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Model specific boards => Golf mk4 => Topic started by: Serhado on 29 April 2019, 20:55

Title: New to the forum problems already
Post by: Serhado on 29 April 2019, 20:55
Hi so i just bought my first golf and its a 1.8t gti Yreg

Car was all fine however one problem has arised when i full throttle the car it hesitates and doesnt seem to be any more urgent than say half throttle and also when the revs reach to about 4 5k rpm again it hesitates as if ive completly let go of the throttle sometimes to the extent where it feels as thoigh ive pressed the brake pedal instead.
What could be causing this issues anyone with similar problems?
Title: Re: New to the forum problems already
Post by: Mr_Orange on 29 April 2019, 22:47
Welcome to the forum.
Hesitation as you describe is a difficult one to advise on. Have you been able to scan the car for any fault codes?
Is it in good shape in terms of service and usual stuff, such as air filters replaced etc?
Title: Re: New to the forum problems already
Post by: Serhado on 30 April 2019, 14:32
Hi thanks for the reply yes i have a fualt code p0172 which isnalong the lines of car running too rich.

Also have noticed my coolant tempreture guage rises extremely slowly and in town barely manages to get to 90°c and on motorway sticks to around 70 80° i mean because i cant step on it extremely hard because of the given fault at hand mototway speeds it rarely gets anywhere near 90
Title: Re: New to the forum problems already
Post by: Simeon on 30 April 2019, 16:31
Ok, so first step is a new coolant temperature sensor, easy to change and cheap (do it when engine is cold!). If this is faulty then you could be getting incorrect readings to ECU and the dash - common cause of rough running as will cause it to run rich (P0172 fault code..)

If you still aren't getting up to temperature on the dash after changing sensor then you need a thermostat and coolant flush - thermostat will be stuck open preventing the engine getting up to temp.

Clear codes, take for a run and rescan and see what you get.

Also, give it a full service if it is new to you and you've not done it already
Title: Re: New to the forum problems already
Post by: Serhado on 30 April 2019, 20:20
Thanks alot mate do you have a place i can buy geneiune vw parts from or is eurocarparts good enough
Title: Re: New to the forum problems already
Post by: Simeon on 01 May 2019, 11:21
Genuine VW parts from the dealer (I tend to go to Skoda as it's sometimes cheaper) or just buy a known brand from GSF/ECP/Ebay, think last one I fitted was a Febi one and was fine, cost £10ish

Do double check, but I believe you want 059-919-501-A for the temp sensor

eg: https://www.ebay.co.uk/itm/OEM-Germany-VW-AUDI-SEAT-SKODA-4-PIN-WATER-COOLANT-TEMPERATURE-SENSOR-059919501A/191571988595?hash=item2c9a949073:g:GqUAAOSwVtZaKBW9

I tend to reuse the o-ring and clip off the old sensor, but some prefer to replace - some sensors are supplied with these parts, some without, so check when you buy if you're bothered
Title: Re: New to the forum problems already
Post by: Serhado on 01 May 2019, 20:34
Thanks for your reply mate but bad news ive got a few problems mechnaics saying turbo needs changing

P0102 Mass airflow sensor signal too low intermittent
P1200boost pressure control valve(n249) mechanical malfunction
P1297 prrssure drop between turbo and throttle
P1137 fuel trim bank 1 (add) system too rich

Looks as tho i may have been sold a fualty car and because its private cant do f**k all
Title: Re: New to the forum problems already
Post by: Simeon on 02 May 2019, 11:16
You could also just need to fit a temperature sensor.. :p

Fair enough, I'd get a second opinion though before chucking a grand at a new turbo etc [or scrap it and buy another]
Title: Re: New to the forum problems already
Post by: Serhado on 02 May 2019, 13:27
Second hands going for 80 quid on ebay and 150 labor so the cost dont worry me im just thinking the turbo is stuck the guy i bought it off has only using this for nips to the shop what not hes barely used the turbo i reckon i just need to some how clear the gunk build up because boost comes in fine only when you rev to say about 4 5 k does ot hesitate then a little while later the eml will come on.

