Toyota Previa Does Not Go Beyond 60Mph?

[awaisgondal]

Hi my toyota previa 2001 diesel drives very good till 60mph but does not go beyond that. And if i try it harder it gives strange noises beyond that

Can anyone help me understand why it is so and what should i do to makd it better

Thanks

[korat102]

Based on your previous posts regarding braking issues, I think a lack of speed is probably a good thing...

Anyway...assuming the engine doesn't sound like a bag of spanners, lack of power on a diesel is usually due to insufficient air or insufficient fuel. Try changing the air filter first. If that doesn't help, try changing the fuel filter. If neither of those make any difference, we'll have to start digging further...but get those brakes sorted first!

[awaisgondal]

Yeah thanks i ll sort brakes first

N i have recently about 1000 miles ago changed air oil n fuel filter .

[korat102]

What do those 'strange noises' sound like?

If fuelling and air are ok, I'd be suspicious of the turbocharger. They don't last long unless they've been looked after properly. If it's failed, it'll need to be rebuilt or replaced.

Might also be worth taking a quick look at the MAF sensor (it'll be in the throttle body, just past the air cleaner). It measures air passing into the engine so the ECU can adjust fuelling to suit. Don't touch it though, it's very delicate. If it looks dirty give it a squirt of electrical switch cleaner or a MAF sensor cleaner.

Check the clutch as well, if it's slipping it'll be noticeable in higher gears, hardly at all it lower gears...

[awaisgondal]

Turbo is reconditioned fro reco turbo about 3000 miles ago

N clutch is fine . Like i said till 60 it drives brilliant but beyond that so noisy

May b drive shaft or 5th gear or what

Taking rpm to 3000 in 5th gear is impossible

[awaisgondal]

What is MAF sensor?

[Devon Aygo]

Just a possibility but I have seen a case like yours before, on the front slam panel under the bonnet is the air intake scoop this should be fixed down to the slam panel, if it is not or is loose it sucks up to the underside of the bonnet making a loud induction noise and totally starves the engine of air, obviously at idle or with bonnet open the fault never occurs.

[luludog]

Tell you what I would be looking at me old fruit, (suction control valves) and collapsed turbo intake hose. both these will not allways trigger the m i l.