Horrible mechanical "whirring" sound coming from the engine

thanks for the suggestions; all fixings are present on the lower cover, 2 hex heads, 1 cap head and the t-bolt from memory. it feels really solid so doubt its that rear tin plate.

it does sound more like its coming from the inlet manifold area or the gearbox. I was thinking could it be something to do with the clutch or starter motor sticking out?

I turned the water pump and alternator by hand and it made no sound or either had much play.

do you have a photo of the tin plates on the transmission please?

I'm thinking about removing the intake manifold for a better look as it must be leaking because when I spray starter fluid in the that direction the revs change.

The piece of tin plate that I had trouble with is behind the  intermediate shaft sprocket, from mmemory you have to take the lower belt cover off to see it. I do remember I couldn't straighten it in situ and had to take it off.

Please have a look at this topic
"Loud and irritating noise from cambelt/generator/waterpump area"

Succes
Kris

To check if the alternator or water pump are noisy just remove the alternator belt completely and start the engine, don't run it for to long as no water is pumped around the engine and the battery is not being charged but you should be able to run it long enough to hear any different.

mark1gls said

To check if the alternator or water pump are noisy just remove the alternator belt completely and start the engine, don't run it for to long as no water is pumped around the engine and the battery is not being charged but you should be able to run it long enough to hear any different.

Thanks mate, I appreciate your input but please refer to my first post.

Oh yes, just read the 1st again….. sorry.

Does the sound change or go away when you rev the car?

It does sound like metal rubbing metal?

Very unlikely but if you have already checked everything else - have you had a look at your cam shaft? Unlikely as the engine would be about to sh1t its guts but you may have a problem In there with poor oil distribution and it's slowly eating itself away - easy to tell once you take the cover off as you will see the wear.
Just thought that because from watching your video it sounds like the noise is near the top of the engine when you go into film the throttle body.

Also, on headphones it sort of sounds like a vacuum leek, but with how loud it is your engine would be really struggling to even run - is it a metal on metal sound? - again hard to tell from the video really, is it possibly a partially blocked pipe kicking out a high pitch noise from a air passing by? - then again I suppose you would hear the tone change when you have the engine a bit of a rev.

You mentioned the gear box side - can you tell if it's coming from there ? Use a long metal bar or screwdriver - put it on the engine and put the other end on your ear and you should be able to get a rough idea of where the sound is coming from .

thanks again everyone for all the suggestions but the last post mentions a lot of things that do add up.

1. It does sound like the noise is coming from the top end so I already suspected camshaft but not sure why that would just suddenly start making a racket without any initial signs.

2. The car does have a vacuum leak that I think happened at the same time it started making that noise.  the car was hard to start and when it did start that was the first time I heard that noise (thought it was too much coincidence for both issues to happen at once)

3. The car does struggle to run and I can't get it to tick over. I need starter fluid to get it going and when it is running (just) and a spray fluid towards the mixture screw on the throttle body that faces the firewall the car revs up (I'm wondering if I've lost the screw).

4. I'm not sure which pipe would be blocked but something strange happened the last time I drove the car before all these issues arose. I was doing about 100kph on the highway then it sounded like something burst in the engine bay and realised air pressure. now when I try and start it there is a massive what I can only describe as a suction sound like when you open throttle bodies with K&N filters on.

sorry for the long and rambling post but I'm keen to get it sorted and have more stuff I want to maintain on the car now I'm gaining enthusiasm again.

all the things above sound connected to what squideatingdough has said but I just can't piece it together.

I'd appreciate any feedback on my plan of attack next weekend when I work on the car. I'm away at work at the moment on a 10/4 roster.

a. remove bottom timing cover and check the tin plate although I'm pretty sure its not that as it went back together well with all bolts torqued up.

b. get a mirror to try and see if the mixture screw has gone; I've already replaced the hose connection to the distributor vacuum pipe in that area.

c. remove rocker cover and check for signs of wear; I really hope its not eating itself alive.

not really sure what to do after all that to be honest. I want to remove the intake and renew all gaskets anyway and I have ordered, intake manifold gasket, cold start valve gasket, injector seals x 4.

and this turned up to assist with any timing belt adjustment required now I have the confidence to work on it thanks to all your help!