He said theres nothing wrong with the sensor it comes to 90 then the thermo opens and cools it back down to 60 70. If im not mistaken everyother car ive owned has always stuck at a healthy 90 once it warmed up.

Im getting another opinion today lets see what he says
Title: Re: New to the forum problems already
Post by: barrym381 on 03 May 2019, 00:46
Second hands going for 80 quid on ebay and 150 labor so the cost dont worry me im just thinking the turbo is stuck the guy i bought it off has only using this for nips to the shop what not hes barely used the turbo i reckon i just need to some how clear the gunk build up because boost comes in fine only when you rev to say about 4 5 k does ot hesitate then a little while later the eml will come on.

He said theres nothing wrong with the sensor it comes to 90 then the thermo opens and cools it back down to 60 70. If im not mistaken everyother car ive owned has always stuck at a healthy 90 once it warmed up.

Im getting another opinion today lets see what he says

Your problems nothing to do with the turbo don't take it back near the mechanic your using it will be a sensor at fault or a boost leak
Title: Re: New to the forum problems already
Post by: Serhado on 03 May 2019, 14:16
Thank u mate hopefully gona havw it looked at today
Title: Re: New to the forum problems already
Post by: Serhado on 04 May 2019, 00:15
Just been back from the mechanic which is a friend also his sayi  the turbos gone aswell. Also the tempreture gauge issue is actually the guage its self not the sensor that also came up. He said a certain part of the turbo has fell through and gone i to the cat said he can hear it rattle i  there, in turn i am having variable boost hence the hesitation some times and it. His sayin the ocar otherwise is in good condition
 His anit of a mod head and has almost persuaded me to buy a mamba turbo replacementwhat do you giys think
Title: Re: New to the forum problems already
Post by: Dr Mike Oxgreen on 04 May 2019, 11:39
Just been back from the mechanic which is a friend also his sayi  the turbos gone aswell. Also the tempreture gauge issue is actually the guage its self not the sensor that also came up. He said a certain part of the turbo has fell through and gone i to the cat said he can hear it rattle i  there, in turn i am having variable boost hence the hesitation some times and it. His sayin the ocar otherwise is in good condition
 His anit of a mod head and has almost persuaded me to buy a mamba turbo replacementwhat do you giys think

I'd find another mechanic.  If this one thinks that "part of the turbo" has "fell through" and ended up in the catalytic converter it must have found its way past an inlet valve, survived the combustion process, and then exited via an exhaust valve before becoming trapped in the cat, then I'd look for a second opinion.
Title: Re: New to the forum problems already
Post by: Serhado on 04 May 2019, 12:32
Lol this was the second opinion both have now said turbo
Title: Re: New to the forum problems already
Post by: Simeon on 05 May 2019, 14:45
As above, the guy's explanation sounds like bollox. However, you can't diagnose via a forum unless you change parts and it sounds like you aren't a spanner man, so you're gonna have to trust your mate knows what he's doing.

How did the chap work out the clocks are at fault and not the temp sensor?

Title: Re: New to the forum problems already
Post by: Serhado on 05 May 2019, 22:15
3 electronic fualts came up on his diagnostics app
Central locking
Rear speaker
Instrument clustertemp gauge

Along with the turbo faults i mentioned earlier even though that was througg a different mechanic my friends app was pretty detailed to be fair
Title: Re: New to the forum problems already
Post by: barrym381 on 06 May 2019, 06:16
3 electronic fualts came up on his diagnostics app
Central locking
Rear speaker
Instrument clustertemp gauge

Along with the turbo faults i mentioned earlier even though that was througg a different mechanic my friends app was pretty detailed to be fair

Is the guy using a cheap diagnostic app as I've never heard a speaker store a fault code and I've had over 30 mk4s

Get it checked  via vag com or post your location and see if a member that's confident with vag com to check your car 
Title: Re: New to the forum problems already
Post by: Serhado on 06 May 2019, 09:15
East london area anyone willing to come give it a once over is free to
Title: Re: New to the forum problems already
Post by: Serhado on 07 May 2019, 23:18
So i just changed the temp sensor and gsf car parts had %60 discount going today so thought ill change the MAF sensor too....... well ive just had time to drive the car now and the temp guage works as it should now and the car does not stutter any more fingers cross this solved it.

