The car is a 2007 mini cooper s r56 with 85k miles. It all started with an over heating problem. And from there I noticed a coolant leak and oil leak from the valve cover. So I knew I needed to replace the thermostat, the water pump, and valve cover. I thought might as well as add in some diy carbon buildup cleaning to to it all off.

Everything seemed to go well until I got everything put back together. The car has power and I can hear it turn over but it doesn't started all the way. At first I thought it was a dead battery since I worked on it over several weekends with the battery disconnected. I also took everything back apart and looked at the valves through an inspection camera and I didn't see anything wrong. The rods still move up and down fine in all cylinders.

The only other thing I can think of is some carb cleaner leaked down into one of the cylinders. After that happened I left the valves open in that cylinder over night hoping it would evaporate. Will this stop the the car from starting?

Right now I've got the battery hooked up to a battery tender and tomorrow I might add some gas as it only had 20 miles left on it when I started working. My gut tells me those arent going to do it. Any ideas or suggestions? Thanks in advance!

 

Assuming that you have anything reconnected properly, this can happen after carbon cleaning. Just keep cranking it.

 

I've tried starting it three time now and it just splutters a little but never really starts. It's late now so maybe I'll continue in the morning. I should also add that I also changed out the accessory belt and I've verified that it is turning correctly when trying to start.

 

So I did some more searching and found this: https://www.northamericanmotoring.co...-cleaning.html

From that post a person describes messing up the timing chain by pushing the car backwards. I also read this post: https://www.northamericanmotoring.co...s-problem.html Where it suggests that rotating the engine in the wrong direction can cause the timing to go messed up. When I rotated the engine to close off the valves in each cylinder I did not pay attention to the direction. I probably did both directions. Would that causing the timing chain to go out of timing? Is there a way to check?

Also from that post it says I should also change out my spark plugs after a carbon cleaning. I'll pull the plugs tomorrow and see if they are gunked up and need replacing.

I've read in a lot of posts where people say it took sometimes 10-15 tries before the car starts. I've tried 3 times so far, but I am afraid to do more in case my timing chain was messed up from me manually turning the engine in the wrong direction. To those two have done carbon cleaning, what did the engine sound like during those 10-15 times before it worked?

 

It took me 4 trys to get it started. It ran poorly for a little bit. I turned it off, then restarted. Been perfect since. I really wouldn't worry too much about it. Keep trying and it'll go. It just takes some cars more trys than others.

 

Thanks for your input. Did you clean/replace your spark plugs when you did the carbon cleaning?

 

I had replaced them a couple months prior, so I left them alone.

 

Yeah similar situation I changed mine 10k miles ago so it didnt even occur to me to change them out for the carbon blasting procedure.

 

My plugs got flooded when I tried to start my Mini after carbon blasting and wouldn't start. Maybe take the plugs out and blow air in the plug holes, or let it sit overnight to dry out.

 

So I got home and pulled the spark plugs and everything seemed fine with the plugs. I looked into the cylinder and one of them clearly had some black carbon goo on the top of the cylinder head. It seems my problem is similar to this: https://www.northamericanmotoring.co...ml#post3631902

I wonder what kind of solvent is used?

 

If you want your combustion chambers clean try a few bottles of BG 44K Fuel System Cleaner, it's the last step one would take short of removing the head for cleaning. I had a ton of black carbon on top of my pistons, it was bad! I went through six bottles of the BG 44K and now piston tops are clean. You can't just buy it anywhere, Ebay or a BG dealer.

 

I got some at Amazon. Stuff is pricey, but it sure pays to be a Prime member for shipping. I just used my first can in a fill up recently but did not use a can in the successive fill up. I can tell the difference. I just had my valves cleaned, too. Next tank of gas gets another can. I'm going to change out the tank fuel filter this time as well. I think I'm on my way to solving a rough idle cold start that has been haunting me the last few weeks.

 

Don't forget to refill your gas tank after you run your tank to half full, this why your maximizing the product. It treats 20 gallons and we only have 13.2 gallon tanks.

