1990 gsx galant

[jcuellar]

I have a question for anybody who can answer it. My 1990 gsx galant is making a vibrating noise when the rpms go over 3 or 4 in 1-3 gear. someone told me it could be the manifold...(exhaust or intake manifold i have no idea which). And i'm wondering if this could be the problem. once i hit 4 and 5 gear the car run great but below that it just runs like crap. If anybody can answer my question please let me know.

jcue

[RockinWRX]

Might be the exhaust. Mine does that too sometimes. I think the bolts on the downpipe may be loose. I also have the exact same model and year. Mine has a Thermal-R catback

[jcuellar]

I've had mine for only a few months and it's seems like a really good car. The car run awsome on the highway but the thing is once it starts hitting high rpms it makes a loud vibrating noise.. other than that the car is great. I plan to fix up the car once I starting making money. How long have you had you Galant? Are they pretty realiable cars?

[RockinWRX]

In another 4 1/2 months I'll have had it for a year. They seem to be just as reliable as any other DSM , which means they will last forever and then bite you in the ass. I drove mine to NY from Colorado , and back. About 4000 highway miles at 90+ mph with no incidents. Mine also had the transfer-case recall done and a new T-belt when I bought it.
Do you mean it vibrates at certain mph speeds , or only beyond certain rpm's , there is a big difference between the two .

[jcuellar]

it vibrates at certain rpms

[RockinWRX]

Originally posted by jcuellar
it vibrates at certain rpms

Sounds like some weird harmonics. T-belt done recently? Might want to check the motor mounts , make sure they are all secure. Do you get this same vibration revving it in neutral , or only in gear? Might actually be a drivetrain vibration. Those can get real complicated to find.

[jcuellar]

it makes that sound running or in neutral as long as the rpms are the sound is right along with it

[RockinWRX]

Could be anything from a warped flywheel to a bent pulley. Or possibly one of the balance shafts is a touch off. The front BS runs on a belt , so that would be the likely suspect. Are you planning on doing any modifications?