Mk6 GTI - possible starter motor hanging up on flywheel?

[Lucas_R]

Hoping to find some feedback from the more tech savvy mechanical guys on here.

My 2010 model Mk6 GTI rattles on cold startups. Pretty much every cold start will rattle, with only the odd exception that it wont. Sometimes on a warm startup (eg left parked for an hour) it will also rattle, but only sometimes. Hot starts it basically never rattles.

Car has 69,000km on it and the engine is perfect apart from this rattle.

I've had the timing chain tensioner replaced last year - no difference. I removed the N205 valve and cleaned it - no difference. Engine is full of Liqui Moly VW504-507 oil and last oil change was only 5,000km ago. No errors of any sort on VCDS scan.

After more research into this noise, im now thinking it could possibly be my starter motor hanging up on the flywheel for a second or so after starting.

Do you think this is a possible culprit? I jumped under the car last night to check the OEM starter motor, and its a Valeo unit with part number 02M 911 023M.

I have just recently rung my local auto electrician who said they can source a new replacement Valeo starter motor for $450 overnight from Queensland. ECS sells them for around $400 but then you have the conversion rate plus shipping, so it makes sense to purchase locally.

I am happy to buy a new starter motor if it gets rid of this damn engine rattle - any feedback from the mechanics on here as to whether this is realistic would be appreciated.

Below is a photo of my starter motor. Is this the stock item? The listing on ECS shows a slightly different part number, so i assume the stater motor has been revised at some stage? 403 Forbidden

[Umai Naa!!]

Is it worth lubricating the pinion?

[brad]

pull it apart, clean all the carbon gunk out, tidy up any burrs & lubricate. It might work...

[Snail Style]

Lithium dry lube on the pinion and ring gear. I'd be swapping a starter over to test first before buying one if that is an option.

[Lucas_R]

Thanks for the feedback. I had found another thread from America and the guy had a Mk4 Golf and he used synthetic wheel bearing grease to lubricate the pinion.

VWVortex.com - DIY - Starter Motor Grind Fix and Starter Motor Replacement

So what would be the most suitable lubricant or grease to use? I do have a pot of normal bearing grease in the shed (nothing special) that i bought about 10 years ago. Happy to buy the right stuff and give this a go.

[brad]

Thanks for the feedback. I had found another thread from America and the guy had a Mk4 Golf and he used synthetic wheel bearing grease to lubricate the pinion.

VWVortex.com - DIY - Starter Motor Grind Fix and Starter Motor Replacement

So what would be the most suitable lubricant or grease to use? I do have a pot of normal bearing grease in the shed (nothing special) that i bought about 10 years ago. Happy to buy the right stuff and give this a go.

Within the starter motor itself you can use anyoldgrease(tm). For the bit that's within the bellhousing /clutch area you either need to be very sparing with anyoldgrease(tm) or use a dry lube as the sticky grease attracts all the thrown off crap from the clutch disc and clogs up the sliding surfaces.

As you know I'm a dodgy bugger with most things so i doubt the mechanical world would benchmark me very highly.

[Lucas_R]

Going to give this a try over the next few days. I purchased some Nulon grease thats heat and water resistant...hope its the right stuff to use.

Will report back with results.

Nulon Extreme Performance L80 Grease Tub - 450g - Supercheap Auto Australia

[Lucas_R]

Got home last night and was motivated to pull the starter motor off my car and give it a clean/service to see if it's the cause of the startup rattle i get about 80% of the time when the engine is cold.

Wasn't hard to get out or disassemble. 30 mins had it removed and in pieces on my garage floor. It was pretty filthy inside (clutch dust and other crud) so i gave everything a good clean/degrease, then put a good quality Lithium grease on all the gears/pinions and put it all back together. I used a full can of degreaser on it, and got alot of gunk off. Looks brand new inside now.

I've done 2x cold starts since and haven't had the rattle yet, but it's too early to tell whether this was the source of the noise. If i can get another week or so rattle free then i'll be happy that i have fixed the issue.

I also took the solenoid apart and theres a piston/shaft piece in there that sits inside another piece of metal with a spring on it, so i put some grease on that too. It was clean though, so didn't need to clean that.

Here it is (airbox removed for access):




Dirty sucker:




All in pieces (motor section is already clean in this pic which is why its so shiny compared to the other bits):




One part of the internal gears after removing them and cleaning/degreasing them:




All back together, greased up and ready to reinstall:

[brad]

that's a lot of grease on the pinion gear

[Lucas_R]

that's a lot of grease on the pinion gear

Haha yes perhaps a bit excessive, but once it engages on the flywheel a few times it will spread the grease out. At least if my clutch starts slipping shortly ill know why