467 replies to this topic

[sonscar]

Sorry to hear of your troubles and wish you a speedy recovery.smoking on startup is unlikely to be ring wear I would have thought,more likely guide wear.Reconditioned does not always equal good sadly.Steve..

[stuart bowes]

in fairness, new valve guides are are a lot less aggro, albeit a pain already having been done, at least you don't have to hoist the engine out (if it is that, I have no idea)

 

best of luck with the recovery mate

 

also, lucky to get 2.5-3k ?  what were they smoking lol that's mint as far as I can see going by pics

Edited by stuart bowes, 26 March 2026 - 10:18 AM.

[1984mini25]

Well prior to fitting the new cylinder head as pictured, it was smoking heavily on start up and between gear changes until it had fully warmed up. It was also towards the end of 2024 using a pint of oil every 50 miles.

I think I've already posted that the previous cylinder head was a used second hand unleaded 998 head bought from a member on this very forum 20 years ago. So for a previously used head it was knackered anyway and had got my use out of it. I did also try adding a can of stop smoke and cleaned out the engine breather (flushed it through and blasted with a heat gun) which made little difference.

I then bought the pictured cylinder head around November but didn't get around to fitting it until July because of previous eye issues and surgeries. I did however lap all the valves and change the valve seals, as even though it already had a full set of the brown ones I didn't know how old they were, so replaced them like for like with a new set (I've kept the ones I removed). What's been bugging me though is I had no way of telling if the valve seals I'd bought and sent were the genuine viton ones and not some knockoffs in the correct colours.


Once fitted the smoke on start up all but disappeared (tiny amount that would be considered normal) and oil consumption was a more reasonable 840 miles to a pint.

So it's a bit odd it's now started smoking out the street on start up.

If the engine had to come out for a rebuild or at least a hone and new rings, it obviously wouldn't be that simple and while it's out there would be other jobs and the front subframe could do with being blasted of original rust and painted.

As for the valuation, the British mini club got back to me with a valuation of 18 k (obviously for insurance) but even ones that have sold via Mathewsons in not as nice original condition have sold for between 5.2k and 6.8k, still more than the lucky to get 2.5k.

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[1984mini25]

I did try within my current health limitations yesterday to remove the tappet breather and flush it through until clear with white spirit. I had previously cleaned it out an burnt off with a heat gun only 600 miles ago.

But after leaving it to dry out and refitting. Starting it up from stone cold (when the blue smoke is at its worst) all I got was the normal white condensation from it being a bit colder and no James Bond style blue smoke clouds.

So there's still probably a valve/seals or ring issues, but cleaning out the breather has certainly helped.

Curiously I thought I'd cut open a spare breather I've previously flushed though, although it doesn't look like it did much good as it's still clogged with oily gunk.

And then I had the idea of replacing the mesh with a stainless pan scourer (not a new idea) but I'd need to find someone to weld the end back on, as I obviously can't at the moment (I might not be able to at all if it might affect my eye in the future)

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Edited by 1984mini25, 29 March 2026 - 02:23 PM.

[1984mini25]

Well scrap what I've previously posted about the breather having any effect. Just started it up after sitting a few days. No initial smoke on start up, but as soon as the choke is pushed in to reduce the idle and given a few light revs (sometimes needed to wake the alternator and rev counter) a huge cloud of blue smoke, that not only stinks but also hangs in the air.

If it's still not smoking when warmed up and driven, is it likely to be the valve seals?
Although it didn't smoke immediately after doing the oil change and taking it on a quick drive to the end of the street and back (about as far as drive it with current eye issues) although the gearbox did feel nicer.

I can't see it being the valve guides as they were all pretty tight clearance wise when I lapped the valves. I did keep the original viton seals, but can they be replaced by not removing the head again?

Edited by 1984mini25, 29 March 2026 - 02:36 PM.

[lsto]

Generally if it's stem seals you get smoke on start up then it clears. If it's continuous or under load then it's more likely to be rings. When my breather was blocked I found it smoked when idling whilst hot but when driving the smoke cleared.
You can change the seals by removing the spark plugs, filling the cylinder with paracord or some similar rope then turning the engine till the piston pushes the rope against the closed valves. Then you can change the seals although it is a pain to refit the collets after. If I was you I'd pop the rocker cover off and see if any of the stem seals have come unseated. If it's not hammering out smoke when it's warmed up just enjoy it and pencil it in as a future job.
If you have a compression tester then maybe try a wet and dry compression test and this may give you an insight into the ring health.

