Low rev torque on my V6 is crap

[sudso]

Torque at low revs on my V6 is crap however it goes like shower of shit once it gets around 3000 rpm.

Its a 6/98 V6 Rodeo with 230000kms on the clock and new valves/seats with o/hauled heads at 180000kms.

Is this an inherent trait of these motors or could there be a problem?

I've done 15000kms since I bought it and it hasnt used any oil and its still pretty clean but its due for a change.

Will changing the cam timing improve things without any probs?
I dont care about top end rev power as I rarely take it to 5000rpm

BTW I love this forum.

cheers, sudso

[sudso]

Oh yeah its on gas too the low torque is there on petrol too.

[Utemad]

I have never owned a V6 but I was under the impression that a lot of V6s have little low down torque? A trait of V6 motors perhaps?

According to my owners manual the V6 has
133kW @ 5400rpm
265Nm @ 4200rpm

That is pretty high in the rev range.
Compare this to the turbo diesel 4 cyl motor
74kw @ 3800rpm
225Nm @ 2300rpm

or the 4 cyl petrol (my motor)
88kw @ 4600rpm
201Nm @ 2600rpm

By the looks of these figures the V6 really likes to rev in comparison to the other two. I am guessing there is nothing wrong with your motor and that is just how it is.

These figures were all obtained from my 1997 Rodeo handbook. They may vary slightly from the 1998 Rodeo. Considering the V6 wasn't even available in Aussie Rodeos til 1998

[sudso]

thanks ute mad

I have that same info too but it only gives the claimed maximum torque which is quite a healthy figure.

I suspect that the torque curve rises quite sharply when the V6 gets up around the 3000 rpm mark

I guess its just something I'll have to put up with unless the cam timing can be changed without any probs to raise the low down grunt.

cheers

[Utemad]

As you say the it has quite a lot of torque. However it isn't much good if it is only available at high revs. You need to find out from somewhere what percentage of that torque is available at say 2000rpm. Like when you read in magazines they will say that a motor has 500Nm of torque at 3500rpm but 80% of that is available at only 2000rpm.
Although I guess you can have a pretty good guess just by driving it and from what you have said I guess it is bugger all below 3000rpm.

[sudso]

utemad;

As you say the it has quite a lot of torque. However it isn't much good if it is only available at high revs. You need to find out from somewhere what percentage of that torque is available at say 2000rpm.

I found out the first time I took it up a sandhill up the SA/VIC Border track. had to rev it to stop stalling but just spun and bogged in. (Was trying to see how far up I could go with highway pressures. Got close )

My bro in law in his 2.8D Hilux just walked up and over it at 1500rpm and 25psi. in nearly worn out 10R's and that was after I'd churned the shit out it

I decided then to let my 40psi down to 18 but still needed revs and a bit of speed.

So I'm wondering if changing the valve timing to improve low end torque is possible on these engines.

[Utemad]

I found out the first time I took it up a sandhill up the SA/VIC Border track. had to rev it to stop stalling but just spun and bogged in. (Was trying to see how far up I could go with highway pressures. Got close )

Leaving your tyres at highway pressure is a good way to cook your motor and gearbox. Nothing to gain from using hway pressures on soft sand.

My bro in law in his 2.8D Hilux just walked up and over it at 1500rpm and 25psi. in nearly worn out 10R's and that was after I'd churned the shit out it

He had much better flotation with the low pressures. The trick is to have as much momentum and flotation as possible without spinning your wheels. Worn tyres won't hinder your progress in this situation.

So I'm wondering if changing the valve timing to improve low end torque is possible on these engines.

Best bet would be to ask an engine tuning place if this is possible but I am guessing no. Although that is just a guess.
Maybe get a low range reduction? Then you can rev the tits off it while still going slow.

[benandvon]

Sudso

I've got a 97 3.2 V6 jackaroo and it's exactly the same.

Feels like a slug until the revs hit 3000 and then it goes like a shower of shite. When 4WDing i just use low range alot and keep an eye on the taco to keep it in the power band.

I suppose your rodeo is the 3.5? Had any problem with your gas setup?

Still looking at having mine converted. Getting close to the real reason why some people say it is not recommended.

