TD4 Air-Flow Meter??

Three times today the trusty Singvogelmobile (2004 TD4) went into 'limp' mode for a short period.

Just after a roundabout at the foot of a steep hill - but perhaps that was just coincidence.

After the first time I stopped, switched off, and on restarting, it was OK.

No OBD codes at all - and no engine light.

It happened again 3 miles further on - so as I was close to the main LR dealer I asked them for an opinion as to why.

A helpful mechanic dude plugged it into their diagnostic kit and found a code for the air-flow meter. He showed me exactly where it was - the sensor in the plastic tube bit part way along the turbo hose. (Which I always thought was an air temperature sensor)

I thought the MAF was the only air-flow meter on the engine! Was this mechanic talking bo**ocks?

The biggest LandRover dealer in the NE of Scotland didn't have the £22 sensor in stock, so I simply cleaned the thing with a spray de-greaser and refitted it - abracadabra, away she went - fixed I thought - £22 saved.

But no - it happened again after another 5 miles or so.

I had to leave it alone as I needed to attend a meeting

Three hours later it fired up completely normal and I drove 50 miles home with no more bother.

Was it really the sensor?

How can I test this sensor?

What happens to a TD4 if this sensor is disconnected? Does yours go into limp mode? Could someone try it and let me know, please?

All comments and suggestions of a non-pyrotechnical nature appreciated.

Singvogel.

Lol td4 mafs are more than £22 surely he was looking at the wrong part?


DD

Has all the hallmarks of a failing fuel pump to me . . . . . .

What does the Book of RAVE say?

Pretty sure I have a spare one from when I fitted a new hose complete, let me know if you would like me to post it.

the sensor in the plastic tube bit part way along the turbo hose

Click to expand...

looks like this :
Air temperature sensor | Meat and Doria

( going by it's physical design .. can't see that being an air Flow meter )

~~~~~~~~~~

from the m47r pdf ..

failure modes :
air temp .. over rich fueling, some black smoke, slight rough running
air flow .. reduced power, egr shutdown, idle control to default

defaults:
air temp .. minus 5 degrees C
( there's a " - " before the " 5 " .. so assuming they mean 'minus'
( seems pretty low .. though i guess that would explain 'over rich fueling '
air-flow .. default map based on engine speed

~~~~~~~~~

with the amount of mileage you do singvogel i would have a look at the filter inside the tank my was coverd in gunge i cleaned it but do to it sucking and nothing going up it must have given up.I can not see it being the air flow meter as if it had gone once it would not mend its self as they are a type of resistor I have not figuared out which one but once a risistor goes there is not coming back

Singvogel said:

.

A helpful mechanic dude plugged it into their diagnostic kit and found a code for the air-flow meter. He showed me exactly where it was - the sensor in the plastic tube bit part way along the turbo hose. (Which I always thought was an air temperature sensor)

I thought the MAF was the only air-flow meter on the engine! Was this mechanic talking bo**ocks?

Singvogel.

Click to expand...

Thats your Air temp sensor.

MAf is just to the left of the airbox.

If you unplug it , it should run at default settings. Not quite as economical ,but should run alright. Might be a good first step.



Would be interested to know which main dealer you went to btw?

Vissie said:

Would be interested to know which main dealer you went to btw?

Click to expand...

wouldn't surprise me if it was the one in aberdeen

Vissie said:

Thats your Air temp sensor.

MAf is just to the left of the airbox.

If you unplug it , it should run at default settings. Not quite as economical ,but should run alright. Might be a good first step.



Would be interested to know which main dealer you went to btw?

Click to expand...

Good advice.

Thanks for the replies guys.

Its starting to make sense now.

The mechanic at Town & County (main dealer in Aberdeen) definitely said air flow sensor, which made no sense to me at the time, but I now believe he must have been meaning to say air temp sensor, which is what I thought it to be. Slip of the tongue perhaps. Anyhow he didn't charge for the time spent on the computer. No bill at all in fact.

I reckon this sensor feeds the air intake temp to the OBD port as I notice I'm getting nonsensical temp readings on my Scanguage2 scanner.

The sensor had a light coating of black oil of course, as does everything in the turbo pipes, so perhaps it just reached the end of its days having been well marinated for 8 years!

I sourced a replacement today from a friend who like nick had a spare left over from having to buy it along with the turbo hoses as a complete set.

Thanks for the offer to post me your spare one nick - but I'm sorted now and you may still need it yourself.

I think LR have changed their parts thinking on several items like this and now sell the hoses and sensor as separate items.

I'll report back later in the week after I actually replace it. It ran OK today though - but I only drove it 10 miles or so.

Oh, and I'll check the tank for gunge at the weekend too.

Singvogel.

Hi Singvogel hopefully the new one that came with the new inter cooler hose from Guy Salmon should last for a while, certainly couldn't buy the hose separately last year just wished I'd bought the older version and cut it or gone for the silicone version like you have.

Update:

The limp mode happened twice on Monday - 6 days ago.

All I did was clean the temperature sensor with degreaser.

It hasn't done it again since, but the temperatures sent to the OBD port have been silly - sometimes telling me the temperature in the hose was 3 degrees less than the outside temperature and at other times that it was 40 degrees above. Totally crazy.

Today I fitted a replacement known good sensor and the temperature readings now make sense. a constant few degrees above the ambiant outside temperature.

Drove over 100 miles and all seems well.

If I do get the limp mode back again I'll try substituting the MAF next and see what difference it makes.

Singvogel.

nice one Singvogel,
its always good to get a cheap repair..