Edited by lsto, 29 March 2026 - 07:13 PM.

[1984mini25]

I've since been able to drive it on a trip of around 20 to 25 miles.

Started up no smoke, once reved though loads of blue smoke that pretty much stayed and followed for the first 2 to 3 miles (think overfilling a 2 stroke level of smoke) after that it did slowly begin to clear until it was no longer smoking.

I did also have a couple of other issues. The speedo/cable refuses to work below 20 mph (could just need some oil down the cable) the alternator bearing/s are grumbling and I've temporarily quietened them with a spray of wd40 while it's idling (obviously not while standing directly in front of it) and unbeknown at the time the rear exhaust mount had sheared and the exhaust shifted and knocking, rubbing and vibrating on the rear subframe and rear valance. I know I heard something while driving (was changing down for a roundabout) and then trying to work out what was up with the worrying noises coming from the rear/rear subframe area.

Lucky I've had a spare exhaust mount that I've since swapped over. Only discovered it after giving it a quick wash and going to do under the rear valance and finding the exhaust not central/wedged up against the rear valance.

Even with the mount replaced though I still have another issue with the exhaust/mountings. The band clamp on the center one even done up fully is still allowing the exhaust to move and vibrate inside it. So that's something I need to look into and see if I have a smaller band clamp or come up with something else that will work.

But back to the smoke issue. After the run the smoke cleared, I've since started up and run it and it's no longer smoking on start up or being reved when cold and despite all the blue smoke out the back it hasn't used any oil. So what the smoke was or from I'm not too sure.

[1984mini25]

Not much of an update, but I'd found someone to weld the top back onto the breather I cut open to clean up and change the mesh inside. Well I've been trying for the past week to collect and have made several trips to his premises (pre arranged) only to find the place all shut up. So as I haven't paid for it and I really can't be arsed with wasting anymore petrol he can keep it and stick it somewhere the sun doesn't...

So I've robbed the one off the spare engine, which was just a clogged up inside and given that the same treatment, just need to drop this one off to someone else to weld up this time.

[1984mini25]

I renewed my insurance with footman james who I've been with on the mini since 2018 yesterday as that's due at the end of the month, paid the extra £20 to increase the agreed value inline with my current valuation.

I got an email today saying that they aren't accepting the valuation from the British mini club (who are sponsors) and instead have changed it market value, which is actually less than the first British mini club valuation I had done in 2020.

Starting to wonder why bother paying for the club membership, then the valuation and the extra to change it for what?

[1984mini25]

I eventually got the insurance to agree to agreed valuation, lots of frustrating back and forth repeatedly sending the same info as I'm assuming whoever wasn't bothering to read or look at it properly.

But the smoking issue has been getting worse. It doesn't do it on every start up from cold, but when it does it's a lot.

I've managed to borrow a compression tester and have gotten the following readings.

Stone cold engine after sitting overnight.
90,110,115,110psi (1,2,3,4)

Fully warmed up after a 20 mile drive.
100,105,110,105psi (1,2,3,4)

And with 2 squirts of oil down each cylinder.
130,130,140,135psi (1,2,3,4)

So it's pretty convulsive that the rings are worn.
I can't really afford a full engine rebuild and I can't have the mini off the road for any longer than nessary. So I've come up with a plan, as the oil pressure is still 60psi cold and 40psi when hot/60psi at 3k, is to pull the engine and gearbox and just do the rings, oil pump and gearbox swap.

I've already ordered the new rings and gasket sets and I need to remove the engine off the other gearbox. But I'm hoping I can have the engine out etc and then pull the front subframe off (I need the car movable to give me room in the garage to work) clean that up and paint it and attend to any scabby bits that aren't accessible on the lower bulkhead.

I had hoped on finding a second front subframe, but can't find anything reasonable within a reasonable distance. I also tried getting a quote for getting one blasted, and that was £200 plus vat just for the blasting a full stripped frame. So I'll pass on that and do as best a job I can with power tools.

The other issue I can see having is swapping the diffs over if I need too. As I'd have to swap the crown wheel and pinion from the old gearbox onto the diff of the rebuilt one.

