Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[nuclear onion]

I got my 2.5 v6 auto recently and for the most part am very happy with it.  There are a couple of things that need looking into but I don't know where to start with an engine this complex. (my last car was a skoda!!)

Half the time it starts up perfectly normally but the other 50% of the time the engine races up to around 3000 rpm and holds there.  There are no fault codes and the eml goes out after starting just as it should.  If you drive the car for a while it seems to settle and be ok but obviously I'm worried what stresses it's putting on the gearbox when I shift into drive at 3000 rpm.  I also get check oil lack on the display even though the level is fine and the oil is clean and fresh.  Anyone know what's wrong and are the two faults linked in some way.

Any help and advice would be greatly appreciated

Mike

[JasonH]

For a start clean your Idle Control Valve (ICV) fairly straightforward, should be some detail on it somewhere on this site. There's a hidden torx bolt but that's about it (and you can use something like an 8mm socket on it).

[nuclear onion]

Ok thanks, I'll do that and see what happens.

[TheBoy]

Don't think the ICV will allow it to rev that high.

Clean the throttle bodies out (and breathers while there), check throttle cable (from pedal and cruise) not too tight, and check for air leaks.

[nuclear onion]

Just done the paperclip test with engine running and got code 136 (ecu). Does this mean the ECU is knacked, should I be worried??

[nuclear onion]

If anyone is interested, this morning  I took the ecu out, cleaned the terminals then put it back.  The car seems perfectly fine now and hasn't over revved all day.  Is this co-incidence or cure??? :-/

[Admin]

Well a poor contact could cause some weird effects, but I have never come across it bofore.  :-?

Now it is time to do the maintenance to avoid other potential problems.

Where in Derbyshire are you by the way?

[nuclear onion]

It does seem strange doesn't it.  However, I took the car for its MOT this morning, its still acting normally and it passed the emissions with no problems.  Compared to how it was the few days before, cleaning the ECU contacts certainly seems to have fixed the problem. By the way I live in Holmewood, Chesterfield. Two mins away from junction 29 of M1.

[hotel21]

.... I also get check oil lack on the display even though the level is fine and the oil is clean and fresh......

I get oil lack coming up on mine now and again, particularly on long sustained motorway runs.  It only appears when the oil level drops to the 3/4 mark.  No probs at all if its upto the max mark.

edit - its the 'check oil level' warning that appears, not oil lack.  Sorry for the confusion....  

[ians]

I get 'check oil' when it drops to about half way (1/2 litre) between the marks (as it did when my cam cover seals were leaking).  Have never seen oil lack but I think this comes up at a lower level (or pressure??), hence more concerning.

[nuclear onion]

yeah, it concerns me too.  The oil level is just short of the full mark and is fresh oil suggesting a recent change.  The oil pressure light goes out when the engine is running so I don't think its the pressure.  Not being as knowledgeable as some I have three suspicions at this point,

1. The pressure relief valve may be faulty

2. partly blocked breathers pushing crank pressure up into the engine forcing the oil down and partially starving the uppermost parts of the engine (I know, get them cleaned ASAP)

3. Sensor giving an incorrect reading.  I read somewhere that there are sensors to detect oil lack and if the engine has been changed from one type to another where it doesn't have the sensor, it will produce this error.  I can't say for certain if the engine has ever been changed but my thinking is that if a sensor malfunctions, it may have the same effect.


I'm probably barking up the wrong tree here and would welcome anyone's thoughts as you are all much more experienced than me in this kind of thing.

By the way, its an intermittent fault, don't know if that's relevent :-?