VU Maloo check engine light..... HELP!

[lake666]

Hello everyone! long time reader of these forums, first time poste!


6 months ago i brought an R8 maloo 2001 VU. I have been battling a check engine light issue for the past month. I will start the car and drive up the road, for however long it takes for the thermostat to open, temp guage jumps up to just under half (where it has always been) and then.... BAM..... engine light comes on! fark!

So it will stay on untill i park the car and the temp drops, but as soon as it hits running temp its back on!

I have replaced the oxy sensors, TWICE! also in desperation the coolent temp sensor? what am i missing?

I had the codes read and there is nothing!

Any thoughts?

Cheers, JOE

[Darcon666]

Here is a thought... take it to someone who can hook it up to diagnosis tool(Tech2) to check what error codes it has before you start to madly change things.

Even Holden will do this for you... but prepare, they will charge you $$$.

[GEN3RATD]

Classic oil pressure sender switch fail, fairly common, had mine go a few months ago.

[MrSirWantalot]

Yea same as GEN3RATD, mine did the same thing & thats what it was. It will pay to shop around, I had no choice but to go genuine....OUCH!!!...check Ebay for pressure sender price.

[lake666]

THANKS FOR THE PROMPT REPLIE GUYS!

I have a new oil sender unit sitting waiting to go in actually! that was my tomorrow job.
I will be so happy if it works out i tell ya! will let you all know how it goes!

Cheers, JOE


OH, and deacon666 or whatever, please dont bother treating me like an idiot, if you had infact read my origional post correctly you may have noticed that i stated that i had the codes read first and nothing showed up. so yeah you are helpful.

[lake666]

OK, chucked a new oil press switch in this morning, did nothing. still have my origional problem.

I got it re scanned and got a fault this time! it was "lean on bank 2"

it looks like one of the oxy sensory is not fluctuating as much as the other, i have changed oxy sensors twice before, so i put some oxy's off of my mates ute in which work good to see what happens and i still have the same problem..... lean bank 2 engine light comes on.

Can anyone tell me where else i can go from here? it has 4 into 1 headers and no cats, but it has been that way for ages and i only have this problem now?

Any advice would be great.



JOE.

[lout]

I was going to say it is classic crank angle sensor symptoms until your lean code

[MrSirWantalot]

Is it idling rough Joe?. ....Idling low? Is motor standard? Mafless? I guess you may have narrowed it down to a fuel prob maybe. Only other prob Ive had like that is the O2 sensors, one was playing up....reading different to the other, but along with that I had a TPS prob because I had installed a ported & polished 85mm TB. Only way I sorted that was to get it tuned originally but now mine mafless....I wonder if you take it to a car tuner (performance) & let them run it with the software they have, they maybe able to pin point it?

[lake666]

Well if it helps, it is pretty stocko, its only got 4 into 1 headers, 2.5" exhaust, no cats. SS inductions maf meter, running the PCV through a catch can.

All of these mods have been on the car aslong as i have had it. (except the cats, did that the first day i got it, they hung so low i couldnt get it in my driveway!)

I did notice after messing around swapping oxy sensors and shit, that the engine light is going off every now and then?!

It runs great no matter what! engine light is purely giving me the shits, it is just annoying having to look at it and know something is not 100%

I had a feeling it could be a dicky sensor plug, i think it may have extensions on the origional plug for the oxy sensors, because of the headers.... OR.... maybe an exhaust leak at the header flange?

As far as i know, it has to be something messing up the oxygen sensor, because looking on the scan tool, one oxygen sensor is just going spastic!

Cheers, JOE

[accentstencil]

Another common problem is the PCV hoses perishing, especially the "Y" piece at the rear.

[lake666]

checked all that horrid shit hanging off of the top of it when i did oil sender this morning..... was all good.....

[Lazza78]

hey lake666, this sounds the same as what my vt was doin a few years ago... everytime we put the scan tool on it would say it was one of the o2 sensors on low voltage.. replaced them and the prob went away for a few days and came back again.... as u said once it hit operating temp the light would come on... i ended up just dealing with it...

but..

when i got my mafless tune done about 6 months later the light hasnt come back on since

[BlackVXGTS]

Hmmm. If you don't have any cats the Police will be able to smell you from a kilometer away. Unless they mistake you for a Toyota.

