996 TT oil level not working

[mat59]

Hi all,

I've alluded to this in a couple of other threads. My 'new to me' 2001 996 Turbo has a fault with the oil level readout from the digital display. The readout either shows it as being over full or completely empty. The previous owner used a specialist that changed the oil level sensor many years ago, which didn't work so then believed the clusters were at fault and required replacement. Since I picked up the car I've used a different specialist who diagnosed the fault to be with a sensor. They recommended I change the oil level sensor (again). They've since replaced the sensor, which again, has not worked. They now believe another sensor on the engine needs replacing, which requires an engine drop. I've told them to only initiate this work if they are certain it will fix the problem as it s going to be quite expensive on labour. Otherwise I will be faced with a bill for this work plus having to spend out on new clusters etc.

The oil pressure dial works fine. I'm at a loss as to what is going on. I guess this could be sensor, wiring or cluster related!

Any ideas as to what is should be looking at?

Apologies for all the posts I've been making but I'm keen to get the car into good health so I can use it as it was intended.

Cheers,

Matt

[White987S]

I wouldn't drop the motor just for the sensor. Maybe in the future, if other, major, work is required. Just ignore the gauge. Monitor your oil level. And change it with the correct volume every 5,000 miles, or yearly.

 

I know there's no dipstick on a 2001 but does it have a functioning low oil indicator light of some sort? If so, go by that. If the low oil level indicator comes on, add 1/4 litre to 1/2 litre until the lights goes off. Motor on. Rinse & repeat.

Edited October 18, 2014 by White987S

[mat59]

I wouldn't drop the motor just for the sensor. Maybe in the future, if other, major, work is required. Just ignore the gauge. Monitor your oil level. And change it with the correct volume every 5,000 miles, or yearly.

 

I know there's no dipstick on a 2001 but does it have a functioning low oil indicator light of some sort? If so, go by that. If the low oil level indicator comes on, add 1/4 litre to 1/2 litre until the lights goes off. Motor on. Rinse & repeat.

Hi,

What you've said makes a lot of sense. Can anyone confirm there is a secondary low oil indicator light that will come on if the oil gets really low? My plan is to change the oil for the correct amount every 3-5k Km's anyway. I'm not planning on doing big miles in it. The turbo also has the oil pressure gauge. Would this register some odd readings if the oil level was low?

[Silver_TT]

You could still have good oil pressure but be low on oil.  Just my 2 cents, but oil is one of the most important things to monitor on these cars (or any car for that matter).  The 996TT does burn oil, especially if you use a thinner oil like 0w-40, so it's important to keep a tight eye on it.  I would go with the GT3 dipstick, if possible as jpflip stated.  Maybe your best course of action is to see if either this or the sensor replacement can be done by an ace mechanic without dropping the engine?  I don't know, but my guess is someone who is really sharp should be able to do it.  I do a lot of DIY but for some things like this it pays to just outsource to someone with very deep experience who can shave major time on a job.  Might be worth your while to ask around if there are any especially sharp Porsche mechanics in your area (they're usually -- but not always -- indys in my experience). . ?  Keep us posted on the progress.

[mat59]

Thanks so far guys,

I really do want to get this fixed. I've searched all over for answers to my query but I can't find anything. Are there any other sensors that may fail causing my inaccurate oil level sensor or could this be a wiring or cluster issue?

[binger]

From what you told us it sounds like both mechanics are parts changers. You need to get to the root issue before you invest 20 hrs of money and find out its a connector, bad wire or cluster. If I were doing the diagnosis I would start by looking at the Ohm specs of the sensors. Porsche will give Ohm specs= level 1/4, 1/2, full tank of oil as a reference.

 

I would then pull the suspect sensor connecter and substitute it with a resistance decade box. IE: A box that can substitute any Ohm value. I use this tool a lot to prove out bad sensors with out buying parts and saving unneeded labor costs. Now you can pinpoint if that sensor is bad or good. If the substitute Ohm value matches Porsche Ohm specs the sensor is good and you have to start looking at connectors, wires, or the cluster.

 

This is what I would say to your mechanic. If you are so sure that the sensor is bad I am willing to pay you for all parts and labor. However if it dose not fix my issue I will pay for parts and you refund me all unnecessary labor cost. The bottom line, someone that know how to diagnose this needs to be found.  Just my 2 cents. Hope this

helps.

 

PS: this is what a decade box looks like.

 

http://www.amazon.com/Extech-380400-Resistance-Decade-Box/dp/B00023RTZO/ref=pd_bxgy_hi_text_y

 

 

 

[Silver_TT]

I doubt it's the cluster, but electrical problems like this are a PITA to isolate sometimes.  To binger's point, have you started from square 1 and read the codes (using a PIWIS, Durametric, or PST2)?  If there are any codes, could you state what they are?  I agree that throwing parts at the problem is not the best approach.  Hopefully it's throwing a code(s) and will make troubleshooting much easier.

