What tools do i need to change the camshafts on my W126?

[jontyash]

So..after visiting Olly this week, he reckons my tappety noise from the engine is, in fact caused by worn camshafts. I'm looking at around £1500 to redo that which is out of my price range totally.

So I was chatting to my dad about it and we both quite fancy having a go at doing it ourselves but before I jump in and order the bits to do the car over Christmas - can anyone offer any advice?

The main things I need to know are:

1. What specialists tools will I need to do the job?
2. What other bits should I change/other jobs I should do whilst I'm doing there
3. How much will those bits cost me? Camshafts and what not?
4. Where should I get the bits from to ensure they're a good price/quality.
5. How long can I expect it to take us?
6. What are my chances of completely ruining my W126 in the process?
7. When doing a big job like this - what guide is best to use - ie: Haynes/Merc CD or other and what will that cost?

I know it's a lot of questions to answer but if anyone can help out here that would be great - then I can gauge whether to give it a go or to just run it round as is until it breaks!

Thanks guys, I'll await your replies! :bannana:

 

[alexander patie]

this is not an easy engine to do this job on. the tappets, although hydraulic, will need shimming to work properly with a special tool. the guide rails need changing too, as do the oil pipe plastic glands. the camshafts need the housings unbolting to remove insitu - this can be tricky as half the bolts for these are cyl head bolts, and the others tend to seize! you will also need a tool to press down the valves to remove the followers. has olly seen worn lobes then? the 500s were mostly ok, but the much earlier 350s were terrible in this respect. good luck!

 

[jontyash]

Thanks that's great. I know it's not going to easy but that's kind of why I want to do it. I'd learn so much from my dad in the process it would be awesome. My dad's not a mechanic or a brilliant amateur even but he's never failed at anything he's tried to do in the past so you know...I have complete faith! Lol.

Olly had a good listen but didn't see worn lobes no. Saying that, he was pretty sure that would be the problem. I wish it wasn't..

Which manual would recommend to use for novices?

 

[goldestate]

A second opinion before starting work !
Oh and my congratulations for having one of those can do dads they are very usefull !

 

[Smiley]

I would re-read Alexander Patie's post. He is telling you a lot in there that is answering your question 6 - my take on it is that the answer to Q6 is about 50/50.

 

[grober]

I would be somewhat wary of rebuilding a V8's valve gear as a complete novice on this type of engine unless your Dad has rebuilt Merc V8's before. This is no 4 cylinder cast iron block Ford we are talking about here. No offence to your Dad intended. You need to ask yourself some hard questions . What is the overall value of the car --is it worth rebuilding the engine at all--how many miles has it done? Is the body badly affected by rust? etc Is it worth looking out for an MOT failure car to transplant the engine-- I would not recommend buying a second hand engine that you can't hear running however --hence an entire mechanically sound donor car that's failed on body rot is your best bet . An engine transplant is in many ways a better "gifted amateur" proposition than an extensive top end rebuild. If the car is not terminally noisy and liable to blow up I would be inclined to run it as is and keep a look out for a good donor car.

 

[alexander patie]

I would re-read Alexander Patie's post. He is telling you a lot in there that is answering your question 6 - my take on it is that the answer to Q6 is about 50/50.

HARSH!! . "can-do-dads" generally make good in the end, even if they have to pay for it .

tappets on these 117 engines can be very noisy, have the rocker covers off to inspect the lobes and followers before ordering any parts - if they are ok have a rethink.

 

[jontyash]

Brill thanks guys - I'll duly discuss it with dad, see what he says! Buying a rottter with a good engine was also on the list of possibles.

You see the rust problem is ok on this merc, it needs a little work but it's generally ok. I thought - if I could get the engine sorted then it would be my labour of love over the next few years to bring it back up to standard. I'm probably just dreaming but you know, it would be great to have a car to work on like that.

The suspension bushes need redoing in time, as do the front wings but they can wait till I've got the money you know.

