Hi, If I leave my 16v KR overnight on start up she fires straight into life with a lively (no throttle applied by me) blip up to 2000 rpm. Problem is, as she does there’s an fairly intense clacking sound that lasts about 1 second only. I’m thinking that the noise is a worn hydraulic valve lifter that’s losing its oil so has a little “moment” to itself until oil pressure is restored on start-up. Two questions for the tech gurus, does this cause any harm to the engine, ie, should I be looking to replace all 16 sooner rather than later? And secondly, what controls that enthusiastic start up to 2000rpm? Is there anyway of lowering this to a more gentle wake-up as I feel I need to switch off the key soon as she fires so not to do that initial, stone cold Rev and clank? Thanks guys.
The cold start / warm up regulator makes it Idle high. 2000 seems high though. I imagine if left alone, eventually the rattle could cause cam wear. Worth trying the ATF trick maybe? It has worked for me. https://www.clubgti.com/forums/index.php?threads/engine-oil-the-atf-trick.140012/
It only blips up to 2000rpm for start, like I’ve got my foot on the gas a bit but I ain’t, then immediately drops to a more sensible 1000rpm it’s just that initial 2000rpm can I tweek that to be lower anyhow? And thanks, I’d forgotten about the ATF trick, I may give it a go next oil change, I’ll have a think about it.
My old 16V developed a start-up rattling/clatter, I started using fully synthetic on it as opposed to the semi-synth, never did it again for as long as I owned it.
The 1st D reg 16v I had (back in 1999) used to do the same, made me wince every cold start, never got to the bottom of why it did it.
I’ll try fully synth then, and still looking into the ATF trick. And GVK, yes, I do the same, sounds harsh as on the engine. Did you replace your hydraulic lifters in fault finding the noise? Any other things you eliminated would be useful too as I try to diagnose it. Ta!
I have fixed many higher mileage mk2's by changing the oil several times to stop the clatter,never had any luck with any of the "so called " remedys one being using atf,worst thing to use is lifter flush ,the stuff makes the problem worse.
My 8v got rattley twice, both times a 50:50 cheap 10w40 and ATF mix for half an hour seemed to stop the rattle. Obviously then drained and refilled with good oil.. It had 200k on the clock
Thanks guys for your thoughts and tips on this. I think I’ll try the ATF trick, then switch to fully synthetic oil and if that doesn’t help replace the lifters next time I do the timing belt as they’re aren’t going to break the bank.
Thanks GVK. I’m wondering if it might be the resting position of the airflow plate because they do specs do have a very precise point for this and I’ve never been able to figure out why that would be. I try a few things too and see if I can get anywhere. Cheers
Disconnected the wiring for the 5th injector and it starts much more gently with that out of the circuit. Takes a bit more cranking but doesn’t blip up to 2000rpm but can’t leave it off cos as I understand it provides a bit more fuel at full throttle setting so would be down a few bhp there which know one wants. Maybe I’ll try a different 5th injector if I can find one.
Try setting up the base idle as per Rubjonny's set up 16v guide Pity you can't look inside the ISV when it fires up to see if its flat out open.
Thought about the ISV and I do have a spare which I think I’ll swap over to see what difference that makes. I’ll let you know if it does anything.
I believe its supposed to do the rev up thing to aid cold start, though not exactly sure what process makes it do that. perhaps the ISV control unit with the clacky lifters do an oil flush and refill with good 10w40 semi-synth, and make sure you use a genuine VW or MANN filter with built in non-return valve which stops the oil draining out the head
One of my 16v engines always used to rev up and one didnt. the one which reved fired up nicer than the one that didnt
It’s certainly an enthusiastic start alright. So maybe I should just leave well alone. Start messing with it and next is it won’t start. RJ, are you an advocate of the ATF flush or could you recommend a good off the shelf product? Ta! I phoned VW parts to see if they still do the lifters. Good news is they do, bad news is 16 will set me back £630! I’ll defo try I flush first.
Set of 16 INA tappets for £74 here...https://www.ebay.co.uk/itm/17125263...691849&hash=item27df73e4aa:g:51AAAMXQEgpTDfeo or FEBI for £88....https://www.ebay.co.uk/itm/151385962153?epid=23007938004&hash=item233f4e76a9:g:I7YAAMXQVT9S~NdA