PS just noticed from watching the video again that you can hear the rough running from the exhaust note at the end.

it sounds like its cammed but I can tell you unfortunately it is not…

Sounds like one of your main issues is a vacuum leak somewhere. If it was driving fine then pop and it's not and it's changing tone when you spray starter fluid then it's looking to be a vacuum problem.

From your comments you will deffinatly want to take your idle screw out anch check the O-ring - you will be able to get a replacement o ring from any half decent hardware store - or just buy one of those packs that has every size in it.

But if your problem started all of a sudden and made a pop it's unlikely to be the screw - check your large hoses for cracks etc - especially the ones on the back of your intake as that's where your spraying the fluid and saying it's changing the revs. - under your throttle body will be a metal pipe - that also forms part of your vacuum hoses - I had problems with a loose clip on my one that made a pop when it went, on a bloody roundabout in the rain and dark non-the-less…

This was the hose that went POP on my car,


Get the vacuum leak sorted first - track it down with starter fluid and or a long screwdriver listening for it. Then move on to that other sound.

It's not hard to take off the cam shaft cover so just take that off and check it over - it's a 5 min job at best and worth it for the peice of mind.

thanks again mate, sound advice!

sorry i had to laugh at  your hose going pop on a roundabout in the rain, it reminded me of home so much. Not too many roundabouts here or rain either.

I'll definitely go with your diagnosis steps, only thing i'm a bit concerned about is winding out the idle screw. i've never been that great at fine tuning cars and wondered if it will be difficult to set up again. should i count the number i wind the screw out or will it be really easy to set up afterwards just based on the rev counter reading?

thanks in advance

hey

that screw is not a problem at all to set, all it does is basically allow a bit of air to the engine to keep it running when your idling so when you put it back in just tighten it up till closed then back it off like 5 turns - start the engine and slowly wind it back in while running and get the revs to the 900rpm mark - you can do it by ear easy enough but if you wanted you can just turn it a little then check it on the speedo to see what the rev-counter reads.

if i were you, once that vacuum leak is sorted and if the noise is still there i would drain the oil from the car - see if any chunks of metal come out, take the sump off and look at the bottom end from below and take a look under the cam cover as well.

do you have a copy of the Bently manual? you are going to need to start hitting troubleshooting sections as i think as you fix your problems you may find more - and to be honest, you could not be working on a better engine as apart from the K-Jet's these engines are great to learn on and the k-jet is not too bad once you have got your head around how it works.

If that idle by-pass screw turns easily by hand then your o-ring is bad.

Count the number of turns to remove it write that number down.  Go get a replacement, then prior to re-installing it wrap the threads and threads only with Teflon Tape (white or yellow) White 2 wraps, Yellow one.
Return it to your count.

Or bottom it out then back it out about 1 to 1 1/4 turn.

thanks squid and briano; I'll definitely take that advice. I will also look for further maintenance required as I'm really enjoying working on the car and learning how it all works.

I've just ordered the parts to make a fuel pressure tester and wire my old pump relay on a switch.

I'll report back regarding the vacuum leak and status of the awful noise after nexts weekends efforts.

cheers!

FYI as you talked about the mixture screw…

The screw on the back of the throttle body (7mm spanner) is idle speed only.

The mixture screw is in a small tube in on top of the meter head and needs a long Allen key to adjust it. It's best not to touch the mixture as it's only very small adjustments and best done once everything else is spot on, timing etc and use a CO gauge, about 2% is what you are looking for.

Pictures I've posted before.

View topic: 1800 DX idle low (Update Now Sorted) - The Mk1 Golf Owners Club

well I think I might have found my problem regarding rough running and hard starting.

I'm guessing there should be an idle screw in here…



and that you shouldn't be able to poke a piece of wire through in to the throttle body…



so I've ordered one of these and will install it before I diagnose any further.



