14 replies to this topic

[brivinci]

Well, my Monte has been on the road for something like 800 miles...and I think thats it:-( Here is what happened.

I was driving on the highway at about 70mph in forth. Was only on the road for 10 minutes or so. I suddenly noticed that the car didnt seem to pull well with the throttle pressed. I was questioning whether it was just me or the Mini. Then, I noticed a juttering sound so I looked for a place to pull over. Then I dipped the clutch to coast off, the car stalled. I stopped and sat for a second. I tried to start it again and it would barely crank like the battery was weak. Thought the alt came loose. No dice. It was fine and tight. I instantly thought I was seizing the engine. I let it cool, checked the oil (it was fine) and waited for a tow. During which, I started the car, didnt hear the noise and was able to go forward and reverse. I then got a tow.

While waiting I received a call from Mini Sports USA head Mike as I was placing an order for parts. He was REALLY helpful in talking me off the ledge. Here is what we came up with.
We thought that the motor might have overheated and was seizing. The water level was checks and was perfect. Also, the AUX fan is operating perfectly. Gauge appears to be working as it should
The car starts and idles perfect now. The oil light goes off instantly, even at a low idle of around 700. I replaced the plunger with the ball bearing relief valve during rebuild.
Also, the car has both an extended magnet drain plug, magnet plug up on the top of trans, as well as a central oil pick up.
I think that I must have put the clutch in when I tried to start it up the first time after stalling. I tried it again and when the clutch is pressed, the idle drops down a bit. After a short drive, the engine will stall sometimes when clutch is in. Also, while the car was warmed up i tried to give it the beans and it would not rev past 5k. When i got back the oil like started flickering on on idle but would turn off with the slightest touch of throttle

So, it seems like i have a thrust washer problem. The crank is maybe being moved and jammed when the clutch is being pressed. If this was causing a lot of friction, it could have created a lot of heat and cooked the oil, leaving it thin. I drained it and it did seem a lot thinner the 20/50 should be. Also, the magnet was covered in muck. Most from the isky rev lube I used putting the new cam and cam bearings, follower, and a mess of new trans parts. I filtered all the old oil with a paint strainer and nothing was there. No junks of metal.
I have not tested the oil pressure with a gauge but will do next. The compression of the cylinders was done and they are all perfect and within a few pounds of each other. Also, I removed the started and tapped on the flywheel to get it as far away from the engine as it would go. I have my father step on the clutch to see if there was any movement. I could not see or feel any at all. I want to try this again and really give the flywheel a good few whacks with a rubber mallet to really get it away and then put a dial gauge on it to see if it is in speck.

So, that is my sad story. I want to try everything before I pull the motor. Can anyone think of anything else I am missing? Any info would be much appreciated. I am absolutely gutted over here. A sad, sad day:-(

[brivinci]

Well, I have pulled the motor but have not has time to look inside. Should be getting to that tuesday night. I am a little worried at what I might find...

[jamesmpi]

Hope it's not as bad as you think it is....keep us posted

[RayBoogs]

Some of the symptoms you have described sound like a failed or failing crank sensor (located on flywheel housing). When its cold its fine, maybe takes a few cranks to start, but as it gets hot the contacts get hot and distort and don't give a correct position of the crank causing it to judder and fire incorrectly and cut out, then after it has cut out it will not fire as it cannot get a correct position of the crank, but when it gets cold it, obviously, is able to work correctly again until it gets hot.

Also if your engine has kept all its oil and there was no temperature warning light and all the coolant was there, I dont think it would of seized, and if t was going to seize it would happen pretty fast and go very badly wrong!

[brivinci]

It didnt seize. Actually, the compression is perfect still. The main thing that gets me is that when you dip the clutch, the engine idle dips or, when warm it seems, the engine dies all together.

The car fires right up when cold, but also when hot I believe...unless the clutch is pressed. Then I can hear a little strain trying to get it to crank. What is strange is that it is only sometimes that the clutch causes that problem on start up.

I guess I should see what happens when I get into the engine. I really hope the crank is ok. They are just so pricey on this end of the pond.

[RayBoogs]

Yes it is strange, mine had a crank sensor failure and had similar symptoms to yours. It seems strange when you dip the clutch it doesn't start.

Have you checked the crank sensor?

Hopefully someone who knows a bit more than me will be along soon! I hope it isn't the crank either, there not cheap this side of the pond so I dread to think what they're like over there

[brivinci]

The crank sensor is in place and looks ok but that really doesnt mean anything or what is going on internally.

