First time on this forum

my friend has a 1996 960, 100,000 miles on it...Mint condition, not a scratch on the car .....

it developed a misfire the other day on the highway... i thought spark plugs, wires, or coil....he took in to the mechanic,the mechanic told him cylinder #3 is failing (burnt exhaust valve)......i have a feeling that the mechanic has misdiagnosed this.........why would it happen so sudden? all other cylinders have 300 compression according to the mechanic...
is this a known issue? i just read someone over here say this is usually misdiagnosed, and it is something else not cylinder faliure....the mechanic wants 2500+ to fix....the car is not worth that.....and my friend can't afford it....
some help please .....[sm=drlove.gif]

 

I had the exact same problem on my 1997 S90. Check engine light was on and the engine would ide rough and sounded like it was going to stall. Theengine light would flash intermittently briefly at low speeds and rpm's.However the car would drive fineover1500rpm.Shortly before this problem I noticed that while driving at around 80-100km/h the car would surge or chugwhenI would accelerate. I took thecar to the shop andOBD said engine misfire cylinder 1 and 3.It was determined that the spark plugs (original Volvo ones, in terrible condition) weres the culprit. The problem still presistedand after2 days in the shopchecking fuel pump, injectors, ecm, modules, and misdiagosis etcI took it to another mechanic who told me itwas the intake manifold gasket and injector rings.$87 in parts and$100 in labour. The car drives fine now.He said thiscommon problemhappensin thewinter becauseof the hotfrom the engine and cold air causes these seals to break, especially if you dont warm up the car before driving it fast... ie highway, etc.This could be your problem...
hope this information helps and good luck

 

try spraying some water around the seat of the injectors. listen for an audiable change in the engine tone. its possible that the injector o ring seals need replacing. blocked fuel filter, faulty fuel pump? there are a number of probable causes beside those mentioned by KZS 983.