Startup - hi revving, then low revving, pop!

[Squire 0]

Hi All,

 

Just got in my Rado, started her up and my heart started to sink. Engine turns over, bursts into life but then revs high (prob about 3 grand - must admit didnt check), then drops low again to almost stalling, then revs hard again, then there was a pop. Almost like a bang but not quite so loud. The sound came from the engine bay and sounded a bit metallic. Anyway, turned off and tried again - same thing happened but the bang happens at random times. I thought of maybe starting her again and leaving it for a minute but im a bit scared I could do some serious damage. I turned the engine off after about 7 seconds because of the noises.

Last drove her yesterday without any indication of a problem looming. Wasnt driving her hard either.

 

So any ideas? start her up and see what happens or be cautious and get a mobile machanic out?!

Its a 1995 VR6 with 124K on the clock. Last serviced in August.

 

Cheers

Steve

[CorradoVR6-Turbo 0]

You should get vag com on there to check for codes,could be cam sensor on crank sensor,saying that it will still run with a faulty cam sensor and wont start if the cranck sensor is at fault.

 

Check the wiring on the big round multiplug engine harness for any corroded and snapped wires.

 

Other than that prey... :lol:

[Squire 0]

Thanks for that. Ill have to find someone with VAG COM. The vw specialist near where i work charges £70 to hook it up :(

 

I cant find any broken wires and the contacts on the multiplug look good. did squirt some WD40 in there though and dried it out.

 

Well.... engine starts and the revving seems to have gone, still got that "clack" periodically though. Seems to be from the lower part of the Engine towards the bulkead.

Would taking it for a quick spin around the block be unadvisable? (i dont mean quick, snails pace is fine!)

 

Bugger!

[CorradoVR6-Turbo 0]

what miles is on the girl? have the chain guide been done?

 

If it has a mechanical noise i would advise against it untill you know what the fault is.

[Squire 0]

Shes done 124K.

Looking through the service history the upper chain front and rear guides were replaced 20/3/2007.

 

Can i attach files on here? i could make an avi clip with sound.

 

Cheers

[CorradoVR6-Turbo 0]

Shes done 124K.

Looking through the service history the upper chain front and rear guides were replaced 20/3/2007.

 

Can i attach files on here? i could make an avi clip with sound.

 

Cheers

 

Yes you can attach a file,give it a go.

 

put in a request to use someones vagcom in your area.

 

viewtopic.php?f=1&t=7209

[Squire 0]

Unfortunately I cannot attach the file. Had to trim it a lot. Its a wmv file now as i used movie maker. The forum wont let me upload a wmv file.

 

pants :( !

[mattkh 0]

Hi

Put it up on youtube

[Toad 0]

Where in southampton are you? I have VAG COM. And live in Winchester. (Please say somewhere nearby.....)

[Squire 0]

Hi,

 

Ok good idea. I pop it on youtube and put the link on here. The clip makes it sound like someone putting their finger in their mouth and making a pop sound!

 

I live in West End. J7 M27 is the nearest exit.

 

Back in a mo.

 

 

Thanks

[Squire 0]

Hi,

 

The link is: http://www.youtube.com/watch?v=M-s59WqycME

 

Ive chopped off about 20secs at the start is it didnt make that clanking noise. Just revved a bit hard then calmed down (by itself). Towards the end of filing the engine almost died falling to about 500rpm or something.

 

Cheers

[CorradoVR6-Turbo 0]

its poping back through the intake,(or is that you :lol: )so it has a missfire...it sounds gash or mabey its the camera phone? sound like it has chain noise..could be the recording.

 

Best get it plugged in or a mechanic on the job :?

[Squire 0]

Yeah the clip makes it sound like a misfire - i think thats just down to the quality of the film clip.

 

Rado being looked at Monday morning. I'll let you know the diagnosis as soon as I know. Fingers crossed its not too big a problem!

[dr_mat 0]

That sounds well bad..!

Maybe it's slipped a cog on the timing chain?

[bigpants baby 0]

Yeah the clip makes it sound like a misfire - i think thats just down to the quality of the film clip.

 

Rado being looked at Monday morning. I'll let you know the diagnosis as soon as I know. Fingers crossed its not too big a problem!

 

Isv clogged & plastic damper damaged?

[CorradoVR6-Turbo 0]

bigpants baby ,thats good thinking 8)

[Squire 0]

Hi All,

 

Thanks for the suggestions/advice. I managed to get in touch with Alan White the former Autotechnik guru. He came to look at the car at the start of the week and diagnosed that the problem wasn't major afterall. phew

The breather had been damaged and eventually broken apart - it sits somewhere near the manifold at the back of the engine and silences airflow. As it was damaged the engine management was "out" resulting in the engine running too lean so there was misfiring. This was happening in the engine somewhere rather than backfiring so it sounded like a clacking sound. So yeah not something metallic afterall. Anyway in case you're interested the part number is 021133429a. Cost just over £20 for the part. Might help someone in the future?

 

Alan fitted the part today and shes running fine again :) Might go for bit of a drive this weekend, ive missed the fun!

 

Cheers

Steve

[CorradoVR6-Turbo 0]

bigpants baby you were spot on 8)

 

Glad its sorted mate :D