blue smoke and mot

[MarkyB]

It's not a huge job to change the rings

It may not be for you, but it is for someone with little or no experience?

As has been said, unless it smokes like a chimney it will be fine.

[JOWETTJAVELIN]

I believe the visual test is for 'excessive' smoke, so it really is up to the tester. Look on the bright side - at least there isn't a catalytic converter or lambda sensor to go wrong.

[JaneHibbert]

lol, thanks everybody. I'll get some of that wynns treatment (thanks for the advice) and shut up for now on here and just see what happens on the test day next week. but wont book it in til ive added the wynns. as for syuddenyl happening, i dont know how long it has been smokey, a little worse than opther cars ive seen for a while, but only recently did i notice the plume when i accelerated. it sends a cloud, but doesnt obscure any vision...

ill report back as soon as I have put it through its mot!

assuming it passes, it is still okay to drive for many miles yet isn't it??

[bmcecosse]

No technical skill required to pop the head and sump. Loosen the big end bolts and push the pistons out. Care needed when fitting the new rings to the pistons (but again no great tech skill) - and then put the pistons back where they came from. This is the bit where great care must be taken - either using the fingers to ease each ring in - or simply oil it up and use a ring compressor. then again it's just a matter of refitting everything that was taken off. Compared to say timing in a camshaft or rebuilding a gearbox - or almost ANY bodywork - the rings are easy peasy!

[bmcecosse]

I wouldn't add the wynns.....and yes it will run fine for many a mile. If you have any kind of rapport with the MOT place - take it round there and ask them - will they pass it or fail it - before going for the MOT. Always best to get the MOT done during the last month before it runs out!

[JaneHibbert]

why not add the wynns?

[Dean]

Each to their own Jane, just put it in and see if it cures the smoke. What do you have to loose.

It will run for many a mile longer, you'll just need to check the oil level more frequently, that's all.

[JaneHibbert]

true, true Dean.

[les]

I don't know how you can expect someone not familiar with mechanics to do piston rings in a morning Roy, I really don't.
I'm sure I couldn't get it stripped in that time let alone put back together. Then it would take me the afternoon to clean all the bits and a good part of the next day to assemble, maybe even more!

[bmcecosse]

Well - it was a guide to how long a GARAGE would take to do the job....so they would have ramp/tools etc etc to hand and not be tempted away to watch Bargain Hunt half way through......

[les]

---oh yea, then there's the tv and tea breaks, I'd definitely be into the second day!

[mike.perry]

That is an open ended question as the engine will need stripping down. Then it depends on what else they find, worn bearing worn bores etc, Thats the pessimistic outlook

[JaneHibbert]

I am extremely offended by you BMCECOSSE... how DARE you suggest I watch bargain hunt

[JaneHibbert]

No, engine rebuilds will come, but that is for another day. i am still trying to get familiar with even simpler things like what filler to use, brake systems, what points to use in petrol pumps and things... but one day ill get there.

[autolycus]

Forgetting for a moment the discussion about whether Rome can be built, or a Minor engine overhauled, in a day, let's go back to the original problem: will Jane's car fail its MoT?

The tester's manual gives the Method of Inspection as:

Raise the engine speed to around 2500 rpm or half the maximum engine speed if this is lower. Hold this speed steady for 20 seconds to ensure that the inlet and exhaust system is properly purged. Allow the engine to return to idle and the emissions to stabilise:
a. assess the engine idle speed
b. assess the smoke emitted from the tailpipe at idle
c. rapidly increase the engine speed to around 2500rpm or half maximum engine speed if this is lower and assess the smoke emitted from the tailpipe. Allow the engine to return to idle.

and the Reasons for Rejection:

1. The engine:
a. is idling at a speed clearly above its normal idling speed
b. emits dense blue or clearly visible black smoke for a continuous period of 5 seconds at idle
c. emits excessive dense blue or clearly visible black smoke during acceleration which would obscure the view of other road
users. Note: Older vehicles, particularly pre-1960, may emit unavoidable smoke due to their design. Such smoke is not a reason for rejection.

These are the only relevant reasons for rejection for a pre August 75 car.

So the puff of smoke on accelerating really has to be of the scale that Roy with his other hat (or rather grease top) on would be ashamed of. I've put cars using oil at 75 miles per pint through MoTs without a problem.

So my advice to Jane is: put it in for a test, but be prepared to make sure the tester has read the manual in case he tries to fail it for a quick puff of "normal" smoke.

Kevin

[bmcecosse]

Well done kevin 'dense blue' should be the let-out then! And yes - we do try hard to minimise Loco smoke - it's the sign of a poor Fireman.......

[JaneHibbert]

thank you autolycus, thats reassuring and am going to wait and see what heppens saturday

[bmcecosse]

It'll be fine - 'dense smoke' is highly unlikely.

[whyperion]

How many miles do you do in the car normally each day. I dont think the driving with no MOT allowance if going to a pre-booked MOT specifies the route you have to take as long as you dont stop off , it sounds like it really needs a run of about 10 to 20 miles to get warmed up , the puff of light smoke on initial acceleration through the gears seems to have occured on all my engines.

Anyone know the book hours on remove head , drop sump , remove pistons , check size , order rings , new tab washers , refit rings , refit pistons , head and sump, fill with oil ? I work it out at 10 hours over three days for me , but I work at a funny speed ( would actually be 20 hours over a month with my facilities ! )

[bmcecosse]

I've already pointed out that it is 5 hours work for a well equipped garage......