Low power at high revs - 2.5 V6

Hello,
I have a 2006 Freelander 2.5 V6 auto with 57000 miles on the clock and I am experiencing an annoying problem. The car has low power at high revs, above 5000 rpm. So if I kick down going up a hill, the tachometer gets stuck at around 5500 rpm and I have to use manual shift to change gear, so the rpm drops to 3500 and the car accelerates again. On a plain surface, the car is able to reach above 6000 rpm and change gears by itself (auto), but the engine struggles a lot and takes a while to do this.
The car is driven by my wife, so I am not sure how long it took to get so bad. I think it worsened slowly, not suddenly. My wife never complained about this. She uses the car only for city driving. I noticed the problem when used it for a road trip.
My mech (not a LR specialist, as there is none in my town out of the untrustworthy LR dealer – I live in Brazil) changed fuel filter (no improvement), fuel pump (no improvement) and finally the VIS valve motors (both were not working, valves stuck closed). The car didn’t improved a bit . The air filter was changed as well.
My guess was that the engine was not getting enough air, so it worsened at higher revs. I think the stuck VIS valves were not harming the engine performance because there was something worse going on.
Any suggestions on how to fix this will be welcome.
Thanks.

5,000 rpm - That's about 2,000 rpm higher than I have ever pushed mine. Generally the maximum for me is 2,500rpm then it changes gear and the only time it goes above that is when I'm on the motorway where it sits on around 2,750 at close to 70mph.

How fast are you going when you're doing 5,500 rpm?

Andy.

upstream said:

5,000 rpm - That's about 2,000 rpm higher than I have ever pushed mine. Generally the maximum for me is 2,500rpm then it changes gear and the only time it goes above that is when I'm on the motorway where it sits on around 2,750 at close to 70mph.

How fast are you going when you're doing 5,500 rpm?

Andy.

Click to expand...

Hi Andy,
50 mph, 2nd gear. The same problem can be noticed in 3rd gear, at higher speed. Never tried to put anything near 5,500 rpm in 4th gear.
I also think the car is weak at mid revs, so I have to kick down frequently. But to be sure about this I would have to drive other FL in order to compare. I remember the car was much better when purchased 3 years ago.
At high revs the problem is very easy to detect even if you’ve never driven the FL before, because this car should perform well at high revs. The power peak is at 6,250 rpm (not in my FL, of course).

Hi,
There are a few knowledgeable guys on here with the same model as ours (one guy in particular is VERY helpful). Stick around for a while and I'm sure that one of them will be able to shed some light on it for you. As I'm a really sedentary driver I can't be of much use on this sorry.

Andy.

If you drive at 5000 revs in 2nd gear uphill then I take it your either trying to accelerate up hill, or your pushing it harder than you need to? The v6 is quick, but not super charge quick. 0 to 60mph is 10 seconds.

Hippo said:

If you drive at 5000 revs in 2nd gear uphill then I take it your either trying to accelerate up hill, or your pushing it harder than you need to? The v6 is quick, but not super charge quick. 0 to 60mph is 10 seconds.

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Hippo,
Actually it is not a steep hill. I checked the dictionary and found a word that may be better suited: slope. Trying to upgrade my English and fix the car at the same time
I made this same question to myself. “Am I asking too much from this car?” As you said, the 2.5 V6 is not that quick. My other car is an Audi A6 3.0 (220bhp), so there is a huge difference in performance. I’ve always thought this difference as normal. But when I made a road trip (2 adults + 2 kids + luggage), I was amazed how the car just couldn’t cope with the slightest slopes, unless I changed gears manually. If I left it in “Drive”, it couldn’t reach 6,000rpm in order to change gears by itself.
On a plain road, the car is able to change gears without my help, going beyond 6,000rpm. But from around 5,000rpm there is a progressive drop in acceleration. It gains speed very slowly if compared to the 3,000-4,500rpm range. Trying to overtake a truck on the road was a nightmare, as I had to use manual gear change to keep the revs below 5,000 and never used the full engine potential.
You must agree this can’t be considered normal. I do believe the mid revs performance is also compromised (much less, though), but can’t assure this, as I don’t have other FL to drive and compare.
Do you think a video would be helpful to show what is going on? Not sure if my text is clear enough.
Cheers!
Sebastjr

...and as if by magic - He speaks ;-)

Does it change to 5th fear at 38 to 40mph if your gentle with it? Does it sit at 2500 revs at 60mph in 5th gear?

