# 1.8t limp mode



## maximallard (Dec 21, 2011)

Been hitting limp mode in my awp 1.8t 2004 gli, was throwing the pressure drop code ( no check engine light ) and would only go away by clearing, or turning the car on and off. Since then i have done the evap,n249,pcv,sai delete, and played with dv springs. now I only hit soft limp ( goes away if I let off the gas pedal) pretty much stumped, I've logged everything from n75 to maf sensor and can't find any issues, no cel no pending faults nothing. Could my diverter valve be do for servicing? Currently running a 93oct file 23psi boost, I've also cleaned and adjusted the tb, and pressure tested as well, only leak I can find is coming from the valve cover


----------



## maximallard (Dec 21, 2011)

Bump


----------



## maximallard (Dec 21, 2011)

Bump


----------



## maximallard (Dec 21, 2011)

Bump


----------



## Mic17a (Feb 4, 2013)

You need to do a boost leak test. I believe the how to is in the faq


----------



## maximallard (Dec 21, 2011)

Already did that as stated in orginal post, no leaks


----------



## Mic17a (Feb 4, 2013)

Sorry must have skimmed over that.


----------



## maximallard (Dec 21, 2011)

Pretty much done it at all, possible dirty map sensor ? Exhaust leak ? Fueling issue ? I've logged everything and can't seem to hit limp when I get s chance to data log, if anyone wants to see those I can send them to you. Only code I was hitting was 
Fault Found:
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!) 
P1297 - 35-10 - - Intermittent
Readiness: 0000 0000

but when I increased dv spring pressure I stopped throwing this code. And hard limp mode all togther ( had to restart the car to clearlkmp) now I only have to take my foot off the gas. I replaced companents in my pcv system hard limp came back, I've done the deletes since then. Now I only hit soft limp again, everything I do seems to make it better or worse, I no longer throw this code now though


----------



## maximallard (Dec 21, 2011)

Update, my tip was coated with grease, possibly Interefering with the n75, going to go for a test drive and see what happens


----------



## HECTIC20VTurbo (Jul 23, 2006)

the small leak can tigger that limp mode. fix ALL leaks first. service the diverter valve for sure and make sure to use red grease as for high temp and pressure


----------



## maximallard (Dec 21, 2011)

No leaks via pressure testing the TIP, will buy a repair kit for my 007 dv, I've only used the red Mobil 1 grease


----------



## maximallard (Dec 21, 2011)

Can anyone else chime in on this, hear there are a lot of 1.8t gurus here, but activity seems to be low. Only thing I haven't tried is buying a new piston and o rings for my 007. I've data logged and every thing seems up to par, couldn't hit limp mode while data logging. ( personally don't have vagcom had someone else log for me )


----------



## maximallard (Dec 21, 2011)

Bump


----------



## Mic17a (Feb 4, 2013)

Just out of curiosity - when you were doing your boost leak test, did you check your injector cup seats too? It's an easy spot to overlook that's a common problem.


----------



## maximallard (Dec 21, 2011)

Yep even sprayed them with soapy water for ****s and giggles, no leaks, only leak I had was a valve cover gasket, but I replaced that , engine is 100% tight, i have pressure tested cold and hot incase of expansion , but nothing


----------



## maximallard (Dec 21, 2011)

Going to data log again this weekend, and hopefully catch it in the act this time, could a faulty map sensor cause limp mode ? I've tried and older revision spare n75 valve that i kicking around and that hits limp mode as well, what baffles me is the car doesn't throw any codes


----------



## Mic17a (Feb 4, 2013)

Another thing to consider is your wastegate cracking pressure. If the wastegate has ever been tampered with, that can cause it too. Also make sure the nuts for the adjustment aren't loose. Pay attention to how much boost it's making when you go into limp mode


----------



## maximallard (Dec 21, 2011)

Hi, thanks for the assistance, I am unsure if the wastegate was tampered with , I am running a stage 2 tune right now 23psi boost , I have dialed it down with a manual boost controller to 20 psi, limp mode will only hit , low rpm, low boost and low highway cruising speed, limp mode only hit when you gradually put your foot down, doesn't get a chance to go past 5 psi, you can drive like a bat out of hell 23 psi and not hit limp. Only happens low boost, low speed low rpm . Hope that makes sence


----------



## maximallard (Dec 21, 2011)

Going to check the waste gate nuts on the actuator rod if they are. Tight , any way to actually check the adjustment ? Would a faulty map sensor or faulty dv create the symptoms I am experiencing


----------



## Mic17a (Feb 4, 2013)

I had the exact same symptoms before with a frankenturbo GTI. The silicon inlet pipe was cracked allowing unmetered air to get into the turbo. Had an underboost code and would constantly hit limp mode during partial throttle boost, but under WOT driving, it would be fine. I believe this is because under WOT, the car adjusts A/F according to the O2 sensor instead of the MAF. ( i might be wrong, don't quote me on that)


Try removing your PCV valve from your turbo inlet pipe and plugging the hole tight with something. Then see if the car still does the same thing.


----------



## maximallard (Dec 21, 2011)

What would the next course of action be if plugging the pcv cures it , I use to get the pressure drop code , until I fiddled with the dv and delete it pcv


----------



## Mic17a (Feb 4, 2013)

The next course of action would be to make sure you have absolutely no leaks in the PCV system. That includes the O-ring coming from the crank case. On my car, I have the PCV system deleted and I have the valve cover and crank case venting to atmosphere via a hose running to the ground. I live in South Carolina so there are no emissions requirements for me. For liability reasons I cannot recommend it to you. But I will say it works for me. Also check for any leaks with any of the lines running to the turbo inlet pipe AFTER the maf, but before the turbo. 

