About a month ago I got a check engine lite. The code indicated I needed a new turbo boost sensor. For a month after changing it, everything was fine. Now I am losing turbo boost at random but getting no check engine light. It happens at all speeds including startup. For some reason, most of the time when I allow the engine to come to an idle and then give it throttle, the turbo works fine again. Happens at all engine temperatures. Any ideas? I am stumped!!!

 

How do you know you are loosing turbo boost? Can you not here the whine when you are out driving around? Do you have a boost gauge monitoring your boost and it drops down every now and then? You will not build any boost while in park or neutral and are revving it. Could also maybe be a boot "opening" up while under certain boost PSI...

 

I know I am losing turbo boost, not because of the sound but an EXTREME loss of power. Then suddenly, the turbo kicks in and the power is back and I can hear the turbo whine.

 

remove the intake hose off and see if you can spin the turbo with your fingers .... it should spin free with out any "catching".... if it doesn't, replace turbo

 

It spins freely, so I am really clueless. Seems mainly to happen until the engine gets up to warmer operating temp. I cannot figure this out.

 

check the wastegate, make sure it is not sticking open

 

hey i something similar happen with my truck but i have gauges and my pyro was running high because of the shortage of boost. did you get bad fuel?? thats what happened to mine. i changed the fuel filter and it ran fine.
Jared

 

How do I check the waste gate to make sure its not sticking open?

 

get some gauges. worth the money and you will need them when you start making mods anyways

 

I am going to get guages next week. In the meantime, can I test the waste gate to see if it's sticking and if so does that require a new waste gate or a new actuator?

 

you could just block the waste gate completely to make sure its your boost.. on the afc housing there is a tube going all the way over the engine unclamp it from the afc housing and block the rubber part of the tube with a bolt or whatever you can find. doing that you should be able to figure out if its your boost or not take it for a drive and see how it works.
Jared

 

i had a problem like that on an IH dt466, it ended up being a bad wire harness on the map sensor

 

Sounds a lot like dead pedal to me. Check for code P0216. This will cause the turbo not to spool, because it is not getting fuel.

 

Now that I observe this issue more, it does it only until the engine temp comes up and then after that it works fine. In addition, I can let off the throttle and when I get back on the throttle and then the turbo spools up just fine. At the risk of sounding ignorant, what is the AFC housing so I can try the test you mentioned trying.

 

SORRY thought you had a 12valve!! that was my bad ignore everything i have said except the gauges part!