56 plate 1.4 16V Fabia Auto engine rattling noise

[Zebedee2001]

New issue! After putting the car back together after the compression test it will not start! It just churns over & after about 5 seconds the oil pressure warning light comes on & it beebs (while still turning over). Ignition off then on again & it does the same. Would doing a compression test cause an airlock in the fuel system? No error codes when the ECU was read.

 

Help!

[Breezy_Pete]

Got a multimeter to measure battery voltage?

[sepulchrave]

No, an airlock is not possible from a compression test.

The oil light behaviour is normal as well.

What is possible is that the coilpacks are not fully seated or you haven't reconnected the loom properly.

[Zebedee2001]

Currently down the pub! Battery is on charge. Just realised that I reconnected the battery with the door unlocked. Got in and turned the ignition. I wonder if the anti theft has kicked in. Will try again tomorrow.

[Breezy_Pete]

7 minutes ago, Zebedee2001 said:

Currently down the pub! Battery is on charge

Perfect.

[bigjohn]

Pub sounds like a plan

 

Fresh light of a new day will hopefully show something not put back together correctly (connector missed off etc). Re- trace your steps and check.

 

 

Edited 12 February, 2019 by bigjohn

[Zebedee2001]

Well looked all around & can't see any problems but will not start! No smell of petrol either so assuming that there is a fuel issue. You can hear a wiring noise when ignition is first switched on but that stops after around 5 seconds. Checked fuses. Also pushed the valve on the fuel rail with the ignition on, a small amount of fuel (thimble full) came out & that was it.  HELP! Still no fault codes, jut churns over & no attempt at springing to life. Batteries back on charge at moment (had jump battery on too)

[sepulchrave]

This does sound like an immobiliser issue, do you have the red flashing LED next to the drivers door button or a yellow key shaped lamp on the dash?

[Zebedee2001]

42 minutes ago, sepulchrave said:

This does sound like an immobiliser issue, do you have the red flashing LED next to the drivers door button or a yellow key shaped lamp on the dash?

No, both seem fine!

 

With the  N80 valve next to the coolant header tank & the fact that it has to be moved to get the engine mount off to the cam belt it was an area I was looking at. Also the fuel pipes are near there & can be moved up & down a little.......... had another look & still no joy!

 

[Zebedee2001]

Hi All,

 

Been an interesting week or so. I got the car started, it had error codes for all the coil packs, I found this with a different code reader! Reset the codes & it started & ran. On 2nd & subsequent starts it ran rough!

 

Decided to change the cambelt as I was so close but also gave the wife the choice of whether she wanted me to change the tappets. She went for it & I have changed them.

 

Now the new problem, the car started & ran OK (quiet!) but on subsequent restarts it runs rough, hesitant. I suspect if I disconnect the battery & reconnect it will run OK. I'm going to try this. Any thought of what could be wrong. I suspect I may have disturbed something while looking for why it wouldn't start!

[sepulchrave]

You may need to re adapt the throttle body to get it running better, you don't say whether you changed any coil packs or the spark plugs but these engines absolutely eat spark plugs and you may have at least one failing coil pack since this is also a common failure.

I did mention the dodgy lifters but it got kind of lost in semantic arguments about oil jet size.

Glad you were able to see it through in spite of the muddied waters.

[Zebedee2001]

1 hour ago, sepulchrave said:

You may need to re adapt the throttle body to get it running better, you don't say whether you changed any coil packs or the spark plugs but these engines absolutely eat spark plugs and you may have at least one failing coil pack since this is also a common failure.

I did mention the dodgy lifters but it got kind of lost in semantic arguments about oil jet size.

Glad you were able to see it through in spite of the muddied waters.

Didn't change any sparkplugs or coilpacks..........

[sepulchrave]

19 minutes ago, Zebedee2001 said:

Didn't change any sparkplugs or coilpacks..........

 

Change the plugs unless you know it's been done.

[Breezy_Pete]

There's a bolted earth wire from the coil pack loom that may have got left off. Just visible below the oil filler in the second image here https://www.ebay.co.uk/itm/Volkswagen-Polo-MK4-9N-2005-1-4-1390cc-4-Cyl-16v-Petrol-Engine-BKY-3185/372594136777?hash=item56c05756c9:g:1-EAAOSw0qdcXYtl:rk:2:pf:0

Not sure that it would start/run at all without that, but maybe worth a confirmatory eyeballing?

[Zebedee2001]

21 hours ago, sepulchrave said:

 

Change the plugs unless you know it's been done.

Changed the plugs & made no difference but it did help! I took the plugs back out, cylinders 1, 2 & 3 were sooty but cylinder 4 was like new & wet! I already had a 2nd hand set of coil packs on order (got the 4 from a reputable VW breakers for £15) as I thought they might help diagnosing this problem. Hopefully this will sort the problem & I can give the car back to the wife to actually drive!

 

Wino - I had already fitted that connection but I suspect people have been caught out in the past.

[Breezy_Pete]

On the home straight now fella, good work.

Have you still got the old tappets?

[Zebedee2001]

7 minutes ago, Wino said:

On the home straight now fella, good work.

Have you still got the old tappets?

Yep, was going to take them apart when I get a moment

[Breezy_Pete]

Cool.  Any of them unexpectedly easy to compress?

[Zebedee2001]

Only tried between fingers but all seemed firm. I am trying to catch up on all my other jobs while I wait for the coil packs. However, when pressed between fingers some had bubbles of oil coming out of the side hole but others had air bubbles.

[sepulchrave]

You'll need to put them in a vice if you want them empty.

[Zebedee2001]

Back again!

 

OK, The rough running was a coil pack! I also re-adapted the throttle. Now done 800 odd miles & stillhas the rattle (although a bit queter!)

 

I got hold of a fuel rail complete with injectors for £20 so I though I would give that a go in case a dodgy injetcor was allowing through too much fuel (the fact taht cylinder 1 had liquid in it when I first looked) Unfortuantely the injectors on the replacement had white ends & the original had blue. I fitted it anyway & the car runs, it does seem quieter! I have since done a bit of googling & appear to have bought a BBY rail instead of a BKY rail. The injectors on the BKY are 036906031AB & the BBY036906031M both are 1.4 16V.

 

Will any damage be done? Should I swap back to the BKY one?

[Breezy_Pete]

Hmm. A while back I bought a spare inlet mani including injectors and MAP sensor (for a song off ebay) for my BBY, and ended up getting something that had non-matching injectors to what I have on the car.  Will just pop out to the shed and see what it is I got, injector-wise. 

[Breezy_Pete]

Different number from either: seems to be 036906031AC I've got, and neither of the part numbers you quote supersedes to that.

What the differences are I couldn't say.

 

If your car is running quieter now and shows no faults I'd be tempted to leave them for now and see what happens.  Doubt there'll be any risk.

Edited 23 March, 2019 by Wino

[sepulchrave]

The main part number is the same, only the revision is different, the revision probably denotes a different supplier rather than a different spec.

Flow rates are really all that matters with injectors.