Flat acceleration with 2003 Sportivo

[BoostBoy]

Hi guys,

I've done some extensive searching here, but can't find anything related to the same problem I'm having.

Ever since I have owned my 2003 Stivo, I've noticed the acceleration is quite flat. Best way to describe it is that it's like accelerating with the A/C on...or like it's running on 3 cylinders. Takes forever to reach lift...feels like it's struggling.

Previous owner had a CAI, but I got the standard box put back on...so maybe there are some vacuum problems? The car idles correctly so I don't think it's that. I've noticed a crack in the box though. I've also changed the filter, spark plugs, and flushed out my motor and put new oil and also inspected the throttle body and all looks okay.

What else should I check? Gearbox and clutch? I'm going to book into Toyota soon because the passenger side air bag has had a recall. While they are inspecting that I was going to get them to do some diagnostics on the motor, like an ECU check and compression check. Am I wasting my time and money?

Thanks for any help.

[BoostBoy]

No responses? Is it worth getting error codes checked even though I'm not getting an engine light?

[GHOSTIVO]

im not the expert but the crack on the stock air box could be causing it .only reason i say this is because i had a crack in my one also which made the accerleration crap(from 2krpm to 3krpm).

Also when a/c is on,it uses more power and will make the car slower.

[Adam Carr]

Did you find a solution for this in your case man? 

[BoostBoy]

Yeah mate. Ended up taking it to Toyota and they confirmed there was a problem with acceleration and put it down to needing a proper oil change. I regularly change oil and put in what is recommended, so this was a surprise to me, but I'm guessing previous owners had gunked things up with crappy oil/not changing it frequently enough. In my case the ECU wouldn't allow proper acceleration or engage lift properly to protect the motor.

Basically to resolve this, Toyota flushed the motor clean with oil flush several times (I had never thought of doing this before), and put in their oil. I can't remember exactly what weight it was but Toyota tried to tell me I need to use their oil or equivalent and the oil I was using was no good (mind you I used top-notch oil recommended on these forums). To be honest I don't think that will make a huge difference as long as regular oil changes are done and the valves are clear. You have to remember the motors are high revving and tightly wound, so you need a good synthetic oil. As the motor gets older the clearances start to change so you can adjust oil accordingly.

After picking up the car it was like I had never driven a Stivo before. Huge difference, revved smoothly and lift engaged properly. A few years on i still have the car. It's overdue for another oil change and I'm starting to notice the same problems again haha.

[trentmeyer23]

7 hours ago, BoostBoy said:

It's overdue for another oil change and I'm starting to notice the same problems again haha.

Maybe I'm missing something; but, I don't understand what is funny about a potential catastrophic failure and a hefty repair bill.

[BoostBoy]

Geez settle down. Who said anything about catastrophic failure? Missing an oil change by 1,000kms is not going to do anything. Those motors are bullet proof anyway...probably can run with no oil change for a long longggg time before any sign of failure.

[trentmeyer23]

Poor maintenance will definitely shorten its life, regardless of the engine type. Given the previous issues it is not a worthwhile risk, especially if it is at the stage of affecting performance.

[campbeam]

Oil sludge is an engine killer. You "bullet proof"your drive train with both regular and preventative maintenance. Based upon your previous post, Toyota flushed your engine several times because the engine was so full of sludge, it was affecting the proper functioning of the valve train hence the poor acceleration.

You either learn from past experience or repeat the same mistake.  Factors that contribute to oil sludge formation include short distance driving i.e. less than 20 minutes, use of incorrect/poor quality oils and overdue maintenance. If you want performance and reliability, then properly maintain your vehicle