Engine: TD: Volvo s40 slow acceleration / sluggish

[Biotoxic]

Cheers hasitha, The way you described me sounds like the Vac hoses are set up incorrectly.. I'm a 65% sure it's the case as if my memory serves me correctly waste gate should be normally in closed position and only opened when changing the gears/decelerating( whenever there is too much pressure) Right, the thing you could do now is to test it by disconnecting the vac hose from the turbo actuator, block the open end of the hose closer to the turbo and then go for a drive, try to accelerate then but don't over rev it. Do you notice any increase of power/acceleration now?

[hasitha]

Originally Posted by Biotoxic

Cheers hasitha, The way you described me sounds like the Vac hoses are set up incorrectly.. I'm a 65% sure it's the case as if my memory serves me correctly waste gate should be normally in closed position and only opened when changing the gears/decelerating( whenever there is too much pressure) Right, the thing you could do now is to test it by disconnecting the vac hose from the turbo actuator, block the open end of the hose closer to the turbo and then go for a drive, try to accelerate then but don't over rev it. Do you notice any increase of power/acceleration now?

I pulled out the hose from the actuator and plugged in a nail into the hose. as seen in the photo below


well there is actually a more kick to the car than it used to but i didn't wont to rev it above 2500 rpms since the turbo might get damaged.. it still feels like the engine is at peak rpms when closing 3000 rpms. is that normal? because it used to be like that even with he hose plugged to the actuator.

there is a positive difference.


Oh and i unplugged the bolt i used to block the hose and kept my finger there. even at slow rpms there is slight vacuum i could feel.


Please let me know what this might mean? doe that mean the turbo actuator is faulty ?

[Biotoxic]

Turbo might be OK, there might be a problem with the vacuum hoses instead. Check my posts in the signature, you might be able to see the correct vac hose locations. Make sure that the vacuum coming from the vacuum pump(at the end of the camshaft) goes to expansion tank(the round thing connected with two bolts to the inlet manifold) then a vac hose coming from the expansion tank should be connected to the N75 VAC IN bit( if my memory serves me correctly) I might get you the proper vac connection schematics tomorrow.

[hasitha]

Originally Posted by Biotoxic

Turbo might be OK, there might be a problem with the vacuum hoses instead. Check my posts in the signature, you might be able to see the correct vac hose locations. Make sure that the vacuum coming from the vacuum pump(at the end of the camshaft) goes to expansion tank(the round thing connected with two bolts to the inlet manifold) then a vac hose coming from the expansion tank should be connected to the N75 VAC IN bit( if my memory serves me correctly) I might get you the proper vac connection schematics tomorrow.

Thanks alot Biotoxic, Yes i check the vacuum lines and it is the same , like you have described. there is a vac line from the expansion tank to the n75 VAc in as well.

Could it be the turbo actuator? how can we check if the n75 is faulty?
i will be getting a new n75 valve next week. i will update on that as well.

have a great weekend

[bobthecabbage]

Watching your video the actuator moves up correctly but if you rev it, it should move down. If you rev quickly it will move down quickly and further than if you rev slowly.

There should be a hose going from the 'N75' valve to big air hose connected to the air filter box. Is this hose in place and free from obstruction/blockages?

The purpose of this hose is to allow air in to release the vacuum so if its blocked or connected to the wrong thing, the valve can't work properly.

The ECU operates this valve in relation to the signal from the MAF and MAP sensor, so those have to be in working order for it to function. The MAP sensor measures the boost so if its faulty or disconnected, you probably won't get any boost.

[hasitha]

Originally Posted by bobthecabbage

Watching your video the actuator moves up correctly but if you rev it, it should move down. If you rev quickly it will move down quickly and further than if you rev slowly.

There should be a hose going from the 'N75' valve to big air hose connected to the air filter box. Is this hose in place and free from obstruction/blockages?

The purpose of this hose is to allow air in to release the vacuum so if its blocked or connected to the wrong thing, the valve can't work properly.

The ECU operates this valve in relation to the signal from the MAF and MAP sensor, so those have to be in working order for it to function. The MAP sensor measures the boost so if its faulty or disconnected, you probably won't get any boost.

Thank you very much bobthecabbage,

This is the thing. even if i want to accelerate quickly the car wont let me.. it accelerates when not in gear but feels a bit slow, like, even if i stomp on the gas pedal, the car gradually accelerates.. It wont shoot up to about 3000rpms.
Could it be because of the turbo actuator not working properly?

I checked the vac lines and they seem to connect to the right places.


I removed the line from the n75 to the intake and there isn't any blockage either.
However there is new n75 valve on the way. i will update as soon as i get it fixed. It will take appox 10 days to arrive.

Oh as i have mentioned earlier, i did replace the MAF, but still couldn't get the car scanned again. Most probably i will go for a scan today.

Thanks again

[hasitha]

Guys!
I scanned the car again and erased all the error codes that i had, which i mentioned previously.
I changed the MAF ( ebay one) and The MAF error didnt pop up after re scanning
Only the " preheating light . signal too low " error popped up.

And like i mentioned before there is a little rattling noise coming from the exhaust manifold area i thought it was something wrong with the turbo because of running the car as it is. but now i think it could be the catalytic Converter. Maybe it is clogged and may be some ceramic parts are broken inside. There is a Muffler like thing at the place where the the exhaust pipe meets the turbo. and there is another under the car, like under the driver seat position. Which one is the catalytic converter?

My car is a Volvo s40 1.9td T3 engine model.

[skyship007]

It's very unlikely that the power loss has anything to do with the CAT.

[bobthecabbage]

Originally Posted by hasitha

Guys!
I scanned the car again and erased all the error codes that i had, which i mentioned previously.
I changed the MAF ( ebay one) and The MAF error didnt pop up after re scanning
Only the " preheating light . signal too low " error popped up.

And like i mentioned before there is a little rattling noise coming from the exhaust manifold area i thought it was something wrong with the turbo because of running the car as it is. but now i think it could be the catalytic Converter. Maybe it is clogged and may be some ceramic parts are broken inside. There is a Muffler like thing at the place where the the exhaust pipe meets the turbo. and there is another under the car, like under the driver seat position. Which one is the catalytic converter?

My car is a Volvo s40 1.9td T3 engine model.

The cat will be the thing that looks like a 'muffler' (UK - silencer) nearest the engine in order to make best use of the heat (they only work above a certain temperature). Some cars may have two?

On your car it will be the thing you describe just after the turbo. You are correct in assuming that if it is blocked or disintegrated inside then it would cause power loss.

However, I think we established that your turbo is not boosting (not being told to boost) so maybe start there.

[hasitha]

Thanks again skyship007

Thanks again bobthecabbage for the location and info.

well yesterday i removed the catalytic converters.
the one which was the at the very end of the turbo outlet and the one underneath the car.
Well for my surprise the ceramic filters in both catalyzes has been removed by the previous owner.

Therefore the problem still exists.

I am waiting for the n75 valve. i will fit it an update you guys. Hoping the turbo boost problem will be fixed. but we will see.

In the mean time, can an faulty ABS sensor put the car into limp mode. I have read about few Mercedes going top limp mode due to faulty wheel sensors.

I have a faulty Rear Drivers side ABS sensor issue. and the dash broad light is on. can it cause the car to go to limp mode?