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By byrdman454
#56190
What is the latest change intervals (time and mileage) most are following for timing belts and water pumps if using a Porkentensioner? I am having zero issues with the water pump but it has been on there a long time and has went through at least a couple belt changes. I assume everyone is changing the Volvo tensioner bits with a belt change as well?

Thanks
Mike
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By worf
#56221
byrdman454 wrote: Mon Feb 01, 2021 6:10 pm What is the latest change intervals (time and mileage) most are following for timing belts and water pumps if using a Porkentensioner? I am having zero issues with the water pump but it has been on there a long time and has went through at least a couple belt changes. I assume everyone is changing the Volvo tensioner bits with a belt change as well?
Greg Nettles was changing the Audi (I thought it was Audi) roller and oil-filled damper every 30k miles along with the belt.
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By byrdman454
#56306
Yes you are correct. It is Audi not Volvo. My mistake.

I thought there used to be a number of years that everyone assumed for the belt changes and WP changes. The 928s I take care of never see that much mileage. I was just curious what everything was thinking on this. Maybe 5 years for belts? Is there a reason to change WPs if there are no leak issues? I am a little concerned with impeller migration on WPs since I have had this happen to me a long time ago and had to repair the block with Greg Brown's tool.
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By SeanR
#56323
I've been recommending inspection at the 5 year mark but saying no more than 7 years/50k miles. I ran mine for longer than that and saw no reason to replace anything. One customer ran his almost 100k and I did yearly inspections just to keep an eye on things. It was perfect when I tore it down.

As for water pumps, if is a car that I previously did the pump on and I know it's a Laso, I'll feel for any axial play and let the customer know that if it were my car, I'd leave the pump and just restring another belt and replace the roller/piston. Giving them the option of doing the pump if it makes them feel better. I've yet to have a Laso pump fail, ever. The only Geba pump I put in a car at the insistence of a rather cheap customer, failed in a month with leaking. That was a shitshow as he wanted me to warranty the work even though I told him verbally and in writing that I would not warranty any parts or labor on that pump, especially since he provided it. He's also no longer a customer and is paying 1.5x my labor rate with another shop now.
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By ROG100
#56438
I generally agree with Sean - I change the PKT tensioner when ever I change the belt just because I am in there and it is a $70 part. Technically the tensioner is good for 75k miles. With the long life belts you are looking at 3 x iteration of the TB change.
I have customers with nearly 100k miles and 10 years on the belts and they still look new. Laso WP with plastic impeller - leave it alone after checking the play on the pully. Failure rate is extremely low at less than 1/4%. Only failure was coolant coming out of the weep hole and a dry cartridge seal - probably due to low usage.
Caveat - the TB & WP are not normally the issue but something else - rollers, cam, oil pump, crank gears. Bad installation of the original de-tensioner system. I hear so many stories it makes my hair curl 8>(.
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By ROG100
#56439
I generally agree with Sean - I change the PKT tensioner when ever I change the belt just because I am in there and it is a $70 part. Technically the tensioner is good for 75k miles. With the long life belts you are looking at 3 x iteration of the TB change.
I have customers with nearly 100k miles and 10 years on the LL belts and they still look new. Laso WP with plastic impeller - leave it alone after checking the play on the pully. Failure rate is extremely low at less than 1/4%. Only failure was coolant coming out of the weep hole and a dry cartridge seal - probably due to low usage.
Caveat - the TB & WP are not normally the issue but something else - rollers, cam, oil pump, crank gears. Bad installation of the original de-tensioner system. I hear so many stories it makes my hair curl 8>(.
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By Crumpler
#56610
Mike, I’m sorry, but you can only participate in the forum if you use stock tensioners...
I will help you put yours back on.
Best, Dave :)
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By byrdman454
#56841
LMFAO Dave.

No thanks. I never did like those stock tensioners. I am fully committed to the PKT. You need to drink the kool-aid Dave. :drink:

Was at my parents last weekend and decided to check on when I did his belt change last on his Euro. It was back in 2013! Funny thing is that he has only driven it 3000 miles. :rolleyes:

To make things even more scary is that the WP is the original one I put on when he got the car. I can't even tell you the date on it. It was a 928 Specialists rebuild back when companies still sold rebuilt WPs. :banghead:

Lots of work coming up soon for me to bring that car back to driving status.
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By worf
#56843
byrdman454 wrote: Thu Feb 04, 2021 5:33 am To make things even more scary is that the WP is the original one I put on when he got the car. I can't even tell you the date on it. It was a 928 Specialists rebuild back when companies still sold rebuilt WPs. :banghead:
Rebuilt from 928 Specialists would be plastic impeller (always.) So, no block damage risk.

