What to do about my engine!

[340lex]

Not been driving my 1.7 340 for very long.

I've stripped the carb down a bit today to find the base plate gone and the body twisted! Had problems with pier burgs in the past but nothing like this, I've just done the belts etc on the engine.

New carb going on this week, an I likely to experience more engine problems?

I just don't want to sink loads of money into an unreliable engine!

[Chris_C]

It's a super common thing with those carbs. Volvo released a thick (circa 4mm from memory) rubber gasket to take up the movement, but they were NLA when I tried to get one 6/7 years ago.

What I always did with a 1.7 carb was make sure it was the Solex (not the Weber that Volvo tried to replace it with, it's a much much worse design) and that it'd had a recent rebuild, then carefully flat the base off using some very fine wet and dry and a sheet of float glass (not all glass, though most is). As thick a sheet of glass as you can find, mirrors are pretty much certain to be float.

[mac]

Anorak alert!

Volvo never did try to replace the 32DIR with a Weber, Weber marketed a "conversion" kit which some dealers
Tried to "push" (cheeky beggers even tried to claim faulty Webers, of which there were many, on warranty).
We were caused endless grief by dealers replacing the Solex (under warranty) then trying to charge us when the
Weber failed. As far as customer concerned of course "we" were trying to get out of dealing with the problem.

Mac.

[340lex]

Yeah it is the solex, ive had some disappointing work carried out by a chatsworth motor spares in chesterfield.

Paid 175, drove alright for about 10 miles then shitty again, all hes done is clean it and grease the gasket by the looks of it!

The whole unit was replaced (by volvo) in 1993 so shows how bad they were even then i guess.

Ill try your fix chris i think and see how i get on. I have been advised to switch to a weber but i dont want to take away the originality and i think it'd be a pain aquiring a weber.

Needless to say i will be heading back to chesterfield for a word!

The carb is getting to hair pulling stage and i cant find a mechanic who actually knows how to fix them!

[Chris_C]

Don't swap it for the Weber. I've run both, the Weber is a very very poor copy. Anything that isn't the poor copy will be a something from another car that just won't run right without stunning amounts of work.

Air leaks are the main problem with a 1.7. If you get super stuck, take a video of the car, upload it and we can start suggesting things.

[macplaxton]

Volvo never did try to replace the 32DIR with a Weber

Double anorak alert! The 32DIR is a Weber. Do you not mean the Solex 28-32 Z10?

[mac]

Ooooooops serious senior moment!

Of course I meant Volvo never did replace the Solex Z10 CISAC on the B172 with a Weber.

I crawl away to hide my shame, I am indeed a worm!

............................................................................mac

[340lex]

Gotta love the 'anorakism' if you guys! It makes a refreshing change for a car forum! No sarkey scrap it comments!

It idles quite poor and when the choke is applied it misses every few seconds. When driving the problem is worse on the over run but it does miss even sometimes when accelerating. It does feel like an air leak and there is some weaping from the base of the carb.

Also a new problem has arrived, sounds like a bearing...

When out of gear there is a slight 'crunching' this goes as soon as i drop the cluth. Similar noise when pulling off in 1st and second, its not a loud crunch but concering all the same. Any ideas fellas?

[mac]

Hi Lex,

Firstly - your parcel went off this morning as promised,

Secondly the Solex on the B172 is beset by problems almost all of which can be resolved by careful rebuilding and setting up.
If you look in the technical section of this forum you will find an article I have written on the theory, reconditioning, and
tuning of the Z10 - have a read - it might help.
Also - when rebuilding one of these, ALWAYS renew the float - they are solid so don't leak BUT they do go porous so the unit
always runs rich.
The other thing which is a MAJOR cause of rough running (often blamed on the carb) is the distributor cap and rotor arm
- don't even bother to clean - RENEW with the best quality you can find - preferably Ducellier.

Thirdly your noise. Think of what is moving when the noise is there.

