Wicked69

Put in my latest 5.3. Scanned it with Hptuners. No error codes, nothing comeing up weird. Go to drive the car and it won't go into boost. I can hear the turbo whistling but can't get it above 3k or so. One of my turbo's has a little more play than normal and has some oil coming out the exhaust turbine. I think it has a bad seal. However, I can still see the compressor wheel turning so figure it should at the very least be working. If oil is coming out of the turbo exhaust then is the turbo causing it to fight the other new turbo?

I am pulling the turbo to send it in but am trying to figure out if something else is going on with this engine. I checked all the connections to the turbos (silicone) and the intake, etc.. Nothing loose or leaking. Car runs fine just won't go above 3k or get into boost.

Any ideas?

SSZ

Do they both spin free by hand? Does the engine have the original 180000 mile valvesprings still? Everytihing on the cold side tight and leak free?

Nitroused383

iTrader: (10)

When your last motor blew did any pieces make it through the turbine wheels? Pull the exhaust housing off and verify the wheel is not trash inside.

stevieturbo

It could be anything from a simple boost leak, turbo, w/g leak or plumbing issue, bad tuning, etc etc

A little bit of play or oil whilst not ideal, shouldnt have any major impact on performance until it actually goes bang

Higgs Boson

iTrader: (3)

you end up going in circles

Wicked69

I cleaned everything out. The turbo looks as though it is working just some play and leaking a little oil. Hmmm. The only other thing I did was remove my manual boost controller so I couldn't raise the boost. I put a vacuum line on the turbo fitting to the fitting on the bottom of the wastegate and left the top fitting on the wastegate open. I did this on both turbo's. Did I not hook those up correctly?

The tune is the same tune I had and it went to 23lbs easy. I swapped valve springs so it's not the springs. Hmmm.

Wicked69

I am at a loss. Just drove it again. Won't build more than a couple pounds of boost even if you floor it and the car just does nothing. However, the temp went from 160-200 degrees pretty quickly from trying to get on it. It takes for ever to warm up and runs very cool with the E85 but as soon as you try to romp on it and the engine doesn't respond, it wants to get really hot, ie,. over 200 degrees.

stevieturbo

Well that should give you w/g pressure only, which could be pretty low ( usually just under spring pressure )

So exactly what does happen at 3k ? Has it ever been tuned at different boost levels ?

Have you checked for leaks on the boost plumbing ? BOV ?

98Z28CobraKiller

iTrader: (17)

Sounds like you might be leaking some compression into the cooling system care of blown headgasket.

stevieturbo

Something is very badly wrong. It could be a tuning issue or as above a head gasket issue.

Although even if the HG was blown, you should still rev and make boost.

A lot more information is needed here.

Has this engine ever run properly ?

98Z28CobraKiller

iTrader: (17)

Check for a rag or obstruction between the turbo and the MAP sensor in the intake (entire cold side). I didn't see that it would only rev to 3K when I mentioned the headgasket.

Wicked69

Yes, I went and saw the engine run. It was in a 2000 silverado. I checked oil pressure, and asked to let it run for 10 minutes or so, so I could validate that the engine didn't lose oil pressure or overheat. Once I saw everything was good, they pulled it and loaded it up in the back of my truck.

I took it home, put on a new set of LS9 head gaskests, my head studs, and swapped the valve springs from my old engine to this one. I had those set at the machine shop. They are patriot golds.

Is it possible that somehow when the last engine blew that my pcm somehow went into "limp" mode or something? Car drives fine until around 3k. It is just really weird. I can hear the turbo's whistling but won't build boost and just won't do anything when you floor it. I couldn't imagine the head gaskets are blown because it has only been driven twice, and it over heats after you try and floor it and the car won't do anything. As soon as it does, I shut it off and let it cool back down with the fan. Again, it won't over heat at all if I don't attempt to floor it or get it into boost. You can drive it anywhere with the temp at 160 degrees as long as you don't jump on it. As soon as you try to romp on it, about 10-15 seconds later the temp guage shoots up to around 210.

I am going to see if I can scan it and see what happens when I try to stomp it and see if something is happening with the pcm when you romp it.

It does not have a maf sensor. It is a SD open loop tune with a 2 bar map.

Ironmancan

Curious do you have a wideband? You said everything is fine till 3k is that when you start transitioning into boost?

Nitroused383

iTrader: (10)

So did you do what I posted earlier in this thread? If there is damage sometimes it can only be seen from taking the housing off.

96s-10ss

iTrader: (16)

Sounds like a wastegate issue or obstructed exhaust. Stupid question but do you have catalytic convertors on it?

6.0mustang

iTrader: (2)

sounds like a wastegate hung open(maybe a piece of piston stuck in it), exhaust stopped up, loose compressor wheel, intercooler too small or a restriction before the throttle body of some sort. too much fuel, not enough fuel, mass air flow is set to trip at the wrong frequency and wont fail, or you turned the mass air flow to no error reported. 2 step is hung up. if your using an injector driver i would check that too by looking at your AFRs compared to your injector duty cycle. check your trans for any issues...(although that would prolly make it boost easy just not go anywhere)...
to be real honest... it sounds like the cam is off a tooth....
also try a crank relearn.... just for good measure.

bigwillys58

if you have any flex joints in the hot pipes make sure they arent falling apart inside.

skinnies

iTrader: (33)

Will it free rev(neutral) past 3k, what a bout if you hold it in 1st and just go up in rpm, go past 3k fine?

KILLER-LS1

iTrader: (18)

What kind of fuel system and what lb injectors?

stevieturbo

No harm but if the temperature is rising like that, the problem has **** all to do with any turbochargers.

There is a major problem elsewhere. Either with the ecu/tuning, or internally with the engine.