My 1990 W124 300TD Diary

[Sorry Pete]

Ah yes- thanks for reminding me why it's better to suck out the old rather than disconnect pipes: potential introduction of air. I did use a syringe and a similar method to what you describe on my 190D about 7 years ago. I forgot that there's a filter in there and hadn't heard about using 2 filters, though that makes sense. Thanks- I'll follow your advice/instructions.

Others have pulled the return line, and had a friend start the car whilst collecting the old fluid, and watching the reservoir doesn't empty completely. I hear that the fluid runs-out at a rate of knots, and find my method sufficiently effective. In any case, it's better than leaving the 20 year old fluid in there. IIRC The PAS should self-bleed most effectively by raising the front so there's no load on the wheels, and twirling the steering lock to lock 10+ times.

He he- so much for self-priming eh?!

Quite The battery was low in any event, but at least I'll know what to do if it happens again. The Haynes manual says nothing about that eventuality.

Yes, SVO is known to dislodge some of the crap left behind by Diesel in the fuel tank and system when you first start using it..... Didn't seem to affect the tank strainer though- I never had to get involved with it.

That's a relief. Did you pull-out and clean / renew the tank strainer and o-ring in the w201? I know what's involved in pulling out the tank in the saloon w124; I don't particularly want to do it if it's not necessary. Access to the strainer is far better in the estate.

I had my 190D's wiper suddenly stop on me on the motorway once due to the gearbox mech seizing. Scary stuff!
When that happened a few years ago I bought a NOS part from the 'Bay which I have kept hold of, so I have a nearly new backup, but I would like to keep the original going for as long as poss.

I'm not entirely sure the w201 and the w124 wipers are the same though they might be interchangeable. Don't even ask what they're asking for at the stealers. I have an ebay backup as well.

Thankfully the aerial hole's looking OK and there's only the slightest sign of rust starting inside at the bottom of the O/S rear window. I'm wary that seeing a tiny bit of rust could mean that something more severe is lurking out of sight, but will be investigating and hopefully sorting out. Hadn't heard about the tops of the rear door being a potential rust area- will investigate. Do you mean the hatch or the side doors?

The official MB Club gazette ran a piece this month documenting a repair of the rear n/s cargo window. The cost of that repair would have consigned my 300d to the scrapper. The w124's also seem to go at the forward rear suspension bushes. Rot there can, and has spelled the end for a few forum members' cars.

The tops of the rear side doors are a potential rust area, though not many people check here. Most of the cars I saw suffered from bubbling on the top frame, under the rubber seal.

Yeah, the aerial's been sticking sometimes when retracting. I'll get the meths & lube on it. Hadn't heard about the fuel cap potentially sticking- thanks for the heads up, will sort that too.

IIRC I read that any lube heavier than silicone spray will gum-up the aerial. The fuel filler flap - I've heard of it sticking once. When the guy had pulled up to the pump. Preventative maintenance and all that.

Having seen the pics, yours looks to be in good shape. How many miles and how much was it, if you don't mind me asking? I'll be getting an estate at some point as a workhorse to help with my house move and renovation.

 

[chilsta]

Hey.

I had the same light issue with my SL from 94. Guess the systems could be similar? Turned out that the rear lights had been bodged to keep them both on when there was a problem in the lighting system. It was eventually diagnosed as a relay issue, which are in the fuse box behind the fuses. It's a known issue and may have affected yours too. I got the relay replaced but there is some suggestion that it can be dry joints within the relay itself.

Worth a look considering the relay was about a hundred notes!

Good luck with the rest, look forward to hearing updates!

Too right - for God's sake change or check the relay as the last thing Sorry if I didn't make this clear, which I didn't

Thanks to you both. Yesterday I changed the remaining bulbs in the sidelight circuit and cleaned their contacts, yet the flimmin warning light's still coming on. Reminds me a bit of that old Jasper Carrot sketch about trying to turn off Volvo lights... Anyway- next stop is to check out the relay.