If it has firstly i cant believe something as small as a coolant temp sensor is causing so many problems and secondly i almost biught a new turbo because of this. The eml is still on but will wait to see if it goes off on its own if not i will reset it. After ive done a few miles. The car pulls decently right now.

Next i will be changing the n75 valve and clean thw throttle body just to make sure. Nothing else is wrong with the car before i go all out modding.

Any ideas which n75 valve to get?
Title: Re: New to the forum problems already
Post by: barrym381 on 08 May 2019, 02:02
So both mechanics are full of sh!t  :grin: I said all along it wasn't the turbo and I've never looked at the car
Title: Re: New to the forum problems already
Post by: Serhado on 08 May 2019, 08:01
I hope to god you are right. What made you say it wasnt the turbo?
Title: Re: New to the forum problems already
Post by: Simeon on 08 May 2019, 15:36
So the answer (or at least part of it) was in the fourth reply..

Glad it's sorted (ish)
Title: Re: New to the forum problems already
Post by: Serhado on 09 May 2019, 09:45
Right guys after 2 days of decent driving without problems
The hiccups started again. So as already mentioned ive changed the maf and coolant temp sensor. The guage is fine now sticks at 90 in town and drops sloghtly when on the .otorway and not belting it.

What else should i change, i came across a thread where it was mentioned that if your turbo makes a flutter noise when off the gass like a bird churp could be the dv? Alsoblooking into changing the n75 anyone have a part number for this bdw my car is an AUM not a AGU as i previously mentioned.

Even if these were at fualt wouldnt explain the choking i still get when im not on boost between 1k to 1750 revs
Title: Re: New to the forum problems already
Post by: Serhado on 10 May 2019, 11:10
Also coming across the n249 valve too i am so baffled now. Also one of my codes were
Boost pressure control valve n249 mechanical vault.

Could this be the problem and just noticing that my temp guage again is not really stable again gets to 90 in town after say 20min of driviing but motorway again drops significantly back to the 70 75s
Title: Re: New to the forum problems already
Post by: Simeon on 10 May 2019, 22:11
If the temp gauge is dropping when cruising you need a new thermostat. Unlikely to be causing too many issues as the problem with the sensor being faulty is the ECU gets false readings re the engine temp so fuels incorrectly.

If you're getting a few different fault codes then best bet is to take it to a reliable mechanic who has experience of these engines to diagnose (ie; avoid the last two you went to who had no clue).
Title: Re: New to the forum problems already
Post by: Serhado on 11 May 2019, 10:25
Gues so anyone know any good vw mechanics in and around london
Title: Re: New to the forum problems already
Post by: Serhado on 12 May 2019, 21:52
Changed the n75 valve today car seemed slightly better but still erratic boost. Got some carb cleaner today will tackle the throtle body tomorrow night see if that fixes anything. Also im begining to think the tempreguage issue is either a thermostat problem now or the Haas item i biught from ecp is shiddy and gone already because 1st day or two it worked well
Title: Re: New to the forum problems already
Post by: Wazzzer on 13 May 2019, 20:31
A faulty temp sensor won't shut off the choke so you'll be burning fuel for fun. N249 is the valve which gets a signal from your ECU and controls when your DV opens. It's completely unnecessary though as the vacuum from your engine will open it so you can bypass it, plenty of guides around on google to show you what to do.

Which make was the thermostat? Some are better than others, I have used a Meyle item and has been good for a few years now.

As for your electronics questions a dead speaker will show up on VCDS if you still have the standard VW headunit.

The temp sensor fault code will show up as you've unplugged the sensor, might have also been the same with the MAF sensor. Also what make was the MAF sensor? Genuine Bosch units may seem expensive but I've not known a cheap one to last very long at all

BTW I would steer clear of those mechanics, as Barry said they are talking a LOT of sh*t. I bet they would have offered to buy the car off you too
Title: Re: New to the forum problems already
Post by: Serhado on 15 May 2019, 15:19
Thanks for your reply wazzer. The temp sensor was a Haas from euro car parts. Basically the temp guage sits at 90 in town but always drops to 70 75 on motorway speeds. So im guessing thermostat is turning on too quick and cooling the car down prematurely.

