There has got to be some mechanical damage to this engine.

It was reported that it ran fine after the cam belt failure, but some cam followers or other components may have been cracked or over stressed by piston to valve contact and failed some time later.

All this will only be known by removing the rocker cover, and maybe the head, and carefully examining the components. There must be plenty of second hand heads available.

The question is, is the car worth it? Otherwise break it or sell it as a non runner and cut ones losses.

I have no reason to suspect there have been any mechanical damages from the timing belt snap. The replacement was done by a Volvo mechanic who's done it for several decades, checked to make sure it was alright, ran smooth with no weird noises after the timing belt replacement and taken to the Volvo dealership themselves who checked twice that it's done properly and given the all clear.
Sure, I can have a look if nothing's damaged visually but I would likely mess up something if I played with the timing mechanics myself, that's why I don't dabble with it and let the specialist do what they're qualified to do.

An oscilloscope might be a bit above my understanding let alone having one. I've got noid lights and a multimeter but that's about it. Remember a guy a while ago telling me how to test injector signal readings with an oscilloscope but I'm afraid I might need a bachelor's degree to understand and follow what he was explaining to me.
If I can't test it with the 2 items I have, that will be a dead end for me. Might have to sell it... any offers? :_:

If you've tested every injector with the NOID lights and they all show as working, you've already got a visual go/no-go on whether they're working or not, assuming the injectors actually function, something else i believe you've already checked.

Without being rude but picking up on your self-confessed limited technical ability, how competent are you at removing the rocker/valve cover?

If you're ok with that, i'm fairly sure you can identify the valves and their springs and observe their movement as you turn the engine over by hand using a socket and ratchet drive on the crank pulley bolt, obviously in the normal direction of rotation. The firing order i believe is 1-2-4-5-3 with #1 on the right hand end, usually timing belt/crank pulley end. However you know where #4 is as that's the one giving trouble if memory serves so please excuse the teaching to suck eggs! That said, turning it over by hand you should see all the inlet vales open in the same order as the firing order and ~1.5 turns later the exhaust vales should open in the same sequence as the inlets. In other words, as you turn it over, if #1 inlet valve opens, about 1.5 turns from when it starts opening #1 exhaust valve will start to open but the other valves will all be doing what they should at various times throughout the turning over of the engine.

What you're actually looking for is that all inlet valves open a similar amount and that all exhaust valves open a similar amount. If any (probably on #4) aren't opening as they should, look for a problem in the corresponding valve train between the camshaft and that valve. Could be a broken rocker, a dished follower or even a bent valve or broken valve spring - the last one won't allow full compression so power will be down as a result.

If that reveals nothing then i suspect it will be a top end stripdown to ascertain the cause of #4 not firing as it should.

Either that or as you suggest, sell it and cut your losses, someone may amke a good offer and have the bits to fix it cheaply enough to make it worth their while and gives you the opportunity to find one that does run as it should.

Surely a simple compression test would flag up a problem with valves?

It would but being a diesel will need a hefty compression tester and the injectors removed to facilitate the test. The OP sounds as if that might be a bridge too far for him now although i might be wrong.

If some rockers are bent or broken, the valves will just not open as far, or not at all. The compression would be fine since the valves would close perfectly.

The compression would be down as the cylinders wouldn't get their fill of air, even loose valve clearances can make a big difference!

That's true! Hadn't considered that.

Timing belt didn't snap, was the alternator belt
 

Still trying to fully map out all the events that happened so I know where to start, looking back however I'm told that the timing belt didn't snap and I'm wrong.

On the Humber Bridge, instead of the timing belt snapping the alternator belt did and in the process got caught up in and jammed up the timing belt. Having the car towed to my mechanic, the alternator belt was to be replaced and mechanic said the timing belt change was due, so might as well do both at the same time. Hope I got the events and order right this time.

Good news then on possible damage. If timing belt didn't snap as I've been corrected, can't see a way there can be damage.

If the alternator belt snapped and went between the timing belt and the pulley, there's every chance it made the timing jump so yes, there most certainly could be damage! :eek:

How the alternator belt managed to find its way behind all the timing belt covers and cause the belt to jump is another matter though or did the mechanic mis-time it somehow?

Woudn't know how the alternator belt would snag up in the timing belt. Guess that's the dealership quality you pay for, for them to miss everything...

And I should add that the timing belt problem appearing was the first time I went to the mechanic that I've now been going to for a while. He had never seen the car before then.

Are you saying this happened after having it serviced at a dealer? If so i would have had it towed back to them and told them to put it right under their guarantee!

The auxiliary belt & timing belt are next to each other. It can happen very easily.

