boost performace issue

Domo · Post by **Domo** » 29 Dec 2012, 18:45

So I have a 98 v70xc282,000km with a 16t turbo, white injectors, and green lpt ard tune 3" exhaust with a small cat resonator and one muffler, I have changed all vaccum lines all charge pipes for fcp hoses, I have tried changing to the ipd hd tcv, I've also changed the cbv to the ipd unit. I have triedset the turbo actuator rod tot he correct setting and tried sortning the rod all in the quest for 14psi, I have about 5psi at about 3000rpm at wot I have 10.0afr a loud whistle from the engine bay (is this normal) and I reach 10-12 psi then it fades off through gear changes, I hope I have not missed anything but I have tried all the usual stuff.

Also tried a boost tester hooked up from charge pipe leaving turbo, air is pissing out of the the oil drain hole in the intercooler is this normal?

Post by **jtp** » 29 Dec 2012, 20:22

I didn't know our's have drain holes but if they do there should be a plug there. My old intercooler is collecting dust so if the plug would work with your car I'll send it to you if you hit me back for shipping.

Domo · Post by **Domo** » 29 Dec 2012, 21:48

I'll try and check into seeing if there should be a plug, thanks?

Domo · Post by **Domo** » 24 Apr 2013, 20:02

UPDATE
Boost tested from turbo inlet to tb no leaks, all boost/vacuum lines have been changed to silicone tcv has been changed twice, cbv has been changed twice. if I set the actuator at my tune recomended 3.7psi I get 10psi at wot with a reading of 10.0 on my afr, plus a loud whistle coming from the engine bay, if I shorten the actuator rod to its shortest I get 14psi but I still get 10.0 on the afr and a loud whistle. I have made sure the wastegate is seating correctly, I have applied pressure to the actuator and cannot hear any leaks, I have checked the opeartion of the cbv it seems to work fine, the actuator is the last thing to change although it does not make any sense that it is causing the issue.

lk250f · Post by **lk250f** » 24 Apr 2013, 20:42

Have you checked for a vacuum leak? I know the TCU will limit boost below 3000rpm, my stock GLT with exception of NA throttle and snabb intake pipe only boosts to about 3-4psi until 3000rpm and then goes up to 7 or so.. If you are able to, with a scan-tool look at your primary o2 voltage. Also how do your plugs and ignition components look? Could you explain the whistle too as well? I am guessing it isn't like a turbo whistle, but air escaping? Once again, check for a vacuum leak. Sounds like that could be the case for less boost and rich conditions.

Domo · Post by **Domo** » 24 Apr 2013, 21:28

I have changed all vacuum lines including all the engine bay vacuum lines for the evap system at cold start the car reads -20hg of vacuum both o2 sensors are new volvo specific bosch units plugs are new along with volvo plug wires and bosch cap and rotor a rush of air best deccribes the sound I'm hearing, I'm just thinking to myself but the computer must be seeing the correct amount of boost hense the rich conditions its expecting the proper amount of air for the fuel, the air is ecaping but my boost gauge is reading 14psi at the tb vac tree with a whistle/rush of air, and rich condtions

Post by **kcodyjr** » 24 Apr 2013, 22:32

I'm starting to think there's a leak between the TB and the intake manifold, between the manifold and the head, perhaps a cracked intake manifold but unlikely, or possible cracked intercooler unless it's holding pressure after putting that plug into it. Could a really bad or loose IAC valve let air escape under pressure?

Domo · Post by **Domo** » 25 Apr 2013, 21:38

ok today we smoke tested the engine, intake system, no smoke was seen anywhere that you wouldn't expect it during the test, then we went out for a few wot runs so the people that were helping me could hear the noise and watch the gauges, on the last run the car blew the hose off the tb..... back to the shop. it has never, and I mean never done this before. I have been quite hard on the car trying to find this leak, without having it blow a hose off, I think that doing the smoke test rules out intake manifold gasket , and tb gasket ( correct me if I'm wrong) I have checked all the bolts on the intake manifold again aswell, I still wonder if there is a wastegate issue, although today I'm going to check the cbv operation again, couldn't see any smoke from the cbv area today, the cbv was changed just in case and was changed out for the ipd cbv also one of the mechaincs noted how the boost devolpment seems chopy, the boost jumps aroung as the revs climb sort of 10 12 14 10 12 12 with the afr still at 10.0

Could a loose iac valve cause this?