98 V70 T5 Manual - Low boost on ARD Green Tune

Seaway · Post by **Seaway** » 22 Apr 2015, 04:49

Car has been been running great on an ARD Green Tune with boost consistent at 16 -17 psi. Two days ago I had a boost spike to about 22 psi, it was the first time I have had a boost spike running this tune. After that spike I am now only hitting 10psi at WOT. No smoke, nothing obviously wrong and the boost holds steady.

I swapped my TCV with a known good one, reset the ECU and there was no change. Still boosts only to 10 psi and holds there. I have no codes, I did not see any loose vacuum hoses (all are silicone) or charge/intercooler hoses (also silicone).

I rebuilt my 16t urbo under 1000 miles ago and installed a new CBV. After the rebuild the car ran great and always hit the targeted boost.

Any ideas?

Post by **Ozark Lee** » 22 Apr 2015, 06:13

Is the wastegate operating smoothly?

...Lee

Seaway · Post by **Seaway** » 22 Apr 2015, 06:15

Ozark Lee wrote:Is the wastegate operating smoothly?

...Lee

How do I check? Unhook the rod and pull, or ?

Post by **Ozark Lee** » 22 Apr 2015, 06:24

I would just move the rod with everything hooked up and see if it catches anywhere and make sure the spring pulls it back to all the way closed.

...Lee

Seaway · Post by **Seaway** » 22 Apr 2015, 06:27

I will give that a try when I get a chance, thanks.\

If the wastegate is not closing all the way, what is the prognosis?

Seaway · Post by **Seaway** » 22 Apr 2015, 06:33

I guess I should clean the MAF as well? Could be a lean condition making it pull boost? The MAF is only about a year old and I just changed the stock air filter about a month ago.

mika · Post by **mika** » 22 Apr 2015, 08:42

I would not touch that MAF if I were you. Its new. Don't want to damage it with chemicals

Seaway · Post by **Seaway** » 22 Apr 2015, 08:47

Fair enough, I will leave it alone!

Post by **mecheng** » 22 Apr 2015, 11:16

I lost 3 psi from a slightly loose clamp. Triple check all the hoses.

I second, checking the waste gate action. The rod gets quite rusty and can restrict the movement. I lightly sanded it and put anti-seize to make the operation smoother.

I would also check that the CBV is working okay.

Seaway · Post by **Seaway** » 22 Apr 2015, 11:24

mecheng wrote:I lost 3 psi from a slightly loose clamp. Triple check all the hoses.

I second, checking the waste gate action. The rod gets quite rusty and can restrict the movement. I lightly sanded it and put anti-seize to make the operation smoother.

I would also check that the CBV is working okay.

How do I pressure test the CBV? Just hook up a hose to the CBV and add pressure with a hand pump?