Horrible mechanical "whirring" sound coming from the engine

rubjonny said

theres an even easier way to do it on a digifant connect inductive timing light, run the engine till its warm.

disconnect the blue sender, point timing light in the gearbox hole. if necessary, turn dizzy so diamond lines up, tighten pinch bolt and replace blue sender. done

You failed to mention that after removing the blue CTS plug, you have to rev the engine 3 times above 3000 to reset the base time of the ECU…..Yes but over the years I have nicked my hands on the running fan… and I have noticed that Digi is auto-adjusting so that when I do move my Diz slightly, It will again hunt for a wee bit then settle back,,, it will run dodgy down the road if it isn't correct, but…I have used the static method on a Variety of Cars over the years from my MG's and Frog-Eyes, to early VW's of the 60's and 70's…… Just saying….. I rarely get my timing light out, and well what really ticked me off is that about a year ago I got it out to check, and my 30 year old timing light finally gave up the ghost and I had to buy a new one….
 

actually no, you DONT rev the engine over 3k to set base timing, only when adjusting idle and co. maybe thats why your ignition timing adjustments didnt go so well when trying it that way

I did forget to say you have to hold the rpm at 2.25k rpm, so I'll give you that

PRO TIP: when adjusint the timing, have a stack of thick card, credit cards, random paper, etc to hand. wedge cards/paper/etc between the throttle and the stop till 2.25k rpm is achieved. this leaves both hands free for doing the timing. be ready to yank the stuff out, as if the timing is miles out the revs might race off as you get ignition timing closer to spec.



revving the engine 3 times doesnt 'reset' anything inside the ECU, they have no learning code. all it does is put the ecu into idle setup mode so the ecu doesn't try to use the ISV to correct any adjustments you make to the base idle and co.

I've since put an ABF engine in my mk2 which has no setup at all, and my timing light is now sitting at the very back of the garage gathering dust

paceman said

if you can reach it, then you could try and cover the idle screw hole a little bit with your finger - see if the noise changes any. But from the sounds of it (literally) that missing screw is probably the culprit - sounds very whistley to my ears.

Also intrigued to know what parts you bought to make up a fuel pressure tester - something I will need for mine soon and want to avoid a trial and error approach! Are you happy to share?

Good luck!

thank mate, i think you could be right. i'm pretty hopeful that the new adjustment screw fixes it. i just hope the threads aren't knackered but currently working on the theory that the o-ring disintegrated and therefore there was no pressure on the screw so it rattled itself out; time will tell.

I'm away with work for a month so i can't test with my finger unfortunately but the screw should have arrived by the time i'm home. I'll take a photo and provide details of the fuel pressure tester when i get back too.

thanks again

 

i'm a bit confused about all the comments regarding timing; is that something i need to check or are you just providing info for others in general, thanks.

what a confusing topic idle screw  timing whirring sound coming from engine sounding soo complex

Hey, don't get overwhelmed - you have a great car to learn on and it's all quite easy if you take your time and read the guides 👍

So you are going to want to get that idle screw in with the O-ring.

Once that's done, set the screw by tightening it up fully (just hand tight) then backing it off a bit so it's got some air flow then adjusting it until your revs are at 900ish.

 Then - your engine might actually run terribly and you might not be able to get it to run at 900 because if that's been missing for the whole time you have had it then someone before you might not have noticed either and may have messed with the dizzy position and fuel mix to get it to run.

So you will want to check your timing as well, get a cheap strobe and get the dizzy set right.(Haynes or bently will show you how) - this is not hard or complicated , and will only take a few mins - there are plenty of guides online .

If it's running fine then great, if not then - look for air/vacuum leaks, etc and troubleshoot - if you suspect someone has messed with the fuel mix then get a garage to set it for you with their analyser and they will get it spot on.

Then last thing - listen to it and hope that noise has gone! 🤪

nicci21paul said

what a confusing topic idle screw  timing whirring sound coming from engine sounding soo complex

i know, i'm very new to these engines and slowly trying to get my head around it.

so the idle screw is related to the timing? i thought that was set by the belt and the dizzy. i'll re-read the threads and have another crack at what i need to do.

thanks for the help

The idle screw at the back of the throttle body only adjusts the idle speed nothing else, 950 to 1000rpm is book setting for a fuel injection car, I run mine at 1000 rpm as things start to rattle at 950.

