My new 740!

[rogerthechorister]

I had a small petrol generator with old petrol gumming up the carb. I stripped the carb completely and then used an ordinary jetwash on the carb body. I put it all back together and she started first time, and the hunting was gone too. But do NOT jetwash your fingers!

[swedish brick]

Lovely weather this weekend so I did couple of little jobs on the 740, then took it out for a run in the glorious British countryside.

First job was to fix the passenger front wiper arm.
This had come loose from the drive spindle and had been fixed poorly before so I removed the crap previous attempt and found a new 13mm nut with combined washer head. This was fitted with a shake proof 'star' washer and wound on nice and tight. It's done the job and looking at it you'd never know so I'll have that as a win!

Next up was the crankcase breather flame trap.
Knowing these 740's and my previous 244 with these red block engines I know these are notorious for blocking up causing the system to over pressure.
On my old 740 saloon it caused the rocker cover gasket and oil filler cap seal to leak and blow oil residue out. It also caused the dip stick to pop out of its tube when the engine was revved!
This car however had none of those symptoms but there is a tell tale oil splatter on the side of the engine block under the inlet manifold.
Having a look with a torch showed that the two halves of the flame trap casing were separated from each other! This meant the breather system was no longer sealed and just vented into the engine bay causing oil residue to blow out onto the side of the engine block and drip down onto the road under the car. Not good, especially for motorcyclists!
Disconnecting various pipes and wires, then removing the idle valve to get a bit of room to work in meant I could pull the flame trap unit out revealing the reason why it had separated itself.


Here's the top half of the flame trap, caked in oil sludge and the original brass gauze style flame trap. Holding this up in the light showed it to be fully gummed solid so it couldn't 'breathe' anymore. The pressure from the crankcase obviously built up and just blew the two halves apart! The new flame trap is next to the old one, they're plastic now but do the same thing.


Old bits to be reused were cleaned up in degreaser and any hard baked on crud scraped off. The bottom half and oil catch pan sections were also cleaned up but weren't all that bad once given a wipe off with a degreaser soaked rag.


It's not easy to see the flame trap parts for reassembly but you can just make out the bottom half of the round black plastic holder in this pic beneath the inlet manifold.
It's an awkward little job but well worth doing now and again just to help the car run as it should and prevent oil leaks.

Last little job was a bit unexpected to be honest.
After completing the other jobs I put some stuff away in the glovebox, closed the glovebox lid and the front beige trim panel fell off!
It appears that the old glue holding it on had dried out let go so I've cleaned it all up and stuck it back on with some heavy duty double sided foam trim tape. It's meant for sticking plastic trims and badges on so should do the job.

[swedish brick]

Finally, I took it out for a drive.
It's done about 200 miles since going back on the road and other than the wiper arm problem it's been fine.
I want to keep using it as much as possible though just to see if anything else breaks or starts causing trouble, hopefully with use anything like that will show itself sooner rather than later. All seems fine so far though.





It's a good looking car though! The colour is just lovely in the sunshine too.

[Laird Scooby]

Originally Posted by swedish brick

Lovely weather this weekend so I did couple of little jobs on the 740, then took it out for a run in the glorious British countryside.

Next up was the crankcase breather flame trap.
Knowing these 740's and my previous 244 with these red block engines I know these are notorious for blocking up causing the system to over pressure.
On my old 740 saloon it caused the rocker cover gasket and oil filler cap seal to leak and blow oil residue out. It also caused the dip stick to pop out of its tube when the engine was revved!
This car however had none of those symptoms but there is a tell tale oil splatter on the side of the engine block under the inlet manifold.
Having a look with a torch showed that the two halves of the flame trap casing were separated from each other! This meant the breather system was no longer sealed and just vented into the engine bay causing oil residue to blow out onto the side of the engine block and drip down onto the road under the car.


Here's the top half of the flame trap, caked in oil sludge and the original brass gauze style flame trap. Holding this up in the light showed it to be fully gunned solid so it couldn't 'breathe' anymore. The pressure from the crankcase obviously built up and just blew the two halves apart! The new flame trap is next to the old one, they're plastic now but do the same thing.


Old bits to be reused were cleaned up in degreaser and any hard baked on crud scraped off. The bottom half and oil catch pan sections were also cleaned up but weren't all that bad once given a wipe off with a degreaser soaked rag.



