cambelt calamity

[RollingThunder]

First off, Hi everyone. I've been away for a while as I sold my old V70R a few years back but have now bought a nice '97 S70 T5 manual :) This is a long intro, but please bear with me ...

Its been stood a while, and neglected mechanically despite being polished to within an inch of its life, so I've been doing the usual Stage 0 stuff - replacing all the coolant hoses, vacuum hoses, plugs, HT leads (originals still fitted after 23 years!) etc etc etc culminating in changing the cambelt, tensioner, idler, waterpump etc.

I've done 3 cambelt swaps on T5s before, and all went without issue... which is a dangerous thing as I felt (over?) confident in doing it this time. This car is going to be a long term keeper (I regretted selling my 850R auto a few years back, and this is nigh on the same car being a pre-ME7, but with a more compliant ride and a manual gearbox). So I decided to check the cam seals as well - belt & braces - but something I've never done before. I removed the sprockets and only after pulling them off the camshafts did I notice the elongated slots :( And then they moved a touch, presumably due to valve spring pressure - I'd taken the belt off of course. Usually I use a cam locking tool when doing a belt change - but this had also been removed to allow the sprockets to come off...

So, with the cams having moved, I quickly researched getting them set by aligning the slots at the back of the cams. As I don't have the correct tool, I did it visually - they seemed fine after a minute adjustment. So with everything apparently set up correctly and the new belt etc in place, I turned the engine over by hand - no resistance felt through three complete rotations, so I thought I'd dodged the bullet...

After doing some other stuff I finally tried starting it up. It fired up on the button, but sounded like a diesel, so I killed it pretty quickly. I'm hoping that no damage has been done as I was able to turn the engine over easily ??? I've now ordered a genuine Volvo camshaft alignment tool from Skandix which is due in a few days time. Once I've timed everything up again with that, I'm going to fire it up and then do a compression test if it runs ok. I'm assuming that this would show damage such as bent valves as the cylinders wouldn't hold pressure? I'll be looking for something over 140 psi as indicating an acceptable seal - do you think this is reasonable?

Finally, if - IF - the compression test shows up some bent valves, would I get away with just pulling the head and changing them? The contact must have been minimal so I can't see the head itself being damaged? Or am I missing something? I've read elsewhere that the head is a scrapper once the valve have been bent, but I assume this is only if the cambelt has snapped at high rpm breaking the valve heads off and causing damage that way?

Thanks in advance for your patience in reading this far, and for any advice you could offer. I'm still in utter disbelief at what an utter plank I've been. :dunce:

[kmb]

Hope you get away with it, logically thinking there should be enough clearance if the alignment was very minor, keep us posted!

[Dangerous Dave]

If there was no interference when you rotated the engine the you're probably going to be ok as there is some clearance with the valves anyway. The elongated holes allow for the cam timing to be adjusted (for some reason Volvo designed it that way) so a movement in either direction wouldn't cause many problems (not rough running anyway).

When you did the alignment did you set the crank to the right position using the notches on the crankshaft sprocket (the one the cambelt goes around on the crank)?

But before all that you said you did some other stuff, have you messed with any of the spark plugs or HT leads/distributor cap (after doing the cambelt)?

[RollingThunder]

Hi DD, a blast from the past, I remember you :beer:

Yes, the crank was perfectly set - it was my OCD tendancy that made me check the cam seals this time. Must learn to keep that in check!

I've done pretty much a full stage 0, so all vacuum hoses replaced with 5mm ID silicon (checked for correct TCV connections 3 times lol), new Pierburg TCV, new Bougicord HT leads, Volvo plugs, Do88 coolant & heater hoses, new coolant reservoir, heater hose PCV mod (using 5/8" heater hose) with all new PCV hoses/box, new Volvo dizzy cap & rotor arm, Volvo timing belt kit, Volvo waterpump, Aisin belt tensioner, Continental aux belt, Volvo coolant temp sensor... ie pretty much everything on the engine has renewed over the last few weeks - costing just over £1k so far :nut:

[Dangerous Dave]

Indeed buddy, it has been a while :D :D

So did you change the plug leads after the cam belt?

[RollingThunder]

The car last ran about 3 weeks ago - all the jobs have been done one after the other over the last 3 weekends.

I think I know where you're going with this - the engine didn't jump around as if the firing order was incorrect, plus I removed the old leads while they were still connected to the old dizzy cap, and replicated the connections when fitting the new leads to the new cap. So they *should* be correct. But I'll check tonight anyway lol

[Dangerous Dave]

Yeah check just to be sure.

But I've re-read your original post and of course you said it sounded like a diesel. Was it really tappety? (if that's even a word lol)

As for the compression test mine is usually around 11bar (160psi) but remember the test is usually done with a warm engine and the throttle open. Main thing is to get the same(ish) readings across all the cylinders.

[RollingThunder]

Thanks Dave.

I've just checked the HT lead connections to the dizzy cap and they look ok. Damn, if only it was as simple as that lol.

