I had never noticed it in the city, but driving to our place in Belgium, toward the end of the journey on the long ascending toads in the Ardennes, I found myself losing power suddenly and quickly at some point. Once at the top, everything was fine again.
Upon observation, it was clear that if I was in 6th and shifted down to 5th or 4th for the sake of more torque, that’s when I would lose all power. As soon as I hit 2500+ (or closer to 2900+ depending), all power would go.
But then, if I upshifted in order to accelerate again, there was no long any momentum, and I would lose speed even quicker.
So: is it because I have a rev limiter that I didn’t know about? If so, is it faulty? If not faulty, what is the point of the pieces of shit, if they cause vehicles to lose all power on ascents?
Or does it sound like the van has another problem I can’t figure out?
Possibly A: this is just how the turbocharger works. Unlikely unless it's a very old engine.
Possibility B: faulty wastegate. Boost pressure increases linearly with engine speed until a portion of the pressure is dumped abruptly.
Possibility C: faulty MAP sensor. Seems surprising that it hasn't triggered an engine management light though.
Side mounted intercooler? I had a polo that would do this in hot weather most notably a holiday in the ardeche. Prior non turbo and subsequent turbo cars with front mounted intercoolers haven't done it. At lower speeds I think that the charge temp can be higher with this set up, and therefore cause some power loss when the engine gets hot. An expert will be able to confirm or correct
If its the Cdi engine (and depending on the vintage) there seems to be a spectrum of 'limp home' modes so a fault can trigger a degree of power reduction but not flash up the engine management light.
For what the engine management thinks is a serious enough issue it will really cut power and flash up lights but I had several instances where revs seemed to be capped and power tail off at around 3000rpm without any warning lights and for most driving seem to be otherwise normal and a later code read would identify the issues and as in the op this would be most apparent on inclines
Could be a number of things. You mention on climbs, which could well be an overheating issue, resulting in reduced power to protect the engine, but not overheating enough to trigger any warnings.
However without knowing if any faults were stored, that is a pure guess.
Sorry. More details:
2013 Vito 110 CDI
Just got home from sight seeing. It can’t be a rev limiter, as I was able to exceed 3000 rpm on the flat.
The engine light was on all the time before, then the mechanic changed the exhaust filter and reset it. As of today, it seems to be back on. But it doesn’t just come on in response to the loss of power.
If there is a warning light on, then there is a fault somewhere.
I'd also be wondering why the DPF (I'm assuming that's what you mean by exhaust filter..) needed changed, as DPFs on these engines will usually go for several 100k's, unless there is some kind of other fault causing them to clog early, or it's been really abused (aka constantly stuck idling with no long runs to regen properly)
high ambient high altitude (?) so there is probably a derate on post CAC temperature, or might be the smoke limit as there will be less o2 around
The engine light was on all the time before, then the mechanic changed the exhaust filter and reset it.
[diplomacy]”changed” or “removed”?[/diplomacy]
Get a code reader, reproduce the problem, look at the codes. They're cheap on ebay and you can use the free Torque app to read them.
My friend had something similar and it was a failed hose.
Being kind to your mechanic, you may have had multiple problems in the first place. Being unkind, he didn't understand the problem and replaced the wrong part.
If it has gone into one of the limp modes (mine has done this occasionally) a quick reboot via the ignition key usually sorts it while you are rolling
All engines have a rev limiter. These will try and prevent the engine from going faster than it was designed to and damaging the internal parts. But this should kick in around 4.5k/5k rpm on Diesel engine not as early as 2.5/3k rpm.
You might feel a loss in power high up the rev range as the turbo can’t keep up with the engine speed. It will have a window of operation where it works well but outside of that at the lower and higher rev range the torque will fall quite rapidly. But again I would expect the turbo to produce good power at 2.5krpm and maybe up to 3.5krpm then the torque would tail off rapidly.
Engine warning light or not I don’t think your engine is working correctly and sounds more like a fault than a feature the manufacturer added to the engine. Or possibly it’s finding it hard to function optimally at high altitude and high temperatures?
More investigation needed in to what the fault could be. As mentioned get a OBD reader and see what fault codes the car is flagging up. They are relatively cheap around £15/20 available on Amazon and eBay.
I've worked for merc since 1995 as a mechanic and these engines are some of the most unreliable they've ever produced.
The dpf filters in these rarely go beyond 100k and unless it's been seen by a genuine dealer on there star diagnostics recently the amount of stored faults a spurious machine will bring up will not be able to pinpoint the fault .
These 110 engines also eat injectors for fun so lift the bonnet to listen for any slight blowing which will be a mild chugging noise but it's certainly nothing to do with rev limitor it's going into limp mode .
My experience with these and without seeing the vehicle and with only your description it's most likely the exhaust back pressure sensor .
But if your lucky it will of just blown the turbo pipe off but again you will hear a wushing noise upon acceleration if this is the case .
The turbos aren't the best either but tend to last longer than the injectors.
Good luck
Sounds like fuel starvation to me. First things I'd check would be the fuel filter and low pressure fuel pump.