Sign in to follow this  
Followers 0
karl1985

Eratic idle possible ecu update

27 posts in this topic

hi all,

hi have owned a mk4 golf now for a year now but had nothing but trouble with the engine cutting out and eratic idle.

for a while sensors were poping up on vag com that needed replacing ie. coolont temp and lanba sensor.

i replaced the following sensors and vw cleared the fault codes but the problem was still there.

they then scanned vi vag com a week later and the engine speed sensor poped up.

i replaced the speed sensor but the fault was still their.

they then told me that my ecu requires a upate that will cost a hours labour £70. not bad.

But there was a catch. they told me that if my ecu did not accept the update i would then need a new ecu and throttle boddie at a cost of £1095. (what a price jump)

can anyone tell me if this i true or if anyone as had this updae done as i could really do with getting it sorted but cannot afford a £1095 if it all goes wrong.

MK4 GOLF

1.6 16V (AZD)

2000 X REG

ANY HELP WOULD BE HIGHLY APPRECIATED

Share this post


Link to post
Share on other sites

Hi!

Can you describe a bit more in detail when it cuts out?

Thanks!

Share this post


Link to post
Share on other sites

once the engine as warmed up it starts playing up. revs dropping right down to about 500rpm then bounces right back up again and then down which ends up with either my revs bouncing all over the place or the engine stalling.

also the engine stalls when stopping at a juction or lights. this can be quite often as in all day every time i stop and then the next day it could be fine with no problems at all with all the power restored.

but most of the time it just does the following:

eratic idle(when rev nedle drops, the main headlighs start dimming at the same time the needle drops).

hesitation on pull off.(1.2 fiesta left me at lights from stand still) what going on lol

cutting out when stopping and sometimes when i dip the clutch to change gear or ease off the accelerator around a corner which is very dangerous as you losse the power steering aswell.

also not shore if this is releated but there i a load mechanicle clicking sound when i reverse and a squeally sound when driving in a certain rev range.

Share this post


Link to post
Share on other sites

Hmm.

Could be all manner of things.

First of all, it sounds like you could have an air leak, so check all your air pipes into the engine.

How's the battery condition?

Can you check the earth leads to body as well.

When was it last serviced?

The loud click could be a CV joint? Does it click again when you go forward?

Share this post


Link to post
Share on other sites

its just been serviced by myself about a week ago which included oil,oil filter, air filter, spark plugs and even a new set of coil packs but this as made it a lot worst over the last week.

what about the update? doyou think vw are trying to con me.

as for the clicking sound it only happens in reverse. i even dipped the clutch but it still makes the noise.

Share this post


Link to post
Share on other sites

Try another VW garage or try an indie VAG specialist. See that they say when they hook it up.

Share this post


Link to post
Share on other sites

Check around the inlet manifold - check all the hoses for leaks, check vacuum pipes too.

Share this post


Link to post
Share on other sites

Hi all,

same engine, exactly the same problems, all sensors looks ok in vag com, coil packs are changed, throttle body cleaned and adapted, but revs are not stable all the time.

Four or five days idling is fine, but then one or two days in the weekffs.gif revs are erratic.

I spent a lot of time with google looking on reving problems, but still did not find exact solution.

Next step according to Cruisers advice i will check vakum pipes around the EGR and servo.

Karl please public if you find the solution.

regards

Share this post


Link to post
Share on other sites

Hi all,

I have a MK4 VW Golf 1.6 16V AZD Year 2001, and I'm having exactly the same problem....I've read all sorts of posts suggesting various reasons and to be honest, I'm losing hope. VAG COM doesn't show any error messages. I've changed coolant temp sensor, cleaned and adapted the throttle body, cleaned almost every connector with contact cleaner, changed sparks several times....and now I'm thinking of having the coil pack changed. I've read that some of you'd changed it and it doesn't seem to have any effect. What would you advice me to do?

....I'll give you a brief explanation of my problem, just to make sure you're having the same one. The car is OK when it's cold or when not fully at operating temp (90 degrees), but once it gets into operating temp the revs start to fluctuate. It sometimes even goes down to 500rpm, shaking the engine, but it eventually stabilizes without me doing anything. It mostly happens during summertime, when it's hot, or when I'm driving in a traffic jam. It's not all the time, 3 out of 4 days it's gone, but it keeps showing up.