So recently i cleaned the throttle body out was prettty gunked out but not to a extent where i thought it was out of the ordinary considering the car was running rich according to previous fualt codes. And i just fitted a forge 008p dv. Car feels normal under 2k revs now this could be due to the throttle body clean. But in boost again its very erratic lots of flat spots between 2.5 to 3.5k then it picks up again does feel better at least im not having the sudden powerloss as if ive hit the brake. I personally cant think of anything else just picked up a bargain mk4 r32 alloys with almost new tyres for £200 as well car looks great but this situation is killing me now cant enjoy the car :sad:.

Basically so far:
Ive changed the maf bosch oem
Changed the temp sensor Haas brand
Changed the dv forge 008p
Changed the n75 valve to a prefix E not the J everyone seems ti slag off
Cleaned the throttle body
Checked most of the hoses i could without going to deep seem fine no visible or audible leaks.
Got a turbo cleaner now gona run that through it today any one done this before where do i exactly spray this?

Also any other suggestions?
Title: Re: New to the forum problems already
Post by: Serhado on 15 May 2019, 15:26
Also any ideas how to post pics since photobuckets down
Title: Re: New to the forum problems already
Post by: Wazzzer on 18 May 2019, 09:02
Turbo cleaner is only good for diesels really

I would bypass the N249 and change the thermostat next. My mate has just had to change both his temp sensor and thermostat on his recent purchase to get the car running anywhere near normal; owners do skip the basic maintenance on these cars due to age and the problems just snowball
Title: Re: New to the forum problems already
Post by: Serhado on 26 May 2019, 00:48
Just a quick update to anyone that ever has this problem in the future i think the dv was at fualt since switching to the forge after a few days of rough running i decided to run some redex through it too just to clean up anything that would ne clogged from running too rich dor ages, the cars been fine for over 2 weeks now.

Boost is good along the rev range car pulls well havent had any fualts come up. Still feel as tho the idle is a bit inconsistent so will change the plugs soon prob covered up from running rich and mis firing any recommendations for plugs?  Also had a sport cat along with a full exhuast system put in couple days ago car sounds ok however i feel like the car rumble low down but as you get climb the revs indont feel as the car shouts more  ut rather if i full throttle it theres a nice turbo suction noise.like a jet engine thrashing do all systems make.this or isit mine only? Similar to what im seeing called a screamer pipe sound.

Anyway ye basically check your DV!!! as it says on ross tech about n249s
Title: Re: New to the forum problems already
Post by: Serhado on 26 May 2019, 00:52
Next will be a remap planning on going all the way to r tech just because people cant fault them. Or any suggestions for remaps around london?

Also i jabe a replacement green air filter on the way and will be doing a water pump and timing belt service before the remap may  get the thermostat done too while im at it.
Title: Re: New to the forum problems already
Post by: Serhado on 28 May 2019, 23:15
Just another update just been to paris and back today not the slightest hiccup with 2 adults 2 kids and a full boot car was great.

Just a quick question where best to get my timing belt kit and water pump from? Need to change these and im ready for a stage 1 map
Title: Re: New to the forum problems already
Post by: Simeon on 30 May 2019, 08:08
Good to hear

Get a kit from the dealer, or a good quality aftermarket brand, Continental/Dayco etc

Did you tell your mechanic mate who horribly misdiagnosed the issue how you fixed it by the way? What did he say?
Title: Re: New to the forum problems already
Post by: Serhado on 02 June 2019, 23:02
To be fair my friend which i said was a mechanic is a actually just a really good with cars generally he does alot of work on his cars japenese generally but he knows quite abut about turbos he actually said it was prob a boost leak. It was the garage owner which he was geting some work done that ran the codes and saod turbo. Then there was the guy who 1st had a look at the car he was just one of our clients and my colluege recommened him.

Mi d you when he comes to the shop now i dont even talk to him i wont even take my car for a brake change with him