1996 850 T5 Engine Problem

[quantum_man]

Hi everyone, I am the proud owner of a 1996 Volvo 850 T5! Unfortunately the car seems down on power. I drove it home after buying it about 170 miles and although it got home ok, there didn't seem to be much turbo boost.

I noticed a lot of oil around the top of the engine and there was smoke coming out of the oil filler/dipstick when removed. I have been informed that this may be due to blocked breather pipes, can anyone confirm this as a likely cause?

Also the turbo boost gauge seems to be working (goes to half way in the white when on boost) but there is no extra power, just a weezing noise and a sound like compressed air when lifting off throttle.

Any advice would be much appreciated as this is my first turbo!

[Rockatansky]

Sounds like a couple of things going on here.

First off, the oil on top and pressure from the dipstick tube are likely to be due to a blocked PCV (positive crankcase ventilation) system - the breather. This is a known issue on older cars and is often overlooked.

Good write up on the procedure here: http://www.volvoforums.org.uk/showthread.php?t=469...

Secondly, it also sounds like you might have a boost leak. Check over all the hoses from the turbo to the intercooler and then to the inlet. The one at the throttle is quite prone to splitting.

[morgrp]

Blocked PCV or breather as everyone else calls them is mega common on 850's - Its a sign of it being run on crap oil - clean it out, replace the flame trap as it will be full of carbon deposits and run it some quality oil. As for boost, an 850 should never boost higher than 3 quarters on the gauge running standard boost. you can turn the boost up on them slightly on the waste gate - don't go nuts though as the overboost safety cut off will come in on full throttle and will suddenly cut power. failing thst, buy an ECU from an auto model (if yours isn't) and have it chipped - My mate does them for around £150 quid and can put either the "R" software on them (240bhp) or the "308" software (supposedly 308bhp - no where near that but noticably quicker) They'll be loads of people who can sort a chip out very cheaply for you - it really is a case of plug and play

[quantum_man]

Thanks for the advice, I've got the inlet manifold off and bought a new breather box. Currently cleaning out the pipes and giving the engine a general tidy up, there's no history for the last 60k so I guess it's not been serviced much in that time.

Thanks for the link to the article too, should help when I put it all back together! One thing I did notice, there are two pipes coming out of the box, one to the turbo and one to the top of the engine, but they appear to be the wrong way round according to the diagram I obtained from Volvo. Could this have caused any damage if the car's been running with them for some time in the wrong position?