[craigoodwood]

I've done my cambelt recently but I had my engine out at the time, I didn't use a locking tool but put my own marks on the pulleys, I musta turned it 20 times 'to make sure' my marks appeared to keep moving in the end I used the volvo marks on each pulley and they all came right every time so I left it at that ��

[RollingThunder]

Had a text saying the camshaft timing tool will be delivered today, so I'll get it timed up properly tonight and we'll take it from there. Fingers, toes, eyes etc crossed... !

[Dangerous Dave]

Waiting on tenterhooks for the result :)

[MoleT-5R]

I did see your post on the FB channels Rolling Thunder, I hope with DD'S and Shem's advice and your new cam locking tool you are easily able to sort the issue, I'd not ever thought of slackening the cam wheels whilst doing a belt change as Shem mentioned, but if doing the cam seals it's unavoidable, hope your sorted soon.

[RollingThunder]

Well the tool arrived at 16:00 yesterday... and then I had an issue at work so I ended up working late :(

I'm also on extended hours today and tomorrow to cover Clearing (I'm in IT in a university) so realistically it'll be Saturday before I get a chance to look at it properly - I don't want to rush it!!!

I'm hoping that I won't need to strip it all down, but I've priced up the parts 'just in case' - I'm looking at around the £350-500 mark for parts depending upon how many valves are stuffed. I feel a bit better now - I've watched RobertDIY's videos on head replacement & overhaul and it doesn't seem too bad a job. I was expecting to have to send it away to be done (at a cost of £1-2k) but if I can do it for £500, happy days! (I'm usually pretty good at this kind of thing - this is the first major ££££ up in 30+ years of working on cars. OCD is usually a good thing as I check everything so many times lol).

On the positive side, the missus has been very understanding. She was somewhat less than that when I told her I'd possibly written off half the engine, but having explained it all including going through the suck-squeeze-bang-fart cycle she's become quite supportive. I suspect she has added a few items to the 'jobs to be done around the house' list though :D

[MoleT-5R]

I'm pretty sure that once it's all timed back up correctly it will be fine, it wouldn't need to be far out to run sounding like a diesel and as you said it was fully rotated a good few times to check for any resistance, just would scare the crap out of you when you turned the key. Good to see you back here and look forward to the update when you get a chance to look at it again at the weekend.

[RollingThunder]

Well its not good news.


https://youtu.be/HDRVZv0DjW4

I've done a compression test - cyls 1-4 are ok, showing 190+ psi (it needs calibrating?!) but cyl 5 was 170psi and leaking down :( Looks like cyl 5 valves are bent

[RollingThunder]

Just a quick update to this. Shem didn't get back to me with a price so I'm doing it myself - I have the correct cam alignment tool now afterall! :)

I'm currently waiting on parts - I've bought them from various suppliers including one in the US, so I won't be in a position to start until mid September most likely. Current spend is about £260 IIRC, that includes the head gasket kit, the anaerobic sealant and roller kit, a torque-angle gauge, new gasket scrapers, etc but doesn't include any head bolts or valves - I obviously need to see how many valves I need. I *believe* (hope!) it'll be just 1 or 2...

The next bill will be for cleaning/checking the head itself - I have a local place that will cost me around £50 to vapour clean both halves of the head. I might ask them to do the intake manifold as well, just so that it all looks nice and clean when reassembled.

I've also got a spare set of injectors that should be nice and clean having been run on Shell V-Power for a few years. They should stop the injector ticking noise. I've also decided that I will clean the hydraulic tappets as they were quite noisy when the engine was running pre-cambelt calamity.

To be honest, following my initial horror I'm now quite looking forward to doing it. Its been a while since I've been this deep into an engine - I've rebuilt the top end of a few redblocks but have never seen the inside of a whiteblock head. Hopefully, it'll run more sweetly afterwards!

[Dangerous Dave]

Oh dear not good then.

The good news is you'll have a reconditioned head with new stem seals. You could probably do the pcv system whilst the head is off too.

[RollingThunder]

I haven't updated this in a while, but a lot has happened :)

I had a long think about the engine, and concluded that if the compressions were still good, then the valves can't be bent - the compression in the suspect cylinder wouldn't be over 100 psi with a bent valve would it??? So I checked the compressions again, and the results were pretty much the same as the original figures. Over 190psi on cylinders 1-4, and 170psi in the suspect cylinder. So I'm now assuming the valves are all ok, just that they could do with being ground/reseated on cylinder 5...

The noise that I could hear was very tappety, so I guessed that the car had been stood for a while before I bought it. As the garage that I bought it from did an oil change before I got it, I couldn't tell what state it was in, but judging by the rest of the engine bay, I'd say it had been mechanically neglected - so cheap oil and changed once a year? Maybe? Which *could* account for the tappets sticking badly??? Lots of assumptions, but I decided to stick some snake oil 'hydraulic tappet treatment' into the oil. I took the car out for a 30 min drive to thoroughly warm up the oil, then added the treatment and drove it back home. It actually sounded much better even then, but when I started it up again the following day, it sounded MUCH better! I really didn't want to open the engine up as I'd be working on the driveway - the last thing I want is to allow some grit to get inside the engine, hence my decision to exhaust all other options first ;) In fact the engine itself sounds quite smooth now - the most noise is coming from the injectors lol.

