Poorly GTi…what’s the diagnosis, Doc?

[NorthernMonkey]

3 hours ago, RoverFolkUs said:

What's happened here? Looks a bit unhappy from a quick glance!

There is a bit of deep scoring there to be fair but the cam itself is absolutely fine? I really only wanted it for the cams and VVT etc so I’ll see how this one is before I worry too much about it.

I could send photos back and whinge a bit to the seller but annoyingly, that’d mean stripping down the engine again to dig the cam out for photos.

 

[NorthernMonkey]

Anyway, the bit you’re all waiting for…

 

I stuck it all back together, compression figures on all four cylinders are within 5psi of each over at around 165psi and, with the plugs in and started, it lives!!

There’s a few engine lights on including the abs light due no doubt to running whilst on the ramp and the steering angle sensor needs a lap or two of the yard to reset but other than that, it started at the first flick of the key and is currently ticking over beautifully whilst I clean up.

I’m going to run it up to temperature whikst bleeding the coolant before taking it around the block then I’ll drain the oil in the morning, pull the sump off and clean out any mess in the pickup pipe before putting a new filter and oil in and sticking a few miles on it.

 

[SiC]

Possibly a tad low (my 200k engine got 195psi on all cylinders (!)) but if she runs! After all the snail is there to raise pressures anyway 😄

[NorthernMonkey]

10 minutes ago, SiC said:

Possibly a tad low (my 200k engine got 195psi on all cylinders (!)) but if she runs! After all the snail is there to raise pressures anyway 😄

To be fair, I can’t find my decent compression tester so borrowed next doors £10 tool van one so I wouldn’t be at all surprised to see higher figures on mine when I finally locate it.

I’m just happy all four are equal which suggests no major damage has occurred (somehow!)

I think the fact it cut out whilst creeping through traffic and instantly lost fuel pressure due to the pump disintegrating good style probably helped no end?

[NorthernMonkey]

It’s still too early to do a full chicken census but it’s now been ticking over perfectly for 30 minutes and giving the throttle a quick shove, it sounds lovely so, so far, so good!

[NorthernMonkey]

Car is buggered.

 

 

There’s a bulb out. Bloody VAG shite. Cheers, Adolf…

[SiC]

15 minutes ago, NorthernMonkey said:

To be fair, I can’t find my decent compression tester so borrowed next doors £10 tool van one so I wouldn’t be at all surprised to see higher figures on mine when I finally locate it.

I’m just happy all four are equal which suggests no major damage has occurred (somehow!)

I think the fact it cut out whilst creeping through traffic and instantly lost fuel pressure due to the pump disintegrating good style probably helped no end?

Logic would suggest that it'd be a lot lower than 150psi if a valve was bent and/or piston holed. So yeah I can see why you're happy. 

Presumably because the cam dephaser only lost the dowel but still friction fitted on, there was a limit to how far it would have gone out of time too. I mean as you've found out, that bolt is mega tight as it is, so stuff was still moving with the time of the engine at least!

[SiC]

Just now, NorthernMonkey said:

There’s a bulb out

Ime it's always when you close the bloody bonnet! Presumably the bang down is what finishes them off?

[Dave_Q]

Proper chuffed at the success here, if you want I can bring over my knockoff VCDS at some point to give it a good probing, although you probably already have good enough kit to read/delete codes from all the modules.

[NorthernMonkey]

40 minutes ago, Dave_Q said:

Proper chuffed at the success here, if you want I can bring over my knockoff VCDS at some point to give it a good probing, although you probably already have good enough kit to read/delete codes from all the modules.

You’re always welcome if your in the area to come and have a play with it but code wise, there’s little of interest, I’m afraid! 😂

[NorthernMonkey]

In today’s Golf news, sump was as clean as but no harm in checking. It’s now had a fresh fill of oil and a new filter as well as a sidelight bulb to get rid of the warning, then to top it off, some water thrown at it…

I just need to tax it now then it can come home this weekend and have proper test courtesy of Mrs NM before I commit to putting her private plate on it.

