Bobbler
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EGT - does the fail of one cause problems for the other one?Just got another EGT fault in the last fortnight- complete fail of the passenger side, cleared codes and comes straight back again when running.
But the one (G235) that was replaced only a couple of months ago is reporting intermittently that it cant read either:
17865 - Exhaust Gas Temp Sensor 2 (G236): Open or Short to Plus
P1457 - 35-00 - -
17863 - Exhaust Gas Temp Sensor 1 (G235): Implausible Signal
P1455 - 35-10 - - - Intermittent
The second one clears and stays cleared after a good run, but crops up at some point during the last week or so again - boost then goes way down the pan as I can see it topping out way below on the boost gauge.
As I was concerned it could be the MAF on the blink and causing them to burn out I just went out and done a FATs and vagcom logging session.
MAF looks about right - a reading of around 260 @ 6850rpm (WOT in third) which sounds near enough to me - custom MRC map at 315 (dyno'd the day after it was donw) since then I have added RS4 with pre-cats removed. FATS is spot on 5.8, looking at the MRC database again it rings true of somewhere in that region of upto 330bhp approx.
What I wonder is if the failure of one EGT is impacting the other side of the system?
Is that even possible, or should I be budgeting for another EGT in the coming month or so?
I have another EGT on the way from Mr PW, he has one left on the shelf if anyone is having bother getting hold of one  so will see how replacing it goes.
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Bobbler
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Well just in case anyone wants to know, yes it does.
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Contigo
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It does but mine was showing the same when the MAF was duff. I changed the MAF and two O2 sensors and the EGT's have gone. Had same as you.
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Bobbler
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Is that the EGT codes went when you replaced the MAF or do you mean they have gone as in broken? I got them both showing intermittent again now not even a month on.
Its odd because the MAF readings seem spot on, still replacing a MAF is cheaper than two more EGT sensors
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Contigo
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Nope mine have come back last week and it affected my Rolling Road day.
1 Fault Found:
17866 - Exhaust Gas Temp Sensor 2 (G236): Short to Ground
P1458 - 35-10 - - - Intermittent
that's what I get now and I'm having a new one fitted. Hope all is well with the O2 sensors as they were replaced too!!!
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Bobbler
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Starting to sound like German build quality is very much a myth then, I really cannot be replacing 300 quid of parts every month. How come recently purchased EGTs are now failing so quickly, when I don't see a receipt in my very complete history for one in 10 years now I am looking at 4 within months?
This car is driving me nuts, the sooner I get rid the better. It's just a constant battle of fault codes and crap running.
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loomx
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If its gone that quickly I would try and get a free replacement. That surely must be doable.
Also, just guessing here, if one EGT goes then it will cause the car to run rich, I though it was running lean that killed them?
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Bobbler
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| loomx wrote: | If its gone that quickly I would try and get a free replacement. That surely must be doable.
Also, just guessing here, if one EGT goes then it will cause the car to run rich, I though it was running lean that killed them? |
This is what I am not understanding perhaps, I thought EGTs got killed by dodgy MAFs? And as the MAF readings seem good and healthy then I am thinking the parts must be just made of cheese then now?
Both are proper OEM parts from PW Motorsports (as are most bits I buy for the car), 1st one was replaced back in April (the easy drivers side), no fault was on the second one at that time. DTC's cleared and then it started playing up in September when I found both of the codes above.
I replaced the 2nd EGT end of Sept/start Oct.
I had a faulty ABS sensor I have replaced so did a vagcom clear a couple of days ago, only to find both EGTs now reporting errors again.
I would replace the MAF if I thought it was going to help stop 300 of parts every fecking month need replacing on this car.
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Contigo
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Faulty MAF will kill anything downstream of it ie EGT's and O2 sensors. That's what has happened to mine.
I replaced the MAF and two of the O2 sensors and scrimped on the EGT. I am now paying for that and have booked the car in for that work to be done.
I cannot explain why your EGT's keep going pop, maybe you replaced the wrong one? What's your MAF say when you log it?
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Bobbler
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Well both sides have been replaced hard passenger side being the most recent.
I have the following log which is from Vagcom on Group A (last column being the mass air flow reading)
| Code: | 55.71 1320 15 2.04 5.89
56.61 1320 28.6 3.06 11.06
57.52 1360 40.6 4.08 16.5
58.42 1480 78.9 9.86 37.56
59.33 1720 91 10.88 48.11
60.23 2000 105.3 12.58 63.31
61.14 2280 118 13.94 81
62.04 2640 134.6 15.3 107.86
62.95 3080 167.7 24.82 157.67
63.85 3600 191.7 31.96 197.64
64.76 4000 176.7 32.3 206.08
65.69 4480 177.4 35.7 229.64
66.67 4960 167.7 35.02 241.33
67.69 5400 157.1 34 249.08
68.76 5840 150.4 33.32 255.14
69.86 6200 144.4 31.28 258.83
70.99 6480 137.6 28.56 259.92
72.12 6760 132.3 24.48 260.28
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Seems to be reading fine from what I can work out
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Contigo
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Get the car to MRC for a health check!
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kiwi_rs4
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| Contigo wrote: | | Get the car to MRC for a health check! |
Don't genuine OEM parts come with a 24 months warranty? That's certainly the case in NZ. I'm getting my number 1 EGT sensor replaced under warranty after being in the car only 9 months before going dodgy again. Was told that the replacement sensor is an upgrade to the one fitted in Jan this year so that's quite interesting. Re German build quality, as my mechanic said to me these parts are all stamped 'made in the EU' so may not be made in Germany at all. Same goes for aeroplanes by the way - individual components and structures are made all over the world for your European Airbus or American Boeing.
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mrgristle
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Are you sure that the sensors are actually bad? I kept getting 'short to ground' and 'open or short to plus' codes, but this just means that the ECU has lost contact with the EGT control unit. I sorted mine out six months ago by spraying switch cleaner into the EGT plugs, and I haven't had a single EGT code come back since. If this didn't work I was planning on cutting cables behind the nasty 180 degree bend and re-terminating them, but no need so far.
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H8CAK
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IIRC the EGT's and MAF can kill each other. I was told to replace EGT's and MAF at the same time.
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Contigo
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The MAF can kill anything downstream of it ie EGT's, Lambda. Not sure that the same can be applied the other way ie Vice Versa.
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