Timing is adjusted by twisting the dissy, clockwise to advance it and anti clockwise to retard it.
Is so hard to get a timing light into the inspection hole with all the stuff in the way I never use a timing light light and do it by ear, you can get near to where it's suppose to be by the marks on the cam and dissy, mark where is dissy is currently set and if you do start to mess with it you can always set it back to where you started is it all goes pair shaped….

squideatingdough said

Hey, don't get overwhelmed - you have a great car to learn on and it's all quite easy if you take your time and read the guides 👍

thanks mate, the golf was running reasonably well when i acquired it so i'm guessing the motor decided it didn't like the idle screw and spat it out. that was probably the pop and hissing sound i heard while driving the car on the highway.

i'm hoping the screw fixes it once its back in but it has spurred me on to do more so i'll check the setup of the WUR, CS valve and thermo switch a long with the fuel pressure settings once the car is running again.

I'm also going to remove the rocker cover and give it a lick of paint and new gasket and just make sure all looks good under there.

cheers, Richard

mark1gls said

The idle screw at the back of the throttle body only adjusts the idle speed nothing else, 950 to 1000rpm is book setting for a fuel injection car, I run mine at 1000 rpm as things start to rattle at 950.

thanks mate, i appreciate your advice and everyone else's on this forum. so much help being offered is awesome.

thanks everyone!

If you are removing the cam shaft cover clean out the gauze while it's off, plug up the vent hole and leave it to soak in something like Gunk engine degreaser for a day and wash it out via the vent hole to flush the mess out of the gauze.

Engine Cleaner & Degreaser | Halfords UK

Shop around as 1st link I found.

6UiLE said

i'm hoping the screw fixes it once its back in but it has spurred me on to do more so i'll check the setup of the WUR, CS valve and thermo switch a long with the fuel pressure settings once the car is running again.

if it was fine before, then the idle screw will sort it i bet  

but while you are at it if its not been done for a while, I would just give the timing a once over (Dizzy position) and set it up as per the Bently manual - you can do it sort of by ear but best to have a timing light.

Don't worry about your WUR, cold start or fuel mix/pressure unless you actually have a problem, its a relatively simple system but easy to mess up if you are not confident or not clean when taking bits off - one bit of grit or dust or an old fuel line crumbling as you take it off or put it back on and subsequently getting into fuel lines and then into your metering head, an injector or under the WUR diaphragm can be a right pain - so one of those "if it ain't broke don't fix it" situations.

mark1gls said

If you are removing the cam shaft cover clean out the gauze while it's off, plug up the vent hole and leave it to soak in something like Gunk engine degreaser for a day and wash it out via the vent hole to flush the mess out of the gauze.

cheers mate, i'll give that a crack. may as well do it right while its off the car.

squideatingdough said

but while you are at it if its not been done for a while, I would just give the timing a once over (Dizzy position) and set it up as per the Bently manual - you can do it sort of by ear but best to have a timing light.

Don't worry about your WUR, cold start or fuel mix/pressure unless you actually have a problem, its a relatively simple system but easy to mess up if you are not confident or not clean when taking bits off - one bit of grit or dust or an old fuel line crumbling as you take it off or put it back on and subsequently getting into fuel lines and then into your metering head, an injector or under the WUR diaphragm can be a right pain - so one of those "if it ain't broke don't fix it" situations.

I've got myself a Haynes so hopefully the info will be in there thanks, i'll check when i'm back.

I don't have a timing light though, do you think  a cheap one will do the trick or not worth the risk and go straight for a good brand.

i'm looking at this one on ebay

https://www.ebay.com.au/itm/1X-12V-Professional-Ignition-Timing-Light-Strobe-Lamp-Inductive-Petrol-Engi-D8D4/283756125408

I have just read how to refurb the WUR and I now agree not to touch it if it's not broken. I just wanted to try and refresh as much as I can. I also noticed a refurb kit on ebay and the seller is in the same city as me. It sounds like he knows his onions on the k-jet so I thought he might be a good contact to have.

https://www.ebay.com.au/itm/0438140021-Warm-Up-Regulator-Repair-Kit-Non-Vacuum-Altitude-Compensation-WUR/222968243998

I'll check the 3 fuel pressures first before i mess with the WUR.

cheers!

6UiLE said

mark1gls said

If you are removing the cam shaft cover clean out the gauze while it's off, plug up the vent hole and leave it to soak in something like Gunk engine degreaser for a day and wash it out via the vent hole to flush the mess out of the gauze.

cheers mate, i'll give that a crack. may as well do it right while its off the car.

I've repainted my rocker cover a couple of times in the 20 years of ownership and give the gauze a good clean out every time, the gauze can easily get blocked and cause excessive blue smoke from the exhaust as the engine can't breath properly.

