Pulsing acceleration (boost leak or fuel problem?)

[Nith]

Another wee issue with my BP5 GT-B, with accelerating say from 50 - 100 slowly I can notice a pulsing, whether it be the turbo or the engine, though the tachometer isn't showing any change in RPM. Also when this issue occurs, when the vehicle is stationary I can smell a burning smell coming from the air vents, not very strong but its noticable. Could this be a boost issue? Leaking wastegate?

Any help will be much appreciated :-)

Edited September 2, 2015 by Nith

[pmkhoi]

I have wrx and have similar issue, the mechanic told me that the BOV is leaking. Do you use factory or aftermarket BOV? It can be the issue when you still feel the boost (to make sure the turbo and engine is working).

[Rosssub]

 Nith said:

Another wee issue with my BP5 GT-B, with accelerating say from 50 - 100 slowly I can notice a pusling, whether it be the turbo or the engine, though the tachometer isn't showing any change in RPM. Also when this issue occurs, when the vehicle is stationary I can smell a burning smell coming from the air vents, not very strong but its noticable. Could this be a boost issue? Leaking wastegate?

Any help will be much appreciated :-)

When you say pulsing, is the power surging on and off? As though someone's very lightly on and off the gas every few seconds. If so I'd guess the O2 sensor is on it's way out, enough to effect AFR but not enough to throw a CEL.

Is it more noticeable when the engines cold or warming up?

[Nith]

 pmkhoi']I have wrx and have similar issue, the mechanic told me that the BOV is leaking. Do you use factory or aftermarket BOV? It can be the issue when you still feel the boost (to make sure the turbo and engine is working).

Engine is stock to my knowledge, has been rebuilt by Winger in Auckland. Feel it as the turbo is pulling.

[quote name='Rosssub said:

When you say pulsing, is the power surging on and off? As though someone's very lightly on and off the gas every few seconds. If so I'd guess the O2 sensor is on it's way out, enough to effect AFR but not enough to throw a CEL.

Is it more noticeable when the engines cold or warming up?

Yea power on and off feel. Ok O2 sensor makes sense. That can be an easy fix if it is the issue. Possibly explain poor fuel economy. It's not a constant thing though, more noticeable at higher speeds. Definitely think it could be a turbo issue, if a waste gate or BOV is leaking would explain a burning smell?

[Marky]

No a burning smell is generally due to something burning

Maybe put a boost gauge on it and see if that is fluctuating at all, the 02 sensor is a very likely culprit - does the problem go away if you use a bit more throttle?

I don't know why you're dead set on it being a turbo issue

[boon]

Clutch?

[Andy_Mac]

Thats what i was thinking but he's got an auto based from his other problem post which describes gearbox woes, so probably related.

[Nith]

 Marky']No a burning smell is generally due to something burning

Maybe put a boost gauge on it and see if that is fluctuating at all, the 02 sensor is a very likely culprit - does the problem go away if you use a bit more throttle?

I don't know why you're dead set on it being a turbo issue

Well thank you for the obvious statement. But what would be burning, there isn't any smoke. It smells like clutch but being an auto that's not possible. Had the transmission serviced just recently.

Problem goes away with more throttle yes. Thinking it's a turbo issues because it sounds like the turbo is spoiling then losing pressure.

Took the O2 sensor out today and had a look, I can see moisture around the pin input, can't open it up to look in the guts of it. Will replace it and see if it makes a difference.

[quote name='Andy_Mac said:

Thats what i was thinking but he's got an auto based from his other problem post which describes gearbox woes, so probably related.

Think the two issues are separate. Concerning though the burning smell. Make sense if it was a manual. Will dig further online for any auto transmission issues.

[Nith]

So an update to my problem, I was right with my hunch on it being a boost leak. I havent had alot of time to tinker around on the car lately but I took the intercooler off and found the rubber ring on the drivers side was ****ed, and a **** load of oil around. Will clean and replace rubber gasket and see what happens.

[Marky]

Have you put a gauge on it yet?

Leaks do obviously have an effect but shouldn't make it "pulse" as such

[Nith]

 Marky said:

Have you put a gauge on it yet?

Leaks do obviously have an effect but shouldn't make it "pulse" as such

Got a gauge last weekend, will install it this weekend. Pulsing must be a O2 sensor, getting a scan on Thursday

[Nith]

Maybe this could be an issue to... Hmmm