A good day! (Wife's volvo is alright) :)

[LEAKYSEALS951]

There is a car god, and he smiled upon me today.

Brief history- My wife's 2015 volvo v60 was at about 110k, when an accessory belt started whining. Timing is due at 120k, so "yours truly" went and replaced both. I have done 1000 timing belts on the 944's, but this car was bought new by my wife with her money.

Note to self- Don't eff it up her 50k present to herself!....

I replaced the belts, started it up. Worked great for a month- until the accessory belt broke, got sucked into the timing cover, and destroyed the head.

I was sick to my stomach. Still tasting vomit from my own insecurities of 'doing something wrong', I handed it over to a local mechanic friend. $4500+ later it was running again, but it took months before I could look at it again.

A vital part of the fix was determining what broke the 'new' accessory belt. Alignment issue? parts issue? I punted to let a clear mind have a shot at it.


Fast forward to eight months later- Wife and I are going on anniversary to Old Town Alexandria. Thank god she wanted to stop off 66 and in Tyson's shopping mall. In the parking lot, a stutter, and a shake. Something was off. I was driving, and could hear the belt being sucked in AGAIN! I immediately killed the engine.

Anyway, a big long story later, and in the peace of my own garage, I discovered the timing had jumped by about 15 teeth- something like about 120 degrees of cam timing. Doing the compression check was a heart thumper- but- there was compression. How? I don't know.

So, anyhow, I redid the timing, and not wanting to get screwed again, set off to determine the accessory belt problem. Once again, I had my confidence. There was no need for a second opinion.

In the quest for finding the belt problem, I needed to address the timing cover issue. It's supposed to prevent the belt from coming in, not encourage it, as the factory cover does-

Exhibit A:


From this angle, it looks pretty legit, but wait...

Exhibit B:



From this angle, we see they installed a rubber edge, which can keep out water, but not prevent a belt from entering

Here's where it gets worse:



The cover overhangs the harmonic balancer. If a cord shreds, it will get drawn into the timing casing.

(the cover was built this way to provide ample clearance for the timing cams and belt, but leaves a wide open gap for the accessory belt to enter).

This shows the gap to allow the accessory belt in to trash things:



Also, when the belt broke, it smacked the cover with so much force, it shattered the lower plastic housing (seen being epoxied on- red clamp. Also, look at the space for the belt to slip under the housing right into the timing cover (represented by the channel lock arms area)) :



A 'new improved' cover was in order. Of course, the volvo people are all about key fobs and crap. Nothing out there had been made yet in a cool anodized color.

The solution-



1.Use an unused engine mount to make an extension to take the blow of the broken belt
2.Reinforce and fill in the hell out of the lower plastic casing so it can withstand the hit, and fill the channel lock space where something could get in
3.reorient the lower cover on the outside of the casing so it could not collapse in
4. Fabricate a metal timing belt cover, flush with the harmonic balancer, with no overhangs and strong enough to take a hit.





Now the casing is flush and inboard of the accessory belt. Any flailed cords will be encouraged to stay the eff' out of the timing cover.



I am still working on the root cause of the belt failures, but, I feel 70%+ more confident an accessory belt failure will now not involve the timing. Maybe I'll post more on the belt failure causes- but this is long enough for tonight, Pasta time!!!!

[fastfredracing]

That is great news, and you just got back like 20 hours of your life

[LEAKYSEALS951]

This is how I was feeling about the car having compression. It shouldn't. The fact it did was unnatural. It was not right. Perhaps Tyson's shopping mall was built on an indian burial ground.

"It's your cat (car) now..."






But today, was the second day I drove it quite a bit. Confidence is slowly building.

[LEAKYSEALS951]

Originally Posted by fastfredracing

That is great news, and you just got back like 20 hours of your life

That is exactly what I was thinking when I did the compression check....

"What's the worst that can happen...." (check cylinder one)
"what's the worst that can happen..." (check cylinder two..... etc...

By #5 I was a basket case!

[A930Rocket]

Nice work.

