Lambda Fault - Following work

v6matt · 23 Nov 2018

Hi All,

Just wondering if there is a common fix to this next bit of fun.

So the exhaust was dropped/bolts changed and waterpump/thermostat changed today.

Upon refitting the pre-cat lambda sensor keep pushing an engine warning light. The connections/cable has been checked and apparently it physically looks all OK.

Looks like the sensor was on the way out but before it gets replaced wanted to check there isn't a simple fix first !.

It was also mentioned that one of the pipes from the "secondary air system" had a split in it, my garages call to Porsche revealed it only came as a complete system, so he has put a sleeve over to .

Any idea what this is? if just the pipe can be replaced?

Actually if it is what I think it is, it does look replaceable ... https://www.ecstuning.com/b-genuine-porsche-parts/air-injection-hose/99711333902/

Matt

deMort · 23 Nov 2018

Air injection system here ..

https://www.deroure.com/diagrams.asp?TBL=2776&MAK=3&MDL=26&SMA=0&SMO=0&ST=&SC=0

I would guess at a single pipe .. There is only one .. not that accessable from memory... but it sounds like the garage has fixed it ?

Lambda sensors dont like heavy knocking close to them .. they can fail when you replace the flange studs so i would guess at a sensor .. assumeing you have read the fault codes then you know which sensor ..

Ill now give you the bad news .. if you replace x1 lambda sensor it switches faster than the old one the other side .. you might get a fault code in about a week saying the other side is faulty due to ageing .

Basically the new one switches faster than the old one on the other bank.

This doesnt always happen but be prepaired to have to fit one the other side .

There is no fix for a duff lambda sensor .

v6matt · 23 Nov 2018

deMort said:
Air injection system here ..

https://www.deroure.com/diagrams.asp?TBL=2776&MAK=3&MDL=26&SMA=0&SMO=0&ST=&SC=0

I would guess at a single pipe .. There is only one .. not that accessable from memory... but it sounds like the garage has fixed it ?

Lambda sensors dont like heavy knocking close to them .. they can fail when you replace the flange studs so i would guess at a sensor .. assumeing you have read the fault codes then you know which sensor ..

Ill now give you the bad news .. if you replace x1 lambda sensor it switches faster than the old one the other side .. you might get a fault code in about a week saying the other side is faulty due to ageing .

Basically the new one switches faster than the old one on the other bank.

This doesnt always happen but be prepaired to have to fit one the other side .

There is no fix for a duff lambda sensor .

Thanks again demort.

Yep that pipe I linked in number 11 on there "i think" . My garage mentioned he could hear it leaking, so fixed another pipe around it to keep it airtight. My OCD tells me to get it replaced though !

That will be it, he has done a few of these and was I think frankly bemused that it was a problem given the number of cars he has worked on without similar. Ah well, must have been on its way out or inevitable given the work completed.

The jokers at ECP want £100 for it, but its £30 online for a Bosch pre-cat sensor. Not an easy part to find locally as most of the large suppliers inc GSF don't even list it !

Oh joy! Fingers crossed

On another note, I asked this garage (which I trust 110%) about some of the things that I was getting replaced on the basis of the specialist garage.

The waterpump had the tiniest of play, but still had it changed as there are too many reports of failure.

Apparently only a couple of the coil packs had very light cracking vs the "change them asap" advice. However just got them done to avoid issues as I had bought them anyway.

The coolant from front pipe/loosing coolant comment I previously referenced, this garage couldn't find any signs of leakage but did spot that there was liquid around the coolant cap and apparently the 'drain off'. So my garage has got a new cap coming in tomorrow to fix that !

deMort · 23 Nov 2018

I have to admit .. it is difficult .. im going to cause controversy here .. but hey why not ..

Reading the forums verses real life .. we recommend what in out proffessional opinion needs changeing .. thats based on experience.

If a pipe has been sealed .. then its sealed .. the garage would say if it needs replaceing and probably would have done it .

Secondary air lasts for 30 seconds and is a warm up feature for save the planet stuff .. it has NO effect on your cars performance .

Cracked coils ... again i see many but i know which will last till the next service and which need doing now .. you will get told that .. or at least should by the service advisor .