Edited by 1984mini25, 08 May 2026 - 03:30 PM.

[Rubbershorts]

Checked it earlier today now it's cooled down and sat overnight, no leaks from the water pump, radiator and hoses the bottom radiator hose being the usual pita in the past, and the coolant level hasn't dropped.

That was until I looked inside. The heater valve and hoses on the heater (top one) are still proving to be a pain.

I've gone through several new jubilee clips, but I'm still having issues with the top one on the heater (the bottom one maybe?). I've moved the clamp on the hose slightly and retightened it. If it's the hoses it's not getting done anytime soon and to replace that short section the heater needs dropping out. Annoying as all the hose connections with the blue connectors pretty much seal without really needing the clips, the heater valve and the new matrix however.

IMG_20251226_143448_1.jpg IMG_20251226_143623_7.jpg IMG_20251226_143734_0.jpg IMG_20251226_144041_4.jpg IMG_20251226_144114_4.jpg IMG_20251226_144153_5.jpg

What's that heater valve? And where is it exactly? It looks like it's on the side of the heater maybe? Daz.

[1984mini25]

Checked it earlier today now it's cooled down and sat overnight, no leaks from the water pump, radiator and hoses the bottom radiator hose being the usual pita in the past, and the coolant level hasn't dropped.

That was until I looked inside. The heater valve and hoses on the heater (top one) are still proving to be a pain.

I've gone through several new jubilee clips, but I'm still having issues with the top one on the heater (the bottom one maybe?). I've moved the clamp on the hose slightly and retightened it. If it's the hoses it's not getting done anytime soon and to replace that short section the heater needs dropping out. Annoying as all the hose connections with the blue connectors pretty much seal without really needing the clips, the heater valve and the new matrix however.

IMG_20251226_143448_1.jpg IMG_20251226_143623_7.jpg IMG_20251226_143734_0.jpg IMG_20251226_144041_4.jpg IMG_20251226_144114_4.jpg IMG_20251226_144153_5.jpg

What's that heater valve? And where is it exactly? It looks like it's on the side of the heater maybe? Daz.

It's a car builders solutions universal 5/8" inline heater valve, fitted to the right of the steering column inline in the heater hose. As I haven't been able to find if the current batch of head mounted mini heater valves don't explode, which has been an ongoing issue for the last 10 years with the replacements.

[sonscar]

You should have the bores honed when you fit new rings but clearance is likely to be an issue.Check for a ridge at the top of the cylinder which can damage new rings.Check the ring grooves for excessive clearance.There use to be all manner of "special" rings to fitto worn engines.Goodluck,Steve..

[1984mini25]

When I had the head off last year the bores looked ok without much of a lip if any, but I have a honing tool.

I know if I was going to do a full engine rebuild I'd be replacing a lot more, but all of it has been done at some point before and other than the smoking/oil burning issues I'm currently getting high 40's to the gallon and these were the plugs the other day. You can also see the oil round the sealing washers.

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Edited by 1984mini25, 08 May 2026 - 07:13 PM.

[Rubbershorts]

Checked it earlier today now it's cooled down and sat overnight, no leaks from the water pump, radiator and hoses the bottom radiator hose being the usual pita in the past, and the coolant level hasn't dropped.

That was until I looked inside. The heater valve and hoses on the heater (top one) are still proving to be a pain.

I've gone through several new jubilee clips, but I'm still having issues with the top one on the heater (the bottom one maybe?). I've moved the clamp on the hose slightly and retightened it. If it's the hoses it's not getting done anytime soon and to replace that short section the heater needs dropping out. Annoying as all the hose connections with the blue connectors pretty much seal without really needing the clips, the heater valve and the new matrix however.

IMG_20251226_143448_1.jpg IMG_20251226_143623_7.jpg IMG_20251226_143734_0.jpg IMG_20251226_144041_4.jpg IMG_20251226_144114_4.jpg IMG_20251226_144153_5.jpg

What's that heater valve? And where is it exactly? It looks like it's on the side of the heater maybe? Daz.

It's a car builders solutions universal 5/8" inline heater valve, fitted to the right of the steering column inline in the heater hose. As I haven't been able to find if the current batch of head mounted mini heater valves don't explode, which has been an ongoing issue for the last 10 years with the replacements.

Interesting, do you operate that manually at the valve then? Or is there a cable I can't see?