Check your DV's
 

About 6 weeks ago I blew another driver side turbo, at first it was a coincidence that it was the 2nd failed driver side turbo but after some investigation we have found a probable significant contributor to the problem.

A few years ago I had the dealer install some aftermarket DV's along with the the GIAC stage 2 mod, the receipt reads "forged dv's", after pulling the engine to do an inspection of all oil feed lines, etc, we found that both DV caps were about one turn from coming off completely. "A one year old would have been able to remove them" my tech says. This has probably been robbing me of power as well as damaging the turbos :mad:

The next question took me by surprise-
Tech: when's the last time you inspected them?
Me: They need to be inspected?
Tech: Yeah, every 6-12 months
Me: Uhhh...never, had no idea they needed to be inspected. :confused:

Anyone else ever hear/read about checking the diverters on a regular basis???

Another lesson learned is to check what you bought, I didnt have forged, I had a lower quality evos (not to be confused with EVOMs, but I think there may be or have been a relationship). Appearently the evos are infamous for the caps coming loose :mad:

Probably a good time to check your DV's, check the springs and diaghrams, make sure the caps are tight and make sure you got what you paid for.

996 Turbo buyers guide in Total 911 metioned DVs and their not ...
 

unheard of failure. Results in overboost, which is nice as long as turbo (or engine) holds up.

I'd do as you suggest and also keep eye on boost reading. If one starts seeing more boost than 0.7 bar, say 0.9 or higher.... Could be DV trouble.

Sincerely,

Macster.

Chris, sorry to hear about your misfortune...Checking/maintaining DVs depends on the type. The Forge DVs (which are adjustable) do require oiling...The EVO DVs (not adjustable) (reportedly) do not.

problem is that if one side is over/underboosting due to bad DV, the other side may try to compensate, so you may not see anything significant.

Then how to inspect/know DVs working correctly if can't rely upon boost...
 

gage?

IIRC -- only been under car once since I bought it couple of week ago -- is DV control rods and other related hardware located down low under exhaust pipes/turbos.

While I can under car with it backed on Rhino Ramps for when I do an oil change what to look for to determine DVs and related hardware ok or not ok?

Sincerely,

Macster.

DVs are on top of engine.

yeah the totally inaccurate boost gage in your dash:D

If you have any questions about the DVs or other issues, I think you'd better let a mechanic take a look at it...it's going to take you some research on your part to get to know your car better. Have you done any mechanical maintenance to your cars in the past? If you start fiddling around with things without knowing what adjustments to make, you can end up messing up your car. Something as simple as an oil change has messed up other guys cars when they pull out the wrong bolt thinking it's the oil plug.

Yes...some of the DVs require periodic maintenance...they need to be taken apart, clean out the barrel and piston, re-lube the piston and screw it back together tight. Sounds like someone didn't screw the DV's together tight enough and they rattles loose.

Bill: I bought a set of billet DV's from EVO and they are the take-apart type....but just recently, I've noticed that I'm hitting a 1.3 on boost....started wondering and with this post, I think I need to get in there and bloody up my hands to check those DVs....also I used an OEM F hose...and I've seen some instances of them splitting. I may go to a Sampco replacement. Your thoughts?

Hey Chuck...mine are the old EVO DVs that do not come apart...I believe the newer ones do and are adjustable (which means you need to lube them). The boost issue could be wastegates/DVs or hoses. I replaced all my hoses some time ago with the EVO silicone (in red of course).:D

Bill: Are you referring to that "all stock" car you have?

Yes, stock since the first month I got her...LOL:D

It's for this exact reason that I run Bosch 710N valves. They are the uprated versions of the ones that came stock. They do not need to be serviced because they are the same design as the stock valves (but with stronger materials). Plus, they still honk if they go bad because they are diaphragm based. Piston designs don't honk and so it's tough to tell when they've siezed.

Sounds like more justification for periodic maintenance on the serviceable DV's...although there hasn't been a lot of information put out on the fact these need periodic cleaning and lubing. Certainly don't hear that from the vendors do you? What you usually get is how pretty they are in billett or black and how much better they are than the platsic OEM ones.....but somehow they forget about the maintenance issue.

is replacing dv's something a novice can do ?

The most difficult part about any novice is the lack of confidence...and fear that he's going to mess something up. If you have at least a basic level of mechanical ability and can follow pictures and written How-To's....you can do it. I did it as one of my first DIY's....and although I was a bit tenuous, I got thru it in about 2.5 hours....there's been plenty written up on how to do it....so I guess my answer would be yes...if you have a grasp of mechanical issues.....not a difficult DIY....just a bit scarey for someone who's never wrenched on their Porsche before.