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Engine Specific Info and Questions => IDI Engine => Topic started by: Luckypabst on February 04, 2014, 06:36:37 pm
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Does anyone know the advertised, loaded cranking speed for the various starters?
Specifically the Mk1 direct-drive starter vs a gear reduction starter from an automatic Passat (pretty sure that was the application).
My OEM starter crapped out at the same time that I installed a new, aftermarket cylinder head about a year ago. On the advice of a friend at the local starter shop, I installed the gear-reduction starter. The car has never started as easily since and I blamed the new head. This past weekend at ~10 degrees F, it wouldn't start at all. Interestingly it fired right off by bump-starting in 2nd so I know that it'll start easily with a little more cranking speed. Glow plugs are fine, etc. This is either related to starting speed or the head.
Thanks
Chris
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Got compression numbers?
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I find regardless of type, cheap aftermarket starters are nowhere near as good as OE or quality starters.
Case in point the $80 new starter on my Suburban blew the housing apart after about 6 months.
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I find regardless of type, cheap aftermarket starters are nowhere near as good as OE or quality starters.
Case in point the $80 new starter on my Suburban blew the housing apart after about 6 months.
And the rebuilt OE starter on my parents Aerostar failed in a week.
Anyway, he didn't state clearly whether his new starter is one he pulled out of an automatic mk4 (or corresponding passat - i forget the number).
and yeah, compression numbers.
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It was a parts store replacement starter. I'm not looking for a diagnosis, just cranking speeds of various starters.
Chris
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My experience across board is that gear drive starters crank much faster in any application that I have encountered. I put a new Denso gear drive starter on my syster-in-laws 92 F350 last fall. It had a series of direct drive starters over the years and the thing never started worth a crap in the 12 years that she has owned it. New batteries, new factory cables, new solenoids and it would not start reliably, ever. Now it pops of so fast its kind of un-nerving. Before you realize that it is cranking, it has started. She thinks I walk on water. She had previously spent about $2500 trying to get it to start.
That being said this was a quality name brand starter. Everything that I have ever seen that was chinese that had moving parts was crap. Without exception.
I would try a name brand gear drive starter and see whats happens. Even a used one, as long as its factory. I have had such problems with chinese junk starters and parts that I will fix a bad factory on if at all possible and save the china junk for a last resort. Things like 5 brand new bad starter drives from five different brands but all from china and they wouldn't crank the truck. I went to Ford and spent 4 times the money for the drive and it was still working fine 100,000 miles later.
I would suspect if the motor popped right off on your bump start that your problem is cranking speed, not compression. If you had to drag it for a block, that may be another matter.
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Cranking speed and compression are directly related... Low compression engines will leak down fast enough to not fire, if the cranking speed is slow. High compression engines will light-off on the first cylinder reaching TDC, practically regardless of cranking speed.
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I honestly think they will crank the same rated speed, but the gear reduction takes a load better than the direct drive so it doesn't bog down as much under load. Meaning real world the gear reduction will crank faster in use.
That being said and I know you have stated a couple times you don't want diagnosis, but the main question I have is the starter bushing...if it wasn't replaced that can cause very bad cranking and ruin a starter in 2 weeks *I know from experience* So let me know that and how you lubed it as I have a tip to make the bushing self lubing. The auto Passat I don't think has a gear to go into the trans so the bushing is not the issue. But the old voltage drop test that BYM put in the FAQ helps a ton. I have replaced all the battery cables on all my older VW's with new and heavier gauge stuff because they just aren't cutting it after 30 years.
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Thanks y'all. My starter shop buddy said the cranking speed should be the same. He also said I probably have too much compression with a new head.
Anyway, it's strange that the engine goes from firing nearly immediately under any condition, then requiring extended cranking even when warm. The two variables are the new head and starter, both replaced at the same time.
Chris
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Thanks y'all. My starter shop buddy said the cranking speed should be the same. He also said I probably have too much compression with a new head.
Anyway, it's strange that the engine goes from firing nearly immediately under any condition, then requiring extended cranking even when warm. The two variables are the new head and starter, both replaced at the same time.
Chris
Surely newness of head won't affect the compression, unless different swirl chamber size. Newly polished chamber, may retain more heat in the compressed air, but that can only be good.
Have you installed a thicker headgasket perhaps?