For 928s that I see regularly *and* on which I was the last technician to do a full service, I don’t get worried until the job is 10 years old. I worry more about the grease in the sealed bearing for the tension roller than the belt. I check the belt system every two years. Beyond that, I take into account the usage and parking conditions of each 928 I service. Rarely-driven 928s that live in climate-controlled garages can go more than 10 years as long as I get to check the belt system every year. At 12-14 years, though, it’s time no matter what. 928s that see freeze/thaw cycles, 10 years is my limit.

This “controversy” is beaten to death every couple of years. The timing belt is almost never the problem. It’s the stuff the belt touches and the tensioner.
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By Geza-aka-Zombo
#57950
I used the regular Gates when I did mine.

Another data point: after 17 years and 55K miles, I did the TB on my 99.5 Audi last year (V6 - similar config to the 928). There was no need to bother as the belt was is fine shape. Not planning on changing the 928 TB again for 10 years, unless something else in there requires replacement.
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By worf
#57964
byrdman454 wrote: Tue Feb 09, 2021 6:10 am Is everyone running the standard Gates belt or the long life/racing Gates belt?

Standard Gates belt. Factory tensioner unless client wants and has researched PKT themselves.
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By byrdman454
#63386
Finally got around to tearing into this S4 for a WP and TB refresh. The WP was a 928intl rebuild from around 2008. Coming back from SITM I had a WP pulley migration that machined the block. I used GB's tool and Mark replaced the WP on warranty. This is the same WP. Here are some pics of that GB repair and an old cast pulley rebuild. The pulley was still tight and smooth but didn't want to leave it in there any longer. The GB repair appears to be holding up well.
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The other three pics are my cam gears and oil pump gear. These are the original gears. The oil pump gear is Aluminum. I had them re-coated back in the same time frame 2007-2008 by a fellow Rennlister. I think his handle was MrLexse or something like that and I think the coating he used was a dry film lube. It has held up great! However, I believe the coating is starting to wear thin finally. What is everyone's opinion? Do I need to re-coat or replace? Does anyone re-coat these any more? Do most people use the Porsche gears or the aftermarket option from Roger?
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Thanks
Mike
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By worf
#63399
Hard to tell from the pictures if the gear teeth are showing any cupping or not. If not, looks like the coating is still mostly good. If no and yes and If you’re not planning on 30k+ miles before the next belt change then leave ‘em.
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By Geza-aka-Zombo
#63412
Those TB sprockets look to me to be in pretty good shape. When I did mine, the originals (130k miles) were visibility worn to shiny bare aluminum. I replaced them with hard anodized machined billet aluminum ones.
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By byrdman454
#63414
It seems like I barely break 1k miles a year these days. :banghead:

I will try to get a close up of the cam gear teeth and see if you guys see any cupping. If not, I may go ahead and run them.

Thanks for checking these out for me.
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By byrdman454
#63428
Geza-aka-Zombo wrote: Mon Mar 01, 2021 7:04 pm How's your crank torsional vibration damper (harmonic balancer)?
Probably junk. That is why I bought three of your kits Geza. One kit for each of the 3 cars I take care of. I have 2 ATI balancers on the shelf right now. :rockon:
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By byrdman454
#63429
Here are 2 close up pics of the timing gears. Let me know if you think they are good to go for a while.
Image
Image


One more thing. I did these motor mounts a LONG time ago. I think these were the Anchor mounts when we were all trying to find an aftermarket replacement back in the day. The top of the intake manifold is just barely below the crossbar. Are they good to go as well or is there another measurement to check to see if these MMs need changing.
Image
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By Geza-aka-Zombo
#63446
byrdman454 wrote: Mon Mar 01, 2021 7:38 pm
Geza-aka-Zombo wrote: Mon Mar 01, 2021 7:04 pm How's your crank torsional vibration damper (harmonic balancer)?
Probably junk. That is why I bought three of your kits Geza. One kit for each of the 3 cars I take care of. I have 2 ATI balancers on the shelf right now. :rockon:
Sorry Mike, I wasn't sure, I'm working off my phone and didn't have my list of customers to verify.
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By Geza-aka-Zombo
#63449
I think the sprockets look fine, but will defer to the experts.

If you end up changing them, what I did was spray paint the 3 slotted holes. The paint marks left on the cam flange made it easy to line up the new sprocket to the original position.
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By Crumpler
#63452
Not an expert but I would also feel fine using those gears again.
That repair job looks great btw, I forgot you even had to do that.
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By worf
#63453
byrdman454 wrote: Mon Mar 01, 2021 7:42 pm Here are 2 close up pics of the timing gears. Let me know if you think they are good to go for a while.
You can't tell from pictures. You have to twiddle them around under light to make sure you're seeing what you're seeing or not seeing what you're not seeing. Shadows, stains, can throw off your gaze and it's just worse with a picture.

