Sticky front end, 93 Metro....

[automan9482]

93 Metro 4dr. hatchback, 1.0L w/ AT, 115.5K mi.
My question is about a weird "hesitation" when taking off from a stop.
When you hit the gas, the engine revs, but the car takes a second to move. There is an audible "pop" from each front wheel before the cars takes off. There is also a quiet rattling from the passenger side front wheel when the steering wheel is cranked counter clockwise at low speeds, like when backing up.
I just replaced the front calipers, as I suspected they were causing the problem initially; this did help, so I believe the calipers were sticking, but it acts like they are still sticking. The car has all new pads, rotors, drums, and shoes. The brake fluid is fine, trans. fluid is full, CV joints (boots) look good, the tie-rods and balljoints are OK (not great, but solid, and it doesn't shimmy or shake). The car had been woefully neglected when I got it, i.e. no oil changes for 5+ years, trans. fluid low, etc., but I have taken care of the major issues. Could it be a transmission problem? F**k me.... Tranny shifts/feels Ok, but I don't know what to suspect now.
Thanks for any help in advance.

[hot_sd]

Originally Posted by automan9482

93 Metro 4dr. hatchback, 1.0L w/ AT, 115.5K mi.
My question is about a weird "hesitation" when taking off from a stop.
When you hit the gas, the engine revs, but the car takes a second to move. There is an audible "pop" from each front wheel before the cars takes off. There is also a quiet rattling from the passenger side front wheel when the steering wheel is cranked counter clockwise at low speeds, like when backing up.
I just replaced the front calipers, as I suspected they were causing the problem initially; this did help, so I believe the calipers were sticking, but it acts like they are still sticking. The car has all new pads, rotors, drums, and shoes. The brake fluid is fine, trans. fluid is full, CV joints (boots) look good, the tie-rods and balljoints are OK (not great, but solid, and it doesn't shimmy or shake). The car had been woefully neglected when I got it, i.e. no oil changes for 5+ years, trans. fluid low, etc., but I have taken care of the major issues. Could it be a transmission problem? F**k me.... Tranny shifts/feels Ok, but I don't know what to suspect now.
Thanks for any help in advance.

Possibly could be transmission. Measure the line pressure. If it is low at idle that could explain it. Also if the wheels turn freely when turned by hand that could also indicate the transmission is respsonsible.

[91Caprice9c1]

Rattling when the wheel is cranked (especially when backing up) is very indicative of a bad CV joint. How does the rest of the axle look? Sometimes guys will regrease and reboot the axles themselves after excessive wear has done it's damage to the bearings. Check out the trans and engine mounts. A long shot perhaps, but worth it. Has the transmission fluid AND filter been changed?

-mechanicmatt

[automan9482]

Yes, the fluid and filter were changed right after I got it along with a major tune-up, then I re-did the trans. fluid after 500 miles. All 4 wheel bearings were shot and also replaced.
Could this problem be indicative of a faulty master cylinder? Before the calipers were swapped, when you'd hit the brake pedal for the first time after a cold start, the pedal was VERY hard, and wouldn't depress. Hit it the second time, and it went down as normal; it doesn't do this now that the calipers are new......The axles look OK otherwise, boots are good, no grease/fluid leaks at the seals. The rattling noise isn't the same as the "clicking" a bad CV joint usually makes.........What made me sure it was calipers was an old truck I had. When the calipers were shot, it did/sounded the exact same as the Metro, and stopped after they were replaced.

[91Caprice9c1]

Well I suppose at this stage in the game it wouldn't be too irrational to start looking at the master cylinder and brake booster. A bad brake booster might keep the brakes on until it revs for a second and the vacuum source drops off, thus releasing the brakes. Whataya think, maybe disconnect the brake booster hose and plug it up, take er for a test drive?

-mechanicmatt