Were the rings done, at the same time as a 'might as well' after thought, often promoted here?
Same for new shells...
'Improvements' on the timing setting can also influence starting ease.
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Well the other variable is that with a new head is new timing.
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Does anyone know the advertised, loaded cranking speed for the various starters?
It sounds like that's a no.
You guys have really lost sight of the question. Nothing below the engine deck changed. The head gasket is correct for piston protrusion. Pump timing is spot on and exactly the same as before. Glow plugs are new and confirmed to work. Tire pressure hasn't changed. My radio still only works on AM. I still get confused for some drug smuggling hippie. The sun still sets in the west.
Chris
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From my experience, the direct drive starter spins faster,... in the summer.
The gear drive will sustain a higher RPM for longer in the very cold, whereas the direct drive is a little faster at first but drops off.
Nothing official/advertised so personal experience might not count.
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i have used both extensively over the years... i would agree with what fatmobile has said... i never noticed much of a difference other than how they sounded... and my cars always had fresh starter bushings as well. but if it means anything, when id replace any in the future, i'll be buying the gear reduction models.
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I can not try to help, but I thought I said that they should spin the same RPM???
If you didn't adjust the pump after putting a new timing belt on with the head I would guess that is your issue or part of it.
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I might see if I kept the old starter and get it shipshape again. It munched the brush holder on the first few revolutions after doing the head job. I'm afraid that I might have tossed it though.
Maybe I'm the only one that does it like this, but the pump timing gets checked and adjusted any time the belt comes off. I, apparently wrongly, assumed that this was SOP. My bad.
Chris
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Tons of people never check anything.
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The head gasket is correct for piston protrusion. Pump timing is spot on and exactly the same as before.
Chris
If you didn't adjust the pump after putting a new timing belt on with the head I would guess that is your issue or part of it.
If you read his post at all, he said pump timing is spot on in post #11.
What is with the unnecessary 'tude moderator?
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The gear drive will sustain a higher RPM for longer in the very cold, whereas the direct drive is a little faster at first but drops off.
X2
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I still maintain an OEM grade sarter with fresh contacts and brushes will outcrank an aftermarket grade POS starter regardless of drive type.
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The head gasket is correct for piston protrusion. Pump timing is spot on and exactly the same as before.
Chris
If you didn't adjust the pump after putting a new timing belt on with the head I would guess that is your issue or part of it.
If you read his post at all, he said pump timing is spot on in post #11.
What is with the unnecessary 'tude moderator?
No attitude, but when most on this site say "exactly at the same spot before" it means they didn't touch it, at all, which is why I was questioning by saying "if you didn't"...if you read my post at all.
I am tired of your trivial questioning of me, please refrain from doing it further.
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You guys have really lost sight of the question.
Could be folks are looking beyond the question to the real problem.
Let's tally the basics:
Timing is by the numbers
Head replacement was proper
Starter speed is normal
No air in the fuel lines
Functional GPs
One unmentioned factor is injectors/break pressure. If unknown, I'd assume break pressure is stock or lower. Lower would advance injection, which would normally assist in cold start. Not a likely factor in this non-starter.
The major unknown is compression. Ive never heard of a 30yr old diesel engine having too much. Conversely, every VW diesel I've heard of - that started only by pushing, had low compression.
I doubt any starter will spin the engine as fast as a push start in 2nd gear.
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If your car fired off IMMEDIATELY after push starting it, and doesn't fire properly when warm.. I am too thinking you are low low low on compression. Or it could be excessively advanced timing (I know you timed it again back to where it was), as variables have changed and things are different know.. Do you get smoke while it is turning over? Colour?
Why was my post edited?? Did I do something against forum rules??
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your new starter could be defective from day one.
Did you adjust the valves on this new head?
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If your car fired off IMMEDIATELY after push starting it, and doesn't fire properly when warm.. I am too thinking you are low low low on compression.
Low compression will have prolonged cranking/pushing when cold and brief cranking/pushing when warm.
A cold engine that starts on the first crank or push will probably have good compression.
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That's the experience with my buddy's Rabbit at the beginning of winter,.. and it wasn't even very cold.
Borrowing/Testing an engine for a friend while Steve's is being rebuilt, the mystery engine wouldn't start at 30, lots of cranking no start.