Im more of a save it till its knackered type of guy .. spend money when you have to not when its ok but we advise it .. and we advise it to warn you next service you will probably need that item changeing .

Bear in mind .. next service is one or two years away .

On here i say what i think is wrong .. i often say " monitor " it .. thats because i dont want you just replaceing it ..

I see people just replaceing parts as they think thats the problem when a simple fault code read out at a garage plus a bit of advise is actually cheaper .. trust me .. guys like me can give solid advise and save you money rather than some post said this might be the fault so im going to replace it and see if it fixes the problem .

There is a reason most garages when a forum is mentioned roll their eyes .. there is also a reason why im pretty much the only Porsche Mechanic on any forum .. i only know of Pope on Pistoneheads who is OPC other than me .

At the end of the day i come here to try and save you money if you can fix your car by your self thats great .. but dont just throw parts at it ...... PROVE .. then replace .

A water pump .. kinda proves my case .. they WILL have a small amount of play .. hell they all do .. it doesnt mean anything .. when the bearing starts to fail it will be noisy .. it will have a fair amount of play .. hell it will finally ley go if you ignore the warnings and what does that actually mean .. i hope all of you have breakdown cover .. if not why not .. but what it means is it gets recovered to a garage and they replace it ..

Replaceing it because it has a normal amount of play .. hell it could go another 5 years like that .

There is a limit to OCD .. i can understand it , i deal with it on a daily basis but i always try and explain .. you dont change a house light bulb just because its been there for a year .. if it works it works .

Im not going the IMS route on this post as that could be argued either way .. this is a general post from someone that trys to save you money .

Not a pop at you .. just a general observation which hopefully will be taken in the context in which i meant it .. save your money !

v6matt · 23 Nov 2018

Indeed DeMort and understand this is a general comment

I must admit if I had this candid advice (or you could argue less cautious rather than purposefully looking for business!) from the first garage which led to buying the bits, I would probably have given it longer and not bought the bits yet but my reasoning after it was at my preferred garage was:

1) The sparks had to be changed regardless based on the 2 year guidance, so I have saved the labour on that.

2) The waterpumps from what I had read sometimes didn't have any warning signs in some cases and just siezed up - perhaps illogical in hindsight. Given the 50k/10 years it didn't seem entirely unreasonable following the 50-60k warning marks from other people (but perhaps this wasn't quite right!), also I wanted the water dropping investigated and the LTT/Drive belt fitted.

I will see all the old bits in person tomorrow and will be taking the old coil packs for spare, and thermostat home with me (in case there is some issue with the LTT)

Matt Seabrook · 24 Nov 2018

I see people just replaceing parts as they think thats the problem when a simple fault code read out at a garage plus a bit of advise is actually cheaper .. trust me .. guys like me can give solid advise and save you money rather than some post said this might be the fault so im going to replace it and see if it fixes the problem .

There is a reason most garages when a forum is mentioned roll their eyes .. there is also a reason why im pretty much the only Porsche Mechanic on any forum .. i only know of Pope on Pistoneheads who is OPC other than me .

but dont just throw parts at it ...... PROVE .. then replace .

Amen ðŸ™ðŸ» to that :thumbs:

deMort · 24 Nov 2018

V6matt ...its on your thread but not aimed at you .. its something thats been bugging me for a while and after a couple of sherbets i kinda let it out ... not the best place for me to comment like that

Matt will be as frustraited as me at times when people just replace items ..

It goes against the golden rule for Mechanics .. never throw parts at something unless you can justify it ... always try and prove a fault first .

Its also why we are here .. to give free advise where needed.

Matt Seabrook · 25 Nov 2018

deMort said:
V6matt ...its on your thread but not aimed at you .. its something thats been bugging me for a while and after a couple of sherbets i kinda let it out ... not the best place for me to comment like that

Matt will be as frustraited as me at times when people just replace items ..

It goes against the golden rule for Mechanics .. never throw parts at something unless you can justify it ... always try and prove a fault first .

Its also why we are here .. to give free advise where needed.

Test don't guess :thumbs:

Lambda Fault - Following work

v6matt

Silverstone

deMort

Monaco

v6matt

Silverstone

deMort

Monaco

v6matt

Silverstone

Matt Seabrook

Monza

deMort

Monaco

Matt Seabrook

Monza

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