I ordered from overseas so it might be a while before it turns up and I can report back. I'm hoping the JH has the same screw type as the DX.

https://www.google.com/search?client=safari&rls=en&q=Idle+screw+for+Golf+MK1,+Golf+MK2+GTI+%2B+16V,+GTI/Scirocco+/+EX/DX/EG/KR16V&ie=UTF-8&oe=UTF-8
 

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!

I used an old pressure gauge that I had laying about and used a piece of rubber hose to attach it to the fuel rail as it is Digi.  Worked well enough to diagnose a bad fuel pressure regulator and tell me my main pump had an issue.

On the Digifant, there is a way to set the Static timing of these critters that don't require guess work, a second person to hold the idle steady, and you don't have to have the car up to temp with the fan cycling one time.

I have been using it for years, and all it requires is that you use a digital Volt/Ohm/Meter, there is no plugging off of hoses and such either.

You set the timing marks as follows.
Remove the cover on the transmission and set the finger to the (O) mark on the Pressure plate.

The Cam dimple on the back side of the cam is even with the valve cover tin (not re-bar). Or set the cam to the 0 | T mark on the front rear timing cover. The dimple on the back means it is one less thing to take of.

Loosen the Distributor Clamp bolt (13mm) and remove the cap, rotor and shield, then replace the rotor, and verify that the middle of the rotor in in the Stamped hash mark on the Dizzy's side frame.  If you clean the shield well, then you can mark the cut on the plastic cover and you never have to take the rotor off, as you see that the dimple in the plastic on the 12:00 side of it is in the Dizzy stamping…

Once you have aligned all the marks.

Carefully remove the Plug off the Hall Sender.
With the Plug removed, you are going to carefully pull the rubber boot cover off the plug exposing the wires and pins.  Once you have the cover off then replace the plug on the sender.

Turn the car ignition to run.

You will see a green/white wire (Hall Sender wire).  You will place your Positive Probe in that hole.  The Negative lead of your DVOM is placed on Frame Ground (earth).

If you have 0V you are probably in time to 0 TDC if the signal is 10 or 11V then you are slightly off.

Rotate the crank, I use the cam bolt till the 11V goes to 0….Then check your crank, if it is now at 6TDC mark, or the hash you are good to go.  If not, then slowly rotate the diz CCW (Counter clock wise) till you see the 0 to 11V switchpoint, then fine tune it to 0 and set it all back together you are done, and your car is timed to 6tdc…

Take the probes out, carefully remove the plug from the Diz replace the rubber cover, and re-connect the plug.  (take caution as the plastic bits get brittle and can break that I why I tell you to remove the plug to remove the rubber boot).

Read more about it here….
https://www.reflectionsandshadows.com/cabby/static-digi.html

Works like a charm, and you want to never worry about the pulley marks on a Digi, You want the Crank at 0, the cam at 0 and the Diz in the middle of the hash.

https://www.reflectionsandshadows.com/cabby/static-digi.html



TECH TIP

If you wrap the threads and the threads only on the IDLE by-pass Screw with 2 wraps of Teflon tape prior to replacing it, you will find that even when the 0-ring goes again, you will not have a vacuum loss, as the tape won't allow the air to pass.  When going back with the new screw turn it in until it stops then back it out 1/4 to 1/2 turn and you should be at your adjustment.
 

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

other thing if you're adjusting ignition timing the base idle at the very least will need to be checked, so you need to warm it up for that anyway. ideally set CO too, but unless you have pro equipment I wouldn't bother. the DIY sniffers are not very accurate in my experience. tbh I recommend you print off my digifant guide and take it to local garage for them to do for some back pocket tax free money

edit: oh and you shouldn't be touching any hoses or anything else when doing the ignition timing, you only disconnect the blue sender plug. you only need to disconnect and plug the breather if setting the base CO, and even then only if you suspect the oil is heavily contaminated. the only reason you disconnect the breather is to rule out any fumes from the breather affecting your CO measurements. you dont need to disconnect this hose when doing the base idle either