[binger]

I agree its probably not the cluster but its part of the system that's I put it in the mix. We fix clusters and that is not an issue with the ones I have come across. The the reason I did not say anything about pulling codes is a lot of shops out there that claim they specialize in Porsche don't even have Durametric. The other problem out there is the new techs even at the dealer they rely on OBDII too much. A lot of the 25+ gold master techs at Porsche have to show them how to diagnose the old school way and the newer guys are resistant to learn. The method I mentioned is one of the best and fastest ways to prove if the sensor is good or bad with out putting a part on the car. It is also faster the any other OEM diagnostic tree I have seen.    

[Silver_TT]

I think we're in agreement.  There's nothing wrong with physically testing a sensor.  Doing so isn't mutually exclusive with using the computer for diagnostics (sensor specs, like you gave above, are often given in the OEM diagnostic tree for a given code).  The DME is just another tool to help isolate problems, definitely not an end all but these cars are pretty computerized these days, why not listen to the computer if it's telling you what's wrong.  In this case I'm understanding that it's going to cost 20 hours to physically get to the sensor to even test it, so an indicator like any specific codes from the DME could be very useful before the engine is pulled.  Thanks

[binger]

We are in total agreement the using the proper scan tools are the way to go. That's why I have $150,000.00+ invested in OEM tools and subscriptions. My point is its only a guide to point you in a direction. Its not a silver bullet or magic tool that solves the issue at the press of a button. Once you get the codes you need to know what they mean or not as they could  also throw you off of the right path. I guess what I am trying to say once you get the codes you need to prove it out before throwing parts at it.

 

 

[RFM]

+1 Fully agrees with binger at this point.

[mat59]

Update.

The durametric points towards one of the sensors so I've been given a quote to drop the engine to fit a new oil level sensor and oil pressure sensor. Whilst the engine is out they will check all wiring and connectors. Thing is, I thought the oil level sensor was accessible without taking the engine out?

[jpflip]

Hummm strange… Here's the picture of the oil sensor location. Just by lowering the engine about 4 inches you can reach this area. If needed the air pump can be removed…Wiring check can also be done  because being in the right side of the engine the engine connectors (2 big round plugs) are also located on the right side. You can save lots of money by lowering the engine instead of dropping the engine. Same thing for the oil pressure sensor, which got nothing to do with your failure….

Edited October 22, 2014 by jpflip

[jpflip]

Here's a link on how to lower the engine : http://www.6speedonline.com/forums/996-turbo-gt2/159600-2-bolts-drop-tt-engine.html

[Silver_TT]

nice jpflip, very good info as usual from you on the TT.  I had never seen that trick before, easy way to get a few inches of clearance and get in there in the tight engine compartment of the TT, very cool.

[jpflip]

Happy to help Silver_TT! I did my diverter valves that way and the oil pressure transducer without bleeding LOL!!!!

[mat59]

More specifically, it's showing as a 'sender fault'.

[binger]

What are the codes?

[mat59]

What are the codes?

Couldn't get them, unfortunately. I have another garage lined up who will partly lower the engine to fit the sensors (pressure and level) and wiring. They said they will accurately diagnose first. Will report back.

[mat59]

Hi all,

 

Update - I've had this checked out extensively with all wiring and sensors tested. It has been diagnosed as needing a new set of clusters. These are really expensive. Would have the option to buy a used set of clusters and have them coded to the car? If so, what has to be done to code them to the car (what equipment etc.)?

 

Thanks,

 

Matt

[jpflip]

Repair manual page 1709. You will need a PST2 or the newest Porsche tool PIWIS….

[jpflip]

Looking at the diagnostic manual I have found some info. Behind the cluster you got three plugs. The middle one is the B plug (blue) and the pin #2 on this plug is for the oil level sensor. Also the is a fault code 9123 which is related to oil level indication and got some test to follow...

[jpflip]

Also, I remember reading about a shop that fix clusters….I got one in england but don't know how reliable they are http://www.cartronix.co.uk/   And this one in US http://vdorepair.com

Edited December 7, 2014 by jpflip

[Silver_TT]

Be sure pin 2 on connector B isn't bent/damaged and is generally making good contact per jpflip's diagram.

 

It's not impossible but still seems unlikely that the electronic cluster itself just died for this function only but completely works otherwise.  You should maybe speak with some folks with experience on fixing clusters as jpflip already stated.  I don't have a lot of experience with this problem but the first question you might ask them is if they have ever seen this particular behavior before, etc.  Obviously if it's just a bent pin, that would be the best possible solution.....

[mat59]

Jpflip and Silver_tt, thanks for taking the time to respond. I've now had two garages look into this and both have concluded after extensive investigations that the cluster needs replacing. They've used a place here to try to fix the cluster several times but they keep drawing a blank. I'll suggest the places in the UK and US that refurb clusters anyway. If not, I'll check they have PST2 or PIWIS and get a used cluster unit coded. Does anyone know if the mileage can be adjusted using PST2 or PIWIS, or will I have to live with the mileage from the replacement used cluster?

Thanks again!

Will hopefully finally have this sorted in the next few weeks so I can start driving it confidently.