29 replies to this topic

[cobblers]

I just bought a Mini earlier today - Drove it home and got 120 miles before it cut out at some traffic lights and wouldn't start again - Turn over 2 or 3 times, then it would stop. I left it a minute and it started up really quickly. About 100 yards later it did the same, so I pulled off and let it rest for 10 minutes, but I'd noticed that it has now got a bottom end type of knock when revved - Sounds perfect at idle though. The clutch has also got a lot noisier when I press it (I think! but it's a new car to me). When it does start, it spins over very fast and starts within a second or two.

I took the trip steady 55/60mph. Fastest I saw was 70 when overtaking, but it was only for about 20 seconds.

Oil pressure is 45psi at cold idle (been left about 45 minutes from the trip home) and about 20psi warm idle.
The engine is a 1330cc, with a 276 cam, stage 3 head and the engine has Canems electronic ignition.
I'm told the clutch has an orange diaphragm.
I'm also told that the engine was rebuilt 2000 miles ago, and am (perhaps foolishly) inclined to believe the previous owner about this, he did seem very genuine.

The car still pulls great (and I love the thing!)

I read about the issue of clutches coming loose , and I'm (perhaps foolishly again) hoping that this is the issue:
http://www.theminifo...showtopic=60705

Are these oil pressure readings reasonable? I do seem to recall they were higher when I first bought the car though?

The car also has a solid mounted front subframe. I'm also kind of hoping that something has come loose and is causing the noise, and is completely unrelated to the starting problem.

Any help or advice that prevents me from having to get the engine out and take the thing to bits would be sincerely appreciated! Bear in mind this is my first mini, but I'm a pretty experienced DIY mechanic on other stuff.

[bmcecosse]

That oil pressure sounds a bit low! But what matters is the hot running oil pressure - at say 50 mph in top gear. By and large - you should have ~ 10 psi per 10 mph in top gear,up to ~ 60 or 70 psi max. First check of course - is the oil up to the mark on the dipstick ?

[cobblers]

Bugger...
There is plenty of oil in - not sure of the exact amount, but there was plenty on the dipstick. Was too busy banging my head on the bonnet and limping round after pushing the car over my foot trying to shove it out of the road!

For most of the 120 mile trip the oil pressure was 40-50psi at 50-60mph (mainly varying with temperature rather than speed), unfortunately I've not had chance to really take it up to speed since the "issues" as I was very very gently nursing it home (Rather than waiting 3 hours for a 2 mile tow from the RAC) so don't know what I'm getting while it's warm. I'm a bit reluctant to run it much because it's an overbored block and pistons, so I don't want to wreck anything further than the bottom end bearings/crank (Which I've read will be a standard 1275 item on a 1330, so fairly easy to get hold of?)

Thanks for the advice up to now

[bmcecosse]

Yes -will be 1275 crank. You could check if the flywheel has come loose - by taking the starter off.
Any chance you over-revved it and broke the crank ? That would affect oil pressure AND clutch action!

Edited by bmcecosse, 08 September 2009 - 08:50 PM.

[cobblers]

Yes -will be 1275 crank. You could check if the flywheel has come loose - by taking the starter off.
Any chance you over-revved it and broke the crank ? That would affect oil pressure AND clutch action!

It's got a rev limiter set at 6200rpm, which I don't recall hitting - 70mph was something like 4500rpm?

Assuming the worst, and the bottom ends are knackered - I'll be safe enough to steadily drive it a couple of miles whilst keeping an eye on the oil pressure to pick up my tools? I really don't want to scrap the block. Crank I don't mind so much, but it's pistons and machine work that costs, the rest I'm happy to do myself.

I'll have the starter motor off tomorrow morning and see what I can see, and perhaps check all the engine mountings. Anything else that could cause it, IE Timing chain tensioner failing? This could cause a knkcing noise as the chain slapped about, and also allow the timing to fluctuate possibly making it hard to start?

I apologise for my guesswork - It's been dark and raining since I got back, so I've not had a chance to really look at anything!
Thanks again,
Dave

[bmcecosse]

Short drive should be ok - as long as the flywheel has not come loose. I suggest the 'hard to start' etc is probably not related to the knocking.

[cobblers]

Short drive should be ok - as long as the flywheel has not come loose. I suggest the 'hard to start' etc is probably not related to the knocking.

I was thinking the same, but when clutching at straws I get desperate.....

I'll try and get a lift up for the tools, just in case!

[Nightrain]

First thing I'd be doing, is changing the oil. Could have any sort of crap in there as running in oil.

[cobblers]

First thing I'd be doing, is changing the oil. Could have any sort of crap in there as running in oil.

But surely If it's knocking, it's too late anyway?

Saying that, the seller did give me half a bottle of oil amongst the gubbins, and it is cheap looking stuff - 20w50?

[bmcecosse]

20 W 50 is fine.

[cobblers]

Cool, one thing right at least.
I'm going to take the starter off, check the flywheel, check all the engine mounts and the front subframe mounts too, I felt a little "lash" in the drivetrain through the steering column, which moves slightly when you accelerate/let off.

here's hoping it's something obvious, but from the low oil pressure diagnosis (especially for a 2k old engine) I'm fearing the worst!

[WiredbyWilson]

I was lead to believe the oil light comes on at about 8lb - which is too late by all accounts.

My recent 1330 build has about 65lb on cold start up and dropped to 40lb at a constant 70mph on the motorway.

I'm not sure 20lb is too low, but a bit more is always good.

Try the oil change for a Millers or similar and see what happens, otherwise it could be a oil pump problem.

Are you able to describe the "knocking" a bit more?

[bmcecosse]

40 psi at 70 mph is way too low! There may be trouble ahead - fit an oil cooler!

[cobblers]

I was lead to believe the oil light comes on at about 8lb - which is too late by all accounts.

My recent 1330 build has about 65lb on cold start up and dropped to 40lb at a constant 70mph on the motorway.

I'm not sure 20lb is too low, but a bit more is always good.

Try the oil change for a Millers or similar and see what happens, otherwise it could be a oil pump problem.

Are you able to describe the "knocking" a bit more?

I've heard a few knocks - I had a couple of old 106 engines that knocked only when warm, and only at 2500/3000 rpm, and it was a "gentle" knock, and not noticeable any other time. These both did 6 or 7k of abuse and only got slightly worse.

A mate of mine had a 1.9 205 Gti that span a bearing, and it was a very loud knock, but constant. The noise I get is a loud knock, but very "sporadic". Sounds like the 205 did, but comes and goes. On idle it sounds perfect.

40 psi at 70 mph is way too low! There may be trouble ahead - fit an oil cooler!

The seller did tell me that I needed to fit a 4 core rad and an oil cooler ASAP. These are on the list right at the top

[Nightrain]

Also check the oil pressure relief valve.