I had a 84 Corvette that any time under hard acceleration, would shred the serpentine belt. I never did figure out the root cause, because I sold it.

[Baz]

Wow....HELL of a write up, Ron! Fantastic! Especially the photos.

Respect for your dedication in finding the culprit!

Happy for you to get to the bottom of things and find a remedy. Very inspiring!

[sc_rufctr]

Great write up and explanation... You can't be the first person to experience this. You'd think a company like Volvo would already have a solution.

[LEAKYSEALS951]

^Thanks all. I'm genuinely surprised someone hasn't made an aftermarket replacement out of cool aluminum colors to go with all the colorful intake pipes, blow off valves, and such.

If it wasn't for the tight tolerances, I'd go develop this myself, only challenge is that the clearance between the (timing belt/tensioner pulley) and the cover went from about 1/3-1/2 an inch to about 1-3mm. That's way too tight for me to get behind the mule of a mass product without some sort of disclaimer.

I've currently got the outside of the timing belt marked with a bunch of sharpy marker dots to see if it has been rubbing. I'll check it from time to time to ensure it isn't smacking up against the metal cover. So far so good though.

Hell, the way my job is going lately, perhaps I'll do it anyway. Anybody interested in developing this more together, let me know!

[oldE]

When you replaced the accessory belt, were there any idler pullys changed?
Those belts weren't just failing without a reason.
Great work on the failure proofing.

Best
Les

[ckelly78z]

Different parts from different tier 2 supplier companies all put together at a tier 1 supplier, and sent to the assembly plant in an on-time delivery to be installed on the car with 24 hours. All of these facilities are responsible for their own design specs, and quality assurance. It's not likely this problem was discovered until they started getting warranty returns/claims, but still won't issue a recall.

Good on you for seeing the problem, and addressing it !

[LEAKYSEALS951]

Originally Posted by oldE

When you replaced the accessory belt, were there any idler pullys changed?
Those belts weren't just failing without a reason.
Great work on the failure proofing.

Best
Les

ha ha! The tensioners/idlers got changed when I initially did it. I had them rechanged when the mechanic redid it. I re-rechanged them again last week!arghhh I forgot to mention it in the writeup. It makes me suspect damage to a pulley (alternator or ps) either in bearings or damage to grooves, but I can't find anything. Everything looks aligned, but it's hard to definitively measure in the tight space. There is no discernable bearing slop in either, and I examined the grooves under good light and magnification.

One issue I noticed was tensioner tightness. This is a very tight belt which requires stretching the tensioner to full stretch, and even so, when the belt is on, it was in the fully tensioned position, to the point it was putting so much force on the accessories it caused bearing squeal (that's not good). The oe belt size is listed as 1090mm. On my latest experiment, I went with 1095mm belt, which lets the tensioner now work as it should (It's not maxed out past it's spring point). Why an oe size be a problem? I don't know. I'm not convinced that's the problem, or my longer belt is a solution(not necessarliy the right one)- but- until I know, I want a bulletproof as possible case to take a hit providing the accessory belt issue isn't fixed yet. To date, I can only find little issues, not big smoking gun.

So far-
1- belt so tight, is required stretching the tensioner at/beyond it's limit/ excessive tension (using 5mm longer belt)
2-beginning to fail harmonic balancer potentially causing alignment issues (replaced yesterday)
3-slight slop in new tensioner pulley, potentially causing alignment issues (replaced genuine volvo)
4-belt sizing variation between manufacturers(I used contitech belts)- although at least one was a different brand

I never removed, or reoriented the Alternator or PS pumps, so it's not like they got mounted in a different position.

But no 100% certain cause.

One thing I notice now is that there is a slight amount of flutter in the tensioner pulley as it works. Before, it was so taught, there was no movement, it was stretched too tight. It was like Chris Farley ripping through that little suit. Now you can see the spring moving. It is wobbling too much, or just right? I don't have enough experience to know. According to random accessory belt flutter videos on yt, it's right about in the middle. Id' prefer to see none though at this point.