Look lengthwise down the teeth look for cupping. From the top or slight 'off-top' look for variations of the tooth edge.

My best guess from the pictures is that it looks like those'll go another 20-30k if the belt is correctly tensioned. If you don't see any variation on the teeth then they're probably fine.

byrdman454 wrote: Mon Mar 01, 2021 7:42 pm Are they good to go as well or is there another measurement to check to see if these MMs need changing.
Does the motor rock nicely on the mounts when you rev the engine? Or does it kinda just dip a tiny bit or sit there like a lump of aluminum? That's how I "measure."
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By Wisconsin Joe
#63470
byrdman454 wrote: Mon Mar 01, 2021 7:42 pm

One more thing. I did these motor mounts a LONG time ago. I think these were the Anchor mounts when we were all trying to find an aftermarket replacement back in the day. The top of the intake manifold is just barely below the crossbar. Are they good to go as well or is there another measurement to check to see if these MMs need changing.
From that pic, it looks like the MMs are ok...
I think.

A fairly easy way to check is to look under the car from the front.
Does the bottom of the oil pan extend below the steering rack?

If you can get under the car, being able to put a finger between the top of the crossmember and the oil pan is also a good check.
If the MMs are still good, the bottom of the pan should be level with the bottom plate on the rack.
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By worf
#63531
Geza-aka-Zombo wrote: Tue Mar 02, 2021 6:53 am For reference, my 130K mile original.
That one appears to have a ton of gear tooth wear.
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By Geza-aka-Zombo
#65041
byrdman454 wrote: Mon Mar 01, 2021 7:38 pm
Geza-aka-Zombo wrote: Mon Mar 01, 2021 7:04 pm How's your crank torsional vibration damper (harmonic balancer)?
Probably junk. That is why I bought three of your kits Geza. One kit for each of the 3 cars I take care of. I have 2 ATI balancers on the shelf right now. :rockon:
Hey Mike, when you button that one up, let us know how the TVD hub install worked for you. Thanks!
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By byrdman454
#65063
Geza-aka-Zombo wrote: Mon Mar 08, 2021 10:09 am
byrdman454 wrote: Mon Mar 01, 2021 7:38 pm
Geza-aka-Zombo wrote: Mon Mar 01, 2021 7:04 pm How's your crank torsional vibration damper (harmonic balancer)?
Probably junk. That is why I bought three of your kits Geza. One kit for each of the 3 cars I take care of. I have 2 ATI balancers on the shelf right now. :rockon:
Hey Mike, when you button that one up, let us know how the TVD hub install worked for you. Thanks!

Did it last night for the first time. It was so easy. The only thing I deviated from on your instructions was where I locked the engine to install the hub.
I removed the original balancer and used a Sharpie to know where the keyway was located. I re-installed it all and rotated the engine until the mark was at 12 o'clock. I installed my flywheel lock and removed the old pulleys and balancer. It was so easy lining up the keyway with it at 12 o'clock. With the timing at TDC, the keyway was at around 4 o'clock and seemed like it would be a little more difficult lining it up from the top side. It would be totally doable at 4 o'clock, but since this was my first try I wanted to make it as simple as possible. It slipped right on all the way after heating at 275 for 2 hours. Thanks again for the great product Geza.
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By Geza-aka-Zombo
#65081
Great - glad it worked out. Yes, my suggesting TDC was based on assembling the hub from underneath.
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By checkmate1996
#67353
When I went to change the belt in my 85 euro that had sat outside for 15 years, it looked brand new. Admittedly, the PO had changed out probably a 1000 miles earlier but surprisingly it it looked great.
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By Gary Knox
#68057
Personal experience with my '87 S4. Original belt and all gears etc., in '99 had belt changed at 90K miles, Porsche dealer mechanic said he'd never changed one and didn't think it was necessary, but did it anyway (just belt, everything else was OK - this was back before the Rennlist tribal knowledge and recommendations!). I know of a car with original belt for 23 years and 124K miles (but belt did fail before 125K). Rob Edwards recently removed original belt with 27 years service and 48K miles. Stated belt looked very good and gears looked like new.

Quoting Ed Ruiz from 20 years ago - YMMV (Your Mileage May Vary)
By JBRob007
#69358
It’s never the belt... all the other moving parts... well, the stuff the non-928 mechanics DON’T service / replace is when things go sideways. Haven’t seen a belt fail yet without proper motivation from a failing mechanical part, over tensioning, etc. PKT is the way to go!
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