1.6 16v engine violenlty cutting out while driving

[Joe.p]

Hi,

I am new to this site and looking for advise please.

I have a 51 plate golf mk4 1.6 16v with 78K on the clock. Its running fine appart from a intermitant fault which is worrying me. Basically I can be driving along for example at 30mph in 4 gear when quite violently the engine revs will drop by about 1000 rpm then with in a second come back to normal. It has happened whislt driving at slow speed in first gear, and at 70mph on the motorway aswell. It has happened 5 times in the space of 6 weeks like twice in one day then nothing for ages. No warning lights have light up!?! Appart from that the car drives and idles very smoothly. I am worried that when i happens being so violent that its putting alot of stress on the gear box etc.
Has this happenend to anyone else? or does someone know what it maybe?

Thanks

Joe

[Juvi]

I am having the same problem, infact it happened this morning and on thursday. However what has happened the last 2 times the oil light started flashing then a orange wanring light next to the 20mph mark I dont know what that is. So on Thursday I assumed it may be oil i put some oil in orange warning light was still there but it drove fine. Sunday the light had gone and drove fine today the juddering started again red oil light then orange warning light. I pulled over turned the engine off which had cut out anyway , restarted and it drove ok but still with the orange warning light ! Cany any one help ?? Thanks in advance!

[Eshrules]

ok, now first of all...

have you checked serviceable items, such as oil filter, air filter, oil level, coolant level?

my next step would be to check the throttle body, just to be safe, for any obstructions or for any gung that could be clogging it up and making the butterfly valve stick.

there is always the good old MAF issue (do a search on MAF..theres loads of threads on here about it), but i doubt that would cause a spontenous cut out, could be worth a check though.

there have been a couple of threads recently about the oil warning light and cars cutting out, ill try to find them and collate them on here for you ;)

[Toff54]

Sounds bad - i've had the problem also turned out to be cam belt tensioners. If you've got 78k on the clock you should see about getting it looked at.

Cam belts what replacing every 70k with these cars so if you've not had that changed look into it. - cost me £400 all in all they changed cam belt, tensioners and the water pump

Toff54

[Joe.p]

Thanks for your response,
I have had the cam belt replaced about two years at 60k (ish).

That seams like a logical thing that might be faulty seeing as no warning lights come on. Fortunalty it hasnt happened again since i placed the message on this forum.

I will contact VW to see if they will look at it seeing as its still under warranty. I dont want it to break and completely mess up the engine.

Funnliy enough i emailed my local VW dealer in South Ruislip which I use. I explained the problem in detail. They havent come back to me yet to say what the problem might be. I am wondering if there £90 p/h fee is good value!?!

Cheers

Joe.p





Sounds bad - i've had the problem also turned out to be cam belt tensioners. If you've got 78k on the clock you should see about getting it looked at.

Cam belts what replacing every 70k with these cars so if you've not had that changed look into it. - cost me £400 all in all they changed cam belt, tensioners and the water pump

Toff54

[ini]

Sounds like an electrical problem.

I had the same problem in a golf GTI, and it turned out to be a bad HT lead shorting onto the block.

[Juvi]

I had my cam belt chandged to 60k as well , im having mine serviced for the 80k service tommorow so we will hopefully see what the problem is ! I will keep you posted.

[Captain Answer]

Sounds like an electrical problem.

I had the same problem in a golf GTI, and it turned out to be a bad HT lead shorting onto the block.

That'd be my guess n'all, HT, plugs or the ECU.

Cam belt tensioner going tends to make the engine virtually unrunnable

[Joe.p]

Thank for your responses.

You guys are certainly more helpfull than VW.

It has to be said this has been the least reliable car i have had :( which is
a shame because i like it. Weird as my last car a M reg VW Polo was the most reliable thing ever, never went wrong. Infact my sister now has it going strong with a solid 115K on the clock.

The car hasnt been playing up of late, which is good. I guess.

If its a fautly HT lead could i tell by looking under the bonnet, or would i need to get a proffesional to run tests?

If anyone knows of a good VW speacialist in the middlesex area, let me know?

thanks

[ini]

Dodgy HT leads can be difficult to spot, unless you can make the problem reoccur when it is dark, then you should be able to see a spark.

It is best to just replace them.

Also check coil/s (if not part of HT leads), power relay, and crank sensor if applicable.

[Captain Answer]

Thank for your responses.

You guys are certainly more helpfull than VW.

It has to be said this has been the least reliable car i have had :( which is
a shame because i like it. Weird as my last car a M reg VW Polo was the most reliable thing ever, never went wrong. Infact my sister now has it going strong with a solid 115K on the clock.

The car hasnt been playing up of late, which is good. I guess.

If its a fautly HT lead could i tell by looking under the bonnet, or would i need to get a proffesional to run tests?

If anyone knows of a good VW speacialist in the middlesex area, let me know?

thanks

Ring round your local auto factors and get a set of HT leads and plugs, they shouldnt be more than £30 for the lot and you can rule that straight out when you've changed them ;)

If it persists get it hooked up to a test rig, it could be something very stupid like a damaged wire feeding your ECU or one of the connected circuits/sensors which is intermitantly breaking contact

[Joe.p]

Well, I took my car to the garage for a diagnostic check and that found nothing wrong. I was half expecting this as not warning lights came on with the fault.
Then a car electrics speacialist took a long look at the car, the only fault he could find was the the lead which connects the alternator low voltage light was faulty so he repaired that. Last week in a final attempt to put this problem to rest i had the fuel filter changed. The mechanic thinks that it could have been the problem as it was the original VW one and when he drained the tank said the last bit of fuel was very mucky. Probably what has been happening is that when the tank runs low it complelty blocks the filter for a second starving the engine if fuel. The problem hasnt happened since, so i am hoping its fixed now.

Does any one know how often your supposed to get fuel filters changed?

Cheers

[ini]

The fuel filter is a service item, and should be changed every few years or so (depending on car)

A very dirty fuel filter would not cause the symptoms you describe, you would experience gradual decline in power, not sudden stalling.

Intermittent electrical problem (basically no spark) is the culprit.

ECU relay, bad earth etc, could be a number of things.

Tracing problems that only occur now and then can be very difficult, especially if no error codes are logged.