Also, I think this 2.5 l block is used in the ford focus st or something like that. It would be interesting to see if those covers are different.

[recycled sixtie]

When I read your post Leaky, Captain Ahab and his wife come to mind. Well done.

[LEAKYSEALS951]

Stardate: Wednesday. Status update.

Say in captain's log voice: "Now that the Enterpise's timing cover is reinforced, we can leave spacedock- I can focus on the root cause of the failures without the stress of a $20 belt failure chunking a reactor core breach at even impulse power."

Root causes? Add ONE:

FROZEN ALTERNATOR FREEWHEEL pulley.

Add that to the list of problems in the accessory belt saga.

I had no idea such even existed. I thought the alternator was simply attached to a pulley. But oh nooo.... A guy on my youtube newsfeed in a black audi told me such.
Went and tested it. Frozen solid.

[LEAKYSEALS951]

I'm also going to include a pic of the previous tensioner, with the belt lash that marked the tensioner itself. I remember seeing this, but the belt looked good and was nowhere near the black score marks. Of course, that was at idle. This potentially suggest when the engine was downshifting, it would cant the belt right against the tensioner, as the alternator needed to be slowed down everytime the computer decided to upshift through eight thousand gears. Originally, I thought this was the result of the inner cords flailing inboard, who knows...who cares.. because....

This weekend- freewheel time!

[Scott Douglas]

I've never heard of an alternator free-wheel pulley. I always thought the pulley was direct mounted to the shaft.

[LEAKYSEALS951]

Originally Posted by Scott Douglas

I've never heard of an alternator free-wheel pulley. I always thought the pulley was direct mounted to the shaft.

YUP... me too, until I price checked the alternator and the freewheel assembly came up.

That led me on a list of freewheel assembly failure searches, and one of them was the spastic tensioner movement problem, which, after a new belt, tensioner, and harmonic balancer, I'm still getting.

I was thinking I'd bent my crankshaft, or at least the timing crankcam/harmonic mount assembly, but- the frozen freewheel gives me some hope...

I went out and tried to freewheel it, but no love, frozen solid, and, this does appear to be a freewheel unit. I so thought I knew everything...

[smadsen]

Twenty-five years ago I replaced a water pump on the wifey's Buick Century. A week later the serpentine belt shredded itself on the 405 at LAX. I replaced the belt, it shredded again a week later. I replaced it again and it shredded within a week. It was then I discovered there were two identical serpentine belts, one with six grooves and one with seven grooves. The new water pump had the wrong wheel for the rest of the car, so I could have shredded belt into eternity. Had to source a new pump wheel and belt number four to get right.

[oldE]

Originally Posted by LEAKYSEALS951

Stardate: Wednesday. Status update.

Say in captain's log voice: "Now that the Enterpise's timing cover is reinforced, we can leave spacedock- I can focus on the root cause of the failures without the stress of a $20 belt failure chunking a reactor core breach at even impulse power."

Root causes? Add ONE:

FROZEN ALTERNATOR FREEWHEEL pulley.

Add that to the list of problems in the accessory belt saga.

I had no idea such even existed. I thought the alternator was simply attached to a pulley. But oh nooo.... A guy on my youtube newsfeed in a black audi told me such.
Went and tested it. Frozen solid.

Good detective work!
I knew it had to be something like that, but never knew they had got to the point of de-clutching the alternator to reduce fuel demands.

Well done.
Les

[Bugsinrugs]

You are in a superior league then me but when I did my first timing belt replacement it took me two days to build up the courage to start the engine. That was my truck…. Can’t imagine the courage it took to fire up the wife’s car… BRAVO!!

[LEAKYSEALS951]

Originally Posted by Bugsinrugs

You are in a superior league then me but when I did my first timing belt replacement it took me two days to build up the courage to start the engine. That was my truck…. Can’t imagine the courage it took to fire up the wife’s car… BRAVO!!

lol- Starting the engine the first time is always a sphincter tightening moment. Definitely caused a couple of grey hairs!