Could it be the coil pack? I'm starting to think that some of the sensors may overheat and start to give wrong data to the ECU, cause it only happens when the engine gets hot. Please help! It's beginning to get incredibly annoying. Nobody seems to know the reason.

Please share some info with me if you have any progress on the topic. Thanks!

Share this post


Link to post
Share on other sites

Also have an AZD engine in 2001 Golf, have had it 12 months and now on 117K, covered 16K in this time.

Have had a few problems which could help, as follows.

1. Coil Pack Failure - showed in VAGCOM as misfire on the effected cylinder, so doubt if a failed coil pack would cause your symptoms.

2. Poor acceleration and bad idle running was not serious but noticeable - No faults on VAGCOM until 1 morning very rough at low revs ,CEL came on and confirmed EGR errors with VAGCOM, removed and cleaned EGR but no better, blanked off EGR and running problem was resolved, However ,as expected, CEL and EGR errors until EGR replaced.

3. Clean MAP sensor, this made a huge difference to acceleration as temp sensor tip was covered in oil/gunk so I believe was not giving correct inlet manifold temperature.

I would suggest blanking the EGR as it may be failing, also clean the MAP.

Simple jobs which may help to identify the problem without spending any money.

Post back if any other info required to compare blocks with VAGCOM

Share this post


Link to post
Share on other sites
Also have an AZD engine in 2001 Golf, have had it 12 months and now on 117K, covered 16K in this time.

Have had a few problems which could help, as follows.

1. Coil Pack Failure - showed in VAGCOM as misfire on the effected cylinder, so doubt if a failed coil pack would cause your symptoms.

2. Poor acceleration and bad idle running was not serious but noticeable - No faults on VAGCOM until 1 morning very rough at low revs ,CEL came on and confirmed EGR errors with VAGCOM, removed and cleaned EGR but no better, blanked off EGR and running problem was resolved, However ,as expected, CEL and EGR errors until EGR replaced.

3. Clean MAP sensor, this made a huge difference to acceleration as temp sensor tip was covered in oil/gunk so I believe was not giving correct inlet manifold temperature.

I would suggest blanking the EGR as it may be failing, also clean the MAP.

Simple jobs which may help to identify the problem without spending any money.

Post back if any other info required to compare blocks with VAGCOM

Good calls! +++

Share this post


Link to post
Share on other sites

Qualityman, there is a flap in plastic engine cover for hot/cold air regulation,

I think that common fault is that flap is stacked in hot position due to gas cylinder controlling flap fault.

When I fix that flap in cold air position idling is still sometime erratic, but softer and not so many catting outs as before.

You wrote about erratic idling when it is hot and in the crowd, it is very possible that your engine gets hot air when it should be cold.

Check when you put off plastic cower flap should be in position to ensure that engine gets air from a side, not from exhaust manifold.

I changed coil packs, but this is not solved problem.

I note something interesting when erratic idling occurs, disconnecting connector from gas vapour canister stabilizing revs,

again reconnecting connector erratic idling coming back ??????

Next I will clean MAP

KGS is it difficult, can you explain procedure of MAP cleaning.

Regards

Share this post


Link to post
Share on other sites

Niske

The MAP is on the inlet manifold next to the oil dipstick. It is mounted with 2 torx screws to the manifold, and can be cleaned with some alcohol.

Did you try to block off the EGR?. Its easy to try this, just remove the 2 nuts/studs and flip over the metal gasket which is between the EGR body and the engine block. The hole in the gasket is not central, therefore when you flip it, it blocks the hole.

The EGR is held on with studs and nuts. The nuts will probably not come off the studs, without unwinding them, and its quite likey the will get bent on removal. I replaced mine with a couple of bolts.

Good luck.

Share this post


Link to post
Share on other sites

Hi guys, sorry for the late response, I wasn't in town for couple of weeks...

...Thanks for the suggestions, I appreciate it!

