[quote=“Automica, post:19, topic:2202”]…Got an issue with oil on piston 3…[/quote]Usually, if not always, it’s the piston rings which gum up
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@butch_butcher since posted, we’re coming to that conclusion. our leak down and compression test when warm shows no issues or differences between cylinders so we’ll do a cold test to confirm as (from many YouTube) we’re understanding we’re likely to see a terrible result on our cylinder 3. In your experience is this something we can resolve with an additive like seafoam? would rather not strip the sirion unless we really need to. i have a copen waiting in the wings for a full top end rebuild when I’ve stabilised this issue.
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A compression test won’t directly play any role in determining oil loss.
As far as additives are concerned, you might get lucky with pouring-in an engine flush solvent together with fresh oil. Liqui-Moly is one of the manufacturers of such a product which comes to mind.
If that doesen’t help, maybe try switching over to oil which is formulated for Diesel engine use.
If that doesen’t remove ring varnish, an entire tear-down wouldn’t be necessary. You could remove the varnished piston within the vehicle, by first removing the engine’s cylinder head and oil pan for access. New rings wouldn’t be needed, saving you a break-in process
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That’s what what I’m experiencing too. Theres so much travel compared to my copen and feel is distinctly vague. I’m finding it hard to believe that it was designed this way.
I fiddled with the adjuster on the pedal and wasn’t able to remove any play at all. I must have more air in my system as I have to double press to get any pressure in the first place and even though I can get the car to slow and stop its not in a place where id be happy racing on it.
Has anyone tried swapping the brake booster out for something else? Is this a symptom across all Sirion models or just the M1?
Double pedal pressing is indeed a sign of air presence. You may want to try having it pressure bled
We’re getting a rev drop at idle when the pedal is pressed which we think is giving us signs of damaged brake booster diaphragm. We’ve got a spare booster and master cylinder from a copen but reading around it seems although cosmetically similar the two aren’t compatible. Has anyone experience of part swapping to give us an idea of a replacement?
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Hijacking this thread again, I am happy to report that we successfully swapped the brake booster and master cylinder from my parts car L800K and have managed to resolve the excess travel on the brake pedal and have now got what I would consider a pretty normal brake on my M101.
Things we noted.
- master cylinder on the M101 is around 50g heavier than the Copen’s part which we assume is that the steel parts are bigger.
- the reservoirs are different but swappable
- the brake boosters are visibly identical so we assume is the same part.
The initial swap didnt yield any real improvements. when we went round to bleed we actually found a stuck slide pin so one of the front calipers wasn’t working properly. We pulled it, removed the corrosion and refitted and then we got all our results.
Arguably, this may have been the issue initially and the swapping on brake booster and MC may not have had been the problem. One observation though was originally we’d get dropping revs when the brake pedal was pushed but since we swapped the booster and MC this was no longer the case.
We need to do a proper bleed as I think theres still some improvements but considering we just used parts we already had then I’m pleased with the results.
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