The end of the road
 

Been a while. Can't believe it's been 237 days since my last update but here I am with news. Not sure what you've been up to but I've been busy with my S80, more like keeping a mechanic busy rather than myself.

Found another Volvo fanatic that lives not far from me, has his own garage, some 4+ rare volvo's T5's, AWD's the lot, knows his stuff. In a nutsheel we agreed that he'll take apart the engine bit by bit till he finds the thing causing all these issues. I didn't give him an hours cap cause money wasn't a thing anymore, I needed this for my own pyche. I need to know what's at fault so I can sleep better...

Cracked head. More specifically cylider head castings are broken around the hydraulic lifters. Inlet valves can't open correctly or not at all. Mechanic was surprised with such damage the car cranks and runs at all. There's some fighting spirit left in her.

As for when this happened, the only thing we can come up with is that when the alternator belt snapped and jammed up the timing belt, there probably was some hit somewhere with the valves. Not enough to break the head castings that day. Was only a matter of time till these microscopic cracks/weakpoints were gonna give and that fatefull day likely was when we delivered the car off at the dealership. That being said, their attitude still urks me to this day.

Here's some pictures, will help you visualise the issue better:
https://i.gyazo.com/5dceedbc4c689195...66bee5a043.png
https://i.gyazo.com/206135d2caed1e35...29b587bbc7.png

What next? What the sensible choice should have been long ago. The bare minimum repairs I can calculate would be £700-£1500 in used/refurbished parts (mostly the head, prices swing wildly from £200 to £1000 on ebay) + £700 for the mechanic in hours for replacing the head with accompanying parts. That's if nothing else comes up, which I already know isn't gonna happen due to a issue or two we had before the head cracked, plus who knows what might have gona faulty while the car's been sittings around different shops for like 3 years.

I've got the car back, will take a few pictures, can just hope maybe someone can find a better use, future for the car before I let it go for some breakers :speechless-smiley-7
I'm open to offers but who knows for how long. Just gotta remember to get back my number plate from DVLA, £80 just to do that privilege :speechless-smiley-4

What a journey, definetly defines me. Hope this is a fun read for the rest of you and if there's a lesson here, it's this: If there's an issue, actually have someone look into it part by part rather than by elimating the symptoms like I did, by only looking at that the diagnostics said is the next part having "wrong" readouts, rather than searching for the root making part have abnormal readouts. My lesson's also no diesels. Never again. Most likely just a coincidence but I've had my fun.

One thing I can say for certain is that Volvo's a part of me now. Caught whatever my parents had and their loyalness to Volvo. Back to the used car market with me.

this is the most common failiure for d5 engines . it is also possible for the same thing to happen to a petrol engine that has not had cambelt changes so dont ig nore volvo diesels just keep up with the recomended services aux belt tensioners cam belt ect a well maintained volvo d5 can do 500k im on 245k and counting . good luck for the future.

If it's such a common failure then why are there mostly diesel Volvos around? This is the first time me or anyone else I know has really faced with a cracked Volvo head.

Throughout my family, relatives and friends we've all in 40 years collectively had at least 20+ Volvos and never had anything this serious happen. The most repairs that were ever needed was grandfathers T V70 that had an ABS or traction control module fail, just had to have that replaced, my friends D XC70 had both rear bushings broken that needed replacing and another one's D 1.8L had a broken turbo. Don't forget about mine.
Then again diesels have been in the minority. Out of the 3/20+ cars that had repairs, 3/4 are diesels the rest have just need general maintinance.

Still on the fence of ever looking at a diesel, just looking at the history within my close circle of people.

trust me this is a well documented thing check the forum to find posts on cambelt failiure poor maintainance will kill any engine in time.

I think Simmy is referring to the aux belt failure, which then becomes entangled with the cambelt. I believe this is what happened to your car? So it's not surprising the damage you have seen in your head - the forces inside an engine are huge and when valves collide with pistons this is an unsurprising result. The aux belt failure on the D5 is the most common reason one will be "written off". But it's a known issue which can be prevented using the correct Volvo parts and service schedule. Other than that, a D5 engine will go on almost indefinitely.

Is INA making parts for aux set for D5?

I was given to understand that Volvo had a protective guard to minimise the danger. It was some form of hard plastic and fitted behind the drive pulley but I don't know if it became a standard fitment or if it was just an option that a nervous owner could have fitted.

Yes, the alternator belt failed and part of it got stuck within the timing belt causing the engine to halt. Nothing made a part break then but clearly weakened the head till it cracked later down the line.

