Engine Rattle

[Telf 222 2 Cars]

Hi all,

 

I'm experiencing a high frequency vibration on my 1.9 GTI. I can feel it through the floor pan when the engines ticking over increasing as I speed up. There is a weird noise emanating from the cam cover area so I've taken a video of it you can hear it in the video at about 26-27seconds or so.

 

Having just reviewed he video you can hear it as an underlying noise up until about 15 seconds before I revved it too.

 

Anybody think its out of the ordinary?

 

I jacked the car up earlier on the lower engine mount - as soon as pressure is on the jack the vibration can be felt through the jack- hence my concern I have an engine issue

 

Video link below- any help appreciated!

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https://youtu.be/RRlsDHbsEFo

Edited September 29, 2015 by Telf

[Telf 222 2 Cars]

It sounds similar to this video but not as pronounced- yet...

 

[welshpug 1,622]

timing belt sounds suspect, tappet clearance would be first port of call for a rattly top end, some variants of cams are prone to wear.

[Telf 222 2 Cars]

Mei I replaced the belt about 5 K ago - when you say suspect how do you mean?

 

Its not the tappety noise im too bothered about the engines getting on and im building another - its the odd screech noise i think can be heard- or maybe im going potty!

Edited September 29, 2015 by Telf

[hoodygoodwood 70 3 Cars]

Sounds like a mixture of tappet noise from too large a clearance and some sort of ball race noise . The noise in the background ( a rrr rrr sound )could be the cambelt tensioner or water pump on its way out , or over tight . Cambelt could also be rubbing on something - they often touch the black plastic covers . Could be a mixture of many noises , you could try running it for a couple of seconds with the alternator drive belt removed to eliminate those bearings .If the tensioner spins when you turn it with your fingers I would change it , a new one is tight and will not spin - can quieten an engine considerably .

[Telf 222 2 Cars]

Hi Miles,

 

I changed the alternator 3 months ago for a new one. The cambelt, tensioner and water pump were all changed last summer. Having not changed a cambelt before I thought the best way to tension the belt was to apply pressure to the tensioner and i then manually cranked the belt round until it felt tight on the longest run (top to bottom). I then locked the tensioner.

 

So could i have over tensioned the belt? is this even possible to the extent that the tensioner/water pump fail?

 

The engine is tappety-not to concerned at the mo. im bothered about the vibration but on inspection yesterday could only spot this noise. The vibration i mentioned trough the jack is identical to the one i can feel in the car.

 

Ive also changed the rear engine mount and gearbox mount at the same time as the cambelt.

[Telf 222 2 Cars]

Well now Im having random Hesitation issues and misfiring or not starting.

 

Pulled the HT leads off and the dizzy. Made a bit of a new boy error and forgot which lead goes to where from the Dizzy cap to engine( having disconnected the leads completely)

 

Spent an hour scratching my head trying diffeent combinations and got a few shocks off the leads in the process! Anyway eventually it started after alot of banging and popping. Its now running like a complete pig -massive hesitation then a surge then more hesitation- horrible.

 

I'm suspecting the leads may be shot (possibly causing my vibration)

 

Other than that could it be a fuelling issue? I'm at a bit of a loss at the moment!

Edited October 1, 2015 by Telf

[Telf 222 2 Cars]

Bad times.

 

Car broke down on A14. Towed off by police. Massive misfire. Let it cool - got it going - went to mates - played around-changed the ignition amp and coolant sensor. Seemed ok

 

Set off home -down the motorway- As I slowed down massive BANG -pulled over - the entire back box blown open.

 

Thoughts? I can only think a HT lead breaking down and no fuel burning in a cylinder- any advice appreciated

 

Paul

[Tom Fenton 1,525]

First thing first is it running on 4 or not? I can tell by ear but maybe you aren't sure either way.

[Telf 222 2 Cars]

Hi Tom,

 

When it initially starts and is cold - yes its running on 4. Pulls as it should. Once it warms up -no its not. After changing the amp and sensor it was fine. Hence thought it was fixed. It had however had time to cool a bit. Went down the motorway for 10 miles - as soon as I slowed it started hesitating. Got worse then pretty much died apart from I put the clutch in and revved it to keep it running then Bang -split back box.

