Chris1Roll's return to 700 ownership

[Chris1Roll]

Its been a while, the last one I had was in 2007, back when you could buy them for £225 with a long MOT and 4 spare wheels in the back!

Having finally admitted after six months that I simply don't like the way my C70 convertible drives, my wife and I agreed I would get it through the MOT and sell it and return to what I originally wanted to do when I decided to give my company car back, which was to find an uncomplicated redblock engined saloon in decent condition to use and tinker with, which prior to Christmas seemed almost impossible without travelling hundreds of miles to look at rusty things.
Lying in bed one Sunday morning looking at my wifes facebook (I don't do 'the socials', and an '89 G reg 744GL appeared reasonably locally - 82k miles on the clock, looked fairly tidy, and a nice clean MOT history confirming the mileage, so we arranged to go and see it the next day after work.

(I've cropped out the sellers name etc)

I was determined not to mess this up, so I made myself a list of everything I wanted to check, everywhere I wanted to look for rust, everything I wanted to see.
I spent an hour going over the car, I lay down on the wet road to check the usual rust traps and it passed everything on my list, There was no rust in any of the usual structural places. The only faults of note I could find were already noted by the seller - the back box was rotted out, both rear lights were leaking, and one was cracked. There are a few dings that I reckon a decent paintless dent remover could fix.
Couple of minor things like the electric aerial doesn't work, a heat crack on the dash and its probably going to require some dedicated waxing to keep it red.
The car drove like something 1/4 of its age. I went back 5 years through service history and couldn't find any evidence of it [edit - It being the cambelt] having been done so managed to knock a bit off for that and the exhaust, did the deal and set off for home, me in the C70 and my wife in the 740.
I literally said to my wife, "We'll get it home, park it up and do the belt and exhaust before it moves again".



Should have kept my mouth shut

I was so embarrassed I didn't tell anyone for 2 days until I had time to a) calm down, and b) investigate what had happened.



Somehow, the crank managed to do about 320 degrees independent of the cam, got round to the point where it created enough compression to fire, and kept running!

I was pretty sure that the Kjet motors were interference, but found conflicting opinions on this both here and on other forums. My last experience of a cambelt snap (on a diesel S40) resulted in a s/h head going on as the valve guides were mangled, so I was contemplating a head or even a whole engine going into it, but a post on the 'cambelt horror stories' thread over on the 200 forum persuaded me to throw a belt on it to see, so a genuine belt and the crank tool (I can't be doing with jamming the ring gear these days!) was duly ordered.

***

In the meantime I spent some time going through the history file.
It's more of an adoption pack.
The car was originally a demonstrator for Fisher's of Buckland, with the first owner paying £11,200 for it in June '90 (less the part exchange of a Y reg Golf) and kept it for just shy of 30 years
There is a copy of the invoice, a copy of the cheque used to pay for it, a newspaper clipping about the salesman - a Mike Simmonds, - who sold the car. A copy of a completed questionaire about why the original owner chose the car and how they were getting on with it.
There is almost every old tax disc, a copy of every single MOT from when it was 3 years old, a file of correspondence with the servicing dealers and every single invoice.

A bit of research also turned up this!:
https://www.carandclassic.com/magazi...989-volvo-740/
As well as a twitter thread from a previous owner where (on the bit I could see without a login) it sounds like the car very very narrowly avoided being banger raced before he rescued it. I won't link to that, I have reached out to him and wil give him a link to this thread if he is interested he might pop up here.

The oil has been changed every six months without fail, right up until a few months ago. Sadly, for some reason they stopped changing the cambelt in 2008??

