Strange problem

Musty Pie

Musty Pie

Musty Pie

Soldato
Joined
6 Jan 2009
Posts
6,488
Location
Hertfordshire
Ok first of all i never venture into motors because i know VERY little about cars, and i fear for my life in this part of the forum.

however I have a problem with my car which im hoping some people here might be able to help me with

My car (again no comments on the car just help me find out what the problem is :p) Mk2 Seat Ibiza Cupra Sport 8v gti

Its a strange one so bear with me while i try to explain it the best i can with the little technical car knowledge that I have.


The car has been running fine for the time that i have owned it. However recently (After a period of time being off the road due to traveling japan) the car seems to have developed a strange engine cut out/power down problem.

I will try put the above into a scenario:

Last night when driving home from an evening class i approached a turning which needed a gear change down. Approaching in 4th gear i started to change to 3rd and the car completely cut out. Power loss the lot. Power steering goes, full breaking goes however the lights stay on. It doesn't spatter and die, it just dies completely. The only lights on the dash that come up are battery and oil as if the cars key is in the ignition and turned once only to initiate battery power?
The car will then need to be restarted of which it will do but it seems to struggle unless i press the throttle a little.

This has happened multiple times since putting my car back on the road after returning from japan. And only seems to happen on a gear change down. Its pretty worrying and im avoiding driving it at the moment because if it dies on a corner my handling and breaking are extremely compromised.

I have also now noticed that changing down a gear (at night) the lights (front beams) will dim, along with interior lights on the dash. Could this be related? This happens almost all of the time.

Any indication of what to check for would be great, as i am avoiding taking it to a garage at the moment as funds are tight (Japan made my bank balance hurt )

I have a friend who is going to pop over soon with a VAGCOM reader to see if anything gets flagged up but other then that im at a loss?


Cheers guys
 
i doubt youll find much on vagcom.

my bet, after having fiddled with plenty of those 8v lumps, is gunked up throttle body (idle control is a stepper motor on the throttle flap) which can no longer react proprly

dead pcv system allowing unmetered air in.

crank sensor (unlikely to die after a period off the road though)
 
Hopefully Vagcom will give you an idea but in all honesty this is something where you should get someone who knows what they are doing to diagnose the problem and rectify it, it sounds quite dangerous, I had a similar problem with an old car where an alarm fitter somehow wired the wind screen wipers so that when I used them the engine cut out, not fun on the motorway!
 
Matt82 said:
i doubt youll find much on vagcom.

my bet, after having fiddled with plenty of those 8v lumps, is gunked up throttle body (idle control is a stepper motor on the throttle flap) which can no longer react proprly

dead pcv system allowing unmetered air in.

crank sensor (unlikely to die after a period off the road though)
Click to expand...

This mirrors what someone on the Ibiza forums has said.

Are they easy to get to and clean? May as well give this a crack before taking it to a garage. It happens as i take my foot off the revs and then engage the clutch to down change.
 
yeah. pop out, get a can of carb cleaner (its a spray, should be a few quid). get someone to put their foot on the throttle pedal (engine off!) and do some cleaning around the butterfly

the pcv connects from the front of the block to the throttle body area. when youre off the throttle, the manifold vacuum draws in loads of air that shouldnt be escaping in and causes the idle control to go wrong.

the crank sensor. ive known two 8v golfs to have this issue, but i dont see why other golfs wouldnt be as prone as the sensor is typically quite a hardy part

£25 for the pcv pipes and £50 for the crank sensor
 
Have a check of all the hoses and stuff, I had something similar in the rover and it was just a hose that had cracked and worked it's way off.

edit - vacuum hose maybe was it?
 
I had a 8v golf gti a few years ago which used to cut out in a similar way to yours (but mine was random, not when changing gear).
It was a common electrical problem on mk3 golfs which needed the ECU power relay to be replaced. I hooked it up to the laptop 4-5 times but nothing ever showed up in VAGCOM about it.
 
Matt82 said:
yeah. pop out, get a can of carb cleaner (its a spray, should be a few quid). get someone to put their foot on the throttle pedal (engine off!) and do some cleaning around the butterfly

the pcv connects from the front of the block to the throttle body area. when youre off the throttle, the manifold vacuum draws in loads of air that shouldnt be escaping in and causes the idle control to go wrong.

the crank sensor. ive known two 8v golfs to have this issue, but i dont see why other golfs wouldnt be as prone as the sensor is typically quite a hardy part

£25 for the pcv pipes and £50 for the crank sensor
Click to expand...

It went on my 1.8 20v Golf the other week.

Your spot on with the advice though. Throttle Body, if possible get it off and give it a proper clean.
 
just an update to those who want to know

Worked on the car this weekend at my mates garage.

Put the car on VAG reader and it came back with an air in take sensor error (not sure if that terminology is correct)

After stripping out the induction kit/air filter thing that the previous owner had fitted we found he had just bunged the sensor and wire in one of the large pipes behind the air filter itself. As a result the wires had sheared and the sensor was floating around inside.

After cutting and re soldering the wiring and mounting the sensor into the plastic cone on the front of the air filter (drilled the plastic and use some bonding agent to stick it in) all seems to be dandy so far.

We also checked and cleaned all relivant piping (not dirty at all in the first place) and also gave the throttle body a good clean out (also not very dirty)


Does this make sense, and could this have been causing the issues in the first place?
 
Well so far it seems to have yes.

No Dimming lights when changing down and no engine cut outs yet (sorry for slow reply seem to forget i posted in motors, its scary unknown territory)
 
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