First of all, I want to be clear that I am 100% positive the noise is coming from the transmission itself and not the engine or any other part of the driveline.
The facts:
Now, the engine swap in this car was performed by people whom I doubt have much experience working on subies. I myself have performed an engine swap in my 02 forester (w/ manual tranny). During my research into pulling/installing the engine I came across a post (which I can't find now) which warns about pulling the engine away from an automatic tranny without performing a certain procedure to keep something or other from falling out/apart when the engine is pulled off the trans (forgive my ignorance on this). I am fearful this may have been the case when the engine on this 98 Forester was replaced and could be the cause of the current noise. Then again, I don't know this for sure and it could have nothing to do with it, but I thought I would mention it here.
In any case, does anyone have any thoughts? I'm thinking I will pull the tranny base/oil pan to see if I can find anything out of the ordinary. Should I be on the lookout for something in particular? Thanks in advance.
The facts:
- 1998 Forester with Automatic transmission
- relatively low mileage (~ 70k miles)
- recently had the engine swapped (happened before I bought it)
- when first purchased, noticed a rattle/whir/grind noise at startup which went away within 10-15 secs of idling. No noise any other time.
- during startup there is no noise during inital turn-over of the engine (ie cranking)... noise starts upon the engine starting to idle normally on its own (ie 2-3 seconds after stopping cranking)
- suspected the noise was transmission related, so went to the garage and had the trans oil replaced.
- immediately the noise was noticeably louder and did not stop after 10-15sec like before. Noise is now constant.
- Pitch/speed of noise changes with rpm.
- Noise is constant no matter the gear selected (P, R, N, D, 2, etc..)
- Noise is not affected by vehicle speed (other than changing pitch with rpm)
- Temperature doesn't seem to matter (ie starting in a warm garage or after being left out in the cold all night)
- Turning the engine over by hand produces no sound
- After starting the engine, the starter motor was removed, no difference in sound
- Looking into the bell housing (through manual's shift fork opening and the opening for the starter) and turning the engine by hand I can see nothing out of the ordinary (ie no metal shavings or rub marks etc...)
- With the car up on blocks and the engine running, from underneath it is obvious the sound is coming from the tranny, and is loudest when you place your ear in the area between the front wheel's driveshafts and the transmission base/oilpan (ie to the rear of the front axles)
- From underneath, in the area where the trans bolts up to the engine ie the underside of the trans/engine, I can see the lower front of torque converter assembly spinning (I'm assuming there was supposed to be a metal cover which was not replaced when the engine was swapped).
- Noticed that the ATF level was high, so removed about half a litre/quart. No change.
- Just changed the centre diff oil but that had no effect.
- Also, I've noticed that the noise will stop for a split second when shifting from P->R or R<-N
Now, the engine swap in this car was performed by people whom I doubt have much experience working on subies. I myself have performed an engine swap in my 02 forester (w/ manual tranny). During my research into pulling/installing the engine I came across a post (which I can't find now) which warns about pulling the engine away from an automatic tranny without performing a certain procedure to keep something or other from falling out/apart when the engine is pulled off the trans (forgive my ignorance on this). I am fearful this may have been the case when the engine on this 98 Forester was replaced and could be the cause of the current noise. Then again, I don't know this for sure and it could have nothing to do with it, but I thought I would mention it here.
In any case, does anyone have any thoughts? I'm thinking I will pull the tranny base/oil pan to see if I can find anything out of the ordinary. Should I be on the lookout for something in particular? Thanks in advance.