***

So back to the cambelt, the tool and belt arrived, so yesterday evening I set about putting it on.
First I pulled off the camshaft sprocket to make sure the key hadn't been sheared - all good there.
Next I spent some time cleaning all the bits of old belt out from between the teeth, and checked the harmonic balance damper thingy hadn't spun - all good there (so the crank MUST have done 320deg, to end up ~40deg behind the cam!)
After all that the belt was refitted, checking It was definitely at for TDC for Cyl1 by looking in through the plug hole, and checking the cam lobes were obliquely up through the oil cap. Using the marks on the volvo belt I ensured the intermediate sprocket was timed, even though that doesn't actually matter on these, and then, after having spun it over by hand a few times there was nothing for it but to stick the plugs back in, hook up the battery and turn the key.

[YOUTUBE]https://youtu.be/f9SxQUIQd8I[/YOUTUBE]

This is actually two videos smooshed together - the first start was with no other belts on, as I thought it would be immediately obvious if there was a cylinder with no compression.
The second part is once I had put the alt/water pump belts back on, run it up to temperature and adjusted the idle speed back down (aa guy had wound it up to keep it going so it could be driven about a mile to a layby so he could safely load it up - it hadn't broken down in a nice location)

As you can see, it starts easily, idles smoothly, and revs up cleanly on all four cylinders.
So why am I not jumping up and down? Well there is a slight metallinc clinking that you can hear in the last few seconds of the above video that I have convinced myself wasn't there before. That said, looking at the sale video I found, I can't hear a difference! Obviously I have over-sensitised myself to listening for bad noises from it, and if it had bent a valve, how is it running so well?
I can't test drive it as it is currently uninsured and SORN. so idling and revving (not too hard) in neutral is all I can do for now.

My plan now is to do a compression test next, If that comes out OK then off with the valve cover to check the clearances - if none of them are massive then work out the shims I need and do them and declare it golden. If anything looks off, then its 'Off with her head!' I want to be certain the engine isn't going to grenade itself before I get rid of the C70.

A decent Gunson compression tester is on it's way (decided against a cheapy one as I know I simply wouldn't trust it if it said everything was A-OK - found a review of one where every engine the put it on, it sad exactly the same) along with some new feeler guages to replace my rusty ones.

Before it goes on the road there are a few other bits of tinkering I want to do - replace the rear timing cover, the noisy cambelt tensioner, all the V belts, flush the coolant and change the oil+filter (pretty sure its got/had fuel in it from the timing being so far out)

So that's the story so far. Not quite as planned, but I'm still really pleased with it!

[Othen]

What a good result!
You may recall we had a chat about this in the 200 section at the time you had convinced yourself that you would need a new motor. The consensus was that red blocks are pretty tough and it would be worthwhile just trying a new belt. I'm absolutely delighted that has worked out well.

Alan (from the 200 section).

PS. The motor sounds fine in the YouTube video. Checking the valve shims is a good idea though.

[Chris1Roll]

And you and the others were quite right Othen - I must admit to catastrophising a bit, but we haven't had much luck with cars this year - in the previous 24 years of driving we've suffered 1 breakdown.
We've broken down 2 times in the past 3 months.
That and having paid a not insubstantial sum in January to have the autobox in my wifes V70XC professionally rebuilt, they managed to fix the original fault but introduce a severe torque converter shudder for which it has been back 3 times so far and still isn't right.

Here's hoping this "proper volvo" will be an end to the woe!

[Laird Scooby]

Originally Posted by Chris1Roll

Before it goes on the road there are a few other bits of tinkering I want to do - replace the rear timing cover, the noisy cambelt tensioner, all the V belts, flush the coolant and change the oil+filter (pretty sure its got/had fuel in it from the timing being so far out)

So that's the story so far. Not quite as planned, but I'm still really pleased with it!

I think you've found the cause of the timing belt failure! ^^^^^ Could also cause the crank to jump and/or the cam itself.

Originally Posted by Chris1Roll

And you and the others were quite right Othen - I must admit to catastrophising a bit, but we haven't had much luck with cars this year - in the previous 24 years of driving we've suffered 1 breakdown.
We've broken down 2 times in the past 3 months.
That and having paid a not insubstantial sum in January to have the autobox in my wifes V70XC professionally rebuilt, they managed to fix the original fault but introduce a severe torque converter shudder for which it has been back 3 times so far and still isn't right.

