Hi guys, I'm new here and in need of help.

My volvo 940 with a turbo is having trouble accelerating. it seems that the turbo isn't giving the engine that extra boost of power, and since it is a 4 cylinder acceleration is very slow. I think it has an exhaust leak because of the noise its making and i was wondering if that is why the turbo isn't working very well.

When i really want to get up and go, like when I'm getting on the freeway, around 3750 RPM the engine changes pitch (noise) and it sounds like its revving up and down and the car surges forward on and off, but the RPM gauge stays steady.

another problem is when i was driving in town the other day, stop and go every block, the car shutters when i come to a stop and i can feel it in the brake petal.

also when i come to a stop the A/C turns off and doesn't turn back on until i start to maintain a steady speed. it works while idling fine, but when i stop it shuts off. it sounds like air is coming out, but i can't feel it. A/C is important here because it regularly reaches 110+ degrees F here everyday in the summer.

Are these problems all related to the exhaust leak? it definitely need to be taken care of, it is very embarrassing how it has little power surges and that the engine changes pitch.

Thanks in advance.

 

no body huh?

 

I hate to keep bumping this thread, but i would really appreciate some help here. at least a little input as to how to go about fixing the leak and how it effects the turbo.

 

bump.

 

An exhaust leak should be easy to find. I believe spraying soapy water on any suspects works. Can't help you with the turbo since mine still works and hopefully still will.

As for stutters and shudders, I would do the usual tune-up procedures: new spark plugs, plug wires, rotor and cap, air filter. I hesitate to say fuel filter because, if it's underneath the car, it's a bitch of a job.

Good luck.

 

thanks for the reply.

let me ask this then, does an exhaust leak on a turbo vehicle cause i noticeable loss of power?

its is very noticeable and where would it likely to be leaking?

 

An exhaust leak is likely not the culprit here. In order for an exhaust leak to cause loss of power like that it would have to be before the turbo and pretty severe. I'm thinking the noise you're hearing that sounds like an exhaust leak is a faulty wastegate. This can cause the car to surge like you described and can allow your boost pressure to leak out, causing decreased performance.

Also, check for vacuum leaks on the hoses that lead to the air doors in your AC system. If you can still hear the fan running but no air comes out of the vents, the air doors are likely closing due to a vacuum leak.

 

Thanks for your help guys.

I went out and found the leak. its on the exhaust manifold right where it connects to what i think is the turbo. obviously its a bad gasket. i found it by spraying soapy water on it. i could see while it was just idling and when i had someone rev the engine it started leaking worst. I don't know how to describe how bad it is, other than i leaks a fair amount. that means that it is before where the turbo shoots air into the engine.

What and where is the waste gate? is it something that i can replace just by bolting it on?

I have some experience with working on cars, but its very limited and never on a turbo.

edit- is this something that i can just weld shut?

 

this thing actually has two leaks. the first one i found was very minor. Now i discovered a major leak. it blew off a gasket and massive amounts of exhaust are leaking our of one of the cylinders.

does that make a difference? i ordered a gasket kit, do you guys think that will fix it?

 

I'm sure a new exhaust manifold gasket will do the trick for that 'massive' leak. That could be part of your problem too. As for your wastegate, it is more likely a problem with the actuator assembly than the wastegate itself. It is red in this picture. Move the actuator rod by hand and feel for irregularities. It should move freely. Start the car and rev the engine while observing the mechanism as well, you should see it operate, at the point where your turbo is generating maximum boost it should be open (rod pushed out from the actuator) fully. If it sticks, lubricate it and see if that helps. If it doesn't, you will likely need a new wastegate actuator.