 

[chilsta]

Yesterday I changed the fuel filter. It would only just squeeze out past the top rad hose, but not too bad. Filled it with Lubro Moly Diesel purge, but haven't started it yet. Will be using the remaining can and a bit to run a proper purge. Hoping for some injector quietening and smoothness.

Also replaced the 2 o-rings on the oil filter housing central tube. If these become hardened with age they can reduce oil pressure. As I'm replacing all the service items I can, I did these. Part number is A 015 997 94 48 and they're called "seal ring . engine . vlrub". They're only a few pence from MB, but don't come standard with the oil filter (the large o-ring for the top does, as do replacement copper drain plug washers).

Have ordered a new thermostat from MB as the engine is running too cool- it's normally under 80°c and I figure it would make sense to stick a new one in when I flush the rad/ block and add the new coolant.

Also added the car's first 30 litres of veggie oil.

 

[chilsta]

IIRC The PAS should self-bleed most effectively by raising the front so there's no load on the wheels, and twirling the steering lock to lock 10+ times.

Thanks- I hadn't heard that tip before. The PAS change is getting nearer the top of the list- just need to pick up some filters.

That's a relief. Did you pull-out and clean / renew the tank strainer and o-ring in the w201? I know what's involved in pulling out the tank in the saloon w124; I don't particularly want to do it if it's not necessary. Access to the strainer is far better in the estate.

No- I don't think that was done while I had the car. Never had fuel issues other than leaking feed lines at the injector pump shortly after the installation of the Elsbett kit. They needed their seals changing which I entrusted to a local diesel specialist. Also had to replace the return hoses after 6 years due to a small leak that they thankfully picked up on at the MoT one year. It was actually the dead end cap on the end injector that had split, but I took it as a sign to replace the whole run while I was at it.

I'm not entirely sure the w201 and the w124 wipers are the same though they might be interchangeable. Don't even ask what they're asking for at the stealers. I have an ebay backup as well.

Yes, indeed you're right. I had in my head that the part number of the replacement started with 124 so would fit, but having looked at it, it's a 201 part # & the 124 wiper chassis is totally different. I think the gearbox and motor are the same though- might keep it for spares after checking that they would transfer over.

The official MB Club gazette ran a piece this month documenting a repair of the rear n/s cargo window. The cost of that repair would have consigned my 300d to the scrapper. The w124's also seem to go at the forward rear suspension bushes. Rot there can, and has spelled the end for a few forum members' cars.

That doesn't sound too good. Hoping the rust on mine's stoppable or at least slowable.

IIRC I read that any lube heavier than silicone spray will gum-up the aerial. The fuel filler flap - I've heard of it sticking once. When the guy had pulled up to the pump. Preventative maintenance and all that.

Thanks very much- both have been cleaned and well lubed.

Having seen the pics, yours looks to be in good shape. How many miles and how much was it, if you don't mind me asking? I'll be getting an estate at some point as a workhorse to help with my house move and renovation.

It's done just over 200k and was just over £900. I'd budgeted for a fair bit more, so have some funds for repairs and sorting.

 

[Sorry Pete]

Also replaced the 2 o-rings on the oil filter housing central tube. If these become hardened with age they can reduce oil pressure. As I'm replacing all the service items I can, I did these. Part number is A 015 997 94 48 and they're called "seal ring . engine . vlrub". They're only a few pence from MB, but don't come standard with the oil filter (the large o-ring for the top does, as do replacement copper drain plug washers).

Many thanks for that part number. I wanted to renew mine at the last oil change I did.

The forte treatment quietened the injectors incredibly well, but the familiar diesel clack is back. I actually like it!

 

[230K]

Also replaced the 2 o-rings on the oil filter housing central tube. If these become hardened with age they can reduce oil pressure. As I'm replacing all the service items I can, I did these. Part number is A 015 997 94 48 and they're called "seal ring . engine . vlrub". They're only a few pence from MB, but don't come standard with the oil filter (the large o-ring for the top does, as do replacement copper drain plug washers).