I’m also considering one of the RCD330 stereos with AirPlay installed that seem to be quite well regarded as, although the one already in does the job quite well, it’s not quite ‘factory’ enough for my liking, but I would like DAB and streaming along with Waze etc

[NorthernMonkey]

Todays update…

Taxed it this morning and took it out for a tentative run. All seemed well around the block so I decided to take it up the back lanes to the village.

Got to a long uphill bit, put my foot down and then, nothing. It was just like hitting a limiter and it struggled to stay running. 

Somehow, I limped it the two miles back to the unit, plugged it in and guess what? Low bloody fuel pressure!

Exactly the same codes that were there when I picked it up! 🤬🤬🤬

[SiC]

Second hand pump is duff or unlucky just happened to have failed?

[DeanH]

Can they be blanked off and an electric pump fitted?

[SiC]

8 minutes ago, DeanH said:

Can they be blanked off and an electric pump fitted?

It's a high pressure fuel pump as it's a direct injection system. Like blanking a common rail diesel high pressure fuel pump would make the engine not run at all. Lower pressure than a Common Rail diesel though. 

[DeanH]

Just now, SiC said:

It's a high pressure fuel pump as it's a direct injection system. Like blanking a common rail diesel high pressure fuel pump would make the engine not run at all. Lower pressure than a Common Rail diesel though. 

Ahhh, I assumed it was like the old cam driven lift pumps. 

[NorthernMonkey]

14 minutes ago, SiC said:

Second hand pump is duff or unlucky just happened to have failed?

Nope. Got it on live data and took it for a controlled drive…

Low pump feed pressure should be around 5 bar on idle, this one starts at that but gradually drops to around 4 which is lower than it should be. However, if you go WOT where the map demands the highest flow rate, the pressure drops to under 1 bar when the engine cuts back and this then leads to the rail pressure dropping from around 60 bar to less than 7.

This suggests the hpfp is actually ok and is only dropping off because of the failure of the in tank pump to supply enough fuel at the required rate.

The last thing to rule out was the fuel filter…

 

this is the old one which doesn’t look that old but nonetheless was replaced with a new one.

This didn’t make a bit of difference so I’ve ordered a new in tank pump to be delivered next week which should hopefully sort it out.

Unfortunately, I’m now busy with proper grown up finance company work now until later next week so Golf playing will have to wait but I’m still feeling confident 🤞🤨😂

[SiC]

At least it's a cheaper fix, albeit smelly. 

[SiC]

Oh! Also I think these have a control module for the low pressure fuel pump. Iirc lives near the pump. They are known to fail. See if it gets mega hot on a run. 

[NorthernMonkey]

16 minutes ago, SiC said:

Oh! Also I think these have a control module for the low pressure fuel pump. Iirc lives near the pump. They are known to fail. See if it gets mega hot on a run. 

Good point, although the consensus seems to be that if they fail, there’s no pump output at all. I’ll certainly look into it though 👍

[SiC]

Just now, NorthernMonkey said:

Good point, although the consensus seems to be that if they fail, there’s no pump output at all. I’ll certainly look into it though 👍

It's also not unknown for a failing fuel pump drawing too much current and damaging them too. 

I wonder if this fault is actually what killed it first and the act of transporting it got the LPFP moving enough again? 😂

[NorthernMonkey]

7 minutes ago, SiC said:

It's also not unknown for a failing fuel pump drawing too much current and damaging them too. 

I wonder if this fault is actually what killed it first and the act of transporting it got the LPFP moving enough again? 😂

This fault has definitely been an issue for a while as the holding back under load is the exact same issue the previous owner reported. Unfortunately, the garage he took it to told him it was because he wasn’t using high octane fuel.

It certainly wasn’t the cause of the hpfp follower remodelling the cam profile though!

If you start it up from cold and leave it idling, it’s fine and will continue to run on 4 bar of output from the lpfp.

It only becomes an issue when more fuel is required.