Limp Mode

[bbb]

Passat 98 Estate (1.9tdi 110, afn engine) is now in permanent limp mode, ignition off then on is not clearing as it used to with the MAF problem.

Is there anybody in the Notts \ Derbs area with a fault code reader?

Car was running ok into work but on stopping then turning the engine back on it revved breifly to around 2k. Curiously didnt rev when leaving work in the afternoon.

Recent MAF was a GSF not a VW part.

Thanks
BBB

[bbb]

<Bump>

have been getting a loud vibration at tick-over which smoothed out at over 1K. Suspect it may be a leaking exhaust, would that cause over or under boost issues and trip the limp mode?

anybody recommend a reliable specialist in the derby area??

thanks
bbb

[4l04ever]

Hi

I am based in Brierley Hill, but will be in Rugeley on Saturday morning with my Tdi Passat. If you can meet me at Rugeley, I can read your codes and clear them. I have a code reader and a VAG-COM system.

I will do the checks for you, and you can buy lunch at the pub!


I will be at my mechanics place, so if it is anything serious, you can speak to him regarding getting anything checked over further etc. He also has a Tdi Passat.

[dan_1907]

Hey bbb, did you ever find the cause to this problem? As my AHU is doing the same thing and i cannot find the problem, even though I am a qualified VAG technician. Lol.

Please please please help me.

Many Thnaks Dan.

[cazyp]

Hey bbb, did you ever find the cause to this problem? As my AHU is doing the same thing and i cannot find the problem, even though I am a qualified VAG technician. Lol.

Please please please help me.

Many Thnaks Dan.

Are you getting any fault codes?

[dan_1907]

Hey, thanks for replying.

I have one fault in Engine Electronics, 'fuel cut off solenoid - mechanical malfunction' because i stripped the insides of the solenoid as it used to activate by itself and cut the engine whilst driving.
But this fault was in there for a few months before this 'limp mode' started happening.

[cazyp]

Difficult to advise given your job lol.
All of the following can occur without throwing up codes:
Have you checked the vac hose from the ecu for kinks and the connection at each end? I assume you've checked the other vac pipes. (is the one from the turbo red on that engine..?)

Poss clogged intake manifold - you can inspect via the connector below the EGR valve. Or any other air intake restrictions.
Could be the EGR solinoid valve. Have you tested its duty cycle in vagcom? Also check the boost pipe at the back that leads off from the egr as this is prone to splitting.

Fuel restriction. Low pressure or clogged filter/fuel pick up. Clogged exhaust or cat. (Evidently these will sometime' throw out codes.)

There is also a dome screen that clogs up in the bottom of the airbox I believe that might be restricting air intake. There are alsoflexi pipe and ridged pipe from the airbox 'elbow near the MAF that lead to the turbo intake which may be worn/split?

Hope something may help!

(Does yours have the rumble at idle as in the OP's question?-I suspect his alternator pulley was stuck.)

[dan_1907]

Difficult to advise given your job lol.
All of the following can occur without throwing up codes:
Have you checked the vac hose from the ecu for kinks and the connection at each end? I assume you've checked the other vac pipes. (is the one from the turbo red on that engine..?)

Poss clogged intake manifold - you can inspect via the connector below the EGR valve. Or any other air intake restrictions.
Could be the EGR solinoid valve. Have you tested its duty cycle in vagcom? Also check the boost pipe at the back that leads off from the egr as this is prone to splitting.

Fuel restriction. Low pressure or clogged filter/fuel pick up. Clogged exhaust or cat. (Evidently these will sometime' throw out codes.)

There is also a dome screen that clogs up in the bottom of the airbox I believe that might be restricting air intake. There are alsoflexi pipe and ridged pipe from the airbox 'elbow near the MAF that lead to the turbo intake which may be worn/split?

Hope something may help!

(Does yours have the rumble at idle as in the OP's question?-I suspect his alternator pulley was stuck.)

Yeah, i have checked all the vacuum lines and are ok, however i did recently order a long length of samco silicone hose to replace them all.
And it does have the red turbo hose.
Also the EGR has been blocked off but made no difference.
I've checked all fuel lines, filter and air filter (both filters are only 4500k old)
Although the manifold is full of crap, and i will get round to cleaning it as soon as the new gasket arrives.

but i found today that if i turn on ignition, erase fault 'fuel cut off solenoid - mechanical malfunction' then start the engine and check fault codes again, turn it off and take key out, then disconnect code reader then start engine again it runs 100% fine, until i turn it off. which is strange, as i've asked many vag technicians and they've all said that fault wouldn't cause a 'limp mode' as it was there before running problems started.

just after a definate cause really as i love the car to bits, but i'm fed up of throwing money at it and not getting anywhere.
ideally i need bbb to reply with the cause of his, but i can't message him as i need to post 10 threads according to this site

And i'm not 100% sure about the rumbling, as my immature side came out in me recently when i decided to put a straight through exhaust on it. so its pretty rumbly anway

[cazyp]

Is it possible that the injector timing is out?
From what I've read a faulty fuel cot-off solenoid can cause limp mode - which seems to be the case here but mistimed injectors can throw out the code you are getting..?

[dan_1907]

Is it possible that the injector timing is out?
From what I've read a faulty fuel cot-off solenoid can cause limp mode - which seems to be the case here but mistimed injectors can throw out the code you are getting..?

Ok. Thanks for your help, it is due a cambelt change pretty sonn anyway, so i will aim to get it done next week and check the timing.
Plus i will try a new fuel cut-off solenoid, as i found out today they are only £35+v.a.t