About the pistons and valves, is it true that there can't be more damage? Mechanic's said he does head replacements way too often for Volvo's, just wondering as he said the head along with arms needs replacing, plus checking that camshaft is all straight and well.

If the arms got smashed out of place isn't that a hit against the valves from the pistions? Then again, the compression readings came back as perfect as they could be so I guess the valves have to be working even as the engine is running and runs no more than 600~rpm.

There's working when the engine is stationary, and working at operating speed, two different things. I'm guessing you could have a scenario where the compression is fine for each cylinder at some point in its cycle, but that wouldn't necessarily be at the time it is needed, i.e. the timing isn't correct due to damage to the valve gear. I'd just accept the head at least is a write-off, although the rest of the engine should be fine if anecdotal evidence is anything to go by. But if the car had other issues prior to this you've got to ask yourself if it's worth getting it repaired.

First 10'000 mile service since the rebuild
 

Hate to appear out of nowhere like the undead but I feel like I'm due a final update to my little saga of insanity to try and get my S80 repaired. We've got a bank holiday so I've got some spare time to write this up.

I've got the piece of paper for the things replaced somewhere, not on hand tho. I had the car repaired around August of 2022. Upfront bill was some £3333, soon after that the EGR valve also had to be replaced, a full transmission flush so add a bit more like. Car drives great. Sitting on the motorway I get some 50MPG which seems to be within expecation, did 0-60 in some 10~ seconds on **** tyres which seems to be also what I've seen on youtube other do. Engine's doing just fine at the moment. Wonderful I think.

Car sitting around idle for some 2 years in the open, next to a heavily polunating bush which makes everything stick on the car, grow algea due to the water it sucks up and then in the record breaking heatwave in direct sunlight did an incredible amount of damage. My wheels suffered the most, as the insides started flaking. Made the front windshield leaked as a factory error came up and many other very minor things that over the long term do add up. Still chasing these loose ends, slowly but surely.
If there is a takeaway, at least have the car under some shelters, protected from the rain, sun and pollen.

One of the main reasons for going ahead with the cars repairs was its sentimental value. There's a bit of spirit in it.
What I didn't expect was the mental strain it takes on you. I'm now hyper aware of anything my car does, the way it drives, changes gears, engine noise, smells and so on. Most of the time it's some other car making weird engine noises or a big diesel stink, thinking it's me before realising it's others but a bit unsettling. Handbrake, EGR valve and fuel pump failing have made me a bit paranoid, a horrible feeling when the engine cuts out while driving but then again, I'm unphased now. Already made friends with the AA breakdown guy, I'm one expensive breakdown insurance customer I guess :angel_smile:

If you have the money but not the emotional endurance and don't want to, I woudn't recommend fixing a 17 year just for the mental doubts in plants in you. Then again, I still see many new cars on the side of motorways (mainly Vauxhalls, Range Rovers and BMW's) but I've made my bed so it is what it is.

For August, my mechanic's given me a list of things that he wants to do before the next MOT, little things. Exhaust rubber gromits, engine underside screws, runnig light LED's, bushings, new tyres and so on. That's fine. I'm expecting still some £1000-2000 spending spree right before my MOT to sort out the little things. 4 wheel refurb will be £250, 2 new tyres like £120 a pop, that's already £490. When they said Volvo's are expensive cars they weren't lying.

https://i.gyazo.com/606c8bf27d9bf02c...d30f9cf8b4.png
https://i.gyazo.com/526540715aae7c08...2591e70975.jpg
And recently had the oppurtunity to do a 0-60 to see how well I do.
[YOUTUBE]https://www.youtube.com/watch?v=pmu3B_UkW34[/YOUTUBE]

Thank you all, what a long thread, both in terms of pages but time that's passed as well. Hope this was fun to read to some of you as well. This doesn't end here of course, time to dive into the loose ends, so here's to me breaking the 200k mile barrier and many more miles of smiles in my S80 :_: my project car I guess :tongwink:

TLDR: Bit the bullet, went ahead with the head repairs and things that have come up since I repaired the car in August, rough total of some £4000. Since the head repair, I've also replaced the EGR Valve, Fuel pump, resealed the windscreen and the repaired the handbrake. Still have a list of things to fix to get the my car back in ideal state, hopefully before my MOT due this August, currently I'm looking at £1-2k still that's needed, for new tyres, wheel refurbs and so on. Here's to 200k miles and more to go. :cool:

Glad to hear it (seems to be) behaving itself at last! :thumbs_up:

Many of the things you mentioned are things all high mileage (especially diseasel) cars need at some point or another so at least they should be "one-off expenses" certainly for a good few years at least.

Fingers crossed routine maintenance should keep it running for another 180k miles!