hello, i am new here ihave a 1998 v70 car is acting up enginge/shakes/vibrate did engine compression test cylinder2/3 very low/change plugs/wire/cap/rotor/o2sensor front thecar still shakes checked all vacumhose,s any advice out there 4 me before iget rid of this car it,s a nice car but very probmatic,, any help on what to check next,, any1 thank,s

 

I assume you did the compression test with the engine warm. Have you tried doing a "wet" test of the cylinders with low compression? If you spray a small amount of oil into the bad cylinders before doing the test and the compression improves significantly, you probably have bad piston rings. If compression does not improve, it's likely a valve problem. It is possible with a valve problem that carbon build-up is causing valves not to seat properly. If the problem is valve related, it's probably worth trying something like a seafoam intake cleaning treatment before giving up.

 

Definatly do a compression test when the engine is cold. After you test it, try adding the oil and test again.

Nick

 

hello thank 4 the reply i did the compression test,, whenm i added the oil in the cylinder the the car ran quite well until the oil burn off,, so does that mean that the Ring,s are Bad in that cylinder,,, if so what could be done to correct this problem,,, i was looking over all of the vaccum hose,s and found 2 that was not connected and i replace them i also replace front 02 sensor,, now i have a code p0131 low volts,,any help,, please,, thank,s a ton

 

Is it using any oil? Did you do the compression test after putting the oil in the cylinders? You need to know if the compression improved with the oil in the cylinder and then go back down after it burns the oil. If that's the case, the rings are probably bad which means and engine overhaul or buying a used engine and replacing it. Engines for 98 V/S's are not that hard to find. It would be a much cheaper route than rebuilding the engine that is in the car. How many miles are on the car?

 

thank,s 4 the reply the car has 177,000 mi i been tinker around with the car abit and now i am geting this code p0172 that,s telling me it running RICH,, i am thinking about replacingfuel/pressure /regulator,, in hope of this may buy us some time to look 4 aengine altough it seem,s to run stong it feel,s like abad vacuum leak some where on the car, but i know a new engine will be the best,still getp0300/p0302/p0303 /p0172

 

I'm running one with compression lower on one cylinder and it runs fine. 177K is not that many miles. I would not replace the engine if the compression is close to normal.

 

thank,s 4replying can i ask you about this code p0172 freez/frame on code reader, say fuel system1 ol,not ready and it,s run rich,, i relly don,t have fund,d to replace this engine any thoguh about replacing fuel/pressure /regulator my kind of solve at lease thatpromblem thank,s

 

Recheck again for vaccum leaks check every hose.
Also use some carb or brake cleaner and spray around all hoses and the intake gasket.
If the idle changes you found your leak.