2005 XC90 Idler Pulley Seized and Melted. New Engine?

amadeov · Post by **amadeov** » 27 Oct 2016, 22:17

About 2 years ago, I had an idler pulley seize on my 2007 XC90 V8. I ordered a new serpentine belt and idler pulley from Rock Auto, and I got a timing cover from a junkyard pull on eBay.

paz5050 · Post by **paz5050** » 09 Jan 2023, 18:11

2006 XC90 V8 with a meager 120k miles. My idler pulley seized too.

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Hoped I could get away with just a new pulley(s) and belt. I attempted to disassemble, but the bolt wouldn't come out after unthreaded. Moved the pulley aside to see the boss was shredded and twisted, keeping the bolt from coming out.

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Still hoping to save my ride. So looks like I'm going to attempt the solution posted above by jimmy57 and mhcrra1, and also discussed here:
viewtopic.php?p=536435&hilit=xc90+v8+id ... ey#p536435

How do I go about cutting the remaining twisted part of the boss off? Seems like I'll need to remove the wheel to go in from the bottom to get better access to it? If I remove the wheel is there enough room to fit a Dremmel tool in there to cut it off? Or do I need something like a mini hack saw?

Also, inspecting the wheel well, it's not obvious how to remove the molding. They don't appear to take a torx or other bit. Do these fasteners just snap in and I pry them out?

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If anyone has completed this job, I'd love to hear how it worked out a year+ down the road.

Any other tips (or prayers) are welcome. Thanks

nedc · Post by **nedc** » 11 Jan 2023, 16:28

They are aluminum rivets- you have to drill them out!

nedc · Post by **nedc** » 11 Jan 2023, 16:29

Then you can replace them with screws, at least that's what I did.

Post by **ggleavitt** » 12 Jan 2023, 10:37

Worst case scenario is a new front timing cover, PN 30720104 with new seals. You'll need to pull the valve covers to do the front timing cover replacement (can find VCG parts list in here-https://www.swedespeed.com/threads/v8-v ... nt.286873/ as noted on the FCP site (https://www.fcpeuro.com/products/volvo- ... r-seal-kit). Decent amount of manual labor to do it all but the replacement itself is pretty reasonable using standard hand tools. Excellent write-up on this site and also on Swedespeed (S80 with less room at front of motor)- https://www.swedespeed.com/threads/timi ... nt.645472/ , https://www.swedespeed.com/threads/oil-leak.644282/

paz5050 · Post by **paz5050** » 22 Jan 2023, 18:57

Completed this job, and feel pretty good about the results. Overall took only about 6 hours of actual work (most of it fumbling around on dis/reassembly in the tight/awkward workspace of the belt area), completed in shorter stints as I waited for parts - got the pro parts sweden pulleys and belt from FCP for about $75. I got the replacement 'boss' machined - custom order with ID 9.85mm OD 16.9mm, length 12mm. luckily I know someone from a shop who did it for free, said it took him less than 30 minutes from spare steel, and should be less than $50 at most machine shops (depending on labor cost).

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Jacked up and took off right wheel and wheel well liner to get access. Drilled out the wheel well liner rivets, but only about half of them drilled through and the rest spun in place and started eating into the liner, so cut em off with crimps.

Disassembly after that is basically following the serpentine belt thread on SS https://www.swedespeed.com/threads/volv ... nt.338081/. only thing to add there is that you don't need the serpentine belt tool, just a breaker bar and 19mm socket, but it has to be a shallow socket to have clearance, and pipe extension to torque the breaker. also should cut the clamp to disconnect the coolant line at the reservoir (rather than at the block), plug it, and work the belt around it to get the belt off - saves coolant.

after getting all the other two pulleys off for max room to work, still wasn't any way to get a Dremmel in there to cut off the twisted aluminum remains of the pulley boss. so had to use a mini hack saw from the top. wasn't enough clearance to get the mini hack to all angles needed to fully cut off the remaining boss, so used two pops a hammer and long chisel to get it all off, and finally be able to get the bolt out and chewed up pulley/bearing/washer off.

used a rough file to clean it up. followed by a fine file. here's some shots at various points in filing, but I don't think I got a pic of final result after fine file.

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I didn't spend that much time filing, bc I didn't want to take too much off and screw up pulley alignment. I also figured the bolt that goes deep into the block would be the 'source of truth' for the alignment against my steel boss, and if the surface wasn't totally flat/parallel to the timing cover the steel boss would bite into the softer aluminum as I tightened it to align itself. well, after I put it back together and started up, belt stayed on the pulley just fine.

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even though it seemed to run fine like that and tensioner should keep belt in place, the belt was just a little too close to the rounded edge for my liking, so I ended up getting the thinnest 3/8" fender washer at the hardware store, mic'd out to just less than 1/16" thick, and used that to space the pulley out a bit more. after putting that on, it looked just about perfect compared to the other two pulleys.

only have about 100 miles on it since the repair, but feel pretty optimistic about it lasting until the timing cover gaskets crumble (I don't see any reason why it shouldn't - steel boss actually seems like an improvement lol) at which point I might as well replace the tc

chitownV · Post by **chitownV** » 24 Jan 2023, 19:15

Wow, glad you were able to figure out a solution. Hopefully, it will last. Sucks the V8 has this issue as changing the timing cover shouldn’t be the fix.

Post by **ggleavitt** » 25 Jan 2023, 07:17

Idler boss tears up as the idler bearing binds, it's a maintenance item easily resolved by having a properly working bearing.
Timing cover will ideally come off at some point irrespective of a failed boss to fix the inevitable seeps and leaks, same as the valve covers.

Nothing to "suck" about owning an XC90 with the V8, it's a very robust motor which has little room under the hood. As a result, the motor gets regularly heat cycled and eventually seals start to harden, starting with the back valve cover bank and the lower rear (exhaust) side of timing cover. History has shown little if any oil consumption with this motor and with the exception of the heat related issues and lack of maintenance promoting repairs such as is in this thread, the forum statistics speak for themselves.

Seriously, if it were that much trouble to maintain a V8 I would not be owning two of them after 10 years running a 5 cylinder.

edit 012523- own to maintain.

chitownV · Post by **chitownV** » 25 Jan 2023, 08:50

Well, I can’t speak for the OP since people have different experiences, but at 120k miles, it does suck for a simple serpentine belt and pulley service. Not everyone is you, so who know how many V8s haven’t changed these parts well over 120k miles. Timing cover coming off is not “normal” for modern engines; probably the only modern V8 that I know of that “needs” to have it’s timing cover off. That’s unfortunate for maintenance.

Again, as I was originally posting, nice @paz5050 for finding a good solution.

2005 XC90 Idler Pulley Seized and Melted. New Engine?

Re: 2005 XC90 Idler Pulley Seized and Melted. New Engine?