7 replies to this topic

[volvoguy23]

Im new to this site and own a 94 850t wagon!!!! I originally bought car from a dealership with 115k bout 4 months ago and have had a problem with a rough idle that i cant get rid of. The car has all new oem ignition componets new maf, tps, fpr, and ctp. Mods: ard white tune, mbc (14psi), cone filter with heat shield. 1st question, cuttin the temp sensor effect any of the parameters in the ecu? I do have a code for it but lucky said none of the ecu's come with egr. How can i get rid of the code? 2nd question... The car runs great has all kinds of power but has lots of vibration. I cant tell if i have bad mounts or a rough idle cause theres alot of cab and steering wheel vibration...the upper toruque rod i can twist by hand quite a bit (normal?) Bad cv axle cause vibration? Bad cv axle cause car to roll back when parking or thunk when going in reverse? Already changed tranny fluid.. did the drain x3 method with dex/merc (valvoline.) 3rd question, overboosting twice in a row cause intake man. Gasket to blow/ leak? Ok i know i know way to many question im sorry im getting a lil frutrated with it and volvoforums cant give me any good questions and there seems to be alot more people here...again sorry for all the questions just answer what you can thanks!!!!

[MattyXXL]

What is your Idle at?

Look at all your motor mounts, as well as sub-frame mounts.. If they are worn replace them..
Just doing your motor mounts and trans torque rod will get rid of a lot of your vibration, but replacing the subframe mounts will get it feeling like new..
While your replacing you subframe mounts you should do the sway bar bushings while your there..

[volvoguy23]

The only motor mounts i can find are the one by the crankshaft and the big ballon looking one in the rear of the motor by the tranny... Sub frame bushings easy?? Unbolt one at a time put new one in? Press in?

Idle is at 800ish....the needle on the tach/boost gauge dont move at all.

[MattyXXL]

Ok there we have a start... If your boost/vac gauge doesent move you may have a disconnected vac line, that will cause a rough idle.
You need to check all your vac lines including the one going thru the fire wall that connects to the gauge.

on the other note... there are 5 motor mounts plus one trans rod.. they are A LOT easier to change than the sub-frame mounts.
but if the sub frame mounts are bad you will never get rid of all your vibrations and clunking.

[volvoguy23]

No i ment my boost gauge doesnt move as in if i had a misfire my boost gauge works great sits at around -18 lol..

At idle..

[volvoguy23]

Anyone have any advice
?

[volvoguy23]

Anyone have any experience with egr delete??? Should torque rod be able to twist by hand???

[the commissar!]

Anyone have any experience with egr delete??? Should torque rod be able to twist by hand???

Not easily but it depends on how hard you try too...

If you have not done stage zero I'd suggest replacing all your vac lines...relatively inexpensive and can help eliminate a lot of future problems if you upgrade to silicone.

If you still have vibes, I'd move on to the motor mounts. There are three motor mounts, the one under/near the crank pulley, and two fluid filled cone looking jobs one in front and one near back/firewall. Then there are the two parts to the torque arm (one where it fastens to the firewall area ant the obvious part fastened to the top of the motor), and the other lower torque mount easily visible from below with the two bushings. If any or all are in poor shape, then you get vibes...and that can be a cause of your clunk into R or on take-off. If the tranny is closer to the subframe than ~1/2 to 3/4 inch you need the two hydro ones. If the top one twists as you say that one likely needs renewed. The lower rotational one is likely also toast if the top one is gone...

you can also get vibs from bad CV joints in the axels...