Cheers

Ben

[sudso]

I suppose your rodeo is the 3.5? Had any problem with your gas setup?

Nup. 3.2 like yours.

[andyr]

According to my owners manual the V6 has
133kW @ 5400rpm
265Nm @ 4200rpm

These figures were all obtained from my 1997 Rodeo handbook. They may vary slightly from the 1998 Rodeo. Considering the V6 wasn't even available in Aussie Rodeos til 1998

I'll stand corrected but I'm sure the V6 put out 141kw in the '98 onwards vehicles. The 133kw was for the 3.2 SOHC motor as fitted to the Jackaroo/Montereys whilst the V6 fitted to the Rodeo's was the later DOHC 3.2. I'll have a look tonight when I get home. Mines a 9/98 Dual Cab BTW.

Having said that, I've never really thought it had a lack of low end torque; it'll pull from 1500-1800 rpm quite happily in 3rd gear or higher..... all the way to the redline, which equates to about 140kays in 3rd

Andrew

[Utemad]

Redbook says for the 1998 V6 DOHC

Power 140kW @ 5400rpm
Torque 265Nm

http://www.redbook.com.au/vehiclesearch ... y=HOLD98HO

[andyr]

Redbook says for the 1998 V6 DOHC

Power 140kW @ 5400rpm
Torque 265Nm

http://www.redbook.com.au/vehiclesearch ... y=HOLD98HO

Agrees with the owners handbook. The torque peak is at 4200 rpm.

The 4JBIT (turbo diesel): 74kW @ 3800, 225Nm @ 1800.

[sudso]

benandvon wrote

Had any problem with your gas setup?

Only prob was a half stuffed stepper motor but I had a new Gastec 31 processor and stepper motor (magneto not geared or worm drive) fitted and that licked the rough idle and stalling probs.......Cost all up $340.

Last week the engine check light came on so the analyser revealed the O2 sensor is stuffed and sending the wrong message to ECU making it run rich on gas and petrol..........
This may account for the low torque at lower rev's........I dunno...just a guess but in cars I've had with a manual choke that I accidently left on when the engine warmed up made them run crap at low rev's.........till I remembered that I left the choke on

I'll see how it goes when I put the new O2 sensor in.

andyr wrote:

I'll stand corrected but I'm sure the V6 put out 141kw in the '98 onwards vehicles. The 133kw was for the 3.2 SOHC motor as fitted to the Jackaroo/Montereys whilst the V6 fitted to the Rodeo's was the later DOHC 3.2.

Just to chuck a spanner in the works ...... I've read the the Jacks had a tweaked engine man. system to give a higher output than the Deo's but that might only apply to the later ones.

Back to one of my original Q's.......I've still yet to find out if the valve timing can be altered in these engines to give more low down grunt.........would be a matter of altering timing belt position in relation to crank but I dont know if the ECU will allow it

[andyr]

Just to add further to this, I actually drove my 'deo some distance today - it's very much been relegated to second car status now I have a work vehicle (VW Transporter van with a 2.5l 5 cylinder turbo diesel - now theres a vehicle that has got zip below 1900 revs then pulls like a freight train once it comes on boost)...

I digress.... the seed of doubt had very much been planted in my mind with your original post but numerous times today I purposely let the 'deo lug down to around 1500 in 2nd and 3rd and it pulled away fine.

Sudso, I'm seriously wondering if your vehicle has had the timing belt changed at 160,000 like they are supposed to and they managed to get the cam timing out a tooth or something? or is it a problem inherent with having a gas kit put on it?

I'm intrigued.....

[sudso]

andyr wrote:

Sudso, I'm seriously wondering if your vehicle has had the timing belt changed at 160,000 like they are supposed to and they managed to get the cam timing out a tooth or something? or is it a problem inherent with having a gas kit put on it?

Cant say for sure about the timing belt as I only had the truck for about 4 months. Valves and seats were done at 180,000 for gas so the belt might have been renewed then.
It chugs a little bit on petrol up to about 1800rpm but not on gas so I'm thinking it's the stuffed O2 sensor causing rich fuel mixtures and low torque.
Will see on wednesday when I get the new one in if it makes a difference