...Lets get back on the topic... Since I last wrote here, I had the car diagnosed twice. A friend of mine told me that models after 2001 will show coil pack failure when checked with VAGCOM, so I did check it. It showed nothing, apart from bad contact of the lambda probe power supply. I sprayed the probe's connector (the one just over the gearbox) with contact cleaner and hoped that this might solve the problem (I still hadn't read the things that you had previously posted), but NO. The car was fine for a couple of days, then again, erratic idle and sluggish acceleration if I'm not pushing it to the metal. I called the mechanic, had the car diagnosed again and it showed no faults. What a surprise.

Yesterday when driving it for at least 120miles out of town the erratic idle occurred again when i stopped at the first traffic light. Pulled over immediately and took off the plastic cover over the engine (with the air filter and the flap that Niske mentions inside), hoping that this will make it better, but it made no difference...I just wanted to try whether the direct cold air into the throttle body will settle the rpm-s.

To Niske: I've checked the flap inside the plastic cover, and I think that it's not working, cause when I took it out and tried to heat it with hot water it didn't move at all...or maybe it reacts slower, or at higher temp, I don't know. I called the dealership to check if it's sold separately but it comes together with the plastic cover and an air-filter inside (around 160EUR)...I'll try fixing it at cold air position, see what happens...

To KGS: Thanks for the tips, man. I'll surely try everything you suggest. The thing is, I'm sure you know, that the loss of power is not that noticeable and the VAGCOM keeps showing nothing. It really starts to get annoying when everyone says that there's nothing wrong with the car. So thanks for writing. I'll start with cleaning the MAP sensor this weekend and if it doesn't do any difference I'll then try to blank the EGR. I'll keep you posted on that...Hope it will do the trick!

Thank you both for your time! Have a good one!

P.S...Please keep me posted on anything more, you find useful. TX!

Share this post


Link to post
Share on other sites

...Yesterday the weather was fine so I decided to check the MAP sensor... and just as KGS explained in his case, the tip of the sensor was covered with some kind of greasy black gunk (probably because of the exhaust gas recirculation system, or smth else). I used some alcohol and a small, soft brush to clean it, cause the gunk wouldn't fall by itself. After I'd cleaned the sensor carefully, I put it back on its place....and....started the engine...

...And guess what...I couldn't believe the difference in the dynamics of the car before and after I've cleaned the sensor. It felt as if I'm driving a car with 20% more power. I really hope it would stay like this, cause I'm starting to like it. Thanks for the advice, KGS. I owe you one!+++

...Sadly the RPMs remain unstable. Next weekend I'll try to fix the plastic flap in cold air position, and blank the EGR after that. Wish me luck, I'm going to need it. I'll post my results here, next week! Talk to you soon!

P.S...KGS, which part of the EGR system was the faulty one in your case. Have you changed it already? Did you manage to solve the bad idling problem?

Share this post


Link to post
Share on other sites

Pleased the MAP cleaning helped. The improvement in the engine power/response was also amazing on mine. The only part you can replace on the EGR system is the EGR valve/solenoid assembly, as it is one complete unit. The VW part number is 036131503R, got mine from eBay, they are common items to SEATs and SKODAS, and its worth googling. The idling did improve after replacement, think the EGR had been failing for some time but not badly enough to give any codes. This is a sealed unit and really cant be cleaned, but flipping the gasket, which will block the port to it, would prove if this is causing your problem. It will give an ‘Emissions Workshop Error’ but the car will run normally and will prove whether the EGR is part of your problem.

Good Luck

Share this post


Link to post
Share on other sites

Update on Erratic Idle Problem...

I've fixed the plastic flap in cold air position, but it doesn't seem to make any difference with the RPMs. The revs are still fluctuating from time to time...

I'm blocking the EGR tomorrow. I'll do it by flipping over the metal gasket between the EGR Valve and the engine block, just like KGS suggested. And then I'm planning to drive the car for at least a week, to check whether the valve's been causing the problem.....

I'll keep you posted! Have a successful week!

Share this post


Link to post
Share on other sites

Cleaned map. I found just a bit of sludge on sensor.

