Gradual starting issue

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
Over the last few weeks, I've noticed my 1998 Jetta starting slower and slower. I've recently done a bunch of fixes (Heater Core replacement, CV boot, instrument cluster replacement, new battery, new radio) and I don't know if this relates to my starting issue. Just more info.

It cranks fine, but it's just a little weaker and slower each day. It almost seems like it might get slow enough to not let the engine start up, but usually after a moment, it fires up like no problem.

I replaced the battery a few months ago, so I know that is good. I have a voltmeter in my cig lighter, so I know it has decent juice. And the alternator appears to be working fine. When i did the heater core replacement, I pulled all the interior and engine and battery grounds, and cleaned them up.

I'm worried it might be the starter. Do VW starters die like this? Slow deaths or do they just catastrophically fail? If it is the starter, what is a good quality starter that can last another 300,000 miles like my old one?
 

Jetta SS

Veteran Member
Joined
Oct 30, 2006
Location
Grand Bay, AL
TDI
'98 Jetta
My starter was grinding. I replaced it and was surprised by how much faster the new one turns the engine over.

i wasn't working at the time, so i got one off ebay for $50 shipped. It's been over a year now and no probs, but I don't have a lot of confidence in it.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
He’s in LA so cold isn’t likely to be an issue. 300k on a starter, yeah I’d say it’s time to replace it, with a new Bosch of certified Bosch rebuild.
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
The problem seems to correlate with moisture. We had two rains recently in LA (rare events), and both times, it started hard. Cranked for 3 or 4 seconds, and fired up. Kind of weird. Once the day dries out, it starts ok.

One time, I had the battery light on when it idled after a hard start. Once I pulled out of the driveway, and drove down the road, the higher RPM's got the voltage back up over 13V.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
I think you’re going to need a multimeter to diagnose this problem. A cheap one can be had from Walmart or Home Depot for $25 or so. If you don’t know how to use one youtube is your friend.

Sitting in your driveway the battery should read across the posts 12.6-12.7. Below 12.4 is a battery that is not fully charged, but still operational. 12.2 or below is a worn out or discharged battery that will have trouble starting your car if it even does in colder temps.

After starting your car at idle, you should get 14.1-14.5 across the battery posts again. If you are getting less than 13.5-13.6 your alternator is not keeping up. Which could be a worn alternator, alternator pulley or bad wires.

If you get less than 14v at the battery take the red lead from the multimeter and put it on the bolt where the big battery wire connects directly to the alternator, do you get 14 or so there? If not the alternator is bad if you do then that fat wire needs replacing or the terminal ends need cleaning.
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
It rained again today, and the voltage went nuts again. I managed to limp it home and I'll pull the alternator to get it rebuilt.

This is the oddest problem in the world. Every time it rains in Los Angeles, my Jetta voltage goes haywire.

(BTW, i was getting 13.5-14V while driving around before this rainstorm. But in the rain today, it dipped down below 12V and near the end, it was around 11.5V. I barely got it home.)
 

iluvmydiesels

Veteran Member
Joined
Nov 21, 2015
Location
phila area
TDI
AHU
idk-for sure. sounds like your problem is some type of moisture saturation. older alternators /starters and such you could 'clean out', like electronic clean to kind of 'dry out' and try to get working again. you have a high mileage car, and rather old, just like ours. could be something like the alt or voltage regulator collecting ambient moisture. when this happens, you say its moisture/raining. when it happens check in your engine compartment, i mean some moisture gets in whether driving or just by moisture its self. but check compartment for excessive moisture, -spots.
all hot wires coming off and going to the battery, the hot starter wire, you can check for resistance, and the contacts, and clean up, in the same notion, if you know how to do a voltage drop test, for each contact, and wire, etc. same with the alt charging harness, and connections. double check for other grounds you may not have checked and cleaned. from battery post, to motor/trans. from batt to body, a very important one, from another motor or trans point to body ground. check, clean up, test for resistance, even voltage drop test.
another thing you can try as well, run a ground from top, or right in contact with alternator to a meaty body ground. run another ground from same alt spot or another good spot alt you can connect to, to other side of trans tunnel, even the common trans ground point will work. these can help, but in all your recent problems moisture seems to be the main problem causing theme.
another ground you can run is the other ground from where i said above another grounding point on motor or trans to body, do this yourself.
 