Here's hoping this "proper volvo" will be an end to the woe!

What ATF was used in the XC70? Worth finding out as it may be too thin for the AW box i suspect is in there. You may have to change your own ATF in it to fix the TC problem.

[Othen]

Originally Posted by Chris1Roll

And you and the others were quite right Othen - I must admit to catastrophising a bit, but we haven't had much luck with cars this year - in the previous 24 years of driving we've suffered 1 breakdown.
We've broken down 2 times in the past 3 months.
That and having paid a not insubstantial sum in January to have the autobox in my wifes V70XC professionally rebuilt, they managed to fix the original fault but introduce a severe torque converter shudder for which it has been back 3 times so far and still isn't right.

Here's hoping this "proper volvo" will be an end to the woe!

Most of us 200 series chaps are simple country folk that don't understand anything made after 1990.

Dave makes a good point about your squeaky tensioner - it could have had a hand in the demise of your cam belt. They don't often fail, but they are cheap, so it would be worthwhile changing it whilst doing the other work.

If you are going to check the valve clearances it would be worth changing the hushers at the same time, that should make your motor a bit quieter.

Good fortune,



PS. I think testing the compression is a good idea (but then I'm a bit of a closet 2 stroke type of bloke (motorcycles and jet skis), so I probably would say that). In my experience cheap compression testers are perfectly good: they are really simple and last decades; no matter though, if you have already ordered an expensive one it will work just as well.

[Chris1Roll]

It was only raining a little bit this morning, and my compression tester (I wouldn't save it was especially expensive -it cost £40 rather than £15 - but the braided hose still spun in the fitting and I had to uses some pliers to remove it from the engine.. I wouldn't want to thread it into a twin cam engine.) and new feeler gauges had arrived yesterday, so I set about my investigations.

First I started the car up and ran it up to temperature at idle - It was a little lumpy when cold - then shut it off and removed all the spark plugs.
Removed fuses 1 and 11 (Main pump/ignition and in-tank pump), hooked the battery up to the C70 on some jump leads to make sure that was consistent, screwed the tester into No1 cylinder, held the throttle wide open and turned the key.
Nothing.
After a few moments of confusion, and checking which fuses I had removed, I put the gearshift back into P and tried again - at least I know the interlock works now.

Try again, throttle wide open, and cranked until the reading stabilised
No1 - 170
No2 - 195
No3 - 155-170 (was inconsistent over a few attempts)
No4 - 195


I'd have been happy with 170 across all, but apparently it can achieve 195 (which seems high to be honest, but the engine does only have 82k on it?)
I did each cylinder in turn again to be sure (and a few more on number three) with the same results.
13% lower on 1 and sometimes more on 3; I don't think that is quite what I was hoping for.

Then it started to rain so I went and hid in the shed for a bit while deciding to carry on and check the valve clearances.

By the time I got to this the engine had been cooling off for probably 3 hours. I can do it again one evening so it's definitely cold but really its the differences I'm looking at. (my gauges only go up in 0.05 increments, I should have checked that when ordering..)

1E 0.35
1I 0.5

2E 0.4
2I 0.45

3E 0.35
3I 0.5

4E 0.35
4I 0.45

Is the fact that the inlet valve clearances are bigger and out of tolerance even for a warm engine let alone cold, on the same cylinders that have the lower compression of any significance, given that the inlet valves are larger and in theory more likely to get tweaked by the dome on the top of the B200e pistons?

[Laird Scooby]

Have you tried the teaspoon of oil down the plug hole of #3 to see if the compression came up at all?

Might be worth investing in a cheap boroscope (usually abut a tenner, plug into a laptop/tablet/phone) to poke into the plug hole and see if there's anything obviously out of place.

