Suddenly Lost All Boost

[BRAD_PADGETT]

I have an 85 GN with a new motor, new stock turbo, and a new adj. wastegate solinoid. They have 3500 miles on them. The car ran great until today when the turbo charger suddenly stopped boosting. Now boost indicator won't go past one bar and the car is very sluggish even without the turbo.

Can anyone help me find out what has happened? Any help will be greatly appreciated.

 

[Daniel Jost]

is the turbine shaft still spinning smooth and free

 

[BRAD_PADGETT]

I will pull the MAF sensor and check tomorrow. I will let you know. Thanks- Brad

 

[BRAD_PADGETT]

I will pull the MAF sensor and check tomorrow. I will let you know. Thanks- Brad

 

[BRAD_PADGETT]

I checked the turbo wheel and it does not spin freely but seems to bind. Can this be my problem? Can this be fixed? Thanks- Brad

 

[FJM568]

Yes and yes...

Where did you buy the new stock turbo from??? John Craig at Limit Engineering is a good place to have that fixed...

 

[BRAD_PADGETT]

I bought the turbo from Postons. Hopefully the will stand behind their one year warranty. Should I upgrade to a TA33? What do you need? I have 30lb injectors, new stock hot wired fuel pump and a stock fuel pressure regulator. How much improvement would I see? Any input would be appreciated. Thanks- Brad

 

[racemybuick]

If your turbo stopped spinning, or only spins a bit, then stops, immediately stop driving the car...The turbo bearing is shot. inside the centersection, you may have cracked the bearing, or the shaft seized up and collected other parts. the turbo needs to be rebuilt. If you have any warranty with it, go get it fixed. if not, Precision Engineering (precisionte.com) in Hebron Ind. has a replacement turbo called the TA48, which is an upgrade for around $750. John Craig can rebuild your stock turbo for a fair price, but he can also make your stock turbo a monster called a TA33c. It is a real nice upgrade using your stock unit. Either way, dont drive the car, or you'll be shooting metal into that 3500 mile motor.

A reason this may have happened is improper priming before running the car, or low oil pressure to the turbo. I have two turbo's at home that are both in need of rebuilding for the exact same reason, so...I know where you are at! Good luck!

John

 

[Daniel Jost]

i dont want to high jack the thread but im building my motor now and what chould i use to spin the oil pump rod to prime it.

 

[cool 84]

Originally posted by Daniel Jost
i dont want to high jack the thread but im building my motor now and what chould i use to spin the oil pump rod to prime it.

Old cam sensor/distributor with the gear machined off, a tool that Summit sells, or an old long screwdriver in a clockwise rotation.

 

[Daniel Jost]

thanks

 

[Turbo Riviera]

You can also buy or rent the tool from any major parts chain. Autozone has one I know that works well.

 

[BRAD_PADGETT]

Postons will honor their warranty. The new turbo was lost because I did not replace the oil feed line. Their catalogue recommends this for each new turbo installation. I did not get this advice when I ordered the new stock turbo. The oil feed line was original with 90000 miles on it. My mechanic probably tried to clean it. This situation causes an oil flow problem because the oil will not drain out of the turbo because of buildup in the oil feed line(according to Postons). I also have another thread about losing oil. The car would lose one quart every 500 miles. This is a new motor with 3500 miles on it. Poston said that a plogged oil feed line will cause oil to stay in the turbo upon shut down. The oil will the break down and burn while the car cools down. I also had noticed a backfire situation on startup with my old motor upon startup.

I welcome all opinions. Thanks- Brad

I

 

[alec296]

when your turbo went did you get any smoke from tailpipes and missfires on accel?
i accelorate and just pump smoke out the tailpipe but i do get a small amount of boost 3-8 psi but then it falls on its face as it pours out smoke. ate 3 qts of oil in 2 weeks
thinking about a ta 48 if this is junk.thanks andy

 

[BRAD_PADGETT]

The turbo simply stopped boosting with only one bar on the boost gage. The turbo was slowly starved of oil due to a partially blocked oil feed line. No smoke at all. The turbo turbine will turn my forcing it with a screwdriver. Brad

 

[BRAD_PADGETT]

Finally was able to get an actual result of my problem. The seals an the rebuilt turbo leaked from day one. I was loosing 1 quart of oil per 500 miles out of the turbo into the exhaust. The oil line into the turbo was clear. After 3500 miles the new CAT converter became so plugged up from the oil from the turbo that the back pressure stopped all boost from the turbo.

These cars can become a money pit. The new stock turbo works great- the first time I punched it I broke the drivers seat off the floor boards(This is no rust bucket) . More money- Thanks- brad