The thing with the clutch has been said to mean that there is excessive play or float on the crank. Basically, I step on the clutch, it pushed everything up against the opposite side and causes friction. If the thrust washers were in the wrong way around then the steel side would be against the crank instead of the cooper. Over the course of the 800 or so miles I drove, the metal could have worn to a point that the float is too extreme and it is now causing crazy drag on the motor. Enough to make cranking over difficult when the clutch is in and maybe generate way more heat that would have cooked my oil. This is all a theory but it seem to make the most sense.

How do you check that the crank sensor is operating properly though. At this point, who really knows?!!

[brivinci]

Well, my wife surprised me with a gift to help cheer me up...a nice new set of Gaz adjustables!!! Now I am even more excited to get her back on the road.

Heading to the shop tonight.

[RayBoogs]

Well that is good news!!

To check the crank sensor you need to compare the resistance value when cold and hot, they should be the same.

But yes your theory does seem to make sense, I suppose you won't know till you've had a good look at the engine when its out I hope you get it sorted soon though!!

[brivinci]

Well, some not so good news. My crank might have been the problem. The 3 main bearings are all shot and the crank is worn with some grooving. Nothing that cant be ground down except for one thing...

The thrust washed that takes the load when the clutch is pressed is also worn with grooving made to the cranks surface. The rule of thumb I am going with is if you can feel it with your finger nail, its too much and needs to be ground. I am not even sure that part can be ground and if they sell over sized thrust washers to boot? Anyone know this?

I talked to my new best friend. He started Mini Sport in the USA and sells things for the equivalent UK price not the 3x as much most other Mini suppliers seem to want. HE said he could get me a new crank with bearings and thrusts for around 330USD. I might just go that route instead of trying to fix the current one which would cost about 250 at least in labor and parts.

The other thing that worries me is the primary gear. I was able to stick a .4mm feel gauge in there where it should be .1-.18 Not good. If you install the gear and back bronze washer, push it hard against it and wiggle the gear, there is play from the nose. It can move from side to side slightly. Does anyone know the tolerances for this. I want to bring it to a shop and have it all checked out.

[mk3 Cooper S]

Why did you elect to run the engine for 800 miles on the initial engine build oil?

With any rebuild you have to be ultimatly clean and wary of any type of contamination.

Personally I run the in on cheap oil, 200 miles and then change again after 500 mile and then go to regular intervals if no signs of debrit or muck are visible.Es[pecially with a gearbox rebuild too.
Usually fresh build engines with crank problems are due to debrit, regualr oil changes can help.

[brivinci]

It wasnt a rebuild. I only replaced the cam and cam bearings in the motor. The bores where checked and perfect. I never pulled the crank (which was dumb) so all that was left as is...which may have been on their way out the door or this could be a new problem. Still, I should have changed the oil anyway just to be on the safe side.

[Sprocket]

Oversize thrusts are available in +0.003", +0.005" and a massive +0.030" which were designed to be surface ground on the back to achieve the desired size. You are also not limited to using a full set of one size, you can use a different size on each side. each side of thrusts in a set is worth the oversize stated so if you buy +0.003" set it is worth a total of 0.0062 if you use them on both sides. So there is plenty room for having the thrust faces cleaned up

Size options achievable

+0.000" (STD/STD)
+0.003" (STD/0.003)
+0.005" (STD/0.005)
+0.006" (0.003/0.003)
+0.008" (0.003/0.005)
+0.010" (0.005/0.005)
+0.030" (STD/0.030)
+0.060" (0.30/0.30)

The primary gear sounds like it needs re bushing. For the front bush (the one nearest the engine) Minispares do a floating bush upgrade, and removes all the hassle in having the front and rear bushes line bored together. The rear bush (the one nearest the flywheel) will need machining to size, ideally with the correct clearance to the crank, rather than a specified size. I cannot remember off the top of my head what the clearance is.

[brivinci]

Thanks for the great info. The dark clouds are starting to lift...slightly:-)

I am going to bring it to a machine shop and see what they say and what they would charge. If the primary gear end is off for some reason, I think I will have to go with a new crank. I saw that floating front bushing which is nice. Would just have to see if someone around hear could properly machine the rear one then.

[brivinci]

Well...
I tore the rest of the motor apart. Going to have the bores check and the cam looked out. The cam bearings will need to be replaced (sucks). I am hoping the cylinders are ok. If so, I plan to have them very lightly honed and then put a new set of rings on them. I'm this far into it, might as well.

After talking A LOT about this I think I have come to the conclusion that the bearings were not in good shape to start with. The added pressure of the fresh head and new cam maybe sped up the destruction. With the bearings wearing more and more, the hot (90F) temp outside and all the extra clearances, there was a lot more friction. That caused a ton of heat that cooked my oil, turning it to water. That, on a hot day, doing 70-80 on a highway and the bottom end could take no more. Poor motor...and poor wallet. Oh well, lesson learned I guess.