Good time to do as you need to degrease it before painting and also a time to upgrade to a Mk3 Golf style rubber rocker cover gasket.

https://www.ebay.co.uk/itm/Rocker-Cover-Rubber-Gasket-Stud-Set-VW-Golf-MK1-MK2-MK3-1-6-1-8-GTI/401337633300?fits=Plat_Gen%3AMK+III&epid=1338149002&hash=item5d71964a14:g:kIwAAOSwtYJbrg3M


You need to change the studs in the head to fit the rubber gasket as the cork gasket studs have a little collar on them to seat the cork gasket and stop you squashing it to much, the 4 longer studs in the kit you don't use. Or buy 8 new bolts to fit the rocker cover and do away with a stud….

Timing Light - for what you are going to use it for just get the cheapest one you can find! - I think my one cost about £15.

Cam cover gauze
poke out any major bits with some fine wire through the holes in the mesh and Fill the cavity up from the top with cheap dollar store oven cleaner and leave it overnight then give it a good old pressure washer blast and i bet it will be nice and clear.

WUR / Fuel pressure
Do you have a reason to mess with it? - if not, then until you have your other bits sorted what's the point of messing with it?

Watch this a few times and you will have an understanding of what each bit of your fuel system does.
https://youtu.be/a4fJAfXYxWk

with a timing light just make sure it is inductive pickup, they hook over the plug lead. older style fit inline with lead and plug, and can be a bit of a mare to get a decent connection. if you can find one with an advance dial this is a bonus, but not strictly necessary

easy to check on a kjet, its set to 6 degrees BTDC with the vacuum line disconnected and plugged.

in layman's terms, unscrew the big plastic bung on the top of the gearbox. run the car up till its nice and warm, then disconnect vacuum line from distributor, block the end of the pipe. point your light in the hole, the big diamond on the flywheel needs to line up with the arrow on the bellhousing.

once the engine is running tip top andf you run it on proper 97ron+ fuel you can add yourself a little more advance. Around 8 degrees is a good place to start, or in layman's terms, move the diamond so it appears appear a little to the right of the gearbox marker

have a read of this thread regarding timing belt setup, ignore all the setup procedures but the picture of the flywheel applies to you
https://clubgti.com/forums/index.php?threads/how-to-diagnose-and-tune-your-mk2-digifant-gti-8v.124949/

this thread is good for all the kjet testing basics, again ignore the setup procedures plus any of the fancy 16v sections. the cold throttle enrichment part does apply if its a later cabrio/rocco, easy to tell look for the switch on top of the throttle body. if you have one thats for cold throttle enrichment. if not there, its too old to have this:
https://www.clubgti.com/forums/index.php?threads/how-to-check-repair-and-tune-your-mk2-corrado-1-8-16v.195423/

mark1gls said

Good time to do as you need to degrease it before painting and also a time to upgrade to a Mk3 Golf style rubber rocker cover gasket.

thanks mate, I've got one sitting in the spare room I ordered I while ago and never got around to fitting. I'll check which it is before I install it.

squideatingdough said

I think my one cost about £15.

WUR / Fuel pressure
Do you have a reason to mess with it? - if not, then until you have your other bits sorted what's the point of messing with it?

I've just ordered this one at 35 bucks which equates to around 15 quid I think thanks.

https://www.ebay.com.au/itm/12V-Professional-Ignition-Timing-Light-Strobe-Lamp-Inductive-Petrol-Engine-J4U3/164029520922?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20190212102350%26meid%3D4c763905356e4056a368d32512693ff1%26pid%3D100012%26rk%3D6%26rkt%3D12%26sd%3D333483953244%26itm%3D164029520922%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100012.m1985

the car used to be sometimes hard to start but it only gets driven every couple of weeks so that could be part of the problem.

after reading the refurb guide I'm not going to take part the WUR now unless the fuel pressures indicate an issue.

rubjonny said

easy to check on a kjet, its set to 6 degrees BTDC with the vacuum line disconnected and plugged.

once the engine is running tip top andf you run it on proper 97ron+ fuel you can add yourself a little more advance. Around 8 degrees is a good place to start, or in layman's terms, move the diamond so it appears appear a little to the right of the gearbox marker

this thread is good for all the kjet testing basics, again ignore the setup procedures plus any of the fancy 16v sections. the cold throttle enrichment part does apply if its a later cabrio/rocco, easy to tell look for the switch on top of the throttle body. if you have one thats for cold throttle enrichment. if not there, its too old to have this:
https://www.clubgti.com/forums/index.php?threads/how-to-check-repair-and-tune-your-mk2-corrado-1-8-16v.195423/

thanks mate, I watched this YouTube earlier which I thought was pretty good apart from the SA accent and he doesn't mention plugging the vacuum line.

https://www.youtube.com/watch?v=GXvTH1dczmA

I do run it on 98 so I might try your tuning tip cheers.

mine does have a microswitch on the throttle body but only has one wire connected which looks like someone removed deliberately. I'll have a read of the thread to try and understand how it works.