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Just secured a 450 SEL 6.9 after bit of a chase (years)

Started by andrewk, 18 October 2022, 07:38 AM

rumb

My theory is foam in hydro oil is escaped nitrogen from blown spheres.

Paint on your car looks good.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'16 AMG GTS

andrewk

Quote from: rumb on 18 June 2023, 08:11 AMMy theory is foam in hydro oil is escaped nitrogen from blown spheres.

Paint on your car looks good.

That's a pretty solid theory, Nitrogen can definitely dissolve in oil at high pressure. I'm going to replace the rear spheres as they are quite old, despite the ride being relatively smooth - at least it was during the short drives I was able to do. I have not been able to properly stretch the legs as the car is not registered.

I also will replace the hydraulic hoses and return lines along with the struts and rear mounts at the same time. The rear subframe bushings also need to be replaced. This is a rather large job but I needed to get the car registered first so I can make a proper list of things to address and carry out those repairs in an ordered fashion. I might even have the subframe blasted and powder coated while I am overseas, along with sending all the fuel injector retaining brackets and bolts to the Zinc plating shop.

On another note, the car failed its registration inspection today due to oil leaks from the hydraulic suspension valves. I'm hoping this is just residual oil from the change of the valves, but could be something else, such as fittings that need to be tightened. I have asked the shop (CMR Automotive for anyone in Sydney, Australia - they have a lot of experience with classic Mercedes vehicles - I counted 6x pre 1980 vehicles in there today) to check if there is new oil leaking and fix it, as necessary. Fortunately, nothing else came up at the time - all of the work I have done "looks good". Most importantly; there are no fuel, transmission or engine oil leaks. That's a first as i'm used to working on BMWs which are *somewhat* prone to oil leaks.

And yes, the paint looks pretty good now that it has been given a wash. It will need a polish and some small repairs but i'm pleasantly surprised at the condition of the car now that it is relatively clean. It could be a lot worse.

1979 450 SEL 6.9 (#5532) - silbergrün metallic

andrewk

Well, I found the leaks. The rear valve which I had rebuilt was leaking, probably due to the linkage undoing itself during the first drive. There is a warning in the service manual about this problem, and suggests not to allow the lever on the valve to move past 45 degrees from the maximum travel point while the system is pressurised.

I replaced the valve, cleaned up the mess and was able to get the car registered.

In addition, I added a UV-reactive dye into the hydraulic oil so I could find leaks after the new valve was installed. Leaks were found in a few places, including one or two of the fittings on the front valve, the suction line on the HPF pump, from the valve assembly on the HPF oil tank and also out of the front struts.

The UV dye I used was OilGlo Ultra from Spectroline. I bought a kit which contained the dye, a UV torch and dye neutraliser. Very handy diagnostic tool.

Anyway, I have been able to take the car on a ~350 km drive (Sydney to Newcastle and back) and it behaved pretty well. There is some vibration around 80-90 km/h and above 120 km/h, and the steering is very slightly to the left. I hope both issues can be corrected with a wheel alignment and steering adjustment.

Next jobs; replace rear subframe bushings on a blasted and powder coated subframe, install rebuilt rear struts, new mounts mounts and hoses.
Then; send fuel distributor for rebuild as the dosing of fuel for some cylinders is a bit off causing a "lumpy" condition in running.
Will also send all the injector retaining brackets and hardware for Zinc plating, replace injectors with new Bosch parts, replace seals at same time.
Also looking for some decent front struts and hoses which I can send for rebuild. If anyone in the USA has some cores available for sale, it would save me the international shipping to the USA.

Until later...


1979 450 SEL 6.9 (#5532) - silbergrün metallic

andrewk

After some time spent overseas and a short period of enjoyment, I decided to continue with the work on the car, starting at the cooling and fuel system at the engine. 

This evening I found a piece of Aluminium missing from the intake manifold to thermostat housing coolant fitting. Unsure what to do. This job has instantly become a lot more complex.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

daantjie

The connection between the manifold and thermostat housing is a short rubber hose secured with 2x hose clamps.  Not sure what you mean by missing aluminium?
Daniel
1977 450 SEL 6.9 - Astralsilber

Jan S

I see the big "crack" ... i.e. the missing piece of aluminium.

Does it go all the way to the flange, i.e. the rubber hose with the clamp will not seal properly?

1975-mod W116 450 SE with 6.9 engine

daantjie

Quote from: Jan S on 20 September 2023, 12:21 PMI see the big "crack" ... i.e. the missing piece of aluminium.

Does it go all the way to the flange, i.e. the rubber hose with the clamp will not seal properly?



Ah yes I see it now.  That's a tough one.  You can try and epoxy weld (like JB Weld) a piece cut to size to fit into the gap.  Risk is if that piece let's go then it'll end up in the water passages somewhere which would suck.

Other option is maybe a thin sleeve over top?  Failing that you'll have to replace the whole manifold which is a huge and costly job.
Daniel
1977 450 SEL 6.9 - Astralsilber

andrewk

Quote from: daantjie on 20 September 2023, 01:57 PM
Quote from: Jan S on 20 September 2023, 12:21 PMI see the big "crack" ... i.e. the missing piece of aluminium.

Does it go all the way to the flange, i.e. the rubber hose with the clamp will not seal properly?