Not sure i understand what you've said about the valve clearances, i can see the correlation but the larger clearances correspond to the higher compression which is what i would expect.

Would i be right in assuming that all plugs were out for the test and only the tester was screwed in to the relevant plug hole for each test?

Nearly forgot - did you remove the hushers before checking the valve clearances? As many will tell you on here, they can cause false clearances to be ecorded if left in place.

[360beast]

Originally Posted by Laird Scooby

Have you tried the teaspoon of oil down the plug hole of #3 to see if the compression came up at all?

Might be worth investing in a cheap boroscope (usually abut a tenner, plug into a laptop/tablet/phone) to poke into the plug hole and see if there's anything obviously out of place.

Not sure i understand what you've said about the valve clearances, i can see the correlation but the larger clearances correspond to the higher compression which is what i would expect.

Would i be right in assuming that all plugs were out for the test and only the tester was screwed in to the relevant plug hole for each test?

Nearly forgot - did you remove the hushers before checking the valve clearances? As many will tell you on here, they can cause false clearances to be ecorded if left in place.

The hushers don't last long so on an 80k mile engine they will be completely disintegrated and have no effect on the shim gaps, plus you would have to remove the camshaft to remove them.

[Chris1Roll]

Originally Posted by Laird Scooby

Have you tried the teaspoon of oil down the plug hole of #3 to see if the compression came up at all?

No I haven't. Its raining steadily now but it won't take long to do one eve.

Originally Posted by Laird Scooby

Might be worth investing in a cheap boroscope (usually abut a tenner, plug into a laptop/tablet/phone) to poke into the plug hole and see if there's anything obviously out of place.

I was looking at them the other week. The really cheap ones seem to have pretty poor reviews and the ones that seem better are more than a head gasket set from swedespeed or brookhouse. I've got to pop into my trusted local mechanic (I actually do trust him to work on my cars if there is something I cant get at or have time for, should have taken the hint when he said he didn't get involved with autos!) tomorrow to book the C70 in for its MOT so i'll ask if he has one.

Originally Posted by Laird Scooby

Not sure i understand what you've said about the valve clearances, i can see the correlation but the larger clearances correspond to the higher compression which is what i would expect.

My thinking is that if a valve is very slightly bent - just enough to lower compression, then it won't be seating properly, so will sit fractionally lower than before and the clearance between the shim and the cam will be larger. The largest clearances I have measured are on the inlet valves on cylinders 1 and 3 at 0.50mm which are the ones with the lower compression.

Originally Posted by Laird Scooby

Would i be right in assuming that all plugs were out for the test and only the tester was screwed in to the relevant plug hole for each test?

Nearly forgot - did you remove the hushers before checking the valve clearances? As many will tell you on here, they can cause false clearances to be ecorded if left in place.

Correct, all plugs out, just tester in place each time.

No, I didn't remove the hushers. As 360beast says, you have to take the cam out for that?

[Chris1Roll]

Originally Posted by Laird Scooby

What ATF was used in the XC70? Worth finding out as it may be too thin for the AW box i suspect is in there. You may have to change your own ATF in it to fix the TC problem.

That was a thought that had occurred to me. I did put a bottle of lubeguard platinum in to see, but no change.
I do have 16litres of JWS3309 from when I was attempting repeated changes, the interval between which got shorter and shorter before it played up again.
I need to be careful that they don't think I have 'tampered' with it at all - all the bolts including the drain are painted over in silver at the moment- so as to keep the warranty, but TBH at this point it's got so stressful that Mrs1roll would be happy to just walk away from it. Latest was they said the viscous coupling was causing it. That night I took the prop off and now we have a 2wd car with a shuddering TC .
Bizarrely I have driven it for a week in manual mode and it's been fine. My wife went 10 miles in D and it shuddered quite a few times.


By contrast we're not remotely stressed about the 700 on the basis that it's pleasant to work on and I know I can fix it!