Hey guys so I will be removing the head soon, will be working with a friend as my knowledge is limited.

I realise that I will need to have the special tool to lock cams which is fine.

My question is I believe the piston rings are worn (white smoke on idle after driving) which is what I want to replace. A pressure test was done and cylinder 3 and 4 were low with 4 being the lowest.

From pictures I've seen I see that the pistons will all be sitting level when the head is removed. If so how can I lift the pistons and will this mess timing up? I have no access to a Bentley manual and on a serious tight budget.

 

You will need to take the pan off the bottom of the engine inorder toget the bolts off the connecting rods then the pistons can come out the top of the engine. Replace rings and put back in each proper cylinder. Check bore of each cylinder to make sure is round and not damaged. May Require you to pull whole engie out if you need to bore the engine.

 

Try to not remove the chain off the gear at all, some make a mark on the chain and gear, put zip ties on it to keep it from moving or falling off the gear. Use a tie, rope etc. to keep tension on it and hang it from underside of the bonnet up out of the way. if you look at some of the DIY for cam swaps youll see what I am trying to explain, got a link below for one.

http://www.werkinmini.com/R50-R53%20...stallation.pdf

 

Thanks Martin if I need to bore the whole engine, would that mean I would need a bigger piston? Would a visual inspection suffice or do I have measure the bore with a certain tool. And should I wait to order the rings incase.

Also the head gasket seems to come in two sizes I think one is a 0.90mm and the other 1.23mm something like that, would it be safer to get the thicker one incase the head is not flat and needs machining.

And finally I am tryin to wrap my head around this whole timing issue. If I have the special tool and I lock the cams and remove the chain and sprocket, and if for example I have to send the head to be machined, does that not mean I have to remove the locking tool and in turn remove the cams in other words is the timing going to be messed up or is the timing somewhere at the bottom of pistons. I do apologise for the 101 questions, I will be getting help from someone that knows engines but as they haven't done a Mini before I'm just hoping to learn something and spot anything he may miss.

 

Thanks so much for that, I think I got what you mean. But il run it by you.

So BEFORE removing the tensioner bolt I would need to get a rope and tie it from end of chain to the other. Keeping it as tight as it is. Then on the gear mark the chain and arrow to keep it aligned.

Once that's done do I pull the whole chain and sprockets out in one piece and hanging it somewhere. This is the part I'm a bit confused about.

Thanks again for all your help.

 

Yes to all questions you posed in your previous post. I think it would benefit you to buy the Bentley manual as it will make life easier for you and will give you all the specs for the engine. Make sure you get the right manual 1st vs 2nd gen.If you look around on internet you can usually get a cheaper price rather than retail.

 

What were your compression test numbers?

Did you do a leakdown test? I wouldn't be doing bottom end work without knowing 100% where your problem is. You could have something in the top end that is causing the low compression while you're already planning on de-kitting a cylinder Not trying to be a d1ck, but really make sure you are certain what the root cause is!!!

 

I had requested a leak down but the guy did a pressure test and said the problem was cylinder 4.

The machine he used measured in bars. The readings were as follows.

9.8 bar cylinder 1
9.5 bar cylinder 2
9.4 bar cylinder 3
8.5 bar cylinder 4
When he put oil in cylinder 4 it jumped to 12.7 bar.
The spark plug on four was also very fouled looked like oil was blowing by.

I really would have preferred a leak down test as well but he didn't come with a compressor.

So would you say we on the right track or still could be something top end?

 

A compression test only identifies if the cylinder is weak. From there a leak down test is required to find where the leak is occuring. If your friend told you to skip the leak down time to find a new mechanic. It's a known issue that exhaust valves crack and even carbon buildup on valve seats can cause compression problems. It could very well be that, but you need to do the proper tests to determine the root cause. Do not automatically diagnose it as a piston ring issue. I am sitting here clenching my teeth in worry for you now. It sounds like there is a lot of uncertainty with the people that are helping you, and that is not a good thing when you're dealing with engines that demand precision and careful attention.

If I was in your shoes, I would be looking for a mechanic that knows what they're doing.

 

Tell me about im cringing myself, but I'm so pressed for time that I kind of gave up hope on finding a decent mechanic in the country I'm in. Seeing as the parts have been ordered I'm just going to start from the bottom and make my way up I guess. Hard lesson learnt for sure.