 

Probably on 2 cylinders (maybe 3) at that point.

[Telf 222 2 Cars]

1x blown back box!

[Telf 222 2 Cars]

to be welded back together- it blew as I passed a bus stop- never seen people trying to take over in Rural Suffolk before!

[Tom Fenton 1,525]

I have had the back box thing happen to me a long time ago on a 405. It was over fuelling in my case due to a knackered water temp sensor.

[Telf 222 2 Cars]

Well the replacement sensor I fitted isn't new but I don't imagine both the old and replaced item were unserviceable.(although its possible!)

 

I've bought a new set of leads and will have a look a the wiring to the sensor (after I work out where it is connected to!)

 

4 years I've had this car- nearly 30 k covered without any real issues- I suppose I shouldn't complain

 

with the amp, leads and rotor arm all new and the sensors changed are there any other major components that could cause this?

[welshpug 1,622]

afm or wiring

[Telf 222 2 Cars]

Broken down again. Im Sat im the car waiting for it to cool / evaporate the fuel off. Leads changed. Seems ok runs fine then after 10mins on a duel carriageway I came off and slowed down. Instant hesitation. Had to stop because it was so bad I wad expecting another back box explosion.

[scbond 15 1 Cars]

Definitely AFM. As Tom said it's overfuellig and quite badly. I've had a back box blow on an old car where the MAF had been left unplugged...ran very badly and the heavy exhaust fumes cause a blockage and it blew (7am in suburban Manchester...was like a shotgun going off hahaha).

[Telf 222 2 Cars]

So im away now for a week with work. When I get back im planning on checking the AFM resistance and the temp sensor wiring. I took the cover off the AFM. The track is quite heavily scored. Does anybody know which pins I should put a multimeter across to test resistance/continuity?

 

Im also going to check the temp sensor wiring to the ECU. Looking ar the wiring diagram the coolant sensor seems to have a connection to the throttle position switch - does this maybe have any relevance?

[scbond 15 1 Cars]

See here for testing: http://www.205gtidrivers.com/articles/e3-injection.html

 

I found the best way to test was to leave it fitted and plugged in and then test with the engine running by using the internal connections. However, if yours is running poorly I doubt you'll have much success doing it that way. Best testing with a 9v battery.

[Telf 222 2 Cars]

Hi all,

 

Today I changed the ECU and Tacho relay.

 

Wiring wise I've checked the Temp sensor to ECU - pin 10 - Good continuity. Temp Sensor to earth- Fine

 

AFM Pin 7,8,9 to ECU Good Continuity

Throttle Switch pins 2 and 3 to ECU - Good Continuity

 

So far I've swapped out the Ig Amp, Tacho Relay, ECU, Temp Sensor and fitted new leads. There are no pins pushing back when the plugs are fitted.

 

I've checked the AFM resistances and ensured smooth operation resistance wise when the flapper moves. All within the limits on the link above.

 

The throttle switch operation resistance wise has been checked as per the link, and the temp sensor.

 

The car still wont run . Sometimes it starts for a short while but idles then dies (like not enough fuel) Other times it starts then misfires with a load bang. There is sometimes smoke coming out the AFM once it stalls which I think is unburnt fuel?

 

Its been running ok until about 2 weeks ago when I went through a flooded road- not far and not deep. As I came out it popped loudly and ever since then its got worse. Could there be an internal engine fault- I'm at a loss at the moment.

 

Does anybody have any other ideas please?

 

Wiring checks are being conducted as per page368 of the workshop manual

 

Thanks

 

Paul

[Telf 222 2 Cars]

A slightly better video of the problem!

 

https://youtu.be/9J7edPFClq4

[scbond 15 1 Cars]

Probably should've mentioned the water incident before...you still on the same tank of petrol as when that happened?

[Telf 222 2 Cars]

Yes its still the same tank although its about to come onto reserve. I'm not following how water could have got into the tank?

 

The first misfire did happen then though. It wasn't deep water but its possible the exhaust may have submerged for a second o two?

[Tom Fenton 1,525]

Have you removed the plugs and leads and checked there is no water around the plug wells? Also check inside dizzy cap.

[Telf 222 2 Cars]

tom I've had it all apart - no water that I can detect.