Unstump the "mechanic"

Well, i'm quite obviously no mechanic, but i'm quickly approaching stumped.

Taken from my post on the MX6 forums:

"Alright, i've got a problem that seems to be getting a bit worse.

My car is cranking pretty slowly, and seems to crank WAY slower if it's already at operating temperature/hot.

This happened once before, so i threw the battery on a trickle charger, and it held me over for about 3 weeks.

I just tried to put it on a trickle charger again, and the charger told me that the battery is already charged.

For what it's worth, i'm only running a 520cca battery, which i imagine is not what these things take stock, but i'm unsure why it would all of a sudden become a problem.

I am NOT experiencing lights dimming or any signs of a bad alternator.

Starts ALMOST fine in the morning when it's cooler, but starts WAY slower in the heat of the day, and cranks so slow after i've just popped into the gas station after driving it for any length of time that it almost doesn't start.

Could it be anything BUT the battery? If battery is the consensus, how strong of a battery should i be looking at to replace the one that i have?

Thanks in advance. "

It could be that you lost a cell in the battery. Take it to the local advance autoparts and have them put it on their tester perhaps? Other then that it could be your starter is going out..

ha a similar problem with a friends camaro.. the electric waterpump and fans would work, but not the starter. Replaced the starter with no change, tried a different battery and it was fine. Got it tested and its amperage was way down from a cell dieing.

Apexcarver wrote: It could be that you lost a cell in the battery. Take it to the local advance autoparts and have them put it on their tester perhaps? Other then that it could be your starter is going out.. ha a similar problem with a friends camaro.. the electric waterpump and fans would work, but not the starter. Replaced the starter with no change, tried a different battery and it was fine. Got it tested and its amperage was way down from a cell dieing.

Would a cell being shot in the battery still possibly give me a "charge complete" reading on a trickle charger? I know it's not a good way to test a battery, but... you know. I'm a n00b.

I think i still have a warranty on this battery, for that matter. I'll get it tested at Advance tomorrow if i have time and see where that puts me.

Thanks!

Checking voltage drop while under load is the correct test procedure. Other things - an over heating fuel pump relay that expands when hot and then contracts when cooler?

Many a starter motor goes weak when hot. Especially dying ones.

Cables. Check 'em at the battery, alternator, starter, and chassis. Also check the engine ground strap.

Had this same problem on a Mk2 Jetta 16v. Exactly the same. Turned out to be just a weak, old, dying starter. Check cables and grounds and such first though.

Junkyard_Dog wrote: Cables. Check 'em at the battery, alternator, starter, and chassis. Also check the engine ground strap.

Cables are all solid and attached, though some of them have some oil on them from various recently fixed leaks.

I was planning on spending a good 4-5 hours under the hood this coming weekend cleaning everything up.

doc_speeder wrote: Had this same problem on a Mk2 Jetta 16v. Exactly the same. Turned out to be just a weak, old, dying starter. Check cables and grounds and such first though.

Hrmmm... was afraid of that. Starters aren't really as cheap as i was hoping for this thing unless i venture onto Ebay to get one.

from past experience ... a dead cell means a battery that won't hold a charge .. so will always (at least seems like always) "take" a charge from the trickle charger... just won't stay "full"

keep in mind that heat is much worse for a battery than cold is... if the bat is getting "weaker" then it will be stronger in the cool morning than in the hot afternoon or after a long drive with the heat build up under the hood

take it one of the zone/riely/vance.... places that can put the electrical checker on and see if the bat checks out... bet it's on the low side of ok

wbjones wrote: from past experience ... a dead cell means a battery that won't hold a charge .. so will always (at least seems like always) "take" a charge from the trickle charger... just won't stay "full" keep in mind that heat is much worse for a battery than cold is... if the bat is getting "weaker" then it will be stronger in the cool morning than in the hot afternoon or after a long drive with the heat build up under the hood take it one of the zone/riely/vance.... places that can put the electrical checker on and see if the bat checks out... bet it's on the low side of ok

It actually wouldn't take a charge from the trickle charger, the charger was showing it as "full" from the get go.

Will definitely get it checked tomorrow, hoping its battery and not starter, since i was shopping for batteries for a relocation anyways.

Thanks!

They are getting harder to find, but there are shops that will rebuild starters, alternators, and some other auto electrical items. Look for one, it might be cheaper than buying a rebuilt starter at a local parts store.

Try the yellow pages--that book thingy----under auto, electrical.

I had the starter to an ancient marine diesel rebuilt while I waited. .

we had a recently restored 289 cobra come in cranking slowly and some moron mechanic near the guys house had told him the engine was built too tight, even after 1000 miles of flawless driving. i pulled the starter off and bench tested it, it cranked but really slowly. we had a freshly rebuilt ford starter around threw that in and viola cranked like crazy.

definitely look at your starter and electrical connections, and check the voltage drop while cranking.

It shouldn't be that hard for you to rebuild the starter if it turns out to be that.

Most local NAPAs have a device that tests batteries. They visit your car in the parking lot and can tell a bad cell, lower than specified cold cranking amps etc.

Free.

you can get the battery/starter/alternator tested just about anywhere like has been said.

generally, bad battery will give 2 or 3 slow cranks, then quit. bad starter will crank slowly for several seconds until the motor finally kicks over.

93celicaGT2 wrote:

Junkyard_Dog wrote: Cables. Check 'em at the battery, alternator, starter, and chassis. Also check the engine ground strap.

Cables are all solid and attached, though some of them have some oil on them from various recently fixed leaks. I was planning on spending a good 4-5 hours under the hood this coming weekend cleaning everything up.

Other than making sure the cables are there, you have not performed a proper check of the cables.

What you describe is classic for a bad ground cable. Especially the one that goes from the engine, across the rubber mounts, to the chassis ground.

For a quick test, take your jumper cable, clip one end on the starter or engine block, and the other on the negative terminal of the battery. Then try to crank over. You may or may not be able to do the same with the positive terminal to starter solenoid.

A bad solenoid could also be creating a slow crank conditon, only I would expect something to be hot.

It really is not that bad to take apart a starter and clean it up. Not too long after I got my GTV6 it stopped starting. Went to NAPA and was told it would be $600 for a starter. After I regained consciousness I took it apart cleaned it up with brake cleaner and it worked fine for the next 7 years or so until I sold it.

I learned most of what I know about working on cars from my FIL before he was my FIL. He grew up as a farm kind in Nebraska and if there was any way not to have to buy new parts they would be tried before a trip to the store. Great education.

Have you recently adjusted the timing by any chance? Too much advance can lead to slow cranking especially when hot.

Well, it's already been covered, but I was going to suggest starter as well. Went through the same thing once.

TJ wrote: Have you recently adjusted the timing by any chance? Too much advance can lead to slow cranking especially when hot.

Timing belt was just replaced.... but the identical issue happened before then.

Ignition timing has not been touched.

Its a bad starter.

I will agree with bad starter, then bad grounds, then bad battery.

Oil leaks onto cables, huh? I had to replace a cable to the starter on a rx7 that wouldn't start. The strands of the cable were oil soaked.

would a bad starter show up only during hot conditions ? OP said it cranked easily first thing in the am....