General: Disabling the limp mode on V70??

[SkintKnuckles]

Hi Brendan,

I'll definitely check these out tomorrow. Currently banned by the missus from any further work on car this weekend!

In brief, the fuel filter isn't due for another 10 K, as I do the servicing so I know the one inside is still ok (in principle). No smoke on hard acceleration.

The only pattern to the limo mode issue is that it generally drives ok from cold, but thereafter reverts to limp mode. Its 50-50 for full power vs limp mode. The intermittent nature led me to suspect a partially seized EGR valve, but it doesn't seem to be that. My money is currently on the stepper motor/drive for the EGR valve being dodgy. Not sure if this can be replaced separately or is even serviceable. This could explain the error code, or as suggested by 4C, it could be an electrical contact issue, or even a spurious code.

Anyway, I'll check all of your points on Monday and revert back. If nothing else, I'm learning!!

cheers
Neil

[Symes]

As outnumbered has pointed out, your 185 version doesnt have the same reliance on the vacuum mounts (the 163 uses the vacuum to operate the VNT vanes in the turbo) so dont waste time there.

Are you still getting the egr code when it goes into limp mode?

[GrahamBrown1]

When you turn the engine off can your hear the egr motor working? I believe it self cleans the valve after shut off. Is the swirl arm still attached?

[SkintKnuckles]

Hi Symes,

ok, good to know about the vac issue. I was unsure after Mike had said not to and then another user said to check. One less thing to do!

As things stand, despite replacing the EGR position sensor, decoking the entire EGR assembly, exhaust manifold, EGR cooler, new swirl arm rod and connector, it seems that the 44B0 code is here to stay. What is weird is that the car can show this code (having been first cleared) and not be in limp mode, and equally show the code and be in limp mode.

In general, the only code my car is showing is the 44B0. My pet theory is that the (new) EGR position sensor is looking for EGR movement, and the car is sending a signal to the stepper motor/actuator (whatever its called!) that drives the EGR valve but the motor is kaput or on its way out. For sure, the valve can move by hand, but it was very difficult to see how the motor could easily actuate the valve as it seemed very stiff. That said, electric motors can have high torque.

The above would explain all of the symptoms, the intermittent fault, why the car has responded well to the changes I've done (when in high power mode) but ultimately has a problem tthat underlies any changes and causes limp mode. Not sure how to test this theory. I guess I could pass a defined current/voltage through the motor and see if it turns the eccentric that moves the EGR valve. However, I'm a bit nervous of doing this unless someone more experienced says that it won't cause more problems than I've already got!

Thanks for the heads up and clarification on the vac.

cheers
Neil

[SkintKnuckles]

Hi Graham,

no I haven't checked this yet. If you see my comments above to Symes, I've been veering towards a test of the motor for the EGR valve but wasn't sure how to do it, or if it can be replaced ad hoc without the rest of the EGr assembly. Knowing that the motor may cycle through valve movement during switch off is definitely a good way to see if this is happening. Thanks! Certainly, I can hear the swirl arm motor moving at shutdown, so its worth looking at this later. Thaks!

The swirl arm rod is definitely connected to the respective motor. That was one of the things I had to do to try and exclude other causes for the limp mode or rough running. This is one of the fixes that has been successful for me, so I'm confident of this part working well at least.

cheers
Neil

[outnumbered]

Did you check the cogs on the Etm any teeth missing if the potentiometers not doing it's sweep you will not get a signal
Also the Grove in the carbon inlay may have worn out
Mike

[SkintKnuckles]

Hi Mike,

No, I haven't checked the cogs on the ETM. I fitted a new one 25 K ago, but its worth checking. Certainly the flap inside the ETM is working as it moves with finger pressure and springs back, but I don't know about the internal cogs and their condition. I guess I just extract the ETM unit and prise the plastic cover off the side to check this?

I don't know what the carbon inlay is. Can you clarify - this is on the ETM right?

Happy to check this out as its relatively fast and I'm a bit lost. Thanks for the tip

cheers
Neil

[outnumbered]

Hi Neil
Was that with a new one If so then that may be okay
Mike

[Joe Harding]

Shall I compare thee to a dodgy Merc?
Thou art more fickle and intemperate
Rough roads do shake the faults that lurk
And dealer's lease hath all too short a date.
Sometimes too hot the intercooler whines
And often are the oily puddles dripped
And every tread from tyre sometimes declines
By miles, or M40's changing course are stripped;
But thy eternal gremlins shall not cease
Nor shall my barked knuckles heal
Nor shall thy fault codes speak of peace
When in limp mode I weep behind the wheel.
So long as cars have acronyms instead of parts
So shall I drive and drive with wearied heart.

[4candles]

Originally Posted by Joe Harding

Shall I compare thee to a dodgy Merc?
Thou art more fickle and intemperate
Rough roads do shake the faults that lurk
And dealer's lease hath all too short a date.
Sometimes too hot the intercooler whines
And often are the oily puddles dripped
And every tread from tyre sometimes declines
By miles, or M40's changing course are stripped;
But thy eternal gremlins shall not cease
Nor shall my barked knuckles heal
Nor shall thy fault codes speak of peace
When in limp mode I weep behind the wheel.
So long as cars have acronyms instead of parts
So shall I drive and drive with wearied heart.

God, i'd almost forgotten Pam Ayres ever existed,