bmwmilos

450 CDI disassembly and overhaul ( some help needed )

41 posts in this topic

I also went to recharge the AC system. After arguing with the guy at the workshop about gas quantity ( 620g vs 450g he claimed ) he evacuated the system,vacuum tested  and charged it. I went away and the next day again no AC. I went there again to see what is wrong and he wanted me to leave the car there for a couple of days for them to verify where the leak is. We went away for vacation one week so I left the Smart there. I went to pick up the car on Monday, started it and the AC worked,but very weak. It was a very hot day so I thought ok. The guy told me that they checked everywhere for leaks and could not find any. He showed me the special UV lamp, a probe for inserting in air grilles to detect R134a gas leaking from evaporator, and told me that he recharged the system again and the Ac worked for 2 days in front of the workshop.....

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There is an updated hose kit that stops the leaks.  Mine has held firm since 2010.  8 years!

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The next day again no AC ...

I was pissed off, I went there again, he recharged the AC again ( that's a total of 1.8 kg of R134a ) and gave me money back nad told me that I should dosmount the entire car and take it to some other AC tech for diagnosing...

It was 38 degrees C outside so I waited for 8 PM ( a bit cooler then ) and then dismounted the front end in 15 minutes. I took my "special" UV lamp ( 2$ ebay ) and illuminated the condenser and it shined bright green on both sides. I also removed the air filter and checked the evaporator and there were no signs of leaking. I then eemounted the front end and then I realised that the "green" condenser is easily seen through opening in the front bumper.

So now I am waiting for new condenser to arrive, I will install it and then go to recharge the system somewhere else.

This I wrote only so you all can understand why I went to do the engine overhaul myself because most of the workshops here are at the same level of expertise..

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The hoses and connectors showed no leaks,not even on the quick connectors below the car ( I do not know if the hoses are upgraded or not - I did not find what is different about upgraded hoses ). So I think after changing condenser AC will be ok ( condenser is "eaten" by road salt from the looks of it )

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I have worked on a lot of cars that the AC has either failed from lost freon or seized compressors. After assessing the problem most if not all of them are slow leaks somewhere in the system. After evacuating l always use stop leak as a simple repair. Never had one leak afterwards. Stop leak is a must no matter if everything has been replaced. The best insurance l have found.

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This is beautiful...

 

   I wish I had gone to the same extent when I had the engine out. I only replaced the tensioner/gears etc.. and the lifters. You have done a lovely job... I would love to have a fresh engine like that right now.

 

 Well done!

 

 

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On behalf of 450 owners everywhere who read this thread, THANK YOU for sharing this tutorial and including accurate descriptions of the procedures with photos. 

 

Wonderful job!

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Thank you all for the nice words! I do not have a lot of free time, I am always working on some projects so I do not spend time reading the forum a lot, however as I already wrote if someone needs any assistance with engine rebuild or something else feel free to contact  me through PM or email.

Sorry for some photos, I realised later that some of them are bit blurry, but at the time I took them my hands were dirty and I didn't want to mess up the phone too much with oil and grease.

For the AC at the end I only changed the condenser and the AC afterwards is running like new.

I did other things, handbrake cables,rear quarter window seals,...

I am still having problem of water ingress on driver side ( LH ). On the right side I only closed the hole for the screw on mirror holder and the leak is gone. However on LH side I did the same but there is still water coming in rainy weather, I have to investigate further.

I am also having problem with gearbox oil leak and excessive play of inner CV joint in gearbox, but I opened new topic for that, hoping to get some replies. I think I am going to drop the engine again and dismount and disassemble the gearbox so that I can determine the cause and change the bearings when it's already opened.

 

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Well, I am now following your foot steps it seems....finally getting motivated to get it done.
I have engine now out, accessories all off, head striped bare, just need T60 torx to get head bolts out next........injectors are filthy!, lifters are slightly deformed on a few, rocker or two has some deformity where it strikes the top of valve, Oil change has been changed along with timing chain, but they will be replaced again seeing as I have new, I will rebuild high pressure fuel pump also, EGR will be removed permanantly along with all and any heater hoses and preheat tube as in blocking it off before it gets to EGR location, New turbo assembly, valve job and inspect valve guides, finally serious peek at pistons etc.   No sense not going all the way, imho. It'll have new starter, alternator with clutch pulley and rebuilt injectors with new nozzles. Water pump as well and thermostat mod. It already has rebuilt actuator, so now will check clutch fork for punch through issues.

Tomorrow I'll search for that T60 socket and continue.....augh.

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Hi Willy!

I'm glad you are also freshening up the engine. I also started with valve cover and after finding this and that I ended up with bare block.

In the meantime I also rebuilt the CP1 high pressure pump as it was leaking more and more. The seals were gone. The pump rebuild is fairly simple,only thing to watch is absolute cleanliness. I also scraped of the rust from the pump parts when disassembled, passed the pump heads  and non return valve seats with 3000 grit sandpaper on straight block and with polish afterwards. I did use a lot of brake cleaner. And that did solve the famous knocking sound during acceleration.

For the oil chain change also the tensioner and spring, I found that the old tensioner flexes to some extent more than the new one and the spring also showed some signs of wear. If you need any help I'm here.

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Oh and you need a long socket for head bolts. And I do not remember precisely,but I think it was T55, not T60, but maybe I am wrong.

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7 hours ago, bmwmilos said:

Oh and you need a long socket for head bolts. And I do not remember precisely,but I think it was T55, not T60, but maybe I am wrong.

I have a T50 and it was very loose , so I assumed it was a T60....so I will buy a set with both just to be safe, thanks.

 

Thanks for any and all help being offered....I too am a person who hates leaving a stone unturned and normally look for anything that could cause trouble in the future, so i expect the entire engine assembly will be completely rebuilt.

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Again great thread, just reread it again...excellent.
The only thing I am looking for is a good supplier for all gaskets etc and seals, lifter, valve seals, rockers.......did you replace every rubber seal inside engine as a kit or did you need to buy each seal separately..?  I am at the hours if not days of cleaning stage......and am thinking of finding  all necessary parts before I get to the installation stage.  Like you I will give the head over to a machinist and also the block for his opinion about pistons etc. So far everything looks very very good, hope I haven't jinx'd it...lol.  My pistons have a 1.0 stamped on them so from past experiences, that sounds to me like  they are over sized. IF so that'll mean everything else is relatively new also.....but the rockers show signs of pressure damage where the valve stem is striking it. Also lifter show a slight imperfection where they ride in the rockers..?  Everything but one bolt came out perfectly and easily, no fighting required so to speak. Again making me think it was done recently maybe? 

 

Any way if you have a list of the parts and their numbers I would be very appreciated of the information.

 

Going now to find a parts washer or gallons of cleaner...lol.

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