Plus side to this I guess is that it should push the car a couple more years.

 

I rebuilt a 12 cyclinder Jaguar motor once. The machine shop swore the jugs were within tolerance for a hone and re-ring. Thing was the best mosquito fogger ever made. Ring never did seat. Ouch.

 

Best advice in this entire thread. With all due respect, you're WAY out of your depth here.

- Mark

 

Oh I don't doubt it, but you live and learn I guess and that's what forums are for. So I'll keep trodding along and asking away I guess and those that want to contribute by all means feel free.

I'm a person that is not afraid to learn, as daunting as this task seems, I've never backed down from a challenge.

I will keep you guys posted.

 

I'd have to agree with Shane. You don't embark on heavy engine work with little to no experience with LITTLE OR NO MONEY (you said you are on a tight budget) all based on a single compression test and some smoke coming out of the tail pipe.

I do applaud your willingness but if I was you, I'd do a little (actually a lot) more investigative work first. Remember that with any project it will cost three times more than planned and take twice as long.

If you do end up doing the work don't even start without the manual.

 

On the timing thing try not letting the chain come off the bottom gears by keeping it pulled tight and hooked or tied out of the way. leave the upper gear in the chain by using zip ties and also a mark on the chain and gear in case the gear and chain get separated for some reason.

 

Most definitely I agree with pretty much everyone's opinion on here and I know you guys got my best interest at heart.

So just to clarify I have the BMW TIS manual. Where I currently am, I am unable to get hold of the Bentley manual it would require me to order one from overseas and that could take weeks.

I understand that TIS might not be as detailed as the Bentley but I was hoping that whereever I got stuck you guys might be able to chip in.

And to finally clarify I am working with a friend who is a mechanic but has never worked on MINI's, this is not the person that did the pressure test. If you look at my other threads I had contacted this guy to do a leak down test and he said he could, but when he came to the house he said he forgot his compressor but would do a pressure test.

After the test I still told him I wanted a leak down test, and he promised to return but kept giving excuses so I gave up on that. Unfortunately I had to go on a work trip, so I left the car behind and haven't had a chance to investigate further.

I noticed that you guys believe there could be more to the low compression in cylinder 4. I understand that if the exhaust/inlet valves are damaged or carbon built up, it could cause the low compression,

What I don't understand is when the oil was poured down the cylinder, the compression jumped up. I'm not sure how good or bad my compression numbers are anyone care to chime in.

And before I forget, I only saw this cloud of smoke start to appear after the car was decatted. Unfortunately they removed the cat and I didn't think i would need it so they dumped it. This is the first cat (didn't have two cats). Could the cat have just been hiding this problem for a while or did the free flow cause something to go wrong.

 

So if I understand correctly, I should make sure the chain doesn't come off the crank shaft sprocket gear at the bottom, and after removing the head to replace the two gears and find a way to tie it out the way. In other words try to keep the chain in the condition as it is when it is bolted up?

 

Well just thought I should update you guys on whats what. So as you know I had this cloud of smoke coming from my exhaust mainly on idle and it had only started after a decat. Had a pressure test done by a useless not sure what to call him, who claimed cylinder 4 was low on pressure and that it was the rings. After much researching I came across a few people that had decated and also pcv deleted.... and well there was the problem... THE PCV DELETE, there is pages upon pages of people claiming that it doesnt cause any pressure in the crank case few saying it does. But to cut a long story short.... bought a new pcv pipe and within minutes the smoke was gone and has not returned.

I am yet to get a proper pressure test done to confirm is cylinder 4 is really down.

Also discovered today damn today has been a good day... was that the Diverter valve cover that holds the rubber had broken off and was giving the CCID 029. I had a friend run his diagnostic machine which gave the correct code for the diverter valve and no the open ended CCID 029.

Just to make sure it was the DV I put it back together glued the sides down and voila ccid 029 gone and fulllllll boost was back.

So there we have it thank God I don't need to remove the head thats all I am saying.

 

Great news!

 

Yea like with anything start small and fix the small items first before just diving in and saying "It needs a new engine" when in actuality, you just need new plug wires lol (just an example)

 

Glad to hear you got your problem solved with a couple of simple fixes.