it's a meyle one from vw heritage.

 

Is there anywhere online you can buy genuine vw parts, It's awkward getting to my nearest vw parts dealer when my car is playing up.

[coolrado 0]

Simple to check if the pinned crank pulley is lined up, the TDC marks on the pulley and flywheel should line up.

[welshside 10]

Simple to check if the pinned crank pulley is lined up, the TDC marks on the pulley and flywheel should line up.

 

I haven't got a mark on the flywheel, but got all the pulley marks lined up at TDC. All seem correct

[dannyboy 0]

Pressing the WOT switch in on idle should make the engine hunt not idle smoother,so it may very well be your O2 sensor in not brilliant. But that wouldnt account for the misfire. It sounds like the timing is still out,take the hose of the TB and snap the throttle open.If it gives a loud pop-bang,this means your timing is out

[welshside 10]

Do you mean the hose to the ECU? I will try it see what happens.

 

I did an oil change today and took the pipe from the supercharger (the one to the intercooler) off to try and get a better grip on the oil filter which was real tight. The pipe had a bit of oil gathered at the bottom of it, I know a film of oil on the pipes is normal, but should there be any more than that? There is also a bit of oil on the underside of the charger which looks like its been happening for a while.

 

The oil level hasn't changed much since I bought the car a few months ago, so it isn't loosing much oil at all.

 

Could this be causing/adding to the running problems?

[dannyboy 0]

Nah the oil in the bottom of the recirc pipe is normal near the TB,I won't worry too much if level hasn't dropped.the charge pipe near the TB is the one you can take off to give a quick check.snap the throttle quickly,if it pop-bangs your timing is still off. Leave your ecu hose on but make sure you've put it on the correct nipple on the TB.I can't remember which one goes on where but it does make a difference

[welshside 10]

the oil in the bottom of the recirc pipe is normal near the TB,I won't worry too much if level hasn't dropped

The oil is in the main boost pipe coming out of the supercharger not the boost return, seems a bit more than it should be.

 

the charge pipe near the TB is the one you can take off

Sorry I'm a bit confused what pipe you mean. Is it the one from the intercooler to the TB, is it a safe thing to take that off and rev to give it a test?

[dannyboy 0]

Yes the pipe from the intercooler to the TB. Just take it off at the TB to hear if its popping in the inlet.it won't do any harm at all,so long as you don't let anything get in.all your doing is undoing the pipe at the TB and snap open the throttle using the tb. If you get a loud bang,your timing is off but if repeated timing change doesn't fix the popping,you have bent valve.thats worst case senerio though.

[welshside 10]

I am hoping it's not a bent valve, compression test seemed fine and it turns over by hand ok but it's still a possibilty, fingers crossed the valves are ok.

I'll try popping that pipe off for a quick test this week.

 

I took a photo of the supercharger outlet and a small pool of oil on the bottom. I think there is more oil there than should be, but could just be me being paranoid.

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[owen g60 10]

that amount of oil is ok.... if it gets much more than this i would advise a rebuild

[dannyboy 0]

As Owen said that's fine,just keep an eye on it. All you are doing is testing to see if its the timing out or something else.doubt it would be a bent valve if compression test were the same.

[owen g60 10]

have you checked your distributor is timed correctly?? didnt see anything in the thread about checking it

[welshside 10]

The dizzy rotor didn't line up with the notch on the body but we pointed the rotor at the number 1 lead and then used a timing gun to set ignition timing.

 

Just take it off at the TB to hear if its popping in the inlet.it won't do any harm at all,so long as you don't let anything get in.all your doing is undoing the pipe at the TB and snap open the throttle using the tb. If you get a loud bang

I took the pipe off, gave it a bit of a rev and there wasn't a loud bang or popping.

 

Here is a video to hopefully give a better idea

[welshside 10]

I just replaced the plugs, leads, dizzy cap and rotor which solved the problem. Went for a little drive and it's running like a dream now.

I'm so glad it wasn't a bent valve.