Hi

I am puzzled as to why these 2 o rings are quoted by MB as the same part number when quite obviously they are different sizes.

Did you question this too??

230K

 

[chilsta]

Hi

I am puzzled as to why these 2 o rings are quoted by MB as the same part number when quite obviously they are different sizes.

Did you question this too??

230K

The part number I quoted is for the oil filter o-rings, which are both the same size.
Are you thinking of the o-rings inside the fuel filter? They did come with my replacement filter and are indeed different sizes.

 

[230K]

Hi

On our 603 engine the long hollow bolt that goes down through the centre of the oil filter has a taper at the end of it and in my opinion the o rings should be different sizes. The lower of the 2 being the smaller diameter.

Is your not the same??

230K

 

[chilsta]

Yes, you're right- the difference between the 2 diameters isn't as great as the centre of the fuel filter, but there is a difference.
I've bought these twice from MB and both times the pairs of o-rings have been the same. This time I had to find them on the EPC image as the counter guy didn't know what I was talking about- they were both listed under the same part number. Be interested to hear if you can find out anything different.

 

[chilsta]

Fuel starvation and hopefully the cure

The last long journey was interesting. The cruise control worked both directions of the 100 mile round trip, but about half way home I could feel fuel starvation.
This is most likely due to the tank strainer clogging due to the first half tank of veggie oil dissolving some of the Diesel sludge in the tank.

So I'm going to remove the troublesome strainer from the tank completely, run 10mm inside diameter semi-transparent nylon send and return hoses which will offer less resistance and allow any air in the fuel system to be seen and I have bought this filter and hand-pump setup from my brother:



(click for larger)

The pump will be mounted to the inner wing and the filter is connected directly to the pump. I've got a spare filter element and an aluminium bowl that I'll carry in the car in case of any issues. (He's going to be selling these as kits soon if anyone's interested).

This means the initial point of filtration is accessible and road-side repairable, rather than being at the bottom of a potentially full fuel tank.

I'm still planning on adding the larger axillary heated fuel filter in parallel with the factory filter and using the switch as a backup, should the axillary filter get blocked. That and a heat exchanger.

 

[chilsta]

An update on what's happened in the last month.

I've removed the strainer & run 10mm ID nylon fuel lines. Mounted the hand priming pump & glass bowl filter (pictured in the above post) to the inner wing using existing threaded studs to avoid any drilling and associated corrosion problems.
Still to add the secondary heated fuel filter and heat exchanger which I'm hoping will fit near the battery so that it's well insulated. I think I'll wait until next year and things warm up a bit before attempting this work. Will make a separate post about the new fuel lines as soon as I've taken some photos.

The car failed its MoT on parking brake adjustment, corroded flex hose ferrules and a small rust patch next to the N/S rear anti-roll bar mounting.

Adjusting the parking brake took 30 minutes- the star adjusters are pretty difficult to get to (probably easier if you have a special tool rather than a screwdriver). I do have a special tool for similar adjusters from my old '67 VW Microbus, but unfortunately it's too big to go through the wheel bolt hole.
Parking brake now works better than my 190 one ever did.

Had the ARB welding done for £30.

As well as the hoses, I ended up replacing all of the rear brake pipes from the hex joiner under the front passenger floor rearward, as it looked like it could all do with replacing while I had the system apart. The N/S bleed nipple snapped and using a stud extractor proved unsuccessful, so I ended up getting a recon calliper from Camberly Auto Factors (£83 after core rebate). I originally bought one from Euro Car Parts for £65 but when I got back to the car it turned out to be for a smaller diameter disk and had smaller pistons. I guess this was for a 300D.
The correct TD model was cheapest from Camberly's and came supplied with the pad mounting pins, anti-rattle shims and assembly grease (the calliper from ECP only had the grease). Mercedes quoted me £154 for a new calliper.
I have smeared a small amount of the brake assembly grease on the threads and silicone sealant around both rear bleed nipples in an attempt to avoid future problems with them shearing due to corrosion.