Ok, so I understand it's massive task for amateurs to rebuild a V8 but therein lies the challenge no? More investigation required...

Does anyone know a ballpark figure for buying the parts to do the job? Am I talking £200-£300 or £500 or what? That's the real decision maker as far as I'm concerned.

 

[219]

I'd be inclined to give it an oil change with some flushing oil through it in between .

My 500 can tend to start sounding tappety when an oil change is due , but returns to its sweet quiet normal after new oil and filter .

I've had the same on a couple of M103 six cylinders , one of which regularly tapped away for 5 or 10 seconds after startup then settled down , I put 100K on that car without any trouble and just accepted that was the way it was .

If you do decide to proceed , then definitely replace the timing chains when doing it .

Haynes don't have a workshop manual for the W126 or any other car with the M117 engine .

An 'official' MB workshop manual would be your best bet , people sell CD's on eBay and sometimes printed ones circulate as well but they tend to be expensive .

 

[khimani_mohiki]

I was thinking of doing some top end work on my SEC, strictly amatuer though, im not putting grands and grands into it though when second hand engines are a couple of hundred quid on ebay. I have the W126 service manual on my computer, if anyone can point me to an FTP i can upload it

 

[grober]

I don't know if this is specific to your car or not without the chassis number but Êàòàëîã

prices from Inchcape MB online site Mercedes-Benz Parts, Inchcape but will give you an idea. No doubt there are cheaper sources but new engine bits for that engine are going to be rare.

camshaft left A1170510801 =£494-73

Camshaft right A1170510901=£494-73

That's before you start on the timing chain/tensioner/tappets etc

 

[Smiley]

HARSH!! . "can-do-dads" generally make good in the end, even if they have to pay for it .

tappets on these 117 engines can be very noisy, have the rocker covers off to inspect the lobes and followers before ordering any parts - if they are ok have a rethink.

It was not meant to be a harsh post - just a reality check after your v helpful summary that tells me that this job is not exactly a stroll in the park.
But youre right the good ole dad will probably end up with the bill!

 

[jaymanek]

i could sell you a complete engine for a fraction of that!

 

[lynall]

I to would go with the 2nd hand lump idea.

If cams worn that bad what else is worn?

£500 for a cam



Lynall

 

[alexander patie]

one more vote for the s/h engine - depending how bad the noise, and if the cams ARE worn.

 

[jaymanek]

depends how bad the tap is.. have you tried changing flushing and changing the oil?

Ive never heard of worn cams on a W126.. maybe a sticky valve? are you getting any misfire?

My R107 has a light tap, its always been there but does no harm.. its only done very low miles!

 

[andymerc]

As above and remove rocker covers check cam lubes and feed pipes for blockages.

 

[jontyash]

Hi All and thanks for your replies!

I haven't changed the oil yet no but it looks nice and clean. It is misfiring yes, not a lot but it especially when on idle. You can barely notice it though.

One thing I noticed today while flushing the coolant - the noise only comes from the nearside part of the engine. I listened really carefully and the other side is definintely not a loud.

I'm just guessing but wouldn't both the cams wear out equally? Wouldn't I have the same noise on the other side of the engine too? Maybe not but just wondering.

Looking at the price for new cams, there's no way I can do that. I'd definitely go for a second hand lump if the cams are £500 a pop! Jees!

As far as FTP sites go - there's Free File Hosting - File Dropper: File Host for Mp3, Videos, Music, Documents. or A quick and easy way to send large files - simply Mail Big File which are both free - I'd really appreciate you putting that document up there, thanks!

 

[jontyash]

I'll post a video on Youtube tomorrow with the engine running - you can all hear it then! lol. I'm sure you won't be interested but I'll do it anyway, it'll be fun!

 

[khimani_mohiki]

both GSF and Euro Car Parts do cam shafts and most of the other bits you would need, reasonable prices too. Could always try german ebay as well.