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Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
When is the last time you changed the serpentine belt, maybe it’s stretched enough so when it gets damp it slips. Is there a tensioner on the older cars or can you tighten the belt up a bit?
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
I changed the belt recently. I just pulled the alternator last night and I inspected the belt. It's still good. and the tensioner is still ok too. Getting that alternator out around that AC line was a PITA. Man, they really cram everything closely together.

I have an alternator shop that does rebuilds in Los Angeles. I'm bringing in my VW alternator, and I have a back Ford 3G alternator that has a problem too, that I'm bringing it, so it's a good time. If he says my VW alternator is fine, then I'll start inspecting the cables and starter, but I doubt it's the battery and cables, because when I did the heater core job last year, I cleaned up all the electrical, grounds, and connections. Also, I replaced the battery around then as well. Maybe I got a bad battery.... That's an option. But I pulled it last night and put it on the trickle charger for the night. I'll check the voltage later today.
 

genscripter

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Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
Just got the alternator back from the rebuilder. He said the regulator was shot, and other stuff was bad too. It was long overdue for a rebuild anyway. I'd already have it back in the Jetta, but it's pouring again and I'll wait till it clears up.
 

iluvmydiesels

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Joined
Nov 21, 2015
Location
phila area
TDI
AHU
yea, that will/may do it.
so what you do, as some people have pointed out to you. i have a not too expensive sears maybe its a craftsman multi-meter. for us and cars you put it on the 20v setting and go to town. the battery charged like some have said to you is 12.5v+ (note the 'plus'). after you start it, just for a alt voltage test, let the alt charge it and now test. i think mine is about 14.5v charging. this is important. the right charge voltage means you can drive all night and not have to worry. (unless you like have all accessories on and an amp and turn your radio up, like a teen, and then just get to where your going and shut off the car. when you go out to start it, you cannt figure out why you cannt get it to turnover. huh, duhh). <other than that you should be ok.
and other than that after the voltage tests, a voltage drop test, if you know how to do one, will tell you all the rest, well except for such as bad regulator and/or alt.
let us know how you fair out.
 

genscripter

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Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
I reinstalled the alternator (in the light rain) and cleaned up all the connectors and leads. While I had other stuff apart, I cleaned up my air cleaner box and other parts of the engine bay.

I let my charger charge my battery in the garage all night. It got up to 12.7V this morning. I hope the battery isn't permanently damaged from the low charge left on it.

Started it up.... It still started hard, with only 11.7 V on my gauge. It started up though, after 2 cranks, and ran for a bit at 11.7V. Then the alternator kicked on, and it bumped it up to 14V. I let it idle for ten minutes, and it got up to 14.5V sometimes. Seems high. IDK.

I shut it down and fired it up again. Fired right up. I hope this is the end of this issue, but we'll know later today and tomorrow. It's supposed to rain all day and tomorrow.
 

iluvmydiesels

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Nov 21, 2015
Location
phila area
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AHU
idk for sure, perhaps electronic memory, the refreshed alt cleared up? keep your eye on hard starts if that comes back.
after a couple of hours or overnight, do a quick test of battery, this will tell you in a pinch if its holding charge.
the first reading you got from alt is it under charging load. the second test is charge test with charging. what i mean the alt isnt loaded up charging battery, and/or accessories on. 14.5 seems right, like is a good choice thats a bosch alt. (right?)
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
It's a bosch alternator, original to the jetta. My rebuilder took it apart and rebuilt it from scratch. He's a good guy, and he's done my all my 3G and 1G (ford) alternator rebuilds in the past with good success. I suspect he fixed it well, but if not, he stands behind his work until it's right.

I'll know more in the morning. I'll keep you in the loop.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
14.3-5 is perfect while it’s running. That the voltage the alternator is putting out to keep your battery charged and run all the various and sundry electrical items in your car.

12.7 is a fully charged battery, 11.7 was what it did while you were starting it??
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
So, the new alternator has been working great. Car has been starting perfectly for days.

The odd thing is, when I start it in the morning, the battery light comes on, and stays on until I rev the engine. Voltage is around 11.7V until I rev it up. Then it stays up near 14V for the duration of my drive.

Maybe my battery is bad. But I'd expect the starting to be harder if the battery was bad. IDK. Without the voltmeter and battery dummy light, I honestly wouldn't know anything is wrong.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Sounds like the exciter wire is corroded or something. That’s a Rabbit issue, I deal with.

-Todd
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
Bad news. I was driving home today, and I 'm a few miles from home. My AC fan is on (I'm in Los Angeles) and it sounds normal. All of a sudden, it starts sounding super loud. I look down on my voltmeter, and it's around 15.5-16V. I limp it home with the voltages meandering from 14V to 16V.

