Hey Everyone,
Just recently picked up a 2004 R53 as a project. It has 147K on it, does start, run and drive (although no power steering and brakes barely work). Some cosmetic issues (dents, some slight rust issues, nothing major). I posted in the first gear thread, but figured I would start my project thread. Build plan at this point is to get her running healthy and somewhat reliably with some minor performance upgrades for a weekend fun car. I'm not necessarily in a rush so I will will post and document as I go through. Things that need attention:

• Brakes
• Power Steering
• Engine Health, general overhall
• Suspension
• Cosmetic

I'm sure the list will grow as more details emerge. Looking forward to the project and sharing my experiences.

 

So I figured I would create a separate post for some of tonight's findings so i can maintain an on going list in the first post of things to do. Tonight I did a compression test, both dry and wet. Removed the wires and spark plugs, all of which were pretty black. Removed the fuse for the fuel pump and hooked the battery up to a battery booster. Dry compression test resulted in the following:

• Cylinder 1: 100 PSI
• Cylinder 2: 100 PSI
• Cylinder 3: 150 PSI
• Cylinder 4: 120 PSI

Obviously this is not good considering the variation across the cylinders. Just for the hell of it, I did a wet compression test which resulted in the following:

• Cylinder 1: 120 PSI
• Cylinder 2: 120 PSI
• Cylinder 3: 180 PSI
• Cylinder 4: 175 PSI

Considering the increase, I think its safe to say that the engine is in need of a major over hall. Its funny as it doesn't necessarily run that bad. Not rough or anything. Not sure of the history of the engine so I don't know if it was overheated or what (coolant is missing from the tank, I'm aware of the typical coolant tank problems). Being that I'm new to the Mini scene, curious what the success rate is on an engine rebuild. Am I better off buying a used lower mileage engine or should I have the bottom end/head rebuilt and I reassemble? Anything else to consider at this point (is the block one that can be bored or does it have a coating on the cylinder walls etc.). Thanks for all of the info!

 

Since it runs I would just rebuild the head with new valve job, guides and seals as that is what the normail worn out parts are.

 

I was going to do a leak down test to make sure I don't need rings or there is nothing else going on, If I only hear the air coming through the valves, I think your right. While i have the head off, I was thinking it might make sense doing the rings (and rod bearings since that would have to be done). I would inspect the cylinder walls to make sure nothing is needed there. Just want to do a complete refresh on the engine so I can a good 50K out of it still.

 

THIS thread from forum member xsmini should be of interest to you.
Last I saw, he had over 405,000 miles on his engine...

 

So I am picking up the same car from my brother-in-law in two weeks. 04 Cooper S, 96,000. I have to do bushings and steering, not sure what else. I'll be very interested to follow your progress as I am building mine.

 

Finally had the opportunity to make some progress on the Mini. I did do a leak down test and heard air escaping through the oil dipstick tube as well as intake/exhaust and other pistons. So it seems like a full rebuild is in order. Finally got the engine out, separated it from the transmission and it is mounted to my engine stand. Plan is to dismantle completely, have everything checked and put it back together. I will send the head out to get checked and rebuilt as needed.

 

What are your thoughts on getting the supercharger rebuilt or buying a rebuilt one? I'm at 209k miles with my mini and I my supercharger is still alive (knock on wood), but I've heard others say that theirs have only lasted 70k. It would be a shame to rebuild the engine and have the supercharger die right afterward.

Just some food for thought.

Cheers,
Duane

 

 

Had some time to further dig into the engine today. Unfortunately Ihad to drill 4 of the bolts holding the valve cover onto the head as the head of the bolts were so rusted they disintergrated. Luckily I was able to back the rest of the bolt out of the head with channel locks so no biggie there. As i was removing the cam shaft to get the head off I noticed there was some pitting on the 2 of the cam lobes:



I'm thinking Ill need a new cam shaft so I might as well get a mild cam in it. As I dug in further and got the head off, I found the biggest part of the problem:



Looks like it burnt up. Question is why and what is the damage? There was still coolant in the engine and radiator when i brought it home but the tank was empty. Could it have messed up the head in general, who knows. The underside of the head looks decent, although some of the valves look burnt. I'm going to bring it to a local shop to get the head checked and to do a full valve job. The other side of things, the pistons look good aside from some carbon build-up. The cylinder walls look good too. I did hear some piston ring leakage thought when i did a leak down test, so I need to pull the pistons to replace the rings:


I'll continue to strip it down to a bare block to be boiled and checked. I still have some work ahead of me to get there. I will post more as things develop.

 

The cam wore out, most likely was a soft cam. I am sure this caused the cylinders to run poorly and heated the cylinder to the point of blowing out the head gasket.
The cylinders look good. Make sure the head and the deck are not warped!

 

Yeah, there had to have been some sort of failure, in addition to the pto gear that drives the water pump breaking, the water pump housing itself cracked where it meets the blocked. Basically completely broke off. So there was some sort of catastrophic failure. Almost have everything stripped down to the bare block. I'll bring both the head and block to my local machine shop to check and clean. I'm sure the head will need to be decked, but hopefully thats it and i can start reassembly asap. Considering pulling the supercharger apart and replacing the broken gear as it does turn very smoothly.

 

You could always use an electric waterpump! (although, I think it will work as it is) weird brake though!