[lake666]

hey guys thanks for your input so far, i still have not sorted the problem, but i have learnt some things!

I have swapped out parts left right and centre to no avail, still same problem! I will be putting it on the hoist on saturday to check for a few things, like, exhaust leaks at header flange, wiring on the oxygen sensors, and put a fuel pressure guage on the fuel rail and anything else!

i have hopes that it has blown a header gasket on the drivers side where it connects to the mid pipes, just infront of the o2 sensors. if not i will have to like at fuel issues like injectors on bank 2....

will leat everyone know what i find, hopefully it helps someone else out there!

JOE

[MrSirWantalot]

Hey Joe, just a stupid question. Have you replaced TPS lately or maybe the TB?? Does the TB have any type of flat spot?

[lake666]

Nah mate, none of that!

I hoisted it on saturday, no exhaust leaks, wiring to o2 sensors was good, but now i have got 2 more codes, lean bank 1 (was bank 2 to begin with!) and o2 sensor low voltage? WTF?

I will spend a few more hours on it then its off to have an open loop tune so i can just ### these god dam o2 sensors off forever.

Joe.

[MrSirWantalot]

hmm, sounds like a bit of a bitch, if you have the money I'd surgest a mafless tune. I was hesitant at first with all the stories you hear, but now that I have it done...Im pretty happy with it actually. Theres a big difference between a standard 290hp ls1 & 400hp ls1 witch is what it is now, @ flywheel ofcourse

[lake666]

Mrsir, i have just brought an otr actually and was going to get a mafless tune done (mailorder though...)

would this perhaps solve my problem?


I keep getting the same codes "lean" and "o2 sensor low voltage" but it keeps swapping around banks.......!


on another note, can anybody tell me if the wiring loom which runs above my gearbox and holds wiring for a few connections on the gearbox and both the o2 sensors has an earth anywhere which may or may not be dickie??? if so where would i find this?

Cheers, JOE

[TGR 35S]

My engine light just decided to come on aswell once car is warm car runs fine still,, hope I don't have half as much fun as u did trying to find out why ,,,haven't got to my mechanic yet hopefully time this Arvo,,, I changed water pump on weekend then it started to come on a day or so after ???

[MrSirWantalot]

Mrsir, i have just brought an otr actually and was going to get a mafless tune done (mailorder though...)

would this perhaps solve my problem?


I keep getting the same codes "lean" and "o2 sensor low voltage" but it keeps swapping around banks.......!


on another note, can anybody tell me if the wiring loom which runs above my gearbox and holds wiring for a few connections on the gearbox and both the o2 sensors has an earth anywhere which may or may not be dickie??? if so where would i find this?

Cheers, JOE

Hey Joe, well the real reason I got a mafless tune was due to a few reason and they were, engine light coming on, idling rough/lower than normal, I had the same codes come up as urs however the tuner said that my o2 sensors were shot & my new TPS was not in sync with the oversized TB.

As far as the mafless tune goes...... I guess the difference between mailorder & a tuner is the fact that the tuner has everything in front of him & with all the figures in front of him whilst the car is running could be the difference. What Im trying to say is that if all that is in front of him theres every chance he may find the engine light problem as well as fine tuning everything. Since my mafless tune I have had NO such issue since & its been over 12 mths now.

On the other hand Joe another ECU might just do the trick.....I guess it all comes down to money

[lake666]

yeah, true all that! i will get a mafless tune when i can anyway regardless of enginr light or not. if i have no more problems after that then fantastic!

i would still like to know about earth points on the car. i have only found 2, one under the oil fill on the head, and another under the abs module near the batt. any more in the engine bay or chassie area i may be missing?

hey TGR 35S, if you get a fix for your problem let me know ay!? might be helpful!

cheers, joe

[lake666]

OK. Problem was........ rubben wiring harness running above gearbox to o2's. ####.....!!!

[mr031]

the 02 sensors are reading a problem, have you check for manifold and vac leaks?