Power issue.

[Edward0813]

Hello guys. I'm having a problem with my 2005 Toyota Corolla T-Sport 192bhp.

Sometimes I feel the engine dosen't have all the power and the exhaust sounds a little bit different. I drive this car as a daily from 2018 and this problem appeared a year ago, but it started to be more frequently. 

There are no error codes in ECM.

Thanks!

[Bper]

Hi Edward, there could be several potential issues that can cause this problem.Engine issues like power loss and strange exhaust sounds could be caused by air filter, fuel delivery, spark plugs, exhaust system, or vacuum leaks. Check your air filter and consider replacing it. If that doesn't help, a mechanic can diagnose further. There are other problems that can cause this as well but these would be easier to check yourself first. Hope this helps 

[APS]

What is the nature of this reduction in power? What is different and when? Is there a certain rev range? Hesitation? Does it come on lift as normal (i.e. at 6200 rpm)? Details s'il vous plait...

[Cyker]

If this is a problem when you're running at higher RPM, e.g. 6000+, your lift bolts have probably snapped - It's quite a common problem on the Corolla T-Sports.

When we had a big T-Sport group here way back in the day, it seemed like every week someone was replacing the lift bolts  

Otherwise maybe try running a few tanks of Shell V-Power/Esso Synergy/BP Ultimate/Total Excellenium through it, or your preferred fuel additive in case it's guck building up in the fuel system somewhere.

[APS]

Never had that problem on ours. But then, none of them have/had any higher mileage. 🤷‍♂️

For reference, the relevant TSB attached:

liftbolts.pdf

[Cyker]

I suspect it's a function of age and how enthusiastically they're driven as to how well the lift bolts hold up   

Legend has it there are lots of old ladies driving around in T-Sport Corollas with snapped lift bolts that have no idea about the valve lift  

[APS]

Very true. They are really rather tame below high lift and most - what I could consider normal people - would never rev an engine much beyond 5 grand. Blissfully unaware.

[Edward0813]

Thanks for all the replys. When I start the car, sometimes the engine sounds different (a bit louder), and at that moment I know it dosen't have all the power. And it kind of hestitate to accelerate from 1500rpm to 3500rpm and the engine is so much louder in that rpm range. 

The lift kicks in normal at 6200rpm and the car accelerates better, but because I drive this car daily for 6 years, I sense the power loss even when the lift is engaged.

But the power loss, dosen't happen all the time. This morning I drove to work and the car runs well. I've tried to see if the problem is affected by the outside temperature but the problem appeared when is cold, when is hot, when it rains, it dosen't matter.

Thank you guys! 

 

[TonyHSD]

Misfire because of bad coils ? You can run a diagnostic to see if any stored faults in ecu and physical check spark plugs and coils. Replace if needed or if it’s time to do so. 👍

[Cyker]

Things that spring to mind for checking are for dirty MAF sensor, dirty injectors, dirty spark plugs.

May also be a slight leak somewhere on the intake or exhaust from a failing gasket or a mouse-chewed pipe or something like that.

These are all just random pulled-out-of-my-proverbial suggestions though!

[Mooly]

How many miles has it done? Can't just spot that anywhere... 

[APS]

Sound like you may have a leak or power connection that causes this problem to be intermittent. It's worth opening the bonnet when you can hear that it is not running right. Try to locate where the increase in sound comes from. Pull on cables, hoses and intake pipes. If you locate something that appears to make a noise or make a difference in the running when you move it - take a photo and share. 

Have you cleaned the engine recently or driven the car through a lot of rain / standing water? Sometimes water that splashes over the engine can work its way down the spark plug wells and cause rough, hesitant running.

When was the car serviced last? Are the spark plugs old?

[Corolla Mike.]

Catalyst  breaking up and causing blockage?

[Mooly]

9 hours ago, Corolla Mike. said:

Catalyst  breaking up and causing blockage?

Tbh I had that thought as well and simply because the symptoms the op reports such as the lack of power and exhaust noise are exactly the same as I experienced with the 1.33 Auris, although we know why that happened on the oil burning Auris. It is a possibility I think.