Hi All,

Appreciate if someone can help. I replaced a cracked thermostat on my R56 2007 Cooper. Upon starting I get violent vibrations on the engine per the clip:

https://youtube.com/shorts/WGJNJDFXJ-E?feature=share
​​​​​






I removed the driver side wheel liner, belts seem intact, nothing has been shredded/chewed up. So not sure if it's, the water pump, friction pulley, harmonic dampener, or timing. Is there a methodical way to check?

Any help is appreciated as I'm keen to get this back on the road else the missus will do my head in!

Suggestions elsewhere have been the timing belt, tensioner, water pump pulley but I didn't think the vibration would judder the engine so much, I feel like it could be the water pump not getting coolant into the engine? Or trapped air somewhere?

​​​​​​Would be good to get this definitive. I will need to change the drive belt as its cracked per pics.
​
Thanks in advance.

Sparky

 

You can ellimininate all of the following at once by removing the belt and starting the engine:
- belt
- friction wheel (or rather, the friction wheel's bearing)
- waterpump pulley
- waterpump
- alternator and pulley
- ac compressor and pulley
- harmonic dampener

If the noise is gone without the belt, re-install it, pull out the friction wheel lock lash and restart the engine. This leaves out the friction wheel, waterpump pulley and waterpump. If the noise is still gone, one of them is the culprit (though I can't imagine one of them is causing the engine to vibrate like that).

Have you double checked whether you re-installed everything correctly?

Edit/PS: Since Mini users from all over the world are on NAM, I'd avoid using "driver" or "passenger" to indicate a side of the vehicle. Clearly you have a RHD but in different circumstances it may not be as clear.

 

Your drive belt is waaaay past replacement time.

 

Chaps thanks for your help so far:

Drive belt removed. Tensioner in service position. Still getting the knocking with the friction wheel service unpulled and pulled per both clips:



Spitting some oil from exhaust
https://youtube.com/shorts/dLkN2urz1Kg?feature=share

I'm pretty sure I put everything back for the thermostat as was required. The missus did state the engine area started the knocking before the thermostat housing cracked.

Any thoughts welcome as I'm at my wits end, R56s are an exercise in patience and perseverance except I already have kids!

 

I would suspect #5 in the above diagram. Next item would be the transmission mount. The 07 came with a particularly poorly designed lower engine mount (#5). cheap and easy to replace.

 

Farside I think you may be on the money.. Mount rubber is cracked for sure:


However, before I replace belts, mounts, and possible the water pump is this issue responsible for the oil spitting from the exhaust or is that the head gasket, new thermo install, water pump?


I don't want to invest all this time and parts if the car conks out soon as I put it on all fours!

Many thanks for yours and everyone's help. It's a real God send and as a guy who's never picked up a spanner I'm learning shed loads!
​​​​​

 

R56
I think it's running on only three cylinders - check the wires & plugs. Corrosion on the coil plugs is very common; sandpaper & di-electric grease will fix it.
It sounds like you are low on oil, perhaps a quality filter & oil change is due.

 

All,

Many thanks for your help so far which has resulted in a novice changing the below on my 07 R56 Cooper (non S):

Thermostat
Belt
Water Pump
Lower engine mount

Now the most serious issue which I believe happened when the thermostat split and the engine heated up is that I've zero compression on cylinder 4 with a P0304 code. This probably explains the massive engine shudder running on 3 cylinders as MVPeters mentioned earlier. This points to potentially bent exhaust valves.

Tried swapping coils and changing sparks to no avail.
Oil level is fine.

Looking at YT the tutorials for changing exhaust valves are a bit scrappy. And I'm not sure if I've the confidence to remove the engine!

This leaves a few choices:

1. DIY when the weather is little warmer and attempt it myself (if you've any links to a comprehensive guide that would be most welcome).

2. Mobile mechanic mini specialists around Harrow London. Although not sure this is a job they would tackle remotely.

3. Tow to a garage and potentially be held at ransom. And the cost may not even justify the repair given the value of the car.

If anyone has any recommendations for a trustworthy specialist around Harrow/M25 please let me know.

Any recommendations on next steps as I'd hate to scrap the car given all else is pristine and the effort put in so far..

Thanks in advance.

 

Not clear why you believe that overheating will cause bent valves. Might be helpful if you elaborate. I would not expect that to happen as a direct consequence of overheating.

I would expect overheating to damage both head and head gasket and that is the most likely cause of no compression on number 4.

Pulling the head to verify it is still flat is the most likely next step. I can't recall what the spec is for a warped head that is still serviceable but I would think you would want it out-of-flat no more than 0.001" over the length.

If the head is badly warped, best option is get one from the salvage yard instead of repairing a warped one.

Depending on how how hot it got (and for how long), the block may be ok - check it for flatness once the head is removed.