98 OB od engine vibration on warm up

[mnm-bandit]

have a 98 outback, 2.5  engine was replaced or rebuilt at 150k. (bad head gasket failure)  (This engine was getting 30 mpg on our trip when it starting showing signs of loosing coolant).  Anyway, since I can ever remember, even before the engine problems, when it was started and was warming up, it has a vibration that is rythmic.  it comes and goes like a pulse, as the engine warms up, i don't notice it anymore.  I ask, because; if my engine was replaced, why does it still have this same charactistic vibration?  I have replaced some of the usual wear out parts like battery, alternator, starter, radiator, batt cables, plugs/wires, but not a lot of sensors.  I just check it a few days ago and got a 1507 code, and seafomed the iac.  have not had an idle problem since, and no more engine light, which I saw for the first time. Still has the funky vibration on warm up...  My other question?  Why does it sound like the squeeky creaky when you hop in, drive real slow, come to a stop and its like the suspension 'settles', with a creak...  any ideas anyone?  my code reader said every reads ok, (except i had no speedo at the time so it said 0 for it, and the affor mentioned 1507 code)  Gots more power and seems to be doing better on mpgs now too...

[DaveT]

I don't know 98s. You will have a lot more people see questions regarding the outback in the newer generation sub forum.

[1 Lucky Texan]

could be a vacuum leak and the culprit is still underhood somewhere. possibly a sensor....not sure

[Larsen Autoworks]

How old are the engine mounts?

That creaking sound could be your brakes

[wtdash]

- Vibration @ idle can be BAD CV Axles (yes, really). Esp. if el cheapos were installed.

 - The creak may be the top strut mounts (top hats) or springs either wearing or just dry.  If you notice it LESS after driving in the rain, then I'd suspect this.

[mnm-bandit]

engine mounts are probably original.  There are times usually during winter that i notice the creaking less, so your probably right with dry/old and need to replace the slightly bouncy struts...  As to the brakes;  seem to work ok and had enough pad to pass inspection, but i am noticing a squeek sound on the passenger side (window down) now so maybe related,  The vacumm leak idea is something i have not entertained, but , the 'tube' on the intake pipe came off and i black taped the opening  and seems to run fine (as in the same as always).  I did notice less vibration today with a lot warmer weather, so maybe a temp related issue.  I have read that some engines have a lot of noise until warm, if a customer complained when it was a new car, they sometimes swapped pistons or sleeves for a better fit.  i have wondered if my engine was rebuilt, not replaced and thats why it seems exactly the same after its numerous episodes.  I didnt pay for the work, and have no receipt for what was done...  i came the new owner from family members when it had a slight knock sound, but to me a good engine oil change and running seemed to clear that up, until the head went...  I think i drove it about 3-4k  before our infamous holiday trip.  I had noticed that it seemed to lose a little coolant, but could never find any leaks, hoses and connections all looked great, it had had fairly regular service and checkups, no white smoke, no coolant in the oil, regularly got 25-27 mpg for my short 9 mile trip to work.  i suspect now the original noise was coming from the hg starting to go bad, and i didnt realize the signs with this engine.  I will have to do more poking about...  Thanks for the input!  i bet i have front axles wearing out too.  so much fun being the shade tree family fix it guy:)