22 replies to this topic

[Roxoff]

I use my mini daily, but the journeys home from work are becoming difficult. When I've been sat in traffic a little while, the power starts to become a little erratic, spluttering when pulling off, or having no power whatsoever. Moving forward short hops in this state causes problems too, 'because the car can stall when braking again (that's not been a problem so far, though, she's always started 1st touch in this situation).

I know there are some minor problems with the temp gauge, 'because the temp never rises above the blue bit at the bottom, which is probably a new temp sender needed (so I've ordered one - I'm not mucking about for 3.50+vat)

This only happens when I've been sat in traffic, so could it be heat related? Or something else? What should I look at?

[MiniSi]

The stalling under braking might have something to do with the fast idle screw/adjuster....

[davexdavexdave]

yeah i have the exact same problem but i haven't got round to sorting it beause like you sed she always starts right back up again. my mate said that its probably because i have a hole in my manifold and its losing compresion so maybe you should check that but he could be wrong.

[Jammy]

The stalling under braking might have something to do with the fast idle screw/adjuster....

Fast idle screw is what determines the idle speed when the choke is out (once its pulled out more than a couple of cms).

Also, I think if it was an air leak it wouldn't idle very well at any time.



Have you got an oil pressure guage? What oil are you using? Not sure on any of these, but it maybe the oil pressure valve has stuck open?

How many miles has the engine done?

Is there oil in the dashpot (when you undo the piston in it and lift it up, is there resistance when you push it down)?

[Roxoff]

The stalling under braking might have something to do with the fast idle screw/adjuster....

Fast idle screw is what determines the idle speed when the choke is out (once its pulled out more than a couple of cms).

Also, I think if it was an air leak it wouldn't idle very well at any time.



Have you got an oil pressure guage? What oil are you using? Not sure on any of these, but it maybe the oil pressure valve has stuck open?

How many miles has the engine done?

Is there oil in the dashpot (when you undo the piston in it and lift it up, is there resistance when you push it down)?

I dont have an oil pressure guage, but I changed the oil (and plugs and oil/air filters) myself back in November. I used 10W40, iirc, non-synthetic. I bought Halfords regular brand after reading some stuff on here about the best grade to use . The engine has done a sad old 98,000 miles, but other than when warm runs lovely (apart from an occasional lumpy tickover when cold, and the revs dropping under braking).

Deffo oil in dashpot, I checked that only a couple of days ago.

[silvermini]

i had a problem similar to this and it used to spluter when hot but not stall, when i replaced the exhaust system including lcb it seems to have cured the problem.
Although what you discribe sounds alot worse.

[Jammy]

OK, thinking about it more, it *maybe* an air leak.

Have you replaced the exhaust/mountings recently or are they newer than the engine mounts?

My line of thinking is this, because you say it trie to stall when braking I think the engine is moving slightly forward, however if the exhaust is strapped tightly to its mountings this movement might be enough to create a gep somewhere to let air in or cause a drop in pressure.

Of course I'm probably completely wrong, I suspect a doctor will be along soon to tell you exactly what it is!!

[Roxoff]

Just had the exhaust replaced xmas week, they put on a standard one. It was running really quiet after the noise from the back-box of the old one, but there's a little noise at the front now (I wasn't generally worried about that, I've had this with mini's before).

[gsms]

I used to have this exact problem, but solved it on sunday and the car's running better than ever.

I simply replaced the radiator with a minispares unit made for hotter running engines.

It used to get hot just driving along, but now even in traffic it sits at the half way line! Hasn't even come close to overheating, and don't think it will for a while.

The only downside is it'll cost you about £86 for the radiator (inc. delivery)

Guy.

[1293clubby]

try changing the condensor and points.

[Roxoff]

Hmmmm, condenser and points, or a new radiator? Tough call. I'll try the cheap option first, and consider a new radiator at time and budgets allow. It could, of course, just be a matter of draining the coolant and flushing the system.

Anyway, a big thankyou to everyone who's helped here.

[Sprocket]

Service the cooling system. It sounds like an overheating problem and you'll never know if your temp guage is not working :nugget:

[Roxoff]

OK, so now I'm preparing to drain and flush the cooling system. I've been to Halfords and bought the best anti-freeze they had (5 yr protection stuff, but only Halfords own brand, 'because they had nothing else). They didn't have the thermostat/gasket set in stock for the mini, so I'll be using my old one (I dont think there's anything wrong with that tho).

So I need a little more advice. On top of the radiator is a sticker saying 'do not drain'. How on earth do I do this, then? I thought it was as simple as removing the radiator cap, undoing the bottom hose and draining, then flushing through with a hose pipe? If I'm not supposed to drain the radiator, how do I flush the system?

And what do I do with the old coolant after I've removed it? It's not supposed to go down the drain.

[mini7racer]

here we go:

firstly park on the road and close to a drain if poss,

now get the hose pipe out.

undo the rad cap, make sure the heater inside the car is set to hot, and then undo the bottom hose, (mind your feet!)

now run the hose pipe through the rad untill it runs clear, (if you want a sparking rad, remove it and get a big container (bigger than the rad) fill with boiling water and lots of washing powder and submerge the rad in and then adgitate it, (only works while the water is boiling hot and with lots of mixing.))

now refill the system, run the car with the rad cap off on the heater open untill the stat open, then after a few mins, leave to stand to cool a little drain again, (carefull its warm) then refill and do again, repeat untill the water that comes out is clear after a run

or, remove the thermostat (will need a new gasket) and flush the block this way, then refill and run and drain etc.

then fill the system with a 50/50 mix of antifreeze and water from a britta filter style thing, as this remove most of the hardness and stops crud build up.

now run the car with the rad cap off, and the heater open and keep filling up the rad as the water level drops as air locks are removed. (squeezing the pipes gently can also help)

once cold top up if needed and replace the rad cap, sorted.

on a side note when you had the nex exhaust fitted did they refit the mount from the exhaust to the diff housing?? if not this maybe giving you and air leak as the engine moved under breaking.

[Sprocket]

Ethylene Glycol is toxic.

Do not put coolant down the drain if you can help it, and this does not mean parking it close to a drain and alowing it to just spill onto the ground. Use a large washing up bowl to catch as much as possible, put that into a container and take it to the tip and put that into the waste oil. It will then get properly disposed of. Once the mainpart of the system is drained, including the heater, then you can flush it through with water untill it runs clean.

Be a shame to do all this work and not replace the thermostat whill you're at it, they don't cost much either. Find a motor factors, not halfords, get the CORRECT gaskets, not these universal ones and there should be no need for this gunky sealant stuff either. It might be alright now but for how long and you might break down because of it. Some one somewhere in your area will have a thermostat