Rav4.2 D4D Hesitation When Accelerating, Rattle When Accelerating Abov

[Chainsaw86]

Hi, newbie here.... I have a 2004 rav4.2 d4d. A few problems you guys can hopefully help me with.

Firstly is the acceleration. It can be sometimes very hesitant when i put my foot down. Secondly when accelerating over 2000rpm there is a slight rattle. Like a piece tin foil fluttering about tin foil. Im pretty certain it isnt any kind of heat shield. Thirdly (and im not sure if any of these are connected) but the car sometimes goes into limp mode on hard acceleration. The tin foil sound is usually present as it goes into limp mode but im not sure if they are connected. Thanks in adavance for any replys :-)

[Mistermena]

1st off... Have you checked the oil level? When was the fuel filter changed and EGR valve cleaned last? MAF cleaned?

This sound could be injector rattle😳

[Chainsaw86]

Hi thanks for reply. Oil level fine, i have owned the car for 2 months, fuel filter hasn't been changed since ive had it. Bought the car off my boss so i can ask him this. He probably has had it changed at service intervals. I doubt the egr has ever been cleaned

[Chainsaw86]

Unsure about maf aswell. Could this be contributing toward hesitant acceleration? Regarding the hestitation I nearly took the plunge and bought a couple of scv valves. But im not fully convinced it is that yet. Upon reading further it seems to point to many things

[Mistermena]

The MAF reads the air flow and sends signals to the Denso ECU to regulate fuel/air ect. A simple clean could make all the difference! And it takes just 10 mins from start to air drying to finish. I'd be starting there with the fuel/air filter change. Plus an EGR clean. Run a tin of BG244 in the fuel and see what difference it makes... 🚙💨

[Tech01]

A "flappy" noise at highish revs/full throttle is a sign that the first exhaust box (oxidation catalyst, containing a fine ceramic honeycomb) has become blocked. Essentially, the exhaust gases cannot exit the turbo freely, and this causes back-pressure: loss of power, and a chuffing noise.

To check this out, remove the front box (first one after the turbo and down-pipe) together with the rest of the exhaust. Test-drive the car with only the down-pipe in place - it will be surprisingly quiet. If this cures the problem, then you need either to renew the front box, or remove its contents.

Chris

[Chainsaw86]

The hesitant acceleration is very intermittent though. Sometimes i can accelerate fine. Other times it chuggs abit but i can kind of accelerate through it. Would a blocked catalyst not be constant underpower and hesitant? And the rattle sound comes from the engine bay not from underneather the car. Could it cause it to overboost/go into limp?

[Chainsaw86]

Mistermena thank you for your input. I will add it to the list of possible causes and get the maff cleaned. Anything else you think it could possibly be?

[anchorman]

What would you like it to be? Do the bits he told you first and then worry.

[Tech01]

With a cat box producing back-pressure (blocked or partially blocked), the engine only protests (flappy noise) when using substantial and sustained throttle. You can often accelerate through it by using gentle throttle, but eventually the problem will get worse. Disconnect the box and try it - it will confirm or eliminate the problem once and for all.

Chris

[Chainsaw86]

Hi, yes i will try them this weekend. Just to add, i get the engine howling as in the youtube video apparently relating to fuel filter housing. Could this be a contributing factor?

[anchorman]

Not usually. It is caused by the non return valves resonating in the filter head but if one of them is faulty and letting fuel run back or go where it shouldn't go then yes, it might.

[Chainsaw86]

Cleaned maf sensor, went fir test drive, the acceleration hiccuping/hesitation is still there , didnt go into limp mode but sometimes it doesnt anyways. Yet to undo catalyst but will try this on monday when i have tools. Regarding the howling how can i fix this? There is a second hand fuel filter housing unit on eBay. Would that cure the howling?

[Tony Barnsley]

A "flappy" noise at highish revs/full throttle is a sign that the first exhaust box (oxidation catalyst, containing a fine ceramic honeycomb) has become blocked. Essentially, the exhaust gases cannot exit the turbo freely, and this causes back-pressure: loss of power, and a chuffing noise.

To check this out, remove the front box (first one after the turbo and down-pipe) together with the rest of the exhaust. Test-drive the car with only the down-pipe in place - it will be surprisingly quiet. If this cures the problem, then you need either to renew the front box, or remove its contents.

Chris

I think I need to check this out . . .Would you say that it sounds like the exhaust is 'blowing'? because I do get that sound when trying to accelerate sometimes.

Wonder if it's covered by the extended warranty?????

[Big Kev]

Dinnae you bother checking it out, Tony........that is for why ye bought an extendified warrantee (love when that word appears on here......sorry.) In the immortal words of wan Elvis Pressley.......Return to Vendor.

Why.....? How would ye check that out without them knowing you or somebody had been fiddling.....?

[issa]

Hello there, i know this is way to late to post, i hope some one is still reading this.

I have a Daihatsu Sirion 1998 with the same exact problem description, I would like to add the following description, in its worst form i would press the pdel to the metal and the engine will not rev at all and you can hear it chocking trying to breath but no acceleration or engine at all.

to me i have no doubt that the timing of the ignition for all of the spark plugs is off from 700 rpm to 1550 then 2000 then 3000 it becomes better 3100 to 3500 better till 4K when its becomes normal  that is where i get no hesitation and trow power.

I have up started working on the horns the weather got cold, the engine was doing 400 to 500 rpm and rattling suddenly everything goes normal.

So I noticed that the engine  acts normal when the weather is cold, but gets really bad when the weather and engine are hot.

I changed three MAP sensors though they had minor effect the main problem still persists. 

i know its not the cam sensor, nor the DVVT release valve, nore the lambda since i disconnected that, and still no change the hesitation is still there.

So my last resort would be to change the Throttle body sensor, if any one has any idea about this please share.

thank you all and best regards.