Ah yes I see it now.  That's a tough one.  You can try and epoxy weld (like JB Weld) a piece cut to size to fit into the gap.  Risk is if that piece let's go then it'll end up in the water passages somewhere which would suck.

Other option is maybe a thin sleeve over top?  Failing that you'll have to replace the whole manifold which is a huge and costly job.

I was thinking of installing a thin Copper sleeve which could then be attached firmly with JB Weld or similar . Intake manifold is NLA from Benz and I don't have a spare. Have asked after a whole engine as a rather excessive spares kit. PN is A1001404401

It looks like the manifold simply unbolts and can be resealed. I already have the fuel distributor and injectors out... installing a sleeve is not a long term safe solution as it really depends on a very clean joint and heat cycling will eventually cause it to fail.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

daantjie

This outfit in Canada has a new old stock one listed, however the part number he has listed does not correspond with the EPC.  Hmmm.  Maybe email him and have him double check the number cast into the part itself:

http://oldbenz.co/manifod-intake-1001402701-450sel-69

Daniel
1977 450 SEL 6.9 - Astralsilber

andrewk

Quote from: daantjie on 20 September 2023, 06:28 PMThis outfit in Canada has a new old stock one listed, however the part number he has listed does not correspond with the EPC.  Hmmm.  Maybe email him and have him double check the number cast into the part itself:

http://oldbenz.co/manifod-intake-1001402701-450sel-69


Thanks Daantjie, have contacted them to buy it. Part number is different to the EPC and is of course NLA from Benz.

Have asked most other people I know locally if they have a spare or a motor collecting dust. Also working on finding a long term solution to address this- JB Weld and Copper sleeve might be great for a while but the risk / expense of overheating is not in my appetite.

Either way, it can't go back together like I found it.

Thanks all for your help. Hopefully I can get this project back on track in the next week or so.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

andrewk

Well, I have sourced an intake manifold but absolutely struggling to get the existing one off.

I have disconnected the EGR pipe from both ends (32 mm wrench inside the intake plenum was a real pain!) - the right side of engine pipe connection was absolutely seized together and required a lot of persuasion with all manner of hammers and tools.

Does anyone have any tips for removing the intake manifold? It does not seem to clear the valley no matter the position of the EGR pipe and I have tried for hours and hours, to the point of tears and sweat dripping. I do not want to pull the motor out at this time.

I figure there must be a trick or secret manoeuvre, moon phase or chant I must sing ahead of time. I'm an atheist, maybe it requires

I am going to delete the EGR system and seal the exhaust and intake accordingly.

This car is definitely a "labour of love" but I know for sure that the work is worthwhile to get this car properly sorted.

In other news, I can confirm the front suspension mount repair service from Roland Merz is a good one. I sent them my mounts, they confirmed the part is original and suitable as a core and had two refurbished bushings ready to send very soon after my parts were received. Their staff are extremely friendly and they have a stock of W116 parts, genuine and Bosch items that may be of interest to other members here.

I also purchased another set of front mounts from Rumb and those will be on their way to Germany soon, so I have a spare set - in case I finish this 6.9 and find myself with another one. Also good to have spares of hard to find parts...





 
1979 450 SEL 6.9 (#5532) - silbergrün metallic

ramiro

Are all bolts out and none broke off ?
I had my intake 2 times off and when all bolts come out it shouldn't be a problem i don't remember it not fitting between the valley.
I also had an weird retrofitted EGR system that i removed , i cut the pipe just behind the Intake manifold and was able to pull the rest out the intake to the rear to the side and down so it cleared the transmission and firewall.

andrewk

Quote from: ramiro on 08 October 2023, 04:02 AMAre all bolts out and none broke off ?
I had my intake 2 times off and when all bolts come out it shouldn't be a problem i don't remember it not fitting between the valley.
I also had an weird retrofitted EGR system that i removed , i cut the pipe just behind the Intake manifold and was able to pull the rest out the intake to the rear to the side and down so it cleared the transmission and firewall.

I had three stripped bolts but removed them with a special tool. The intake manifold is loose but does not seem to clear the valley. I am fairly sure it is the EGR pipe that is blocking the right side of the manifold, but unsure if it needs to be attached at the intake end to clear the valley - or disconnected (as I have it at the moment). I can cut the pipe, but unsure how to go about that without damaging the manifold.
1979 450 SEL 6.9 (#5532) - silbergrün metallic

ramiro

I did use a similar tool like this to cut the pipe just where it comes out the intake, didn't damage anything :
https://www.amazon.se/-/en/Compressed-Pneumatic-Including-Adjustable-Bracket/dp/B01HEZY5KE .


andrewk

Well, I managed to cut the EGR pipe. The air saw was taking forever (would have been there for hours) so I just sheared it with a cold chisel and then stress fractured it by bending the exhaust end. What a task!

Unfortunately, the intake still won't lift off. It gets stuck at the back somewhere. I am going to give it one more try tonight.

In other news, front suspension struts have been rebuilt and should be ready to ship back with a rebuilt pump, new pressure hoses and the other bits I need to get the suspension completely sorted.

Unfortunately the cores I sourced had two different types different types of internal components, so I had to sacrifice yet another two cores' internals so they would be correct. At least I know for sure they are properly sorted now. Very expensive exercise to overhaul the suspension system properly.
1979 450 SEL 6.9 (#5532) - silbergrün metallic