Hi, I am new here and in need of some help, first of all I understand that there are a lot of threads already regarding boost on 850 turbos but the more I read the more confused I get.

I just recently purchased my dream 1997 850R wagon, please bear with me as all my life I have only ever worked with big old Aussie V8's so the world of sophisticated turbocharged engines is a little new to me.

The car seems to have ok power and I can hear the turbo spool (just) and the wastegate when I back off at high rev's, however the boost gauge never moves past halfway (i.e. needle pointing straight up). I am led to believe that this isn't normal and it's not producing the amount of boost it should. It definitely doesn't perform the way I expected an 850R would.

I have read about checking vacuum lines and intercooler hoses etc, but is there a link I can follow or a diagram that shows me exactly what to check?

I already know that the PCV system is clogged and have ordered a kit from IPD.

Any and all help would be greatly appreciated.

Cheers, Billy.

Car info:

1997 850R Automatic Wagon

V.I.N - YV1LW5806T2236957

 

Hi Billy, Welcome to the forum.

Turbo boost issues, wow, I have learned a lot about this in the past few months.

The most likely cause of a low or no boost issue is a blown bypass valve. If you look over the motor at the turbo, it is attached to the top front side of the turbo. Has a hose that comes off the top of it and routes around to the intake manifold. After 15+ years, they tear, develop holes and bleed off your boost.

Question, does the car have vacuum? While driving, the boost needle should be well into the black area. If the needle does not move at all, it is likely disconnected.

I was working on a turbo system tune up video series but I lost my computer to a mean person.

 

Hey, thanks a lot for your reply.

Yes it has vacuum, that was initially bad as well but last night I found a split in the top intercooler hose. I did a quick fix on it (have ordered a silicone hose kit) and I immediately noticed a slight increase in low end power and also the needle on the boost gauge is now moving nearly all the way in the black at idle where it was only going 1/4 of the way before. However its still hardly moving into the white boost side, maybe only about 1mm or so. Although now I am noticing that when I have the pedal hard down, the needle will spike into the boost side about 3mm between gear changes.

Next step will be to change the bypass valve you told me about and see what happens, thank you very much for your help, it's greatly appreciated.

I feel your pain in losing something to a mean person. I recently lost just about everything I had to an exceptionally mean person. I went and bought the 850R to make myself feel better. Not a bad way to make a fresh start at all