So thats the saga of the cambelt change finally put to rest. I've also replaced the main brake servo hose which runs from the servo all around to the manifold, as it was past its best. This has restored some brake assistance, but the brakes are still not as good as I'd like, so I need to investigate those more thoroughly.

The 17x7.5 Comets look great on the car, but the tyres have been catching the arch liners on full lock. As the roads around here are going from bad to atrocious, I decided to fit some 16 inch wheels - originally I was looking for the 16 inch version of the Comet, but when a set of 16in Satellites came up for sale, I had to have them :)

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This wheel is in good condition, but the others are ragged and have kerbing scars, so they're going to be refurbished -they should be ready at the end of next week. I'm getting a small discount as I'm waiting for another set to go into the workshop so that they can do them together as a batch. They're being done in 'shadow chrome' which should compliment the coral red paintwork without looking too garish. Hopefully! I've also bought a set of new tyres to go on them - I've gone for some 'all season' tyres this time. Hankook Kinergy 4S2 which are highly rated by tyrereviews.co.uk

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I've stripped down and cleaned the contacts in the driver's seat switchpack as I couldn't move the seat in some directions (but the memory switches proved that the motors were ok), so I now have full control restored. It was a straightforward job in the end, just cleaning the contact faces in each switch -

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I've also replaced a front door speaker which wasn't working - courtesy of a £10 ebay find :) To celebrate the new stereo sound, I fitted an old Blaupunkt DAB head unit and antenna -

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I have a more modern one with bluetooth handsfree connectivity which I'll swap into the S70 when it becomes the daily driver, but for now this old unit is fine and allows me to check the antenna is working ok.

I've done many other minor jobs not worth mentioning, but the car is now almost there! I still need the injector seals, and I've ordered some new boot struts as the ones on the car at the moment are probably the originals and are very weak. They're due today, so hopefully I'll get a chance to fit them over the weekend.

[Dangerous Dave]

Glad to hear it is working better for you now.

I've just listened to the video you posted above and it sounded like a sticking lifter. If the valves were bent it would have been idling a lot lumpier than that.

Go forth and enjoy now :D

[RollingThunder]

I've been using the S70 as the daily driver for a week or so now, and while a few more issues have popped up, its turning into a lovely car - very smooth and compliant ride, but still steers very directly and is great fun to drive.

The boot struts that I ordered were replaced by the supplier with their own brand (without notification or financial adjustment) and my complaints have been completely ignored, so I won't be using them again (for info, its a German company that trades under various names including AutoDoc, OnlineCarParts etc ). They've been doing this quite a lot recently according to other marque owner forum posts I've googled.

I've found the reversing lights don't work, but the bulbs are ok, so I need to pull the airbox out again to see if its a broken wire or the switch that needs to be replaced. I've bought a pair of LED bulbs to use instead as our gateposts are barely visible at night and I've already nearly reversed into them :(

The front interior light doesn't work and the console itself is damaged, so I've bought a replacement off ebay which is due soon.

Oh yes, the refurbished wheels and new tyres have been fitted :)

http://www.duckfieldengineering.com/forums/voc/S70/photoshoot1.jpg

http://www.duckfieldengineering.com/forums/voc/S70/photoshoot2.jpg

http://www.duckfieldengineering.com/forums/voc/S70/photoshoot3.jpg

http://www.duckfieldengineering.com/forums/voc/S70/photoshoot4.jpg

http://www.duckfieldengineering.com/forums/voc/S70/photoshoot5.jpg

http://www.duckfieldengineering.com/forums/voc/S70/photoshoot6.jpg

I'm delighted with them - they look great (IMHO) and I'm relieved to say that the greater sidewall height hasn't impacted upon the direct steering response. I'm no track star, but I do appreciate good steering feedback, and these tyres are indeed very good to drive on. They're extra-load rated which helps - they'll have stiffer sidewalls than the non XL rated version I guess.

I've also replaced the only rotating component that I didn't replace when I did the cambelt - the aux belt tensioner. I had a strange engine speed related groan on the overrun that I struggled to find, as the tensioner sounded ok when I rotated it, but as the sound seemed to be coming from that end of the engine I decided to swap it out... and viola! Noise issue sorted :) A lucky diagnosis really, but I'm glad thats all it was.

As usual, it was a case of one step forwards, two back lol. The oil dipstick handle decided to snap off the dipstick, so I need to replace that ideally - but its a NLA part and I need to buy a matching pair of revised dipstick & tube now... But I'm going to try and glue the handle onto the dipstick first. You never know, it might work...

So today I'm going to crack on and check that reversing light switch, fit the LED bulbs and fix the dipstick - then I'm off to help my parents again. They seem to like it - they're already calling it 'the limo' :)