Nothing for ages, then three problems all in a day!
 

Well, I guess this has as much to do with the fact that my S90 has covered only 1000 miles in almost six months, but first the remote stopped working, and the spare was equally defunct.

So four new C1220 batteries later, and £12 the poorer, full remote locking and alarm setting is resumed. Important because locking the doors on the key does just that - but it doesn't set the alarm.

Then on a steamy hot day, the centre air vents were clearly decidedly asthmatic. Remembering what Dave had posted only last week I assumed I might have vacuum problems, so I checked all the vacuum lines under the bonnet. All seemed fine - and then all of a sudden the vents are working. At first I could hear them moving when I operated the switch, so some enthusiastic switching followed, and now they are silent but for a click as the flaps engage. I'm guessing / hoping that it was just lack of use had caused things to stick a bit. Time will tell I guess.

Then I noticed a curious chirruping sound when the engine was gently revved. Thinking that possibly either the aux belt or, more worryingly, something cam-belt-related was amiss I proceeded to strip off the plastic cam cover. And the noise went away!

Careful examination of the rearmost of the two pieces of the cam cover revealed very definite score marks on the inside face. There are a series of ribs moulded into the underside of the cover, just where the profile changes, presumably to provide some structural rigidity, and several of these ribs were very evidently worn down.

So I popped a couple of washers between the engine block and the cam cover, under the bolt holes, just enough to lift the cover clear of the belt. To make things easy for myself I superglued the washers to the underside of the cam cover.

The engine doth chirrup no more. Again, I wonder why it should suddenly be that after 25 years and 125,000 miles, the cam-belt plastic cover should suddenly decide to move just enough to catch on the cam-belt? Could that also be down to simple lack of use? Or could it be an early sign that the belt needs to be changed?

It did I suppose give me a chance to look at the cam-belt, water pump and idlers. It all looks fine, with (touch wood) no sign of any deterioration of the belt, or weeping from the pump. The idlers and tensioner are all silent. But now it has me thinking that perhaps I should change the belt anyway. It was last done 7 years and 50,000 miles ago, and as far as I'm able to find out, the interval is 70,000 miles or ten years, although not all the various reference sites agree. Some simply give it as 70,000 miles.

Anyway, at the end of all this, does anyone know how to access the air distribution flap so that I can squirt in a bit of silicone spray? And do you think it'd be wise to get the cam belt done? I'm still working from home, so the miles aren't going to go up much, and I'll be surprised if the car does more than another couple of thousand miles this side of Christmas.

Thoughts gentlemen welcomed as ever.

Jack

Ebay is a good place to buy button cells for remote fobs, i usually buy 10 at a time for a couple of quid tops (my digital vernier uses button cells as does my remote fobs for the cars) so hae 2 or 3 different types all in a cleaned Chines takeaway plastic tub in a handy drawer. Total cost, under a fiver - excluding the original contents of the takeaway tub!

I don't think i'd go to the lengths of contortionism needed to silicone spray the actuator flap servos on the heater box to be honest.

The problem is the rubber seals on the flaps stick to where they rest when there is no vacuum with the engine off.
My Rover is very prone to this as well for some reason but enthusiasstically changing the air direction sorts it as you found.

Once they're moving again then they'll stay moving until it'a laid up again. The Climate Control pack on my Rover is all pushbutton so periodically if i'm not using it, i start it up and run through all the buttons one by one checking that everything still moves. It also runs the A/C up which helps prevent leaks although i do need to renew the compressor clutch bearing - sounds like a jet engine when i run the A/C! :err:

Sounds like all your problems today have been due to lack of use including that engine cover moving out of shape. With the timing belt, when you looked at it was there a "shadow" of the pulley teeth on the outside of the belt? If so i'd certainly consider changing it soon.

https://autolablibertyville.com/wp-c...t-640x380.jpeg

That's the sort of thing i mean, you can see the "shadows" on the belt on the left pulley and what they eventually lead to on the right pulley. Obviously you need to assess whether it's just a faint "shadow" showing normal wear but good condition or heavier shadows like on the left - hopefully yours is nowhere near the right! :err:

Either way it's probably getting close to needing doing.

Thanks Dave. The cam belt looks way better than the one in your picture!

But now the problem with the air distributor flaps seems to be permanent. The air distribution won't change at all, no matter how many times I operate the switch.

At a guess it's either the vacuum control, or possibly the rotary switch itself that's faulty.

At present I can't get the heater switch panel out of the car - although Robert makes it look easy!

As the heater control is working would I be right in thinking that the vacuum side of things is probably OK? I've found the vacuum tubing in the engine bay and traced it back, and it all looks absolutely sound to me.

If I can't sort it myself I guess it'll be off to the local Volvo indy - luckily we do have a very good one just 15 miles up the road, Dyrdal's in York.

Cheers

Jack

That points somewhere else then Jack, if the heater control is definitely working there's a valve block that switches the vacuum to where it's needed. This has several vacuum solenoid valves on it, all electrically switched. The solder joints that connect these to the PCB often fail due to going dry.

https://i.postimg.cc/TwJrz5vp/IMG-20...-114737103.jpg

The valves are inside that goldy-coloured block about halfway up with the different coloured tubes coming out of it.

https://i.postimg.cc/tTzV70TT/IMG-20...233945-HDR.jpg

https://i.postimg.cc/ydXvBYSr/IMG-20...-141536495.jpg
There are at least 4 dry joints on that pic ^^^^^

https://i.postimg.cc/rmCq5Wvy/IMG-20...641244-HDR.jpg

A close-up of one of them ^^^^^

Time-wise, less than an hour to remove the glovebox and trim under the dash and the valve block. Diagnosis - spray with some IPA or contact cleaner, rub with an old toothbrush then rinse with the IPA/contact cleaner to see the dry joints. Heat each joint with a soldering iron, add a little fresh 60/40 tin/lead solder and then remove it with a solder sucker then resolder with fresh 60/40 tin/lead solder.
The original solder wasn't 60/40 tin/lead because of a new EU Directive in the late 80s, this outlawed certain types of solder in the workplace without specific ventilation so many manufacturers had to use a different solder that doesn't last. This continued because the Directive was never revoked and the ventilation kit wasn't put in place as there were alternative solders.

Now these alternative solders are failiing with age.

Thanks Dave

You are 100% correct.

I found that by rocking the connector block (yellow in your pic, green on my car), the flaps would work. So for a temporary fix I found that tying a cable-tie around the connector block and around the body of the solenoid holds the connector firmly in place, and everything works perfectly.

At the weekend, when I have a bit more time I'll have a closer look to see if I can spot any dry joints.

It is very easy to access, and it's even tempting to see if I can track down a spare one, to have just in case.

Once again, I'm amazed at the detail of your knowledge!

Thanks

Cheers

Jack