[lps_cooper]

Hi All,

Picked up a second hand cooper S on saturday with 57k on the clock. First few hours of driving it, car felt a bit heavy to get of the lights.

The first time we put our foot down in it, the car went to 6000rpms, and then suddenly felt like it hit a brick wall. The car lost all power, the ECU light and traction control light came on and it started to misfire.

We pulled over STRAIGHT away and let it idle, the car sounded like a subaru... very worbly.

I turned the engine off, checked under the bonnet(HT leads, no sensors were popping out etc)

Left it 10 minutes and started the car back up. it started up fine with the ECU light still on and we managed to limp to the garage for them to take it back and look at it.

Any ideas what could cause this? Are they prone to HT Lead problems for example (I know my old MX5 was! and the Subaru previously was prone to MAF sensor issues)

Any advice really appreciated.

Thanks
LP

[Revolution Mini Works]

Quote: Originally Posted by lps_cooper (original)

Hi All,

Picked up a second hand cooper S on saturday with 57k on the clock. First few hours of driving it, car felt a bit heavy to get of the lights.

The first time we put our foot down in it, the car went to 6000rpms, and then suddenly felt like it hit a brick wall. The car lost all power, the ECU light and traction control light came on and it started to misfire.

We pulled over STRAIGHT away and let it idle, the car sounded like a subaru... very worbly.

I turned the engine off, checked under the bonnet(HT leads, no sensors were popping out etc)

Left it 10 minutes and started the car back up. it started up fine with the ECU light still on and we managed to limp to the garage for them to take it back and look at it.

Any ideas what could cause this? Are they prone to HT Lead problems for example (I know my old MX5 was! and the Subaru previously was prone to MAF sensor issues)

Any advice really appreciated.

Thanks
LP

Do a compression and leak down test right away, it will tell you the health of your engine. If it still sounds like a suuby your odds are not good with your pistons. The stock pistons are known to crush ring lands, it's the weakest link in this very strong engine.

[DaFlake]

I think that I would start with the more common checks like plugs and wires. Pull the plugs and see what condition they are in. Also, you did not mention what mods (if any) are on the car.

[Revolution Mini Works]

Personally buying a used car with fairly high milage I would have done a leak down and compression test before I bought the car. Good luck to you and hope it's a simple fix

[DaFlake]

Quote: Originally Posted by Kumho Kid (original)

Personally buying a used car with fairly high milage I would have done a leak down and compression test before I bought the car. Good luck to you and hope it's a simple fix

True...

My point was one that a shade tree mech could do but if the plugs are fouled or worse, melted then he has bigger issues.

[oldmots]

Obviously, your garage will tell you what happend, I can only guess based on your brief description. From the sound of it, you blew the headgasket.

[JAMIE1131]

Same as in the other thread I posted on, this sounds like the bypass valve, mine failed at 60K on the clock, ten minutes after I bought the car!

[lps_cooper]

Quote: Originally Posted by JAMIE1131 (original)

Same as in the other thread I posted on, this sounds like the bypass valve, mine failed at 60K on the clock, ten minutes after I bought the car!

Thanks for the reply...

The dealership took the car back in and plugged in the diag machine to read the ECU. No codes came up and the light went off when they started the car (typical )

They advised they have taken it out for a good run and couldnt fault the car. The car runs fine according to them. The car did run fine after we pulled over and re-started the engine.

Its not head gasket, or piston or major engine related. The car sounded absolutely fine afterwards and the misfire cleared.

I think it is this valve thats causing the problem, but if it happens again, we will insist its changed.

Are they hard to replace if i had to do it myself? Are they expensive (obviously i am going to push for it to be done FOC)

I have seen a lot of posts that relate to this year of car, with the same mileage with the same symptoms and fix.

It may have even been re-seating the HT leads helped if one was loose.

Ta

[JAMIE1131]

Can't really comment on how hard it is to replace because BMW changed it as it was under warranty. I gave them the car at around 3.30 on a Friday and it was fixed by 10am the next day. From what the sales guy told me it was about 2.5 hours labour to remove and re-fit, he mentioned it was very awkward to get at.

[brian.arthur]

I had the same problem on my cooper.........for about 4 years! Gradually got worse, then unbearable. Problem was Throttle Valve Actuator. Approx £200 supply and fit from BMW garage.

I had this part cleaned of any carbon before I changed it but it only lasted 2-3 months before the symptoms re-appeared.

[lps_cooper]

Well mini diagnosed a faulty manifold pressure sensor. Guess what - it just broke down again tonight after the dealer replaced it.

This is a nightmare... only happens at 5500rpms or above!!!

Mini did a full diag on the car (not sure what they would have done) and this was the only thing they could fault/replace.

The brakes have also started hissing as well now when you take your foot of the pedal!! grr!

[Revolution Mini Works]

is it random misfires or single cylinder?

If it's random have them check the valve guides to see if they are worn badly

[lps_cooper]

Turned out to be the throttle body... whole assembly has been changed under warranty and the car drives like a dream now. More responsive in the higher revs and pulls a lot harder