Any time it goes above 15V, my instrument cluster shuts down. When I go back below 15V, it turns back on.

I was thinking about pulling the alternator and have it checked. I was still getting that weird 11.5V thing when I started the Jetta cold, so I figured something was up. I'll check out that exciter wire as well. Bummer. I thought I had this all finished.
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
Sounds like the voltage regulator took a crap. Easy to swap out. I wouldn’t drive it, until you do.

-Todd
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
I took my alternator back. He tested it and said the new regulator was faulty. He replaced it and I've been driving around for days without any voltage issues (13.5-14V while driving).
 

iluvmydiesels

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Nov 21, 2015
Location
phila area
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AHU
i have no idea about my alternator, i never remember my dad (PO) replacing it. yet its a bosch, i suppose some how its possible to be the original alt, idk.
but dude i think i checked not too many days ago. battery was fully charged, so the alt wasnt charging with a load, and of course all accessories off. i got 14.5V.
13.5V-14V is rather weak, and id suspect the regulator, and/or the alt. its a 120A alt right? think he installed an off-brand voltage regulator.
 

genscripter

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Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
If my voltmeter reads 14.5V or more, then my instrument cluster shuts down (probably a VW safety measure, to protect the cluster). I think I'm ok with it running between 13.5-14.0V for now. It's been ok so far.
 

turbodieseldyke

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Joined
Jun 6, 2010
Location
Free Mustache Rides
TDI
98 jetta
I doubt it. Mine had 20v pumped into it, by a defective 2-watt solar charger. The high voltage was definitely not blocked by any safety circuit, and the cluster sustained some minor damage.
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
I'm back.

Basically, everything was fine for weeks, as usual.

Then we had a decent rain this weekend and today, and the car is starting hard again. It cranks really slow. Maybe two or three cranks, and then it fires up. It almost feels like the starter is having a hard time.

My voltages look good. 12.6-12.7V at the battery, 13.5-14.0V while driving. It only starts hard when the engine is cold. Once it's warm, it fires up ok. According to my voltmeter, it looks like my alternator is working ok.

Any chance my battery was damaged when it got high voltage or near fully-discharged? I'd assume if I was getting 12.6V, then the battery should be ok, but maybe it needs to be checked.

My other plan is to consider investigating the starter or solenoid. IDK. What do you think? Aside from this odd electrical situation I've been chasing, the Jetta has been my most reliable car. I'm really hoping I can resolve this once and for all.
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
I had the battery tested. It was fine. The store manager was so busy, he just gave me a new battery regardless.

I put in the new battery. Tried to fire it up and it cranked 2-3 times again.

I'm still getting the slow crank issue. I'm leaning toward pulling my starter and getting it rebuilt. I'm going to read up on diagnosing starter issues.
 

genscripter

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Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
According to my Bentley Manual....

Section 2: Starter turns slowly or fails to turn engine:
a. Dirty, loose or corroded starter connections
b. Dirty , loose, or corroded ground strap between engine and body
c. Starter worn or faulty

When I did the heater core job, I cleaned up all my grounds and inspected my cables. A also cleaned up the starter connections as well.

I'm thinking this is the starter. I'm going to pull it off and have it rebuilt. I read up on the replacement job. You gotta be kidding me. The starter is integrated into the engine mount bolts?!?!? Why the H can't VW make one job simple on this thing?
 

ToddA1

Top Post Dawg
Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
The shared bolts have been a watercooled VW trait, since at least 1975.

It can be done with a floor jack, but an engine bar makes it easier.

I’m not one who tells people to spend money just because, but the mount needs to be pulled to replace the CPS. If yours is original it’s something to consider. It’ll leave you stranded, if it decides to randomly go out.

-Todd
 

genscripter

Veteran Member
Joined
Feb 18, 2008
Location
Los Angeles
TDI
98 Jetta
Good info to know.

So today I pulled that starter (wasn't as bad as I thought it would be), and had it rebuilt. I put it back in, and now it starts up well. HOWEVER, now I have a hint of the gear spinning before it engages the flywheel. I'm guessing the solenoid is delayed or something.

Just my luck. I thought this was wrapped up.

It does start up, after a 1/4 second of a high pitched whine. Any ideas on how to fix that? I checked all my connections and they look clean. I put dipole grease on them to keep them from corroding. The mounting screws were torqued as per the Bentley manual (something like 33ft-lb and 44ft-lbs IIRC) and it appeared to line up exactly as it had been uninstalled.
 
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