wont go over 80kmh

[danm]

G'day all, my 2012 MN diesel has started this thing where if you floor it it will rev out in 1st then second as normal but then starts losing power wont go over about 80 in third, it will eventually change up but again wont go past 80, it will get to 100 but no acceleration.
Any ideas?

[Merts]

It sounds like it's in limp mode. Is the engine check light on?

[danm]

It sounds like it's in limp mode. Is the engine check light on?

nah no lights on, have done a scan with torque and it showed U1109, I just had a look in the air box and there has been rats in there and it is full of shit etc so filter may be clogged up , I will put a new filter in and see if that does anything.
Bigger concern is the transmission has been doing some random funny things every now and then.

[danm]

New air filter , no different, looks like a trip to the dealer.

[roadblock]

how long since you've changed the fuel filter? does it feel like it's losing power at higher RPM? A blocked filter will do that for sure.

[danm]

how long since you've changed the fuel filter? does it feel like it's losing power at higher RPM? A blocked filter will do that for sure.

Only has 75000 km on it, I assume the filter was changed at the last service but it revs out to red line fine in 1st and second but faulters at around 80kmh in third and hesitates to change into 4th.

[Cowboy Dave]

I wonder if your turbo vacuum hose has fallen off?

If you get under the car and get your head in near the sump, there's a spot where you can get a look straight up under the base of the turbo. There should be a thin rubber hose running to a metal spigot which comes out the bottom and heads towards the front. If that hose comes off you lose all boost and it gets hard to accelerate. Alternatively you can stick your hand under there and feel around for it, but unless you know exactly what you're feeling for it isn't always easy to work it out that way.

[RHKTriton]

The filters take a bit of effort to change so I wouldn't assume the dealer actually changed it.

Engine revs don't really prove whether you're 'stressing' the filter its loading (as in being in a higher gear) that uses more fuel.

You've got the 'usuals' to check before spending money, MAP and MAF sensors, vacuum hoses, sticky SCV, etc.

Rats! I had a bush rat that just about chewed off all the poly wool layer on the air filter. I put a wire mesh on the inlet to stop any future incursions. The b!**/¿ thing then must have got stuck between the firewall and wiper motor and proceeded to the state of decay where one hot day it revealed its final act.

[variflex]

Maybe send a PM to haro5l, he has been suffering these symptoms for quite a while now

[ag9111]

Maybe send a PM to haro5l, he has been suffering these symptoms for quite a while now

Rats or Decay?

[biggibbo]

Same symtoms mine was showing when the MAP sensor was buggered. Would rev out in 1st and 2nd, Get to 3500 in 3rd, and then only hit 3000 in 4th. Was dropping fuel pressure as the revs got higher.

Replaced the MAP sensor and was back to normal.

[Cowboy Dave]

Maybe send a PM to haro5l, he has been suffering these symptoms for quite a while now

Rats or Decay?

Or is his little hose flopping around loose?

[variflex]

Maybe send a PM to haro5l, he has been suffering these symptoms for quite a while now

Rats or Decay?

Or is his little hose flopping around loose?

I was thinking unable to accelerate past 80kph however the other symptoms seem to fit well also

[fridgie]

It sounds like it's in limp mode. Is the engine check light on?

nah no lights on, have done a scan with torque and it showed U1109, I just had a look in the air box and there has been rats in there and it is full of shit etc so filter may be clogged up , I will put a new filter in and see if that does anything.
Bigger concern is the transmission has been doing some random funny things every now and then.

Admittedly mine is an ml, but had virtually same symptoms. Would run/rev out in first or second but as soon as I hit third would surge like a biatch (bunny hopping kinda surging) in third at 80kph and struggle to go faster. Replaced fuel filter and all ok since.

[danm]

Fuel filter it was, changed it tonight and back to normal

[Cowboy Dave]

Geez that's a worry isn't it. You'd think they'd have to be pretty bloody full of crud to cause so much restriction. On the bright side I guess we know they can hold onto the crap without it getting to your injectors if you're up it at 80 and it's refusing to let anything more through.

[danm]

Geez that's a worry isn't it. You'd think they'd have to be pretty bloody full of crud to cause so much restriction. On the bright side I guess we know they can hold onto the crap without it getting to your injectors if you're up it at 80 and it's refusing to let anything more through.

The white plastic cap in the bottom of the filter had a small amount of fine dust/silt in the bottom but not what I would call filthy, I haven't cut the filter open to have a look but as you say it must be doing its job.

[RHKTriton]

I opened a filter recently for a sticky and surprised at the actual size of the element, probably not much more area than an injected petrol setup would have. These filters are getting a workout with the constant circulation of fuel.

Must remember though that the lower portion of the filter housing is the water gathering area.

Probably worth carrying a spare on board.