I pull started it with the Rabbit and it started instantly, on gravel. Suspicious. Hillbilly compression test showed good resistance to turning.
He put a fresh bosch remanufactured in it and now it will start at -14F.
The old one didn't seem to be cranking noticeable slow.
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Lol... I'm glad I walked away
Follow-up for you diagnostic guys:
I've been spending more time in and intend on moving soon to a much colder climate. I had to resign myself to the fact that this isn't something that can be band-aided with a different starter.
Here's the numbers, first is hot compression, second is hot compression with oil, and last is a note about which valve is leaking, working from pulley to flywheel:
360, 390, E
250, 300, I
350, 350, E
350, 360, E
I replaced the head in April of last year due to cracking the OG head. I now have 22,000 miles/11 months on what was a brand new out of the box Topline head. At the same time that I replaced the head, the starter crapped out (on the first crank as I was purging lines) and the GP relay stuck on... bad luck, Murphy's law, whatever... After getting everything sorted the Caddy went from starting immediately in all conditions to requiring excessive cranking, even when warm, in mild air temperatures. There was no lead-up to the hard starting, it came suddenly with the head job.
In talking to the company that sold the head (Aluminum Head Rebuilders in OR), they mention that the head has a one-year warranty but with the many hundreds of Topline heads they've sold, there have been no complaints.
I now have the valve cover off and when pressurizing #1, it's leaking rapidly into the exhaust while the lifters are free spinning so it's not a lifter problem, at least on this cylinder.
Chris
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did the glow plug blow apart in the head?
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The glow plugs are fine. They worked fine before installing the new head and were replaced with new Bosch plugs when I swapped heads. I even saved the old ones for spares.
The Topline head looks good on the bench, full of nasty spooge on the intake side. I'll be doing a ring job on Sunday, slap it together and hope it's good for another 300k.
Chris
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If you did not test the GPs now, yoy do not know that they are "fine" NOW. Just that they were fine before. You did mention a stuck GP relay on initial start up with the new head,
There should be ZERO leakage past the valves on a good head, especially with 22,000 miles since new. So don't be too hasty in pulling the rest of the motor down.
One thing that strikes me as odd is that is starts worse warm..... This is not typical. I have only seen it once, and that was on a 2000 Jetta TDI. The hotter the weather got the worse it started until I had to park it in July. If I got it to start, it ran just fine and got good mileage. Compression was 500 across the board +/- 5 psi.
It turned out to be an IP leak. I have absolutely no leakage of diesel fuel anywhere. I replaced the the quantity adjuster & pump body O rings, and the shaft seal on the car to no avail. When I pulled the pump and replace the rest of the seals it started on the first revolution.
In an effort to ascertain what the problem was I pinched off the fuel inlet and return hoses and put vacuum of the small return hose barb on the fitting. It would suck air like crazy. When I replaced ALL of the seals it would then hold vacuum and start reliably.
I suspect that the variable was fuel viscosity. The thinner it got the longer it took to suck the air out and fire.
I would suggest that you vacuum test the pump before you take anything else apart,
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Um yea...
New rings fixed it. Still a little tough to start after sitting overnight below freezing but no more push starting it. I was blown away at the accumulation of carbon in the ring lands. This engine has never been babied, and I guess the 20k oil change is only a myth.
Valve leak was a bad lifter (see 20k oil change). It wouldn't bleed down properly and held the valve slightly open after idling for a minute or so. Now all you guys can holler and moan about a bent valve. It's not, don't worry.
And the glow plugs still work wonderfully, Toby. Thanks.
Headed to Montana in 3 weeks. Here's to hoping I don't hit another deer along the way.
Toodles
Chris
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great it got sorted
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I guess the 20k oil change is only a myth.
LOL whut? with a 4 qt sump?
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hahaha... that Amsoil has gotten really expensive so I went on strike. They claim a 15k oil change - what's a few more thousand miles?
Even synthetic gets sludgy with enough abuse.
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I did a 19,000 mile on the TDI with a filter change and new added in between on my schaeffer's oil. They do an analysis for free if you use their oil and it came back that it was still "usable" at that mileage but the additives were getting lower. It wasn't new oil, but I did a couple samples in between as well to try and know what was going on. The ISO viscosity was going up as well as the additives coming down, but what do you expect after 19,000 :D