 

I typically refill with 93 with 1-2 kernels still showing. Pour in additive, add fuel for a good mix if it mixes. I think it must. I like the strength of a can per full tank! >: ) I'll get it that low for filter change too.

 

Is there any way to verify that the injectors are clogged due to carbon gunk that leaked into the cylinder? And would a single gunked up cylinder so the car from starting?

 

I seriously doubt that, those injectors are under so much pressure. How many crank sessions have you had?

 

I am probably up to 15 tries total. Tried on three separate occasions 5times each.

I just got done doing a compression test and its my first time doing one so please let me know if I should do anything differently. I took out all the spark plugs and then attached the guage to each spark plug hole individually. I tried cranking for about 8-10sec before taking the final reading.

I did the dry test first and by the time I was done testing all cylinders dry, the cylinders were alll pretty flooded. I then added about a 1/2 capful of oil to each cylinder and did the wet readings.

1. Is there a way to stop the fuel injectors from injecting during this test?
2. Does the gas in the cylinder affected the oil from properly coating the top of the cylinder head for the wet test?
3. How long should I let it crank and pressurize before taking a reading?

Dry
cylinder1: 80
cylinder2: 60
cylinder3: 60
cylinder4: 60

Wet
cylinder1: 170
cylinder2: 100
cylinder3: 100
cylinder4: 180

 

Also, I was reading through the bentley manual and saw this: page 130-40 "After reinstalling (throttle body), use MINI scan tool to check for fault codes and reset the ECM memory. Reset throttle plate adaptation values following on-screen directions. If the adaptation process is not completed, the engine does not start.

 

Were you measuring compression with engine at operating temperatures? If these were operating temperature reading things don't look so great, you don't want all 4 cylinders that far apart, 180 versus 100.

 

Well, my car doesn't even start right now right, so definitely not operating temps.

 

1. You can remove the appropriate fuse(s) to disable the injectors, but don't need to.

2. No. You're not coating the cylinder head....you're getting oil down around the piston rings to seal them.

3. Just crank long enough for the pressure to stabilize. Need to be watching the gauge while cranking.


Your test readings vary sooo much, You need to do them again, carefully, to verify.

Dry test low...bad rings or valves
Wet test greatly improves compression....bad rings
Wet test does not greatly improve compression...bad valves and still maybe bad rings.

A bad valve indication could also be (If you DID screw it up by rotating the engine backwards) caused by bad valve (cam) timing.
The Bentley Manual has the procedure (simple) for verifying timing.

All that said...I doubt that the timing is messed up. Check it anyway.

If the timing is OK, the low compression (if it actually exists) won't keep the car from starting. So you're back to square one.

As you have noted...messing with the throttle body WILL confuse the ECU. You can have MINI reset the system or keep cranking until the car figures it out for itself (Hopefully).

 

I am at work and don't have the manual handy, but don't I need some special tools for this procedure?

Also, I plan on redoing the test. I will let it crank until the pressure stops going up whereas before I only did a 5sec count. This morning before I left for work, I still see pools of gas through the spark plug hole of each cylinder. Can I continue to do a compression test with fuel in there?

Is a half capful of oil enough for the wet portion of the compression test?

 

If you try to start your Mini with fuel in the cylinders that would be very bad because fuel isn't compress-able, it's a solid. I bet by now you wish you had just paid the money to have a professional clean your valves, I have learned form threads like these. What a nightmare!

 

I've only done the compression tests with fuel in the cylinders. so I don't think it ever compressed as the chamber was not fully sealed because of the sparkplug hole. Before I was able to vacuum it out with a small tube.

Yeah hindsight is 20/20

 

Hard to imagine that you're getting THAT much fuel retained in the cylinders. You mentioned coolant in the original post...and overheating. If, after your repairs, there's any coolant in there, you've probably lost the head gasket. If no coolant, there's probably not enough fuel to cause hydrolock, but would likely "wash" the rings and negate the sealing effect of the added oil. I'd either suck or blow (rag over hole) the excess fuel out. Yes...1/2 cap of oil should be enough.