Also, if you have a forge diverter valve, make sure that the bung on the charge pipe side hasn't come loose. It is threaded.


----------



## maximallard (Dec 21, 2011)

No leaks on my pcv system to catch can, and no leaks on any of the lines coming off the TIP after maf, before turbo. Maybe there is a leak from heat expansion that happens temporarily, but no luck finding it


----------



## maximallard (Dec 21, 2011)

I also deleted the n249, evap, sai, so only lines going to tip are the n75, dv, and pcv


----------



## cmdshft (Oct 17, 2011)

Did you smoke test the motor? I had this same issue, couldn't find any leaks or anything until I smoke tested it.

Found that the intake manifold gasket was bad as smoke was leaking from where it meets the head. Replaced it and no more leak, no more pressure drop code.


----------



## maximallard (Dec 21, 2011)

No I haven't smoked tested it , I've double checked with a normal pressure test , I've checked over the fuel trims ect and everything is in spec. Trying to hit limp while logging, i also have replaced the intake manifold gasket when i did the deletes and it is torqued down evenly, currently logging measuring blocks 032, 002, and 115. Anythjng else i should log?, havent hit limp mode while logging yet. But i sm seeing tiny over boost here and there with requested vs actual


----------



## maximallard (Dec 21, 2011)

17584/P1176/004470 - Bank1: O2 (Lambda) Correction Behind Catalyst: Control Limit Reached

Possible Causes
Intake Air System leaking
Oxygen Sensor(s) and/or Oxygen Sensor Control faulty
Possible Solutions
Check Intake Air System for Leaks (False Air)
Check Oxygen Sensor(s) and/or Oxygen Sensor Control (all of them!)


----------



## cmdshft (Oct 17, 2011)

You should do a smoke test to catch all the leaks. A pressure test alone wont show you all the leaks.

I bet you you have a leak in the system somewhere that you will only see with smoking it. Be sure to check EVERYWHERE for smoke leaking before concluding that you have no leaks.

Also, if you have a boost guage install that has vacuum readings, what is your idle vac at? Normal range is 18-22inHg, if you are lower than that then you likely have a leak.


----------



## maximallard (Dec 21, 2011)

I am -18 to -22 within range


----------



## maximallard (Dec 21, 2011)

Yea last night on pressure test it wouldnt hold on my tire inflater gauge , couldnt find a leak , but a buddy of mine said he felt a cold breeze coming from behind the engine, waste gate area and tip area


----------



## cmdshft (Oct 17, 2011)

Use an actual air compressor if you can. Tire inflator didn't work for me when I pressure tested my 1.8T, I could only hear leaks when I used an air compressor. Also, pull out the PCV valve on the tip and plug it (use a hose clamp to secure it) when pressure testing so you don't put too much pressure into the crank case.

Let me know what you find with the smoke test.


----------



## maximallard (Dec 21, 2011)

I did use an air compressor, i ment the inflater / gauge


----------



## cmdshft (Oct 17, 2011)

Then it makes sense that you didn't hold pressure and you felt air from those areas, that's a big leak area and explains the rear O2 code. I'm surprised it didn't make noise (did it?).

Take the TIP off and inspect.

Inspect the charge pipe off the turbo outlet as well just in case.


----------



## maximallard (Dec 21, 2011)

Ok so i smoked tested no leaks, now im throwing
16727/P0343/000835 - Camshaft Position Sensor (G40): Signal too High

Hope she didnt skip timing *rolls eyes* 
Car seems to be running fine dialed the boost down to 19 psi no more limp, now the ****ty thing is im throwing this timing related code, car runs fine, just doesnt want to crank over on the first try, like its guessing ignition timing, as if the sensor were unplugged or failed.


----------



## cmdshft (Oct 17, 2011)

Check the actual timing with the crank/piston 1 at TDC and see where the cam gear notch sits.

I changed my cam sensor anyway because I am a preventative maintenence kind of guy but I too had incorrect timing with hard starts.

Try replacing the sensor first if you want, it's a 10 min job. The sensor is probably going to run you a hundo or so. But it beats having to physically retime the motor.


----------



## maximallard (Dec 21, 2011)

Wouldnt i throw an incorrect correlation code ? My timing belt is only half way thru its life span. But probably 150000kms on the sensor


----------



## cmdshft (Oct 17, 2011)

Not necessarily. My code was a cam sensor code which persisted after replacing the cam sensor. I saw that my cam gear was off timing by one tooth. After retiming the engine, the code never came back.


----------



## maximallard (Dec 21, 2011)

Ok


----------



## maximallard (Dec 21, 2011)

Timing marks all line up, sensor will be here today sometime


----------



## maximallard (Dec 21, 2011)

Ok sensor cured it, i tappered boost down to 17-19 psi no limp mode yet, no leaks found with pressure test, that o2 sensor code only popped up paired with a "tba didnt start" code. Because i screwed up a throttle body adaption


----------



## maximallard (Dec 21, 2011)

Smoke test* sorry. 
I really got t start editing my posts... Lol


----------



## maximallard (Dec 21, 2011)

Still hitting limp


----------



## Chubby savage (8 mo ago)

maximallard said:


> Pretty much done it at all, possible dirty map sensor ? Exhaust leak ? Fueling issue ? I've logged everything and can't seem to hit limp when I get s chance to data log, if anyone wants to see those I can send them to you. Only code I was hitting was
> Fault Found:
> 17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
> P1297 - 35-10 - - Intermittent
> ...


How did you reset the ecu to come out of limp mode im having a similar issue but honestly i think my turbo might be blown


----------



## Vegeta Gti (Feb 13, 2003)

People don't respond to 7 year old posts.


----------