This is the max you'll get out of a standard v6:

[ame=http://www.youtube.com/watch?v=vjv4EOE4Kb4]Land Rover Freelander 1 v6 0 to 60mph Acceleration - YouTube[/ame]

Hi Hippo and Andy,
Finally I’ve done the videos. Now you will be able to see what is going on, despite the poor video quality. It is in full throttle during all the time recorded.
The first video shows car acceleration on a plain road, no slope, to compare with Hippo’s video. It starts already on 2nd gear. The comparison is not fair because the air conditioning was on. If necessary, I can try to record 0-60mph.

[ame=http://www.youtube.com/watch?v=R-IVqdDMOME]P1260016 - YouTube[/ame]


The second video shows the car struggling on a slope. At 0:27s it reaches the top of the hill and the slope angle decreases, so it is able to reach 6,300rpm and change from 2nd to 3rd gear.

[ame=http://www.youtube.com/watch?v=af_YcMzGHcY]P1240002.MP4 - YouTube[/ame]

Hippo, if I’m gentle the car changes from 4th to 5th gear at around 45 to 50 mph. It does sit at 2,500 revs at 60mph in 5th gear.

The 0-60mph never bothered me. The real problem is when I am cruising at 45-50mph in 5th gear on the road then I have to overtake a lorry as quick as possible. I press the gas pedal to the floor, the car changes to 2nd gear and keeps at 50mph (6,000 revs) for a while. Then I have to use the manual shift to change to 3rd gear, the revs drop to 4,000 and the car keeps accelerating.

I scanned it with Scangauge (OBD-II). It showed the following code: P0327 (Knock Sensor 1 Circuit Low Input (Bank I or Single Sensor)).

Thank you.

Hey!! 57000 miles on the clock and it still revs to 5500, you lucky bastard.

It does seem to be accelerating slower than my v6. The revs don't pick up as much, which is the noticeable bit. Gear selection is based on driver demand (accelerator pedal), speed of the vehicle, torque and power in/out/converted in the gearbox. The computer then orchestrates gear selection to create a smooth power curve for the required demand.

For some reason your v6 won't increase the revs fast enough whilst accelerating. I haven't a clue why this could be. What ever it is, it's causing the auto to hold gear longer, before changing up a gear to continue going faster, as it seems to think it doesn't have the power to change.

I think it's the engine, but don't know why. It just seems logical. It could be the engine can't create enough power due to lack of air flow or something like that. But as you've changed the fool filter, air filter and fool pump then that rules them out.

It's interesting the vis motors were faulty and replaced. If you look in this video it shows the power curve of the rover kv6 engine, which is what you have. I'm starting to think the vis values aren't working as you would notice a change in power as it accelerates. Bit this is just a guess. Video gives info on the kv6 and also how to change the cam belts. If it's not the vis, then it's something causing the engine to fail to create enough power.










I have to be honest the above is just a guess. This sort of fault is one which you'd have to check a number of items, or go to a garage with experience in this engine, or betterer still get a good diagnostic computer looking for faults.

Thank you, Hippo. I agree it is a problem in the engine. And I also think it gets worse at high revs. I will follow your advice and get a good computer diagnosis, maybe at LR dealer.

sebastjr said:

Thank you, Hippo. I agree it is a problem in the engine. And I also think it gets worse at high revs. I will follow your advice and get a good computer diagnosis, maybe at LR dealer.

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hi sebast, bear in mind that brazilian petrol has a lot of ethanol 25% (or even more plus water and some crap diluent) Land Rover vehicles are apparently not adapted. It causes corrosion on vis that became no longer variable that stuck in some position (that provides torque in low or high rotation). This is very commom in all brazilian FL KV6. i think hippo guessed rigthly

I also recomend you to call luiz fraga and ask some info. I lerned from him. Its free of charge and may save a lot of money. Usually LR stealers will ask you to change your engine, tires, roof, seats.... and the problem remains

The Specialist

good luck

Problem solved. It was caused by oxidation of the harness/wiring that connects the knock sensor to the ECU. That is why the scanner was showing P0327 code.
I cleaned fuel injectors and changed fuel pump, VIS valves (they were stuck), fuel filter and knock sensor. Waste of money (except for the valves). When I ask the mech to check the wiring of the knock sensor (got this advice searching landyzone forum) he easily found the source of the problem:doh:. Cleaned up the harness and, voilà, the car is running strong now.
I was absolutely wrong in pointing the air intake as the culprit.
Now I have a completely different vehicle. As I suspected, the performance was crippled not only at high revs. Now it is much stronger at mid revs and is able to reach 6.000 rpm without much effort.
I’ll look for other garage to do the maintenance on this car. The mech took 18 months to solve the problem and did so only after I pointed where the source should be. Too bad.

Thanks fer letting us know the fix.