In neutral - engine, clutch, release brg runs in contact, clutchshaft, propshaft, g/box input shaft. Remember small noise will
be magnified by hollow alloy propshaft. Gear chatter at idle is normal. Crunching could be release bearing.
Try to detail exactly when the noise occuurs. Neutral or in gear, clutch released or depressed, noise from front or rear,
Whatever it is - somebody on here will have heard it before. Can you record it and post an audio file??

Mac (currently still a worm).

[340lex]

Mac, ill definatley have a read later. The brick wall im hitting though is that its way beyond my mechanical knowledge and mechanics think they know better and say just leave it its running 'reet' or say it doesnt warrant a rebuild etc, you get the picture.

The noise is apparent in neutral And goes when i depress the clutch. It also makes the same noise when pulling off from a standstill, seems less the more revs. Its coming from the rear of the car.

Appreciate your help with this Mac and thanks for getting the seals out so promptly!

[Chris_C]

Mac, ill definatley have a read later. The brick wall im hitting though is that its way beyond my mechanical knowledge and mechanics think they know better and say just leave it its running 'reet' or say it doesnt warrant a rebuild etc, you get the picture.

Macs guide is good, read it first then decide you haven't the knowledge! If you haven't, ask about the points you are stumbling on. You've hit the nail on the head about mechanics, most don't see carbs that often now adays anyway. You are just as good with a bit of reading as the mechanic.

You've noted an air leak on the carb base. Can you hear it or did you wave something flammable at it? If you can hear it, that is huge and needs to be fixed first, before anything else is tried.

Mac is also correct on dizzy caps. Duclier ones will last about 15,000miles. Anything else, between 5 and 10,000. They really do make a difference. It's worth if you don't already joining the realm of the geeky side and keeping a log of fuel consumption (even in your head, it's noteable) MPG will really drop off when the dizzy cap starts playing up, as it will with most problems.

[mac]

Ok - lets think some more about your noise .

Due to the design of the power train on the 300 (gearbox, hence gear selection at rear) you have a situation quite different to most other rear drive cars.

With the engine running, clutch released and gearbox in neutral the prop shaft will be turning as will the gearbox input shaft and layshaft. (in neutral no gear cluster will be turning other than the input/layshaft pair). The only source of noise , generated from the rear of the car has to be from the g/box, or something physically touching or rubbing on the prop. In this condition you will also get a degree of "chatter" from the gear selector plates. Any noise will be amplified by the hollow alloy propshaft.

When you depress the clutch the "drag" in the system will rapidly bring the prop and gearbox input to a stop, and with it , it seems the cause of the noise. When pulling away, the same components will of course be rotating.

Suggestions :-
Ensure nothing is touching or fouling the propshaft.
Check to ensure that the g/box oil level is correct (level/filler plug on side plate of box) will be filled with either 10W 40 engine oil or ATF - either is OK. Low oil will cause noise.
Have someone 300wise listen - it's possible that you're hearing a "300 quirk"

And yes - we're all anoraks here!

All the best - Mac.

[macplaxton]

Gotcha! macworm,

RENEW with the best quality you can find - preferably Ducellier.

Can I add (again) that the Ducellier has long been part of the Valeo Group.

(known from the joys of running a Citroen with ropey French electrics)

[Chris_C]

Gotcha! macworm,

RENEW with the best quality you can find - preferably Ducellier.

Can I add (again) that the Ducellier has long been part of the Valeo Group.

(known from the joys of running a Citroen with ropey French electrics)

But in 1700 terms, Ducellier ones are generally still the nice green ones with good contacts in the cap (not just upright bits of monkey metal), Valeo are the browny/red ones with the monkey metal contacts. Maybe old stock being used up still?

[macplaxton]

Fair point Chris, I meant to come back to edit the post with the disclaimer of what you are saying. i.e the new-new stuff could be shite compared to the new-old stuff.

Ditto, Lucas / TRW stuff. Had a Hillman Imp make it 3 miles on a new new monkey-plastic rotor arm. Stuck the old one back in to get home.

With crap caps and rotor arms, maybe best chuck them in the bin and finish the electronic ignition job off properly?