It's not easy to see the flame trap parts for reassembly but you can just make out the bottom half of the round black plastic holder in this pic beneath the inlet manifold.
It's an awkward little job but well worth doing now and again just to help the car run as it should and prevent oil leaks.

Great work on the flame trap! I didn't realise the inserts were available at the time i did mine so i meticulously cleaned the "gauze" using various tiny screwdrivers, drill bits etc.

When i refitted it i extended the hoses to raise the level of the trap to reduce the risk of further oil fouling :



I think Volvo did a similar mod themselves to certain models but it worked well for me and means it's almost a "fit and forget" item after as the oil runs down the inside of the hose but the vapours still get drawn through the flame trap itself.

[swedish brick]

Good idea moving the whole thing, it's a real pain to get to under the manifold.
I might do that next time it needs cleaning out. I've got some heater hose somewhere that should be ok for extending it enough.

[stephend]

+1

In fact, I would have said it wasn't accessible with the manifold in place: I did mine when I did the head gasket, and the manifold was off anyway. So I'm impressed you managed it, swedish brick!

And I too may copy m'Laird Scooby's clever modification.

[Laird Scooby]

Thanks, it's a well worthwhile mod!

You can see the rocker cover has a film of oily dust (or should that be dusty oil?) on it where it was breathing heavy and blowing out the filler cap.
I cleaned it just after doing the mod and it remained clean during the rest of my ownership including when i used it to tow my 827 Coupé back from Bristol (or as they call it in tham thar partz, Brissle) and the good old B230E had to do some hard work dragging 2.1T of trailer and Rover down dale and up hills.

Worst bit was coming through Milton Keynes, as you exit one roundabout the sat-nav says "in 1/4 mile go straight on at the next roundabout". The distance varied but sometimes it felt as if the trailer was still on the previous roundabout while negotiating the next!

Really gave the poor old beast a workout but the rocker cover stayed clean!

[swedish brick]

Originally Posted by stephend

+1

In fact, I would have said it wasn't accessible with the manifold in place: I did mine when I did the head gasket, and the manifold was off anyway. So I'm impressed you managed it, swedish brick!

And I too may copy m'Laird Scooby's clever modification.

Yeah, it wasn't a hard job but just fiddly and frustrating as I had to do it mainly by feel and only one hand will fit through the gap! You can't see anything really except through a thin gap between the manifold sections.
It took me ages on my old B230E saloon as before that I had a B21A 244 which was really easy to do!
I knew how best to do it on this car though from the saloon one! Still well worth moving the whole thing though as it's not easy at all.
My backs aching now too from squatting and leaning over the front of the car.

In other news I've found the cars radio cassette code, entered it and the radio came back on. Only thing is it's not working!
It powers up, electric ariel works, all lights and display etc works, it even seeks for channels but it just makes an irritating electrical ticking noise from the speakers. No idea what's wrong with it?

[Laird Scooby]

Originally Posted by swedish brick

In other news I've found the cars radio cassette code, entered it and the radio came back on. Only thing is it's not working!
It powers up, electric ariel works, all lights and display etc works, it even seeks for channels but it just makes an irritating electrical ticking noise from the speakers. No idea what's wrong with it?

Have you checked the speakers? They may not be there or they may have rotted or perhaps the unit is still searching for a station and all you're hearing is static - the ticking could be side-band harmonics from the nearby emergency services or maybe even the Air Traffic Control up the A27 at Botley/Hedge End area.
Any number of possibilities really, have you tried it with a cassette instead to give it a known sound to play?

[swedish brick]

Could be the speakers, I've not checked them but I'd expect at least one to work? They can't all be knackered?
I'll try a cassette, assuming I can find one! Nobody uses them now and I'm sure I threw most of ours away!

The noise is almost like that static noise, or that sound on really old cars where you got interference from the distributor if you didn't use one of those special cap covers!
The radio seems to work as it should other than this, it has pre-sets which work and do change to channels and if you use the seek buttons it finds and sits on channels but there's just never any sound other than the constant ticking noise. It does this constantly as soon as you turn it on.
I don't think this is the cars original unit either. It might be a 940 stereo?
Edit; it's a Volvo CR-702 unit.