Hello All,
I am new to the Volvo world but not to the car scene. I am considering purchasing a 1997 850 GLT auto that revs in neutral but will not go above approximately 15 mph. Car is a great price. I am not sure if I should run towards it or away from it. The current owner says it is likely a wastegate issue but I don't think so, it sounds to me more like a sensor/wiring/ ECU limp mode issue. Car is about 70 miles from me so I want to have some ideas if I do decide to go out there. Is there anyone here with knowledge of this issue?
Thanks in advance.

Also how does the low pressure turbo compare to the other higher pressure turbos as far as power potential after parts swapping?

 

Does anyone have any suggestions at all to help me? Anything????

 

Lets go with his 'Wastegate issue' theory. Lets say I strapped the wastegate wide open. The car would run and perform like an N/A, it just would not build boost but would still run fine. All it does is let the exhaust gases bypass the turbine. So that is not it.

In limp mode you should be able to get above 15mph. If you are wondering if this is the issue, pull the ECU out for about 30 seconds then put it back in. It should be out of limp mode if it was.

Ask him is there is a lit yellow up arrow on the dash. This issue sounds more like the transmission than anything else.

 

Similar thought - have them disconnect the battery for about an hour which will reset all the computers including the engine ECU. It should not be in limp mode but if there's a transmission issue setting off the computers, it will probably reset the codes after a short drive and go back to slow... If it starts off slow then I'd be looking for some other issues - airflow/MAF/clogged cat/sensors etc... I'd hope the cars throwing out some codes to clue you in so that's the first thing to do after your test drive... see what codes appear after the reset. As to your question on LPT vs standard, LPTs use a smaller turbo tuned to faster boost at low RPMs in favor of top end HP. You can get a remap of the ECU to retune for more top end - putting the car in the T5 HP range (see IPD's web site for their ratings), or do both the remap and replace the turbo with a 16T etc.