No noticeable change in dynamics, but four days without idling problems.

I will see if something changes for another few days before blocking EGR.

Regards

Share this post


Link to post
Share on other sites

Update on Erratic Idle...

EGR is the word I've been searching for...+++

To all of you with erratic idle problems...Check the EGR valve! I'm ordering a new one tomorrow. Thank you, KGS!

Good luck!

Share this post


Link to post
Share on other sites

Glad you got to the bottom of it, remember to adapt the new EGR with

VAG COM.

All the best

Share this post


Link to post
Share on other sites

HI all, intersting thread here as my pals car is a 2001 1,6s AZD engine code car and this has been displaying the same issues, wher ethe car would rev fine when throttle pressed but idling was very rough and erratic and it hunts on the verge of stalling.

The throttle body was shot so that was changed. Some other parts (some mentioned in previous posts) have also been eliminated by swapping them out with off the shelf new parts temporarily.

Codes from diag tool my mechanic pal used (maybe elsa or vag com - cannot remember) showed problems with barometric sensor and thought that there could be an air leak but this has been swapped / tested. One other odd thing is that there seems to be no earth whena probe is connected, for this barometric sensor either. After many hours of various checks, he suspects ecu, but will check out earthing points and the fusible link under the battery first.

It's been a nightmare of a problem to cure so far!

Cheers

Dek

Share this post


Link to post
Share on other sites

hi im new to this site sorry for jumping in ive got a seat leon although does have the 1.6 AZD engine my car broke down few months ago and wouldnt start andwhen it did it ran like a dog with 3 legs , so i took it to a garage who hooked it up to there computer and a number of faults came up includeding system bank 1 to lean ,voltage short to B+ (didnt knowe what that meant really), random misfire and a number of other faults including EGR and lambar so the garage replace my EGR and lamber clean my TB £750+VAT later my car was running perfect apart from running 0.01% lean at idle the garage decided that this is down to me having an aftermarket induction kit fitted which to be honest has been on the car 2 years and had no problems .

So one month later as i was going to Blackpool (ok i did hit 110mph at one point) my EML came on so called AA out and fault code came up sayin system to lean which id suspected considering it was lean at idle so must bit alot more lean at 110mph <so anyway had that cleared few weeks later EML is back on so i call AA out again fault now is EGR and lambda whish was replaced with Brand new parts direct from VW so had them cleared once again a few more weeks go by my cars idle start becoming erractic when warm to the point where it shake the engine and as describe in other post cutting out when steering applied ,only on certain days tho and after a long drive other days its fine o and EML light on again now im in a dilemma really my cat has decided to melt its insides so its rattling like a metal ball inside so need to have this fixed before i go back to the garage as i know they will prob put that as the cause .

My question is will my aftermarket filter affect this and what can i do myself to check this idling problem im sure it cant be EGR or Lambda as there new they have got 12 month warranty tho just in case

Share this post


Link to post
Share on other sites

What filter is it? The K&N ones are sometimes too oily and the oil gets dragged through to the MAF which then send faulty info.

Replace the filter with a normal job and see what happens for a while. Then if all is good, replace with a Pipercross cotton job (no oil)

Share this post


Link to post
Share on other sites

not a K n N a fleabay special does my car have a MAF or a MAP i search for the answer but get confused

Share this post


Link to post
Share on other sites

Hi all, I have been having very similar problems with a golf of mine. I bough tit with the head gasket gone and after rebuilding the head I have no end of idling problems. Numerous fault codes came up to begin with, started with replacing all the coil packs this made it run a lot better. Then cleaned throttle body and replaced lambda sensor, this helped further and got it to run up to operating temperature 90 degree. Once it hit 90 degrees though the engine management light came on along with the EPC light. Replaced EGR valve, adapted throttle body and MAP sensor, and no change. The idle is a little unsteady, but hits 90 degrees, throws up the EPC light and eventually starts to hunt and then goes into limp mode and wont rev up at all. If you shut the engine off it wont restart until it cools down again. But when it does cool down starts and runs fine until it hits 90 degrees. Any one got any ideas???

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0